Vegetarian/Vegan

Med Hypotheses, November 1, 2003; 61(5-6): 543-60.
MF McCarty A moderately low phosphate intake may provide health benefits analogous to those conferred by UV light - a further advantage of vegan diets.
Pantox Laboratories, San Diego, USA

  Although exposure to ultraviolet light is often viewed as pathogenic owing to its role in the genesis of skin cancer and skin aging, there is growing epidemiological evidence that such exposure may decrease risk for a number of more serious cancers, may have a favorable impact on blood pressure and vascular health, and may help to prevent certain autoimmune disorders - in addition to its well-known influence on bone density. Most likely, these health benefits are reflective of improved vitamin D status. Increased synthesis or intake of vitamin D can be expected to down-regulate parathyroid hormone (PTH), and to increase autocrine synthesis of its active metabolite calcitriol in certain tissues; these effects, in turn, may impact cancer risk, vascular health, immune regulation, and bone density through a variety of mechanisms. Presumably, a truly adequate supplemental intake of vitamin D - manyfold higher than the grossly inadequate current RDA - could replicate the benefits of optimal UV exposure, without however damaging the skin. Diets moderately low in bioavailable phosphate - like many vegan diets - might be expected to have a complementary impact on disease risks, inasmuch as serum phosphate suppresses renal calcitriol synthesis while up-regulating that of PTH. A proviso is that the impact of dietary phosphorus on bone health is more equivocal than that of vitamin D. Increased intakes of calcium, on the other hand, down-regulate the production of both PTH and calcitriol - the latter effect may explain why the impact of dietary calcium on cancer risk (excepting colon cancer), hypertension, and autoimmunity is not clearly positive. An overview suggests that a vegan diet supplemented with high-dose vitamin D should increase both systemic and autocrine calcitriol production while suppressing PTH secretion, and thus should represent a highly effective way to achieve the wide-ranging health protection conferred by optimal UV exposure.

PMID: 14592785

  In HIV patients, chronic treatment with protease inhibitors often precipitates a peripheral lipodystrophy associated with insulin resistance syndrome and premature coronary disease. In vitro studies demonstrate that these drugs can compromise the ability of adipocytes to store triglycerides; in vivo, peripheral subcutaneous adipocytes appear to be most affected, such that body fat often redistributes to visceral or truncal adipose stores. Dysfunction of peripheral subcutaneous adipocytes - ordinarily quite efficient for storing fat - can be expected to give rise to an excessive flux of free fatty acids (FFAs) following fatty meals; chronic overexposure of tissues to FFAs is a likely explanation for the insulin resistance syndrome associated with lipodystrophy. These considerations suggest that a very-low-fat diet - less than 15% fat calories - may ameliorate the cardiovascular risk associated with lipodystrophy; such diets are known to have a favorable effect on the insulin sensitivity of healthy subjects. Very-low-fat whole-food vegan diets are particularly recommendable in this context, as they may help to shrink visceral fat depots while markedly reducing LDL cholesterol. Appropriate adjunctive measures may include aerobic exercise training - beneficial both for insulin sensitivity and weight control - as well as administration of statins or policosanol, and of fibrates or fish oil, to decrease LDL and triglycerides, respectively. Despite perceptions to the contrary, very-low-fat diets can meet with good compliance in well-motivated subjects given appropriate instruction.

PMID: 14592786

  It is the position of the American Dietetic Association and Dietitians of Canada that appropriately planned vegetarian diets are healthful, nutritionally adequate, and provide health benefits in the prevention and treatment of certain diseases. Approximately 2.5% of adults in the United States and 4% of adults in Canada follow vegetarian diets. A vegetarian diet is defined as one that does not include meat, fish, or fowl. Interest in vegetarianism appears to be increasing, with many restaurants and college foodservices offering vegetarian meals routinely. Substantial growth in sales of foods attractive to vegetarians has occurred, and these foods appear in many supermarkets. This position paper reviews the current scientific data related to key nutrients for vegetarians, including protein, iron, zinc, calcium, vitamin D, riboflavin, vitamin B-12, vitamin A, n-3 fatty acids, and iodine. A vegetarian, including vegan, diet can meet current recommendations for all of these nutrients. In some cases, use of fortified foods or supplements can be helpful in meeting recommendations for individual nutrients. Well-planned vegan and other types of vegetarian diets are appropriate for all stages of the life cycle, including during pregnancy, lactation, infancy, childhood, and adolescence. Vegetarian diets offer a number of nutritional benefits, including lower levels of saturated fat, cholesterol, and animal protein as well as higher levels of carbohydrates, fiber, magnesium, potassium, folate, and antioxidants such as vitamins C and E and phytochemicals. Vegetarians have been reported to have lower body mass indices than nonvegetarians, as well as lower rates of death from ischemic heart disease; vegetarians also show lower blood cholesterol levels; lower blood pressure; and lower rates of hypertension, type 2 diabetes, and prostate and colon cancer. Although a number of federally funded and institutional feeding programs can accommodate vegetarians, few have foods suitable for vegans at this time. Because of the variability of dietary practices among vegetarians, individual assessment of dietary intakes of vegetarians is required. Dietetics professionals have a responsibility to support and encourage those who express an interest in consuming a vegetarian diet. They can play key roles in educating vegetarian clients about food sources of specific nutrients, food purchase and preparation, and any dietary modifications that may be necessary to meet individual needs. Menu planning for vegetarians can be simplified by use of a food guide that specifies food groups and serving sizes.

PMID: 12778049

  A considerable amount of evidence is consistent with the proposition that systemic IGF-I activity acts as pacesetter in the aging process. A reduction in IGF-I activity is the common characteristic of rodents whose maximal lifespan has been increased by a wide range of genetic or dietary measures, including caloric restriction. The lifespans of breeds of dogs and strains of rats tend to be inversely proportional to their mature weight and IGF-I levels. The link between IGF-I and aging appears to be evolutionarily conserved; in worms and flies, lifespan is increased by reduction-of-function mutations in signaling intermediates homologous to those which mediate insulin/IGF-I activity in mammals. The fact that an increase in IGF-I activity plays a key role in the induction of sexual maturity, is consistent with a broader role for-IGF-I in aging regulation. If down-regulation of IGF-I activity could indeed slow aging in humans, a range of practical measures for achieving this may be at hand. These include a low-fat, whole-food, vegan diet, exercise training, soluble fiber, insulin sensitizers, appetite suppressants, and agents such as flax lignans, oral estrogen, or tamoxifen that decrease hepatic synthesis of IGF-I. Many of these measures would also be expected to decrease risk for common age-related diseases. Regimens combining several of these approaches might have a sufficient impact on IGF-I activity to achieve a useful retardation of the aging process. However, in light of the fact that IGF-I promotes endothelial production of nitric oxide and may be of especial importance to cerebrovascular health, additional measures for stroke prevention-most notably salt restriction-may be advisable when attempting to down-regulate IGF-I activity as a pro-longevity strategy.

PMID: 12699704

   BACKGROUND:: Phenylketonuria (PKU), an inborn error of phenylalanine (Phe) metabolism, is treated with a low Phe lifelong diet, which is a vegetarian and contains many antioxidants.
  AIM:: The aim of this study was to evaluate the effect of diet on plasma total antioxidant status in our PKU patients.
  METHODS, RESULTS:: Twenty-two PKU patients on strict diet (group A), 24 PKU patients who did not accurately follow their dietary control (group B) and 40 healthy children (controls) of comparable age took part in this study. Nutrients, as well as blood levels of lipids, vitamin C, beta-carotene and alpha-tocopherol were evaluated in all groups. Vitamin C intake and its blood levels did not differ between the groups. However, the intake of beta-carotene, alpha-tocopherol (2211+/-116, 14+/-1.0 mg/24 h) and their blood levels (0.7+/-0.09, 34+/-0.9 micro mol/l) in group A were statistically significantly higher (P<0.001) as compared with those of group B (1352+/-118, 10+/-1.0 mg/24 h and 0.49+/-0.08, 22+/-0.6 micro mol/l) and controls (1290+/-120, 9.0+/-0.9 mg/24 h and 0.40+/-0.09, 24+/-1.6 micro mol/l). Lipid intakes and their blood levels were lower in patients on the strict diet. Plasma total antioxidant status was higher in the same group of patients (group A). Additionally, positive correlations were found between the antioxidant vitamin blood levels and the plasma total antioxidant status in the groups, especially in the group A. PKU patients of group A showed significantly higher antioxidant status (1.6+/-0.2 mmol/l) as compared with those of group B (1.0+/-0.19 mmol/l; P<0.001) and controls (1.01+/-0.2 mmol/l).
  CONCLUSIONS:: The high plasma antioxidant status in patients with PKU, especially in those with a good compliance with their diet, is possibly due to the amounts of antioxidants which are present in their special low Phe vegetarian diet.

PMID: 12571675

  Diets rich in fruits and vegetables have been of interest because of their potential health benefits against chronic diseases such as cardiovascular disease (CVD) and cancer. The aim of this work was to assess the association of the dietary intake of a food group that includes fruits, berries and vegetables with all-cause, CVD-related and non-CVD-related mortality. The subjects were Finnish men aged 42-60 y examined in 1984-1989 in the prospective Kuopio Ischaemic Heart Disease Risk Factor (KIHD) Study. Dietary intakes were assessed by 4-d food intake record during the baseline phase of the KIHD Study. The risk of all-cause and non-CVD-related deaths was studied in 2641 men and the risk of CVD-related death in 1950 men who had no history of CVD at baseline. During a mean follow-up time of 12.8 y, cardiovascular as well as noncardiovascular and all-cause mortality were lower among men with the highest consumption of fruits, berries and vegetables. After adjustment for the major CVD risk factors, the relative risk for men in the highest fifth of fruit, berry and vegetable intake for all-cause death, CVD-related and non-CVD-related death was 0.66 [95% confidence interval (CI) 0.50-0.88], 0.59 (0.33-1.06), and 0.68 (0.46-1.00), respectively, compared with men in the lowest fifth. These data show that a high fruit, berry and vegetable intake is associated with reduced risk of mortality in middle-aged Finnish men. Consequently, the findings of this work indicate that diets that are rich in plant-derived foods can promote longevity.

