Meat

  Many changes in diet and in physical activity are occurring simultaneously in the developing world. These diet shifts include large increases in energy density, in the proportion of the population consuming a high fat diet and in animal product intake. Animal source foods (ASF) play a major role in these diet shifts. This article documents the large shifts in the composition of diets and obesity across the developing world and notes that these changes are accelerating. Using China as a case study, evidence of the speeding up of this process is presented in descriptive and more rigorous dynamic longitudinal analysis. The implications of these changes for dietary and obesity patterns and cardiovascular disease are great. Indeed, developing countries are at a point where the prevalence of obesity is greater than that of undernutrition and concerns related to intake of saturated fat and energy imbalance must be considered more seriously by the agriculture sector. Current agriculture development policy in many developing countries focuses on livestock promotion and does not consider the potential adverse health consequences of this strategy. Although linkages between ASF intake and obesity cannot be established as clearly as they are for high ASF intakes, heart disease and cancer, the potential adverse health effects linked with an increased ASF intake should no longer be ignored.

PMID: 14672288

  Endogenous opioid peptides within the nucleus accumbens, a forebrain site critical for the regulation of reward-related behavior, are believed to play an important role in the control of appetite. In particular, this system is thought to mediate the hedonic aspects of food intake, governing the positive emotional response to highly palatable food such as fat and sugar. Previous work has shown that intra-accumbens administration of the mu-opioid agonist D-Ala2,Nme-Phe4,Glyol5-enkephalin (DAMGO) markedly increases food intake and preferentially enhances the intake of palatable foods such as fat, sucrose, and salt. [Quite probably an internal hunger control that mediates consumption of milk in the infant -ljf] Using information from recently performed c-fos mapping experiments, we sought to explore the involvement of structures efferent to the nucleus accumbens in this feeding response. Free-feeding rats with dual sets of bilateral cannulas aimed at the nucleus accumbens and one of several output structures were infused with DAMGO (0, 0.25 microg/0.5 microl) in the accumbens, and fat intake was measured over a 2 hr period. Concurrent temporary inactivation with the GABA(A) agonist muscimol (5-20 ng/0.25 microl) of the dorsomedial hypothalamic nucleus, lateral hypothalamus, ventral tegmental area, or the intermediate region of the nucleus of the solitary tract blocked the robust increase in fat intake induced by intra-accumbens DAMGO at doses of muscimol that did not affect general motor activity. Muscimol alone also inhibited and augmented baseline fat intake in the lateral and dorsomedial hypothalamic nuclei, respectively. These results suggest that intake of energy-dense palatable food is controlled by activity in a neural network linking ventral striatal opioids with diencephalic and brainstem structures.

PMID: 12684475

Study: Burgers are as addictive as heroin.

  A hamburger and fries can be just as addictive as cigarettes and even hard drugs, a surprising new study claims. Scientists at the University of Wisconsin say high doses of fat and sugar in fast and processed foods act the same way as nicotine, heroin and other substances in becoming habit-forming. "A high-fat diet alters brain biochemistry with effects similar to those in powerful opiates such as morphine," lead researcher Matthew Will told a British television documentary. In Will's research - detailed in the documentary "Big Mac Under Attack," which airs in Britain tomorrow - he fed a group of lab rats high-fat diets and discovered that when the fat was taken away, the rodents displayed withdrawal symptoms similar to those of a drug addict denied a fix. He also found that a steady diet of fat alters the development of the brain so much that it is almost impossible for a fast-food "junkie" to switch to a healthy diet. The research was also reported in yesterday's Sunday Times of London. Lawyers have launched a series of high-profile lawsuits against fast-food chains, claiming that they have misrepresented the effects of their products - and the new research is sure to add to the debate. Although nutrition requirements vary according to height and build, general government guidelines recommend a daily intake of 2,300 calories for an adult male and 1,800 calories for an adult female. Of those, no more than 35 percent should be derived from fat and no more than 11 percent from sugars.

  There is a long-standing interest in the role of endogenous opioid peptides in feeding behavior and, in particular, in the modulation of food reward and palatability. Since drugs such as heroin, morphine, alcohol, and cannabinoids, interact with this system, there may be important common neural substrates between food and drug reward with regard to the brain's opioid systems. In this paper, we review the proposed functional role of opioid neurotransmission and mu opiate receptors within the nucleus accumbens and surrounding ventral striatum. Opioid compounds, particularly those selective for the mu receptor, induce a potent increase in food intake, sucrose, salt, saccharin, and ethanol intake. We have explored this phenomenon with regard to macronutrient selection, regional specificity, role of output structures, Fos mapping, analysis of motivational state, and enkephalin gene expression. We hypothesize that opioid-mediated mechanisms within ventral striatal medium spiny neurons mediate the affective or hedonic response to food ('liking' or food 'pleasure'). A further refinement of this hypothesis is that activation of ventral striatal opioids specifically encodes positive affect induced by tasty and/or calorically dense foods (such as sugar and fat), and promotes behaviors associated with this enhanced palatability. It is proposed that this brain mechanism was beneficial in evolutionary development for ensuring the consumption of relatively scarce, high-energy food sources. However, in modern times, with unlimited supplies of high-calorie food, it has contributed to the present epidemic of obesity.

PMID: 12117573

  Our previous studies have shown that stimulation of mu-opioid receptors within the nucleus accumbens preferentially enhances intake of palatable food containing sucrose and fat; thus, opioids in this brain area may mediate the rewarding characteristics of food by modulating taste and macronutrient preference. The present study was designed to further explore the nature of the involvement of striatal opioids in feeding behavior, such as the location of sensitive subregions of the ventral striatum and the brain neural circuits involved in opioid-mediated hyperphagia. In Experiment 1, we conducted a microinfusion mapping study of feeding behavior by microinfusion of the mu receptor agonist, D-Ala(2),NMe-Phe(4), Glyol(5)-enkephalin (0, 0.025 and 0.25 microg/0.5 microl per side; equivalent to 0, 0.04 and 0.40 nmol/0.5 microl per side), into several striatal subregions. In Experiment 2, detection of the expression of the immediate early gene, c-fos, was used to examine brain areas activated following intra-striatal microinfusion of D-Ala(2), NMe-Phe(4),Glyol(5)-enkephalin. The microinjection mapping study demonstrated a broad anatomical gradient within the striatum, with sensitivity highest in relatively more lateral and ventral regions of the striatum (ventrolateral striatum, lateral shell and core). The Fos mapping study demonstrated that circuitry including hypothalamic areas, the ventral tegmental area, the substantia nigra and the nucleus of the solitary tract was recruited by stimulation of mu receptors within the nucleus accumbens. A similar pattern was observed following stimulation of mu receptors in the dorsal striatum; however, the extent of activation was much smaller in magnitude. These results suggest that the role of mu receptors within the striatum in palatable feeding primarily involves ventral and lateral regions. Moreover, the pattern of activation in hypothalamic, midbrain and gustatory-visceral relay areas suggests that striatal mu receptors may participate in integrating motivational, metabolic and autonomic aspects of ingestive behavior.

PMID: 10938432

  PURPOSE: In Asian populations, there is a high prevalence of right-sided colonic diverticulosis, the cause of which is uncertain. It is suspected that dietary habits may interact with a congenital predilection to cause this condition. To evaluate the relationship between long-term dietary habits and the prevalence of right-sided diverticulosis in the general population, we performed a retrospective case-control study.
  METHODS: We reviewed the records of 3,105 screening colonoscopies performed on healthy, asymptomatic adults. All cases of right-sided diverticulosis were selected, and a similar number of gender-matched and age-matched controls with negative colonoscopies were randomly sampled from the same cohort. All case and control subjects were interviewed by a single-blinded nurse to establish their dietary habits during the past decade, in addition to other demographic characteristics. Based on consumption frequency, they were assigned to one of three diet classes for each of three food categories of interest: meat, vegetable, and fruit products. Staple foods such as rice were not included. Odds ratios were then calculated using multivariate conditional logistic regression and tests for trend were performed.
  RESULTS: A total of 86 cases of right-sided diverticulosis were included, whereas 106 controls were randomly selected. There was a marked association between meat consumption frequency and right-sided diverticulosis, with a trend P value of <0.01 and an odds ratio of 24.81 between the most and least frequent consumers of meat products.
  CONCLUSIONS: The prevalence of right-sided diverticulosis is strongly positively associated with past meat consumption frequency. There is no association with vegetable or fruit consumption frequency, laxative use, supplemental fiber intake, smoking, or family history.