PMID: 12514290

  For people in Western countries, the vegan diet has the advantage of low energy intake, but the calcium status of this strictly plant-based diet is still unclear. The aim of this study was to determine the calcium balance of individuals on a vegan diet in comparison with a lactovegetarian diet in a short-term investigation. Seven women and one man, ranging in age from 19 to 24 years, received during the first 10 days a vegan diet based on plant foods and calcium-rich mineral water and a lactovegetarian diet during the following 10 days. Portion size was adapted to the subjects' individual energy requirements. Calcium status was assessed by means of calcium intake in food and calcium output in feces and urine as measured by flame atomic absorption spectrophotometry. In addition, deoxypyridinoline was measured in urine as a marker of bone resorption. The results show a significantly smaller daily calcium intake with an average of 843 +/- 140 mg in the vegan versus 1322 +/- 303 mg in the lactovegetarian diet. Apparent calcium absorption rates were calculated as 26% +/- 15% in the vegan and 24% +/- 8% in the lactovegetarian group (NS). The calcium balance was positive both in the vegan diet (119 +/- 113 mg/day) and in the lactovegetarian diet (211 +/- 136 mg/day) (NS). Deoxypyridinoline excretion showed no significant difference between the two diets (105 +/- 31 and 98 +/- 23 nmol/day). The present results indicate that calcium balance and a marker of bone turnover are not affected significantly when calcium is provided either solely by plant foods or by a diet including dairy products, despite the significantly different calcium intake levels in the diets. We conclude that a well-selected vegan diet maintains calcium status, at least for a short-term period.

PMID: 12491091

  OBJECTIVES: To examine whether adolescent vegetarians were more likely than nonvegetarian peers to meet the dietary recommendations of the Healthy People 2010 objectives and to examine differences in other nutrients between these 2 groups. DESIGN: A total of 4746 adolescents from 31 middle and high schools in the Twin Cities area of Minnesota. Data were collected via self-report surveys, with a student response rate of 81.5%.
  SETTING: Urban secondary schools.
  PARTICIPANTS: Participants were equally divided by sex. The mean age was 14.9 years; 34.3% were in junior high school and 65.7% in high school. The racial/ethnic distribution was 48.5% white, 19.0% African American, 19.2% Asian American, 5.8% Hispanic, 3.5% American Indian, and 3.9% mixed or other.
  MAIN OUTCOME MEASURES: Questions on vegetarian status and whether particular foods (eggs, dairy foods, chicken, fish) were excluded. Dietary intake was assessed using the Youth and Adolescent Food Frequency Questionnaire.
  RESULTS: Vegetarian adolescents were significantly more likely than nonvegetarian adolescents to meet the Healthy People 2010 objectives. This was particularly noteworthy for total fat (70% vs 48%), saturated fat (65% vs 39%), daily servings of vegetables (26% vs 14%), and 5 or more servings of fruits and vegetables (39% vs 28%). Vegetarians were also less likely to eat fast food or drink regular soda and fruit drinks. Vegetarians consumed less vitamin B(12), more diet soda, more caffeine, and more iron.
  CONCLUSION: Adolescent vegetarians have a dietary pattern that is more likely than nonvegetarians to meet the Healthy People 2010 objectives.

PMID: 11980547

  BACKGROUND: Relative risk estimates suggest that effective implementation of behaviors commonly advocated in preventive medicine should increase life expectancy, although there is little direct evidence.
  OBJECTIVE: To test the hypothesis that choices regarding diet, exercise, and smoking influence life expectancy.
  METHODS: A total of 34 192 California Seventh-Day Adventists (75% of those eligible) were enrolled in a cohort and followed up from 1976 to 1988. A mailed questionnaire provided dietary and other exposure information at study baseline. Mortality for all subjects was ascertained by matching to state death tapes and the National Death Index.
  RESULTS: California Adventists have higher life expectancies at the age of 30 years than other white Californians by 7.28 years (95% confidence interval, 6.59-7.97 years) in men and by 4.42 years (95% confidence interval, 3.96-4.88 years) in women, giving them perhaps the highest life expectancy of any formally described population. Commonly observed combinations of diet, exercise, body mass index, past smoking habits, and hormone replacement therapy (in women) can account for differences of up to 10 years of life expectancy among Adventists. A comparison of life expectancy when these factors take high-risk compared with low-risk values shows independent effects that vary between 1.06 and 2.74 years for different variables. The effect of each variable is assessed with all others at either medium- or high-risk levels.
  CONCLUSIONS: Choices regarding diet, exercise, cigarette smoking, body weight, and hormone replacement therapy, in combination, appear to change life expectancy by many years. The longevity experience of Adventists probably demonstrates the beneficial effects of more optimal behaviors. [Note: Adventists, collectively, could be characterized as 'quasi-vegetarians' - ljf]

PMID: 11434797

  Induced apoptosis of autoreactive T-lymphocyte precursors in the thymus is crucial for the prevention of autoimmune disorders. IGF-I and prolactin, which are lymphocyte growth factors, may have the potential to suppress apoptosis in thymocytes and thus encourage autoimmunity; conversely, dietary fish oil rich in omega-3 fats appears to upregulate apoptosis in lymphocytes. Since whole-food vegan diets may downregulate systemic IGF-I activity, it is proposed that such a diet, in conjunction with fish oil supplementation and treatment with dopamine agonists capable of suppressing prolactin secretion, may have utility for treating and preventing autoimmune disorders. This prediction is consistent with the extreme rarity of autoimmune disorders among sub-Saharan black Africans as long as they followed their traditional quasi-vegan lifestyles, and with recent ecologic studies correlating risks for IDDM and for multiple sclerosis mortality with animal product and/or saturated fat consumption. Moreover, there is evidence that vegan or quasi-vegan diets are useful in the management of rheumatoid arthritis, multiple sclerosis, and possibly SLE. The dopamine agonist bromocryptine exerts anti-inflammatory effects in rodent models of autoimmunity, and there is preliminary evidence that this drug may be clinically useful in several human autoimmune diseases; better tolerated D2-specific agonists such as cabergoline may prove to be more practical for use in therapy. The moderate clinical utility of supplemental fish oil in rheumatoid arthritis and certain other autoimmune disorders is documented. It is not unlikely that extra-thymic anti-inflammatory effects contribute importantly to the clinical utility of vegan diets, bromocryptine, and fish oil in autoimmunity. The favorable impact of low latitude or high altitude on autoimmune risk may be mediated by superior vitamin D status, which is associated with decreased secretion of parathyroid hormone; there are theoretical grounds for suspecting that parathyroid hormone may inhibit apoptosis in thymocytes. Androgens appear to up-regulate thymocyte apoptosis, may be largely responsible for the relative protection from autoimmunity enjoyed by men, and merit further evaluation for the management of autoimmunity in women. It will probably prove more practical to prevent autoimmune disorders than to reverse them once established; a whole-food vegan diet, coupled with fish oil and vitamin D supplementation, may represent a practical strategy for achieving this prevention, while concurrently lowering risk for many other life-threatening 'Western' diseases. Copyright 2001 Harcourt Publishers Ltd.

PMID: 11461185

  Three recent case-control studies conclude that diets high in animal fat or cholesterol are associated with a substantial increase in risk for Parkinson's disease (PD); in contrast, fat of plant origin does not appear to increase risk. Whereas reported age-adjusted prevalence rates of PD tend to be relatively uniform throughout Europe and the Americas, sub-Saharan black Africans, rural Chinese, and Japanese, groups whose diets tend to be vegan or quasi-vegan, appear to enjoy substantially lower rates. Since current PD prevalence in African-Americans is little different from that in whites, environmental factors are likely to be responsible for the low PD risk in black Africans. In aggregate, these findings suggest that vegan diets may be notably protective with respect to PD. However, they offer no insight into whether saturated fat, compounds associated with animal fat, animal protein, or the integrated impact of the components of animal products mediates the risk associated with animal fat consumption. Caloric restriction has recently been shown to protect the central dopaminergic neurons of mice from neurotoxins, at least in part by induction of heat-shock proteins; conceivably, the protection afforded by vegan diets reflects a similar mechanism. The possibility that vegan diets could be therapeutically beneficial in PD, by slowing the loss of surviving dopaminergic neurons, thus retarding progression of the syndrome, may merit examination. Vegan diets could also be helpful to PD patients by promoting vascular health and aiding blood-brain barrier transport of L-dopa.

PMID: 11516224

  Vegetarianism within the U.K. is growing in popularity, with the current estimate of 7% of the population eating a vegetarian diet. This study examined differences between the attitudes and beliefs of four dietary groups (meat eaters, meat avoiders, vegetarians and vegans) and the extent to which attitudes influenced intentions to follow each diet. In addition, the role of attitudinal ambivalence as a moderator variable was examined. Completed questionnaires were obtained from 111 respondents (25 meat eaters, 26 meat avoiders, 34 vegetarians, 26 vegans). In general, predictions were supported, in that respondents displayed most positive attitudes and beliefs towards their own diets, and most negative attitudes and beliefs towards the diet most different form their own. Regression analyses showed that, as predicted by the Theory of Planned Behaviour, attitudes, subjective norm and perceived behavioural control were significant predictors of intention to follow each diet (apart from the vegetarian diet, where subjective norm was non-significant). In each case, attitudinal ambivalence was found to moderate the attitude-intention relationship, such that attitudes were found to be stronger predictors at lower levels of ambivalence. The results not only highlight the extent to which such alternative diets are an interesting focus for psychological research, but also lend further support to the argument that ambivalence in an important influence on attitude strength. Copyright 2000 Academic Press.

PMID: 11562154

  This paper deals with the distribution and activity intake of 210Po and 210Pb in food, diet, and potable water samples of the Goa region and the estimated committed effective dose due to ingestion of these radionuclides. The activity concentrations of 210Po and 210Pb were determined in about 30 food and diet samples from different places of Goa in order to know the distribution and intake of these radionuclides. The activity concentration of 210Po in fish and prawn samples were significantly higher than concentrations found in vegetable and rice samples. Higher concentrations of 210Po and 210Pb were observed in leafy vegetables than in non-leafy vegetables. Among the diet samples the activity concentrations of 210Po [polonium] and 210Pb [lead] in non-vegetarian meal samples were relatively higher than in vegetarian meal and breakfast samples. The committed effective dose due to annual intake of 210Po was found to be 94.6 microSv, 49.1 microSv, 10.5 microSv, and 2.2 microSv and that of 210Pb found to be 81.6 microSv, 59.9 microSv, 14.6 microSv, and 2.0 microSv for the ingestion of non-vegetarian meal, vegetarian meal, breakfast, and potable water, respectively.

PMID: 11569638

  We tested the effects of feeding a diet very high in fiber from fruit and vegetables. The levels fed were those, which had originally inspired the dietary fiber hypothesis related to colon cancer and heart disease prevention and also may have been eaten early in human evolution. Ten healthy volunteers each took 3 metabolic diets of 2 weeks duration. The diets were: high-vegetable, fruit, and nut (very-high-fiber, 55 g/1,000 kcal); starch-based containing cereals and legumes (early agricultural diet); or low-fat (contemporary therapeutic diet). All diets were intended to be weight-maintaining (mean intake, 2,577 kcal/d). Compared with the starch-based and low-fat diets, the high-fiber vegetable diet resulted in the largest reduction in low-density lipoprotein (LDL) cholesterol (33% +/- 4%, P <.001) and the greatest fecal bile acid output (1.13 +/- 0.30 g/d, P =.002), fecal bulk (906 +/- 130 g/d, P <.001), and fecal short-chain fatty acid outputs (78 +/- 13 mmol/d, P <.001). Nevertheless, due to the increase in fecal bulk, the actual concentrations of fecal bile acids were lowest on the vegetable diet (1.2 mg/g wet weight, P =.002). Maximum lipid reductions occurred within 1 week. Urinary mevalonic acid excretion increased (P =.036) on the high-vegetable diet reflecting large fecal steroid losses. We conclude that very high-vegetable fiber intakes reduce risk factors for cardiovascular disease and possibly colon cancer. Vegetable and fruit fibers therefore warrant further detailed investigation.

Copyright 2001 by W.B. Saunders Company

PMID: 11288049

  BACKGROUND: Hydrogen sulfide is a luminally acting, bacterially derived cell poison that has been implicated in ulcerative colitis. Sulfide generation in the colon is probably driven by dietary components such as sulfur-containing amino acids (SAAs) and inorganic sulfur (eg, sulfite).
  OBJECTIVE: We assessed the contribution of SAAs from meat to sulfide production by intestinal bacteria with use of both a model culture system in vitro and an in vivo human feeding study.
  DESIGN: Five healthy men were housed in a metabolic suite and fed a sequence of 5 diets for 10 d each. Meat intake ranged from 0 g/d with a vegetarian diet to 600 g/d with a high-meat diet. Fecal sulfide and urinary sulfate were measured in samples collected on days 9 and 10 of each diet period. Additionally, 5 or 10 g bovine serum albumin or casein/L was added to batch cultures inoculated with feces from 4 healthy volunteers. Concentrations of sulfide, ammonia, and Lowry-reactive substances were measured over 48 h.
  RESULTS: Mean (+/-SEM) fecal sulfide concentrations ranged from 0.22 +/- 0.02 mmol/kg with the 0-g/d diet to 3.38 +/- 0.31 mmol/kg with the 600-g/d diet and were significantly related to meat intake (P: < 0.001). Sulfide formation in fecal batch cultures supplemented with both bovine serum albumin and casein correlated with protein digestion, as measured by the disappearance of Lowry-reactive substances and the appearance of ammonia.
  CONCLUSION: Dietary protein from meat is an important substrate for sulfide generation by bacteria in the human large intestine.

PMID: 11101476

  In 1991, dietary reference values were published in the UK. These refer to nutrients and provide the basis for dietary advice. To complement this, practical food-based guidance on how to plan a healthy and balanced diet has been developed. Interest continues in how best to establish guidance which helps individuals modify their diets so as to better match the dietary targets established as a means of promoting health and avoiding disease. Furthermore, in recent years, interest has grown in the potential to optimise nutrition and so promote health and well-being, rather than just avoiding deficiency. This has been accompanied by an awareness that many foods, particularly plant foods, contain substances that may have health promoting properties but are not, as yet, regarded as conventional nutrients.

PMID: 10885102

  OBJECTIVE: To assess food behaviour and determine nutritional intakes of various vegetarian populations in France.
  DESIGN: A five-day self-administered food record which was mailed to members of the three principal French vegetarian organisations. SUBJECTS: 145 subjects, aged 7-87 y; 94 classical vegetarians (19% of those contacted), 34 Hindu lactovegetarians (17% of those contacted) and 17 macrobiotic (34% of those contacted). SETTING: The survey was conducted between March 1997 and July 1997 in France.
  RESULTS: Vegetarianism in France is represented by three main classes of food behaviour: ovolactovegetarian (AAV), lactovegetarian (KRI) and macrobiotic (MMK). The geometric mean intakes ranged from 1952 kcal/d (KRI), 2051 kcal/d (MMK) to 2384 kcal/d (AAV) for males and from 1302 kcal/d (MMK), 1675 kcal/d (AAV) to 1804 kcal/d (KRI) for females, after adjusting for age and BMI. The energy consumption in the MMK group was significantly lower than that in the AAV (P<0.05) and KRI groups (P<0.01), respectively. A difference among groups was observed for females (P=0.0002), but not for males. The MMK group consumed less lipid than the other two vegetarian groups, 46 g/d for men and 38 g/d for women vs 80 g/d for men and 61 g/d for women in the AAV group and 93 g/d for men and 81 g/d for women in the KRI group, respectively. Differences with AAV and MMK were statistically significant (P<0.001 for men and women for both groups). Mean protein consumption ranged from 60 g/d (AAV), 64 g/d (KRI) to 77 g/d (MMK) for males and from 46 g/d (MMK), 50 g/d (AAV) to 58 g/d (KRI) for females. Mean carbohydrate intakes ranged from 247 g/d (AAV), 321 g/d (KRI) to 338 g/d (MMK) in males and from 209 g/d (MMK), 228 g/d (AAV) to 242 g/d (KRI) in females. There were no significant differences in protein and carbohydrate intakes between the groups. Median calcium intakes ranged from 758.2 mg/d (MMK), 863 mg/d (AAV) to 989.3 mg/d (KRI) for the men and from 500.8 mg/d (MMK), 863 mg/d (AAV) to 934 mg/d (KRI) for the women. In the men, there was no differences in daily calcium intakes between the three vegetarian groups. However, we found a significant difference for women (P=0. 0041). The women in the MMK group presented significantly lower daily calcium intakes than the women in the AAV (P=0.013) and KRI (P=0.0032) groups. The AAV and KRI groups consumed dairy products supplying respectively 36% and 53% for the men and 39% and 59% for the women of total calcium against 0% for men and women in the MMK group. Median iron intakes ranged between 12.5 mg/d (KRI), 13.2 mg/d (AAV) and 22.5 mg/d (MMK) for the men and between 11.2 mg/d (KRI), 14.6 mg/d (AAV) and 16.9 mg/d (MMK) for the women. MMK (men P=0.0172 and women P=0.0131) and AAV (only in men P=0.037) groups consumed significantly higher quantities of iron than did the KRI group. The heme iron median intake in males and females of the three vegetarian groups was very low (<0.5%). Overall, the female vegetarians consumed 58.1 (MMK), 109 (AAV) and 127.4 (KRI) mg of vitamin C per day and the males 76.3 (MMK), 150.4 (AAV) and 150.4 (KRI) mg per day. Median vitamin B9 intakes ranged from 247.5 microg/d (KRI), 312 microg/d (MMK) to 390.4 microg/d (AAV) for the men and from 188.3 microg/d (MMK), 266.9 microg/d (KRI) to 323.8 microg/d (AAV) for the women. Vitamin B12 consumption ranged from 0.2 microg/d (MMK), 1.5 microg/d (AAV) to 1.7 microg/d (KRI) in the women and from 0.6 microg/d (MMK) to 1.0 microg/d (AAV and KRI) in the men. No differences in consumption were observed in the males. On the other hand, the women in the MMK group consumed significantly less vitamin C and B12 than did the women in the AAV (P=0.0006) and KRI (P=0. 0396) groups, while it was at the limit of significance for the females (P=0.0715) for vitamin B9.
  CONCLUSION: Our results suggest that vegetarians have a better understanding of dietary requirements than does the general population. (ABSTRACT TRUNCATED)

PMID: 10822295

  Background. Plasma homocysteine levels have been directly associated with cardiac disease risk. Current research raises concerns as to whether comprehensive lifestyle approaches including a plant-based diet may interact with other known modulators of homocysteine levels. Methods. We report our observations of homocysteine levels in 40 self-selected subjects who participated in a vegan diet-based lifestyle program. Each subject attended a residential lifestyle change program at the Lifestyle Center of America in Sulphur, Oklahoma and had fasting plasma total homocysteine measured on enrollment and then after 1 week of lifestyle intervention. The intervention included a vegan diet, moderate physical exercise, stress management and spirituality enhancement sessions, group support, and exclusion of tobacco, alcohol, and caffeine. B vitamin supplements known to reduce blood homocysteine levels were not provided. Results. Subjects' mean homocysteine levels fell 13%: from 8.66 mumol/L (SD 2.7 mumol/L) to 7.53 mumol/L (SD 2.12 mumol/L; P < 0.0001). Subgroup analysis showed that homocysteine decreased across a range of demographic and diagnostic categories. Conclusions. Our results suggest that broad-based lifestyle interventions favorably impact homocysteine levels. Furthermore, analysis of Lifestyle Center of America program components suggests that other factors in addition to B vitamin intake may be involved in the observed homocysteine lowering.

Copyright 2000 American Health Foundation and Academic Press.