  Meat intake has been positively associated with risk of digestive tract cancers in several epidemiological studies, while data on the relation of meat intake with cancer risk at most other sites are inconsistent. The overall data set, derived from an integrated series of case-control studies conducted in northern Italy between 1983 and 1996, included the following incident, histologically confirmed neoplasms: oral cavity, pharynx and esophagus (n = 497), stomach (n = 745), colon (n = 828), rectum (n = 498), liver (n = 428), gallbladder (n = 60), pancreas (n = 362), larynx (n = 242), breast (n = 3,412), endometrium (n = 750), ovary (n = 971), prostate (n = 127), bladder (n = 431), kidney (n = 190), thyroid (n = 208), Hodgkin's disease (n = 80), non-Hodgkin's lymphomas (n = 200) and multiple myelomas (n = 120). Controls were 7,990 patients admitted to hospital for acute, non-neoplastic conditions unrelated to long-term modifications in diet. The multivariate odds ratios (ORs) for the highest tertile of red meat intake (>/=7 times/week) compared with the lowest (Thus, reducing red meat intake might lower the risk for several common neoplasms.

PMID: 10760833

  In order to examine the risks of cancer of the upper aerodigestive tract associated with food groups, a case-control study was conducted in Uruguay in the period January 1996-December 1997. All patients afflicted with cancer of the oral cavity, pharynx larynx, and esophagus, were included in the study. Cases were frequency matched with hospitalized patients on age, sex, residence, and urban/rural status. A strong association with red meat intake was observed (OR 2.4, 95% CI 1.2-4.8), whereas vegetables fruits and legumes were associated with an inverse association (OR for fruits 0.3, 95% CI 0.2-0.6). Salted meat, a possible source of nitrosamines, was associated with an increased risk of 60% for esophageal cancer. Possible mechanisms for these findings are discussed.

PMID: 10211305

  The intake of a Western diet with a high amount of red meat is associated with a high risk for colon cancer. We hypothesize that heme, the iron carrier of red meat, is involved in diet-induced colonic epithelial damage, resulting in increased epithelial proliferation. Rats were fed purified control diets, or purified diets supplemented with 1.3 micromol/g of hemin (ferriheme), protoporphyrin IX, ferric citrate, or bilirubin (n = 8/group) for 14 days. Feces were collected for biochemical analyses. Fecal cytotoxicity was determined from the degree of lysis of erythrocytes by fecal water. Colonic epithelial proliferation was measured in vivo using [3H]thymidine incorporation into colonic mucosa. The colonic epithelial proliferation in heme-fed rats was significantly increased compared to control rats [55.2 +/- 5.8 versus 32.6 +/- 6.3 dpm/microg DNA (mean +/- SE); P < 0.05]. The fecal water of the heme group was highly cytotoxic compared to the controls (90 +/- 2% versus 2 +/- 1%; P < 0.001), although the concentrations of cytotoxic bile acids and fatty acids were significantly lower. Organic iron was significantly increased compared to the controls (257 +/- 26 versus 80 +/- 21, microM; P < 0.001). Spectrophotometric analyses suggest that this organic iron is heme-associated. Thiobarbituric acid-reactive substances were greatly increased in the fecal water of heme-fed rats compared to the controls (177 +/- 12 versus 59 +/- 7 microM; P < 0.05). Heme itself could not account for the increased cytotoxicity because the addition of heme to the fecal water of the control group, which was equimolar to the organic iron content of the fecal water of the heme group, did not influence the cytotoxicity. Hence, an additional heme-induced cytotoxic factor is involved, which may be modulated by the generation of luminal-reactive oxygen species. Protoporphyrin IX, ferric citrate, and bilirubin did not increase proliferation and cytotoxicity. In conclusion, dietary heme leads to the formation of an unknown, highly cytotoxic factor in the colonic lumen. This suggests that, in heme-fed rats, colonic mucosa is damaged by the intestinal contents. This results in a compensatory hyperproliferation of the epithelium, which supposedly increases the risk for colon cancer.