PMID: 10684746

Barnard ND.
The lipid-lowering effect of lean meat diets falls far short of that of vegetarian diets.
Arch Intern Med. 2000 Feb 14;160(3):395-6.

No abstract available.

  OBJECTIVE: To test the hypothesis that a low-fat, vegetarian diet reduces dysmenorrhea and premenstrual symptoms by its effect on serum sex-hormone binding globulin concentration and estrogen activity. METHODS: In a crossover design, 33 women followed a low-fat, vegetarian diet for two menstrual cycles. For two additional cycles, they followed their customary diet while taking a supplement placebo pill. Dietary intake, serum sex-hormone binding globulin concentration, body weight, pain duration and intensity, and premenstrual symptoms were assessed during each study phase. RESULTS: Mean (+/- standard deviation [SD]) serum sex-hormone binding globulin concentration was higher during the diet phase (46.7 +/- 23.6 nmol/L) than during the supplement phase (39.3 +/- 19.8 nmol/L, P < .001). Mean (+/- SD) body weight was lower during the diet (66.1 +/- 11.3 kg) compared with the supplement phase (67.9 +/- 12.1 kg, P < .001). Mean dysmenorrhea duration fell significantly from baseline (3.9 +/- 1.7 days) to diet phase (2.7 +/- 1.9 days) compared with change from baseline to supplement phase (3.6 +/- 1.7 days, P < .01). Pain intensity fell significantly during the diet phase, compared with baseline, for the worst, second-worst, and third-worst days, and mean durations of premenstrual concentration, behavioral change, and water retention symptoms were reduced significantly, compared with the supplement phase. CONCLUSION: A low-fat vegetarian diet was associated with increased serum sex-hormone binding globulin concentration and reductions in body weight, dysmenorrhea duration and intensity, and premenstrual symptom duration. The symptom effects might be mediated by dietary influences on estrogen activity.

PMID: 10674588

  We combined data from 5 prospective studies to compare the death rates from common diseases of vegetarians with those of nonvegetarians with similar lifestyles. A summary of these results was reported previously; we report here more details of the findings. Data for 76172 men and women were available. Vegetarians were those who did not eat any meat or fish (n = 27808). Death rate ratios at ages 16-89 y were calculated by Poisson regression and all results were adjusted for age, sex, and smoking status. A random-effects model was used to calculate pooled estimates of effect for all studies combined. There were 8330 deaths after a mean of 10.6 y of follow-up. Mortality from ischemic heart disease was 24% lower in vegetarians than in nonvegetarians (death rate ratio: 0.76; 95% CI: 0.62, 0.94; P<0.01). The lower mortality from ischemic heart disease among vegetarians was greater at younger ages and was restricted to those who had followed their current diet for >5 y. Further categorization of diets showed that, in comparison with regular meat eaters, mortality from ischemic heart disease was 20% lower in occasional meat eaters, 34% lower in people who ate fish but not meat, 34% lower in lactoovovegetarians, and 26% lower in vegans. There were no significant differences between vegetarians and nonvegetarians in mortality from cerebrovascular disease, stomach cancer, colorectal cancer, lung cancer, breast cancer, prostate cancer, or all other causes combined.

PMID: 10479225

  Populations of vegetarians living in affluent countries appear to enjoy unusually good health, characterized by low rates of cancer, cardiovascular disease, and total mortality. These important observations have fueled much research and have raised 3 general questions about vegetarians in relation to nonvegetarians: Are these observations the result of better nondietary lifestyle factors, such as lower prevalences of smoking and higher levels of physical activity?; Are they the result of lower intakes of harmful dietary components, in particular meat?; and Are they the result of higher intakes of beneficial dietary components that tend to replace meat in the diet? Current evidence suggests that the answer to all 3 questions is "Yes." Low smoking rates contribute importantly to the low rates of cardiovascular disease and many cancers, probably including colon cancer, in Seventh-day Adventists and other vegetarian populations. Also, avoidance of red meat is likely to account in part for low rates of cardiovascular disease and colon cancer, but this does not appear to be the primary reason for general good health in these populations. Evidence accumulated in the past decade emphasizes the importance of adequate consumption of beneficial dietary factors-rather than just the avoidance of harmful factors-including an abundance of fruit, vegetables, and whole grains and regular consumption of vegetable oils, including those from nuts. Although current knowledge already provides general guidance toward healthy diets, accumulated evidence now strongly indicates that diet has a powerful yet complex effect on health and that further investigation is needed.

PMID: 10479215

  The Oxford Vegetarian Study is a prospective study of 6000 vegetarians and 5000 nonvegetarian control subjects recruited in the United Kingdom between 1980 and 1984. Cross-sectional analyses of study data showed that vegans had lower total- and LDL-cholesterol concentrations than did meat eaters; vegetarians and fish eaters had intermediate and similar values. Meat and cheese consumption were positively associated, and dietary fiber intake was inversely associated, with total-cholesterol concentration in both men and women. After 12 y of follow-up, all-cause mortality in the whole cohort was roughly half that in the population of England and Wales (standardized mortality ratio, 0.46; 95% CI, 0.42, 0.51). After adjusting for smoking, body mass index, and social class, death rates were lower in non-meat-eaters than in meat eaters for each of the mortality endpoints studied [relative risks and 95% CIs: 0.80 (0. 65, 0.99) for all causes of death, 0.72 (0.47, 1.10) for ischemic heart disease, and 0.61 (0.44, 0.84) for all malignant neoplasms]. Mortality from ischemic heart disease was also positively associated with estimated intakes of total animal fat, saturated animal fat, and dietary cholesterol. Other analyses showed that non-meat-eaters had only half the risk of meat eaters of requiring an emergency appendectomy, and that vegans in Britain may be at risk for iodine deficiency. Thus, the health of vegetarians in this study is generally good and compares favorably with that of the nonvegetarian control subjects. Larger studies are needed to examine rates of specific cancers and other diseases among vegetarians.

PMID: 10479226

  Discussants at the Third International Congress on Vegetarian Nutrition considered the nutritional adequacy, benefits, and health outcomes of plant-only (e.g., vegan and fruitarian), plant-based (e.g., macrobiotic, lactovegetarian, semivegetarian, and meatless), and omnivorous dietary patterns. The increased availability of a variety of plant foods, the advent of nutrient-fortified plant foods, the use of vitamin and mineral supplements, and the widespread dissemination of sound information on dietary patterns mean that convergence between the essential nutrient profiles of plant-only and plant-rich, plant-based diets is possible. Special attention should be paid to nutrition among vulnerable groups by age or physiologic status if they consume diets based solely on plants. Research has shown that both plant-only and plant-based eating patterns have health benefits, most notably in reducing the risk of chronic, degenerative diseases. The panel concluded that evidence for a convergence of scientific opinion on the safety and healthfulness of plant-only diets that are appropriately planned to meet all nutrient requirements compared with plant-based diets is considerable.

PMID: 10479241

  Dietary and nutritional status of individuals habitually consuming a vegan diet was evaluated by biochemical, hematologic, and immunologic measures in comparison with a nonvegetarian group. On the basis of 4-d dietary records, the intake of female and male vegans tended to be lower in fat, saturated fat, monounsaturated fat, and cholesterol and higher in dietary fiber than that of vegetarians. With computed food and supplement intakes, vegan diets provided significantly higher amounts of ascorbate, folate, magnesium, copper, and manganese in both female and male participants. The body mass index (BMI; in kg/m(2)) of the vegans was significantly lower than that of the nonvegetarians and 9 of the 25 vegans had a BMI <19. Serum ferritin concentrations were significantly lower in vegan men but iron and zinc status did not differ between the sexes. Mean serum vitamin B-12 and methylmalonic acid concentrations did not differ; however, 10 of the 25 vegans showed a vitamin B-12 deficit manifested by macrocytosis, circulating vitamin B-12 concentrations <150 pmol/L, or serum methylmalonic acid >376 nmol/L. Vegans had significantly lower leukocyte, lymphocyte, and platelet counts and lower concentrations of complement factor 3 and blood urea nitrogen but higher serum albumin concentrations. Vegans did not differ from nonvegetarians in functional immunocompetence assessed as mitogen stimulation or natural killer cell cytotoxic activity.

PMID: 10479236

  The nutritional adequacy of plant-based diets is discussed. Energy and protein intakes are similar for plant-based diets compared with those containing meat. Fe and vitamin B12 are the nutrients most likely to be found lacking in such diets. Bioactive substances present in foods of plant origin significantly influence the bioavailability of minerals and requirements for vitamins. Well-balanced vegetarian diets are able to support normal growth and development. It is concluded that meat is an optional rather than an essential constituent of human diets.

PMID: 10466165

  Results associating diet with chronic disease in a cohort of 34192 California Seventh-day Adventists are summarized. Most Seventh-day Adventists do not smoke cigarettes or drink alcohol, and there is a wide range of dietary exposures within the population. About 50% of those studied ate meat products <1 time/wk or not at all, and vegetarians consumed more tomatoes, legumes, nuts, and fruit, but less coffee, doughnuts, and eggs than did nonvegetarians. Multivariate analyses showed significant associations between beef consumption and fatal ischemic heart disease (IHD) in men [relative risk (RR) = 2.31 for subjects who ate beef > or =3 times/wk compared with vegetarians], significant protective associations between nut consumption and fatal and nonfatal IHD in both sexes (RR approximately 0.5 for subjects who ate nuts > or =5 times/wk compared with those who ate nuts <1 time/wk), and reduced risk of IHD in subjects preferring whole-grain to white bread. The lifetime risk of IHD was reduced by approximately 31% in those who consumed nuts frequently and by 37% in male vegetarians compared with nonvegetarians. Cancers of the colon and prostate were significantly more likely in nonvegetarians (RR of 1.88 and 1.54, respectively), and frequent beef consumers also had higher risk of bladder cancer. Intake of legumes was negatively associated with risk of colon cancer in nonvegetarians and risk of pancreatic cancer. Higher consumption of all fruit or dried fruit was associated with lower risks of lung, prostate, and pancreatic cancers. Cross-sectional data suggest vegetarian Seventh-day Adventists have lower risks of diabetes mellitus, hypertension, and arthritis than nonvegetarians. Thus, among Seventh-day Adventists, vegetarians are healthier than nonvegetarians but this cannot be ascribed only to the absence of meat.

PMID: 10479227

  We review the beneficial and adverse effects of vegetarian diets in various medical conditions. Soybean-protein diet, legumes, nuts and soluble fibre significantly decrease total cholesterol, low-density lipoprotein cholesterol and triglycerides. Diets rich in fibre and complex carbohydrate, and restricted in fat, improve control of blood glucose concentration, lower insulin requirement and aid in weight control in diabetic patients. An inverse association has been reported between nut, fruit, vegetable and fibre consumption, and the risk of coronary heart disease. Patients eating a vegetarian diet, with comprehensive lifestyle changes, have had reduced frequency, duration and severity of angina as well as regression of coronary atherosclerosis and improved coronary perfusion. An inverse association between fruit and vegetable consumption and stroke has been suggested. Consumption of fruits and vegetables, especially spinach and collard green, was associated with a lower risk of age-related ocular macular degeneration. There is an inverse association between dietary fibre intake and incidence of colon and breast cancer as well as prevalence of colonic diverticula and gallstones. A decreased breast cancer risk has been associated with high intake of soy bean products. The beneficial effects could be due to the diet (monounsaturated and polyunsaturated fatty acids, minerals, fibre, complex carbohydrate, antioxidant vitamins, flavanoids, folic acid and phytoestrogens) as well as the associated healthy lifestyle in vegetarians. There are few adverse effects, mainly increased intestinal gas production and a small risk of vitamin B12 deficiency.

Comment in: QJM 2000 Jun;93(6):387

PMID: 10627874

  Amino acids modulate the secretion of both insulin and glucagon; the composition of dietary protein therefore has the potential to influence the balance of glucagon and insulin activity. Soy protein, as well as many other vegan proteins, are higher in non-essential amino acids than most animal-derived food proteins, and as a result should preferentially favor glucagon production. Acting on hepatocytes, glucagon promotes (and insulin inhibits) cAMP-dependent mechanisms that down-regulate lipogenic enzymes and cholesterol synthesis, while up-regulating hepatic LDL receptors and production of the IGF-I antagonist IGFBP-1. The insulin-sensitizing properties of many vegan diets--high in fiber, low in saturated fat--should amplify these effects by down-regulating insulin secretion. Additionally, the relatively low essential amino acid content of some vegan diets may decrease hepatic IGF-I synthesis. Thus, diets featuring vegan proteins can be expected to lower elevated serum lipid levels, promote weight loss, and decrease circulating IGF-I activity. The latter effect should impede cancer induction (as is seen in animal studies with soy protein), lessen neutrophil-mediated inflammatory damage, and slow growth and maturation in children. In fact, vegans tend to have low serum lipids, lean physiques, shorter stature, later puberty, and decreased risk for certain prominent 'Western' cancers; a vegan diet has documented clinical efficacy in rheumatoid arthritis. Low-fat vegan diets may be especially protective in regard to cancers linked to insulin resistance--namely, breast and colon cancer--as well as prostate cancer; conversely, the high IGF-I activity associated with heavy ingestion of animal products may be largely responsible for the epidemic of 'Western' cancers in wealthy societies. Increased phytochemical intake is also likely to contribute to the reduction of cancer risk in vegans. Regression of coronary stenoses has been documented during low-fat vegan diets coupled with exercise training; such regimens also tend to markedly improve diabetic control and lower elevated blood pressure. Risk of many other degenerative disorders may be decreased in vegans, although reduced growth factor activity may be responsible for an increased risk of hemorrhagic stroke. By altering the glucagon/insulin balance, it is conceivable that supplemental intakes of key non-essential amino acids could enable omnivores to enjoy some of the health advantages of a vegan diet. An unnecessarily high intake of essential amino acids--either in the absolute sense or relative to total dietary protein--may prove to be as grave a risk factor for 'Western' degenerative diseases as is excessive fat intake.

PMID: 10687887, UI: 20150595

  The widespread prevalence of diet-related health problems, particularly in highly industrialized nations, suggests that many humans are not eating in a manner compatible with their biology. Anthropoids, including all great apes, take most of their diet from plants, and there is general consensus that humans come from a strongly herbivorous ancestry. Though gut proportions differ, overall gut anatomy and the pattern of digestive kinetics of extant apes and humans are very similar. Analysis of tropical forest leaves and fruits routinely consumed by wild primates shows that many of these foods are good sources of hexoses, cellulose, hemicellulose, pectic substances, vitamin C, minerals, essential fatty acids, and protein. In general, relative to body weight, the average wild monkey or ape appears to take in far higher levels of many essential nutrients each day than the average American and such nutrients (as well as other substances) are being consumed together in their natural chemical matrix. The recommendation that Americans consume more fresh fruits and vegetables in greater variety appears well supported by data on the diets of free-ranging monkeys and apes. Such data also suggest that greater attention to features of the diet and digestive physiology of non-human primates could direct attention to important areas for future research on features of human diet and health.

PMID: 10378206

Mutagenesis 1998 Mar;13(2):167-71
Long-term effects of a change from a mixed diet to a lacto-vegetarian diet on human urinary and faecal mutagenic activity.
Johansson G, Holmen A, Persson L, Hogstedt B, Wassen C, Ottova L, Gustafsson JA. Department of Medical Nutrition, Karolinska Institute, Huddinge Hospital, Sweden. gunnar.johansson@kost.umu.se
  This is an investigation of the long-term effects of a shift from a mixed diet to a lacto-vegetarian diet and of a return to a mixed diet on the mutagenic activity in urine and faeces. The participants were 20 normal weight, non-smoking subjects. Dietary surveys and urinary and faecal samples were collected before and 3, 6 and 12 months after the dietary shift as well as 3 years after termination of the lacto-vegetarian diet period. The faecal samples were assayed for direct acting mutagens with the fluctuation test for weak mutagens and the urinary samples were assayed with the same assay but with a metabolic activation system, the so-called S9 fraction. The dietary data showed an increase in consumption of fruits, vegetables and dairy products and a decrease in meat, fish, eggs, sweets and biscuits during the vegetarian diet period. These changes led to an increase in total carbohydrates, fibre, vitamin C and calcium and a decrease in fat and protein intake. Mutagenic activity in both urine and faeces decreased after shift to the vegetarian diet and mutagenic activity in faeces increased when the volunteers returned to a mixed diet (P = 0.025 and 0.035 respectively when comparing the diets). These data indicate that dietary factors may effect mutagenic activity in urine and faeces. However, it is still not clear whether a decrease in animal products, a change in other nutritional factors or a decrease in frying are the main contributors to this change.

PMID: 9568590

PMID: 9866269

  Nine studies of childhood brain tumors and maternal diet during pregnancy have focused on foods related to the N-nitroso-compound(NOC) hypothesis. An association between frequent consumption of cured meat by pregnant women and increased risk is a consistent finding in most of the studies. The data on fruit and vegetable consumption are less consistent, but suggest decreased risk. Studies that assess all aspects of maternal diet during pregnancy are needed to determine whether the observed associations remain after adjustment for other aspects of diet. Such comprehensive studies also may elucidate other dietary factors that affect the risk of brain tumors in children.

PMID: 9876472

  OBJECTIVE: To compare the mortality rates of vegetarians and non-vegetarians. DESIGN: Collaborative analysis using original data from five prospective studies. Death rate ratios for vegetarians compared to non-vegetarians were calculated for ischaemic heart disease, cerebrovascular disease, cancers of the stomach, large bowel, lung, breast and prostate, and for all causes of death. All results were adjusted for age, sex and smoking. A random effects model was used to calculate pooled estimates of effect for all studies combined. SETTING: USA, UK and Germany. SUBJECTS: 76,172 men and women aged 16-89 years at recruitment. Vegetarians were those who did not eat any meat or fish (n = 27,808). Non-vegetarians were from a similar background to the vegetarians within each study. RESULTS: After a mean of 10.6 years of follow-up there were 8330 deaths before the age of 90 years, including 2264 deaths from ischaemic heart disease. In comparison with non-vegetarians, vegetarians had a 24% reduction in mortality from ischaemic heart disease (death rate ratio 0.76, 95% CI 0.62-0.94). The reduction in mortality among vegetarians varied significantly with age at death: rate ratios for vegetarians compared to non-vegetarians were 0.55 (95% CI 0.35-0.85), 0.69 (95% CI 0.53-0.90) and 0.92 (95% CI 0.73-1.16) for deaths from ischaemic heart disease at ages <65, 65-79 and 80-89 years, respectively. When the non-vegetarians were divided into regular meat eaters (who ate meat at least once a week) and semi-vegetarians (who ate fish only or ate meat less than once a week), the ischaemic heart disease death rate ratios compared to regular meat eaters were 0.78 (95% CI 0.68-0.89) in semi-vegetarians and 0.66 (95% CI 0.53-0.83) in vegetarians (test for trend P< 0.001). There were no significant differences between vegetarians and non-vegetarians in mortality from the other causes of death examined. CONCLUSION: Vegetarians have a lower risk of dying from ischaemic heart disease than non-vegetarians.

PMID: 10555529

  Health status, the way of life and nourishment of 84 vegans in Siberian village (Krasnoyarsk region) were studied and compared with those of 26 meat-eaters. The investigation included work with a questionnaire, clinico-diagnostic and laboratory research. It was shown that a vegetarian diet improves the serum lipid spectrum (cholesterol, LPLD, cholesterol of LPNP, atherogenic coefficient), normalizes weight and cardiovascular system. The vegans had normal levels of vitamin B12 and serum Fe but the calcium level in this group was lowered as compared with the control group. The pathology of internals (nephroptosis, lithic diathesis, tendency to lithogenesis) was observed. Apparently, the high serum Zn levels found in both groups aren't directly caused by the diet but by climate and geographic factors.