PMID: 10582688

  The age adjusted incidence of cancer has increased on average 1% annually since the beginning of this century, and cancer is now one of the most prevalent causes of death. Diet is suggested to be responsible for about 30-70% of all cancer cases. The heterocyclic amines (HCA) produced during processing of meats and fish at temperatures above 150 degrees C are candidate dietary causes. Amounts in food range from less than 1 ng/g in cooked meat or fish up to over 300 ng/g in well done flame grilled chicken breast meat. The most important parameters determining HCA amounts are cooking temperature and cooking time. 20 different HCAs are identified from cooked or grilled meats and fish. HCAs are causing cancer in various organs in mice, rats and cynomolgus monkeys. It is of interest to note that in rats, PhIP, the most abundant heterocyclic amine in cooked food, causes colon, prostate and mammary cancer, which are the most prevalent cancers in humans. Epidemiological studies show a correlation between intake of red meat and colon, mammary and prostate cancer. Based on the adverse effects of HCA, a reduced intake is recommended and practical advice on how this can be done is given.

PMID: 10025205

  Most studies of diet and colorectal cancer have considered nutrients and micronutrients, but the role of foods or food groups remains open to debate. To elucidate the issue, we examined data from a case-control study conducted between 1992 and 1997 in the Swiss canton of Vaud. Cases were 223 patients (142 men, 81 women) with incident, histologically confirmed colon (n= 119) or rectal (n= 104) cancer (median age 63 years), linked with the Cancer Registry of the Swiss Canton of Vaud, and controls were 491 subjects (211 men, 280 women, median age 58 years) admitted to the same university hospital for a wide spectrum of acute non-neoplastic conditions unrelated to long-term modifications of diet. Odds ratios (OR) were obtained after allowance for age, sex, education, smoking, alcohol, body mass index, physical activity and total energy intake. Significant associations were observed for refined grain (OR = 1.32 for an increase of one serving per day), and red meat (OR = 1.54), pork and processed meat (OR = 1.27), alcohol (OR = 1.28), and significant protections for whole grain (OR = 0.85), raw (OR = 0.85) and cooked vegetables (OR = 0.69), citrus (OR = 0.86) and other fruits (OR = 0.85), and for coffee (OR = 0.73). Garlic was also protective (OR = 0.32 for the highest tertile of intake). These findings in a central European population support the hypothesis that a diet rich in refined grains and red meat increases the risk of colorectal cancer; they, therefore, support the recommendation to substitute whole grains for refined grain, to limit meat intake, and to increase fruit and vegetable consumption.