  The Mediterranean diet not only produces favourable effects on blood lipids but also protects against oxidative stress. Oxidative damage is thought to represent one of the mechanisms leading to chronic diseases such as atherosclerosis and cancer. Many studies suggest that a link exists between fruit and vegetables in the diet or the amounts of plasma antioxidant vitamins (ascorbic acid, tocopherol and carotenoids) and risk of death from cancer or coronary heart diseases. Although a large emphasis has been given to different components of the diet, attention has recently shifted to the diet as a whole. The Mediterranean diet is able to modulate oxidative stress through complex mechanisms and not just the high antioxidant compound content. The preference for fresh fruit and vegetables in the Mediterranean diet will result in a higher consumption of raw foods, a lower production of cooking-related oxidants and a consequent decreased waste of nutritional and endogenous antioxidants. The high intake of antioxidant and fibre helps to scavenge even the small amount of oxidants or oxidized compounds.

PMID: 9167133

  Food, particularly dairy products, meat, and fish, has been identified as the primary immediate source of intake of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) for the general population. We previously reported PCDD/Fs in individual analyses of food samples from a number of countries, including the U.S., the former Soviet Union, and Vietnam. We also previously estimated daily intake of dioxins and related chemicals in Americans at various ages in these reports. In this paper, the levels of dioxins, dibenzofurans, dioxin toxic equivalents (TEQs), selected dioxin-like PCBs, and DDE (a persistent metabolite of DDT) were measured in 12 pooled food samples from over 90 individual specimens collected from supermarkets throughout the United States during 1995. Samples were pooled by food groups and then analyzed. Food samples were collected in Binghamton, New York; Atlanta, Georgia; Chicago, Illinois; San Diego, California; and Louisville, Kentucky. In addition to the meat, dairy, and fish samples, a vegan (all vegetable, fruit and grain, no animal product) diet, was simulated; this showed the lowest level of dioxins.

PMID: 9134677

  We assessed the effect of a diet high in leafy and green vegetables, fruit, and nuts on serum lipid risk factors for cardiovascular disease. Ten healthy volunteers (seven men and three women aged 33 +/- 4 years [mean +/- SEM]; body mass index, 23 +/- 1 kg/m2) consumed their habitual diet (control diet, 29% +/- 2% fat calories) and a diet consisting largely of leafy and other low-calorie vegetables, fruit, and nuts (vegetable diet, 25% +/- 3% fat calories) for two 2-week periods in a randomized crossover design. After 2 weeks on the vegetable diet, lipid risk factors for cardiovascular disease were significantly reduced by comparison with the control diet (low-density lipoprotein [LDL] cholesterol, 33% +/- 4%, P < .001; ratio of total to high-density lipoprotein [HDL] cholesterol, 21% +/- 4%, P X .001; apolipoprotein [apo] B:A-I, 23% +/- 2%, P < .001; and lipoprotein (a) [Lp(a)], 24% +/- 9%, P = .031). The reduction in apo B was related to increased intakes of soluble fiber (r = .84, P = .003) and vegetable protein (r = -.65, P = .041). On the vegetable compared with the control diet, the reduction in total serum cholesterol was 34% to 49% greater than would be predicted by differences in dietary fat and cholesterol. A diet consisting largely of low-calorie vegetables and fruit and nuts markedly reduced lipid risk factors for cardiovascular disease. Several aspects of such diets, which may have been consumed early in human evolution, have implications for cardiovascular disease prevention.

PMID: 9160820

  We studied the western lowland gorilla diet as a possible model for human nutrient requirements with implications for colonic function. Gorillas in the Central African Republic were identified as consuming over 200 species and varieties of plants and 100 species and varieties of fruit. Thirty-one of the most commonly consumed foods were collected and dried locally before shipping for macronutrient and fiber analysis. The mean macronutrient concentrations were (mean +/- SD, g/100 g dry basis) fat 0.5 +/- 0.4, protein 11.8 +/- 8.2, available carbohydrate 7.7 +/- 6.3 and dietary fiber 74.0 +/- 12.9. Assuming that the macronutrient profile of these foods was reflective of the whole gorilla diet and that dietary fiber contributed 6.28 kJ/g (1.5 kcal/g), then the gorilla diet would provide 810 kJ (194 kcal) metabolizable energy per 100 g dry weight. The macronutrient profile of this diet would be as follows: 2.5% energy as fat, 24.3% protein, 15.8% available carbohydrate, with potentially 57.3% of metabolizable energy from short-chain fatty acids (SCFA) derived from colonic fermentation of fiber. Gorillas would therefore obtain considerable energy through fiber fermentation. We suggest that humans also evolved consuming similar high foliage, high fiber diets, which were low in fat and dietary cholesterol. The macronutrient and fiber profile of the gorilla diet is one in which the colon is likely to play a major role in overall nutrition. Both the nutrient and fiber components of such a diet and the functional capacity of the hominoid colon may have important dietary implications for contemporary human health.

PMID: 9311957

  Food components which are incompletely absorbed in the small intestine or not absorbed at all but are delivered to the colon have been part of the diet throughout the course of human evolution. Our great ape cousins may derive 30% or more of their dietary calories from colonic uptake of short-chain fatty acids (SCFAs) generated in the colon. The metabolic effects of dietary carbohydrate entering the colon are many and include laxation, the growth of the fecal biomass, nitrogen entrapment and SCFA generation. These SCFAs in turn may nourish mucosal cells, spare glutamine utilization, enhance hepatic gluconeogenesis and lipogenesis and possibly influence renal handling of uric acid. The health implications are significant in terms of modifying risk factors for disease and disease prevention and justify interest in the metabolic effects of non-absorbable sugars such as lactulose.

PMID: 9145438

  A vegetarian diet has a positive effect on various risk factors for coronary artery disease: these include usually lower average body weight, lower total and LDL cholesterol levels, and lower blood pressure. In conjunction with a generally more healthy way of life (more exercise, less alcohol and tobacco use), vegetarians have roughly 30% reduction in overall mortality. The prevalence of bronchial, colon and breast cancer is also lower. In particular in its strict form (total vegetarianism or veganism), a vegetarian regimen may lead to deficiency disorders, in particular vitamin B12 deficiency, [although there is no evidence of this LF] which may occur especially in vegetarian children, pregnant or lactating women. Overall, however, a vegetarian regimen has a more beneficial effect on health than the usual Central European diet.

PMID: 7635375

  OBJECTIVE: To compare nutrient intakes between vegetarians and nonvegetarians with similar health practices, and to assess relationships with eating behavior scores from the Three-Factor Eating Questionnaire. DESIGN: Survey. SETTING: Metropolitan area in western Canada. SUBJECTS: Subjects (n = 45) were participants in a study comparing subclinical menstrual disturbances between vegetarians and nonvegetarians. To be included, women had to be 20 to 40 years old, be weight stable with a body mass index (BMI; kg/m2) of 18 to 25, be a nonsmoker, exercise 7 hours a week or less, consume one alcoholic drink or less a day, and not be using oral contraceptives. Nonvegetarians (n = 22) ate red meat three times a week or more, and vegetarians (n = 23, 8 vegans and 15 lactovegetarians) had excluded all meat, fish, and poultry for 2 years or more. MAIN OUTCOME MEASURES: Nutrient intake assessed by three 3-day diet records; supplement use; body composition; and dietary restraint (conscious limitation of food intake), disinhibition, and hunger assessed by the Three-Factor Eating Questionnaire. STATISTICAL ANALYSES PERFORMED: Anthropometric variables, nutrient intakes, and eating behavior scores were compared between vegetarians and nonvegetarians using unpaired t tests, and among vegans, lactovegetarians, and nonvegetarians using one-way analysis of variance and Duncan's test. Supplement use was compared using chi 2 analysis. The Pearson correlation coefficient was used to evaluate relationships between variables. RESULTS: Diets of all women adhered closely to current nutrition recommendations. Vegetarians had lower protein and cholesterol intakes and higher percentage of energy as carbohydrate, ratio of polyunsaturated fat to saturated fat (P:S ratio), and fiber intake than nonvegetarians. Vegetarians had lower riboflavin, niacin, vitamin B-12, zinc, and sodium intakes and higher folate, vitamin C, and copper intakes. However, many differences were not apparent between the subgroup of lactovegetarians and nonvegetarians (their P:S ratios and carbohydrate, fiber, riboflavin, folate, vitamin C, and copper intakes were similar). In contrast, differences existed between the lactovegetarian and the vegan subgroups. Supplement use was similar between groups, except for greater vitamin C use by vegetarians. Vegetarians were leaner than nonvegetarians, had lower restraint scores, and had significant associations between restraint and BMI (r = .49; P < .05) and energy per kilogram body weight (r = -.60; P < .01). APPLICATIONS/CONCLUSIONS: Current nutrition recommendations can be attained by vegetarians and nonvegetarians alike, but nutrient intakes cannot be inferred from dietary pattern. In this study, the intakes of health-conscious nonvegetarians and lactovegetarians were more similar than the intakes of lactovegetarians and vegans. Vegans' calcium and vitamin B-12 intakes may need attention. Vegetarians' lower restraint scores suggest that they are not at increased risk for eating disorders.

PMID: 7852684

  A vegetarian diet has a positive effect on various risk factors for coronary artery disease: these include usually lower average body weight, lower total and LDL cholesterol levels, and lower blood pressure. In conjunction with a generally more healthy way of life (more exercise, less alcohol and tobacco use), vegetarians have roughly 30% reduction in overall mortality. The prevalence of bronchial, colon and breast cancer is also lower. In particular in its strict form (total vegetarianism or veganism), a vegetarian regimen may lead to deficiency disorders, in particular vitamin B12 deficiency, which may occur especially in vegetarian children, pregnant or lactating women. Overall, however, a vegetarian regimen has a more beneficial effect on health than the usual Central European diet.