PMID: 10098773

  BACKGROUND: Non-Hodgkin's lymphoma occurs more frequently in individuals with suppressed immune status, and some types of dietary fat and protein have been associated with decreased immune responses. In this study, we examined the intake of specific types of dietary fat and protein in relation to the risk of non-Hodgkin's lymphoma.
  METHODS: We documented 199 incident cases of non-Hodgkin's lymphoma in a cohort of 88 410 women, who were enrolled in the Nurses' Health Study and were aged 34-60 years in 1980, during 14 years of follow-up. Relative risks of the disease and 95% confidence intervals (95% CIs) were calculated. All P values are two-sided and were considered to be statistically significant for P<.05.
  RESULTS: Intake of saturated fat was associated with an increase in risk that was not statistically significant; the multivariate relative risk for the highest versus the lowest quintiles of intake was 1.4 (95% CI = 0.7-3.0; P for trend =.42). Intake of beef, pork, or lamb as a main dish was associated with a statistically significantly increased risk of non-Hodgkin's lymphoma; the multivariate relative risk for consumption of these meats at least once per day as compared with less than once per week was 2.2 (95% CI = 1.1-4.4; P for trend =.002). Higher intake of trans unsaturated fat was also statistically significantly associated with an increased risk of the disease; the multivariate relative risk for the highest versus the lowest quintiles was 2.4 (95% CI = 1.3-4.6; P for trend =.01). Higher intake of red meat cooked by broiling or barbecuing-but not by roasting, pan-frying, or boiling or stewing-was associated with an increase in risk that was not statistically significant.
  CONCLUSIONS: Greater dietary intake of certain meats and fats was associated with a higher risk of non-Hodgkin's lymphoma. These relationships and their potential mechanisms deserve further examination.

PMID: 10528026

  Prostate cancer is the most common malignancy in men in the United States, with substantially higher rates among American blacks than whites. We carried out a population-based case-control study in three geographic areas of the United States to evaluate the reasons for the racial disparity in incidence rates. A total of 932 men (449 black men and 483 white men) who had been newly diagnosed with pathologically confirmed prostate cancer and 1201 controls (543 black men and 658 white men) were interviewed in person to elicit information on potential risk factors. This report evaluates the impact of dietary factors, particularly the consumption of animal products and animal fat, on the risk of prostate cancer among blacks and whites in the United States. Increased consumption (grams/day) of foods high in animal fat was linked to prostate cancer (independent of intake of other calories) among American blacks [by quartile of intake, odds ratio (OR) = 1.0 (referent), 1.5, 2.1, and 2.0; Ptrend = 0.007], but not among American whites [by quartile of intake, OR = 1.0 (referent), 1.6, 1.5, and 1.1; Ptrend = 0.90]. However, risks for advanced prostate cancer were higher with greater intake of foods high in animal fat among blacks [by quartile of intake, OR = 1.0 (referent), 2.2, 4.2, and 3.1; Ptrend = 0.006] and whites [by quartile of intake, OR = 1.0 (referent), 2.2, 2.6, and 2.4; Ptrend = 0.02]. Increased intake of animal fat as a proportion of total caloric intake also showed positive but weaker associations with advanced prostate cancer among blacks (Ptrend = 0.13) and whites (Ptrend = 0.08). No clear associations were found with vitamin A, calcium, or specific lycopene-rich foods. The study linked greater consumption of fat from animal sources to increased risk for prostate cancer among American blacks and to advanced prostate cancer among American blacks and whites. A reduction of fat from animal sources in the diet could lead to decreased incidence and mortality rates for prostate cancer, particularly among American blacks.

PMID: 9950236

  OBJECTIVE: To analyze the relation between selected dietary indicators and the risk of uterine myomas. METHODS: We used data from a case-control study on risk factors for uterine myomas conducted in Italy between 1986 and 1997. Cases included 843 women with uterine myomas whose clinical diagnoses dated back no more than 2 years. Controls were 1557 women younger than age 55 who had not had hysterectomies and were admitted for acute nongynecologic, nonhormonal, nonneoplastic conditions. RESULTS: Women with uterine myomas reported more frequent consumption of beef, other red meat, and ham and less frequent consumption of green vegetables, fruit, and fish. The multivariate odds ratios in the upper tertile were 1.7 for beef and other red meat (95% confidence interval [CI] 1.4, 2.2), 1.3 for ham (95% CI 1.0, 1.6), 0.5 for green vegetables (95% CI 0.4, 0.6), and 0.8 for fruit consumption (95% CI 0.6, 1.0). CONCLUSION: Myoma is associated with beef and ham consumption, whereas high intake of green vegetables seems to have a protective effect.