PMID: 7635375

  It has recently been shown that serum antibody levels against Proteus mirabilis decreased in patients with rheumatoid arthritis who improved clinically during treatment with 7-10 days of fasting followed by a one-year vegetarian diet. As P. mirabilis is commonly implicated in urinary tract infections, this study was carried out to examine whether fasting and vegetarian diet may influence the growth of P. mirabilis and Escherichia coli in urine. Urine samples were collected from 22 patients who were referred to a health farm for various reasons. The dietary regimen recommended by the health farm consisted of fasting for 7 to 10 days followed by a vegan diet. The growth of both bacteria in urine samples collected after 8 days was significantly slower than in samples collected at baseline. In urine samples collected after 18 days growth was also reduced, although not significantly for E. coli. Our results show that dietary manipulation may reduce the ability of urine to support the growth of P. mirabilis and E. coli.

PMID: 8546847

Arch Oral Biol 1994 Apr;39(4):283-8
Effect of a long-term change from a mixed to a lactovegetarian diet on human saliva.
Johansson G, Birkhed D. Department of Medical Nutrition, Karolinska Institute, Huddinge Hospital, Sweden.

  The effects of this long-term dietary change on secretion rate, buffer capacity, concentration of sodium and potassium and amylase activity of stimulated parotid and whole saliva was studied in 20 healthy, normal-weight, non-smoking omnivores. Salivary counts of mutans streptococci and lactobacilli were also made. Dietary surveys were carried out and saliva samples collected before (baseline) and 3, 6 and 12 months after the dietary change as well as 3 yr after the end of the lactovegetarian diet period. The dietary data showed an increase in the consumption of fruits, vegetables and dairy products and a decrease in meat, fish, eggs, sweets and biscuits. These changes led to an increased intake of carbohydrates, fibre and water. After 12 months on the vegetarian diet, the secretion rate, buffer capacity and sodium concentration of whole saliva and the secretion rate of parotid saliva had increased significantly. At the 3-yr follow-up, the buffer capacity and sodium concentration were still elevated, while the secretion rate had almost returned to the baseline values. The potassium content of whole saliva showed a tendency to increase during the vegetarian diet period, but had decreased again at the 3-yr follow-up.

PMID: 7517663

  The beneficial effect of a 1-yr vegetarian diet in RA has recently been demonstrated in a clinical trial. We have analysed stool samples of the 53 RA patients by using direct stool sample gas-liquid chromatography of bacterial cellular fatty acids. Based on repeated clinical assessments disease improvement indices were constructed for the patients. At each time point during the intervention period the patients in the diet group were then assigned either to a group with a high improvement index (HI) or a group with a low improvement index (LI). Significant alteration in the intestinal flora was observed when the patients changed from omnivorous to vegan diet. There was also a significant difference between the periods with vegan and lactovegetarian diets. The faecal flora from patients with HI and LI differed significantly from each other at 1 and 13 months during the diet. This finding of an association between intestinal flora and disease activity may have implications for our understanding of how diet can affect RA.

PMID: 8019792

  This epidemiological study compares the frequency of resistant bacteria in stool microflora among vegetarians and nonvegetarians over a 12 month period. Two well characterized vegetarian populations (one in Boston, MA and the other in Loma Linda, CA) as well as appropriate controls were studied. No apparent differences in the prevalence of antibiotic resistance in the microflora were noted; however, vegetarians had a significantly greater incidence of multi-antibiotic resistance. E. coli of the same API biotype had the same frequency of antibiotic resistance in both vegetarians and nonvegetarians. Quantitative studies showed similar percents of tetracycline resistant facultative isolates and of "bacteroides." Klebsiella were more common in the stool of the nonvegetarians. As shown in previous studies, exposure to animal products either as meat eaters or production workers in a poultry abattoir was not associated with an increased incidence of resistant bacterial flora or infections caused by resistant strains.

PMID: 8236755

  We investigated the relationship between animal product consumption and evidence of dementia in two cohort substudies. The first enrolled 272 California residents matched for age, sex, and zip code (1 vegan, 1 lacto-ovo-vegetarian, and 2 'heavy' meat eaters in each of 68 quartets). This design ensured a wide range of dietary exposure. The second included 2,984 unmatched subjects who resided within the Loma Linda, California area. All subjects were enrolled in the Adventist Health Study. The matched subjects who ate meat (including poultry and fish) were more than twice as likely to become demented as their vegetarian counterparts (relative risk 2.18, p = 0.065) and the discrepancy was further widened (relative risk 2.99, p = 0.048) when past meat consumption was taken into account. There was no significant difference in the incidence of dementia in the vegetarian versus meat-eating unmatched subjects. There was no obvious explanation for the difference between the two substudies, although the power of the unmatched sub-study to detect an effect of 'heavy' meat consumption was unexpectedly limited. There was a trend towards delayed onset of dementia in vegetarians in both substudies.

PMID: 8327020

  Culture counts of aerobic lactobacilli in the feces of vegetarians ([8.1 +/- 0.7] of log10 bacteria per gram dry weight) were higher than those of meat consumers ([5.2 +/- 0.1] of log10 bacteria per gram dry weight). Co-culture of Lactobacillus acidophilus and Clostridium perfringens in various media revealed that an interaction between these two species. The pH was the most important factor controlling their relative growth, which might explain the relative abundance of lactobacilli in feces of men and animals on vegetarian diets. Lactobacilli but not clostridia were detected in feces of newborn infants. These findings are discussed in relation to health.

PMID: 2558007

  Recent studies of vegetarian diets and their effects on morbidity and mortality are reviewed. Vegetarian diets are heterogeneous as are their effects on nutritional status, health, and longevity. Mortality rates are similar or lower for vegetarians than for nonvegetarians. Risks of dietary deficiency disease are increased on vegan but not on all vegetarian diets. Evidence for decreased risks for certain chronic degenerative diseases varies. Both vegetarian dietary and lifestyle practices are involved. Data are strong that vegetarians are at lesser risk for obesity, atonic constipation, lung cancer, and alcoholism. Evidence is good that risks for hypertension, coronary artery disease, type II diabetes, and gallstones are lower. Data are only fair to poor that risks of breast cancer, diverticular disease of the colon, colonic cancer, calcium kidney stones, osteoporosis, dental erosion, and dental caries are lower among vegetarians. Reduced risks for chronic degenerative diseases can also be achieved by manipulations of omnivorous diets and lifestyles.

PMID: 3046302

  In a metabolic ward 12 healthy male subjects consumed mixed Western (M), lacto-ovovegetarian (L), and vegan (V) diets in a randomized order for 20 d each. The concentrations of deoxycholic acid, isolithocholic acid, and total bile acids in 4-d composites of feces on the L and V diets were significantly lower than on the M diet. The chenodeoxycholic-to-isolithocholic plus lithocholic acid ratio was significantly higher on the V diet. The concentrations of coprostanol and of coprostanol plus cholesterol were highest on M diet and lowest on V diet. The number of fecal lactobacilli and enterococci on the V diet was significantly lower than on the M or the L diets. This study showed a decrease in the concentration of fecal (secondary) bile acids by the L and the V diets and an alteration of the fecal flora composition by the V diet.

PMID: 3120571

  The normal human microflora maintains a delicate balance between its constituent parts, numbering 10(11) bacteria per gram with over 400 different species. Certain metabolic functions and enzyme activities can be attributed to the microflora, and these play a role in metabolizing nutrients, vitamins, drugs, endogenous hormones and carcinogens. Our laboratory has studied estrogen and cholesterol metabolism and activation of colon carcinogens. Three techniques to change the flora and its enzymatic activities have been used. Switching the diet from an omnivore diet to a vegetarian diet decreases bacterial deconjugating enzymes in the intestine. Administering antibiotics also suppresses the metabolic activity of the microflora. Similar suppressive effects can be achieved by feeding a human strain of Lactobacillus that implants in the gastrointestinal tract. Manipulation of these various modalities can maximize the beneficial activities of the intestinal microflora.

PMID: 3103209

  The provision of small amounts of glucose during fasting is known to spare body protein and to attenuate markedly the metabolic response to starvation. These actions, which are not shared by fat, are generally thought to depend on the ability of exogenous glucose to stimulate insulin secretion. To determine whether fructose, a very weak insulin secretagogue, will also conserve nitrogen and alter the response to fasting, we infused small amounts of fructose, 100 g/d (375 kcal), into 7 obese subjects during a 10-day fast: 4 received fructose days 7 to 10, and 3 received fructose days 1 to 7. Fructose virtually abolished (all P less than 0.05-0.01) the fasting induced: (a) fall in glucose and insulin and rise in glucagon, (b) fall in triiodothyronine, (c) ketosis and acidosis, (d) increased ammonia excretion, (e) hyperuricemia (and hypouricosuria), and (f) fall in plasma alanine and rise in branched chain amino acids. Fructose also significantly reduced urinary sodium loss. Moreover, fructose exerted a prominent protein-sparing action, even though plasma insulin concentrations never exceeded postabsorptive levels. Excretion of total nitrogen was reduced by 40% to 50% during periods of fructose infusion, reflecting significant suppression of both urea and ammonia generation (all P less than 0.05-0.01). Most plasma glucogenic amino acids rose significantly during fructose administration. We conclude that low-dose fructose infusion essentially abolishes the entire hormone-substrate response to fasting, and spares body protein without raising insulin above postabsorptive levels.

PMID: 3510363

  Using repair-proficient and repair-deficient strains of E. coli, we investigated the application of a liquid incubation assay to measure the DNA-damaging activity of ethanol-soluble fecal extracts. This method appears to be suitable for the study of a wide range of sample types. It was used to measure the DNA-modifying activity of ethanol-soluble fecal extracts from a group of European colorectal cancer patients. Data were compared with those from Europeans of similar age and sex distribution who did not have bowel cancer. We also studied groups of Maoris, Samoans, and European Seventh-Day Adventists who followed an ovo-lacto vegetarian diet. There are significant levels of DNA-modifying materials in the feces of many Europeans on a mixed diet, regardless of whether or not they have cancer. The number of positive samples was less in the Polynesian groups, and there were no samples that could be unequivocally scored as positive in the Seventh-Day Adventist groups. [Note: here, "positive' means mutagenic - ljf] We conclude that diet can significantly reduce the level of ethanol-soluble mutagens, at least in New Zealand Europeans. The data may provide an explanation for the reduced incidence of bowel cancer in Seventh-Day Adventist groups.