PMID: 10472866

  BACKGROUND: It has been suggested that nutrition and food patterns, particularly high consumption of animal fat and low intake of fish products, may play a role in the aetiology of multiple sclerosis (MS). METHODS: The relation between nutritional factors and MS was studied among 197 incident cases and 202 frequency matched controls in metropolitan Montreal during 1992-1995. Dietary information was collected by employing a 164-item food frequency questionnaire in a face-to-face interview. RESULTS: An inverse association was observed between high body mass index (BMI) and the risk of MS, with an odds ratio (OR) of 0.76 (95% confidence interval [CI]: 0.61-0.95), per 5-unit increase in BMI, both sexes combined. In addition, taller women showed a greater risk for MS; the OR per 10 cm increase in height was 1.58 (95% CI: 1.06-2.35). In continuous variable analyses, using the difference between the lowest and highest quartile of intake as a unit, a positive association was observed with energy and animal fat intake. The OR per 897 kcal increase was 2.03 (95% CI: 1.13-3.67) and 1.99 (95% CI: 1.12-3.54) per 33 g of animal fat intake above the baseline. A significant protective effect was observed with other nutrients, including vegetable protein, dietary fibre, cereal fibre, vitamin C, thiamin, riboflavin, calcium, and potassium. Similar trends were seen for males and females when analysed separately. With respect to specific foods (as opposed to nutrients), a higher intake of fruit juices was inversely associated with risk (OR = 0.82; 95% CI: 0.74-0.92). A protective effect was also observed with cereal/breads intake for all cases combined (OR = 0.62; 95% CI: 0.40-0.97) and for fish among women only; pork/hot dogs (OR = 1.24; 95% CI: 1.02-1.51) and sweets/candy (OR = 1.29; 95% CI: 1.07-1.55) were positively associated with risk. CONCLUSION: The study generally supports a protective role for components commonly found in plants (fruit/vegetables and grains) and an increased risk with high energy and animal food intake.

PMID: 9839742

  The relation between selected indicator foods, alcohol and coffee intake, and the risk of pancreatic cancer was evaluated in a case-control study conducted between 1983 and 1992 in northern Italy on 362 patients with histologically confirmed, incident cancers of the pancreas, and 1,552 controls in hospital for acute, non-neoplastic diseases. Odds ratios (ORs) for subsequent tertiles of intake were computed after allowance for sociodemographic factors and tobacco smoking. Pancreatic cancer risk was directly associated with consumption of meat (OR for the highest frequency tertile = 1.43), liver (OR = 1.43) and ham and sausages (OR = 1.64), and inversely with consumption of fresh fruit (OR = 0.59), fish (OR = 0.65) and olive oil (OR = 0.58). No appreciable association was found with coffee (OR = 1.21) and alcohol consumption (OR = 1.20). A summary score was derived by summing the six related food items; compared to the lowest level, the OR was 2.7 for the highest quintile, and the population attributable risk was 36% (95% confidence interval, 15-57%), indicating the scope of diet for the prevention of this common neoplasm in the Italian population.

PMID: 9926293

  OBJECTIVE: Some epidemiological studies suggest that diets high in fat, saturated fat, or cholesterol are associated with increased risk of lung cancer. Since meat consumption is correlated with the intake of saturated fat and cholesterol, we investigated the role of meat intake and cooking practices in relation to lung cancer risk. METHODS: A population-based case-control study of both non-smoking and smoking women was conducted in Missouri. A 100-item food frequency questionnaire (FFQ) with detailed questions on meat consumption was completed by 593 cases and 623 frequency matched controls. We estimated quantity of meat eaten (grams/day) according to cooking method, and doneness level. Odds ratios (ORs) and 95% confidence intervals (C.I.s) were calculated using logistic regression. Multivariate models included age, packyears of smoking, body mass index (BMI, kg/m2), education, and intake of calories, fat, fruit/fruit juices, and vegetables. RESULTS: When comparing 90th and 10th percentiles, lung cancer risk increased for total meat consumption (OR = 1.6, C.I. 1.1-2.4), red meat (OR = 1.8, C.I., 1.2-2.7), well-done red meat (OR = 1.5, C.I.s, 1.1-2.1) and fried red meat (OR = 1.5, C.I., 1.1-2.0). The odds ratios for 5th vs. 1st quintiles using the categorical variable for well-done red meat and fried red meat were essentially the same as reported above; however, the increase in risk was associated mainly with the 5th quintile. The ORs for a 10-gram increase in consumption were, 1.04 for total meat, 1.06 for red meat, 1.08 for well done red meat, and 1.09 for fried red meat. CONCLUSIONS: Consumption of red meat, especially fried and/or well-done red meat, was associated with increased risk of lung cancer.