PMID: 3906579

  Human urine from smokers and nonsmokers on strictly controlled diets was assayed for mutagenic activity. Two distinct diets were employed in this study. Diet study A consisted of a high-meat, high-fat diet, observed for 5 days, followed by a vegan diet, adhered to for the next 5 days. The vegan diet contained no meat, fish, eggs, or dairy products. It was comprised of soy products, prepackaged vegan dinners, seeds, nuts, fruits, vegetables, beans and herbal teas. Diet study B consisted of 3 days on a typical western diet followed by a macrobiotic diet of grains and fresh vegetables for 5 days. Portions of 24-h urine samples were assayed in Salmonella typhimurium TA1538. The levels of urinary creatinine and cotinine were measured. Mutagenic activity was observed in the urine of most smokers. However, the levels of mutagens in the urine of light smokers were similar to those of nonsmokers. For both nonsmokers and smokers there was a significant increase in urine mutagenicity when volunteers were on the vegan diet. Several nonsmokers on the vegan diet in diet study A had pronounced mutagenic activity in their urine samples, in some instances at higher levels than that in the urine of smokers on a meat diet. In diet study B no clear differences were observed between the meat diet and the macrobiotic diet. In diet studies A and B the mutagenic potency of smokers' urine could not be correlated with cotinine levels alone or with urinary pH. These data suggest that dietary factors can play a dominant role in the mutagenicity of urine concentrates.
[Note: changing from a meat-oriented diet to a "vegan" one will initiate cleansing and an increased load of toxins and mutagens in the urine.  The Macrochaotic diet is not as cleansing as a more rational vegan diet, as everything is cooked, hiigh protein beans are conumed, and concentrated protein/concentrated starch combinations predominate.  It would have been much more informative if long-term vegans had been compared to long-term meat-eaters. -- ljf]

PMID: 3908928

  This paper reviews the association between a vegetarian diet and a number of risk factors for cardiovascular disease investigated in a series of epidemiological and experimental studies. Ninety-eight Seventh-day Adventist "vegetarians" were similar to 113 Mormon omnivores for strength of religious affiliation, consumption of alcohol, tea and coffee and use of tobacco, but were significantly less obese and had significantly lower blood pressures adjusted for age, height and weight. A random sample of forty-seven Adventist vegetarians had significantly lower home blood pressures, serum cholesterol levels and blood pressure responses to a cold-pressor test than Mormon omnivores carefully matched for age, sex and Quetelet's index. In a controlled dietary intervention study mean systolic and diastolic blood pressures and serum cholesterol fell significantly during feeding with a vegetarian diet--an effect unrelated to changes in other lifestyle factors. Dietary analysis indicated that a vegetarian diet provided more polyunsaturated fat, fibre, vitamin C, vitamin E, magnesium, calcium and potassium and significantly less total fat, saturated fat and cholesterol than an omnivore diet. There was no evidence for a difference between vegetarians and omnivores in levels of catecholamines, plasma renin activity, angiotensin II, cortisol or serum and urinary prostanoids.

PMID: 6596054

  The composition of the fecal flora in two groups of children in primary school age with (a) normal, ad libitum diet (school-group, 20 children), and (b) lacto-ovo-vegetarian diet (Salem-group, 20 children) was examined. Fecal analysis was concentrated upon the isolation of the main anaerobic and aerobic microorganisms. The pattern of S-, M-, and R-forms of Enterobacteriaceae with special regard to E. coli was investigated additionally. In the school-group counts of Clostridium species, R-, and M- forms of E. coli were significantly higher than in the Salem-group. The numbers of Bifidobacterium, Actinomyces, and Enterobacteriaceae species, as well as S-forms of E. coli were significantly increased in the Salem-group, as compared to the school-children. The data reveal a relationship between the occurrence of different anaerobic species and the SMR-pattern of E. coli, with Clostridium species in particular. The SMR-pattern of E. coli may reflect conditions of intestinal metabolism and mucosal immunity. It may serve as a simple parameter in routine examination of fecal specimen.

PMID: 6361854

  The association between vegetarianism and blood pressure was studied in relation to obesity, sex and aspects of lifestyle in 180 Seventh-day Adventists and 113 Mormons aged 25-44 y. 2. Volunteers completed a questionnaire, a 1-day diet record and submitted to standardized measurements of blood pressure, heart rate and body size. 3. Ninety-eight Adventist "vegetarians" were comparable to the 113 Mormon omnivores for strength of religious affiliation, consumption of alcohol, tea and coffee and use of tobacco, but were significantly less obese. 4. Obesity correlated positively with blood pressures in males and females of both diet classes. Age showed a positive correlation with blood pressure in females only. 5. Adjustment of blood pressures for age and Quetelet Index indicated that there is an additional blood pressure reducing effect associated with a vegetarian diet.

PMID: 7140012

  We studied 10 vegetarian and 10 nonvegetarian premenopausal women on four occasions approximately four months apart. During each study period, the participants kept three-day dietary records, and estrogens were measured in plasma, urinary, and fecal samples. Vegetarians consumed less total fat than omnivores did (30 per cent of total calories, as compared with 40 per cent) and more dietary fiber (28 g per day, as compared with 12 g). There was a positive correlation between fecal weight and fecal excretion of estrogens in both groups (P less than 0.001), with vegetarians having higher fecal weight and increased fecal excretion of estrogens. Urinary excretion of estriol was lower in vegetarians (P less than 0.05), and their plasma levels of estrone and estradiol were negatively correlated with fecal excretion of estrogen (P = 0.005). Among the vegetarians the beta-glucuronidase activity of fecal bacteria was significantly reduced (P = 0.05). We conclude that vegetarian women have an increased fecal output, which leads to increased fecal excretion of estrogen and a decreased plasma concentration of estrogen.

PMID: 7144835

  Body size and body composition have been suggested as the best explanation for the temporal trend toward early menarche over the last 100 years. There is evidence from human and animal studies that indicates that body size is not the primary factor in influencing the occurrence of menarche. The data actually show that diet may be a primary environmental control mechanism of menarche especially since it alters hormone levels. We see diet as an etiological factor in both the long term and immediate control of menarche. In the long term it influences body size and development leading to menarche. In the short term it acts at a critical state to precipitate the onset of menarche and related physiological changes. This hypothesis does not exclude other less important factors associated with menarche. Our data shows that the present trend toward early menarche can be reversed when a balanced vegetarian diet is selected in place of the ordinary American diet.

PMID: 7321920

  In a controlled trial, 21 strict vegetarians were studied prospectively for eight weeks: a two-week control period of the usual vegetarian diet was followed by four weeks, during which 250 g of beef was added isocalorically to the daily vegetarian diet and then by two weeks of the control diet. Plasma high-density lipoprotein-cholesterol did not change during the study, whereas plasma total cholesterol rose significantly by 19% at the end of the meat-eating period. Systolic blood pressure (BP) increased significantly during the meat eating by 3% over control values, whereas diastolic BP showed no major changes. Plasma renin activity, prostaglandin A and E levels, and urinary kallikrein, norepinephrine, and epinephrine excretions were within normal limits and did not change notably throughout the trial. The study suggests an adverse effect of consumption of beef on plasma lipid and BP levels.

 A strict vegetarian diet [vegan diet (VD)] was investigated. Six middle-aged vegans (three men and three women) collected copies of 24-h diets using the duplicate portion sampling technique. By chemical analyses, the nutrient composition was determined in detail and compared with corresponding figures of a normal mixed Swedish diet. In the VD 30% of the energy originated from fat compared with 40% in normal Swedish mixed diet (MD). Linoleic acid was the dominant fatty acid (60% of total fat in VD versus 8% in MD). The VD contained 24 g protein/1000 kcal compared to 30 g/1000 kcal in MD, but the intake of essential amino acids by the vegans exceeded the recommendations. Dietary fiber was about 5 times higher in the vegan diet (29 versus 6 g/1000 kcal) and sucrose similar to MD (18 versus 21 g/1000 kcal). Among the inorganic nutrients the concentration of calcium (351 versus 391 mg/1000 kcal) and sodium (53 versus 49 mmol/1000 kcal) were similar in both types of diets but the amount of potassium (56 versus 30 mmol/1000 kcal, magnesium (300 versus 110 mg/1000 kcal), iron (9 versus 6.5 mg/1000 kcal), zinc (6.5 versus 4.7 mg/1000 kcal), and copper (2 versus 0.7 mg/1000 kcal) were nearly doubled. Iodine (39 versus 156 micrograms/1000 kcal and selenium (5 versus 17 micrograms/1000 kcal) were much lower in the VD, selenium even being undetectable in several 24-h diets. The VD was rich in folic acid (301 versus 90 micrograms/1000 kcal in MD) but the intake of vitamin B12 was only 0.3 to 0.4 microgram/day (MD: 3 to 4 micrograms/day). No clinical signs of nutritional deficiency were observed in the vegans. Serum protein levels of the vegans as well as their serum lipoproteins were near the lower range of the reference group. In addition, none of the vegans was overweight and their blood pressures were low for their age.

PMID: 6272567

  A comparison of 13 vegetarian Seventh Day Adventists with 14 nonvegetarian Adventists revealed relatively few statistically significant differences in fecal flora. A separate study involved a comparison of vegetarian Adventists (49 subjects), nonvegetarian Adventists (45), and non-Adventists on a conventional American diet (31) re: the incidence of the C. paraputrificum group in the fecal flora. The Adventist groups had significantly fewer C. septicum and C. tertium isolates than the non-Adventists. Reference to earlier diet studies done by our group revealed certain striking differences. Fusobacterium and C. perfringens counts were very low and lactobacillus counts very high in Adventists as compared with Japanese-Americans on either a Japanese or Western diet or Caucasian individuals on a conventional U.S. diet. Comparison of nonvegetarian Adventists with the other groups on a nonvegetarian Western diet also revealed several statistically significant differences. Finally, there were a number of significant differences in fecal flora when high risk groups (Japanese-Americans on Western diet and Caucasians on conventional U.S. diet) were compared with low risk groups (Japanese-Americans on a Japanese diet and Adventists).

PMID: 920638