PMID: 1018904

  The present study was designed to further investigate the nature of feeding induced by opioid stimulation of the nucleus accumbens through an examination of the effects of intra-accumbens (ACB) opioids on macronutrient selection. In 3-hr tests of free-feeding (satiated) rats, intra-ACB administration of the mu receptor agonist D-Ala2,N,Me-Phe4, Gly-ol5-enkephalin (DAMGO; 0, 0.025, 0.25 and 2.5 micrograms bilaterally) markedly enhanced the intake of fat or carbohydrate when the diets were presented individually (although the effect on fat intake was much greater in magnitude). Intra-ACB injections of DAMGO, however, produced potent preferential stimulatory effects on fat ingestion with no effect on carbohydrate ingestion when both fat and carbohydrate diets were present simultaneously. Moreover, this selective stimulation of fat intake was independent of base-line diet preference and could be blocked by systemic injection of naltrexone (5 mg/kg). We also examined the effect of 24-hr food deprivation on the pattern of macronutrient intake in rats with access to both carbohydrate and fat. In contrast to the DAMGO-induced selective enhancement of fat intake, food deprivation significantly increased the intake of both diets to the same extent; however, in this case, only the stimulated fat intake was blocked by systemic naltrexone. Intra-ACB administration of DAMGO in hungry rats produced an effect similar to that observed in free-feeding rats; preference was strongly shifted to fat intake. Similarly, the opioid antagonist naltrexone (20 micrograms) infused directly into ACB preferentially decreased fat intake in hungry rats. These findings suggest that endogenous opioids within the ventral striatum may participate in the mechanisms governing preferences for highly palatable foods, especially those rich in fat.

PMID: 9580643

  The following study, one of the first done in Puerto Rico, investigate the different kinds of diet and the level of anxiety and depression that the subjects present. The sample consists of 80 subjects between 25 and 70 years age divided into two main groups (vegetarian versus no vegetarian) depending their diet consumption. The basic findings in the three psychological tests given (IDARE-1, IDARE-2 and CES-D) to the subjects demonstrate significant differences in anxiety and depression between groups. More anxiety and depression where reported in the no vegetarian groups in comparison with the vegetarian groups. In addition, diet analysis found more nutritional antioxidant agents levels in the vegetarian group in comparison with the no-vegetarian group.

PMID: 9866269

  To evaluate the relation of job stress and food intake to hyperuricemia, a case-control study was performed in male subjects who had undergone complete physical examinations. Cases (n = 113) were those with hyperuricemia of over 7.5 mg/dl and controls (n = 113) were those with serum uric acid of less than 7.5 mg/dl. Stepwise regression analysis was performed using sixteen items which were significantly related to hyperuricemia by McNemar's method. Consequently, four items; "negative attitude toward work (Odds ratio 5.22, p < 0.01)", "tendency to become competitive in the job and other areas (Odds ratio 5.54, p < 0.01)" in type A behavior, "high meat consumption (Odds ratio 6.94, p < 0.01)", and "high fat intake (Odds ratio 4.05, p < 0.01)", were significantly related to hyperuricemia.

PMID: 9212650

 Traditional monoamine oxidase inhibitors (MAOIs) remain an important class of drugs for a variety of psychiatric conditions, including depressive illnesses, anxiety, and eating disorders. It was the objective of this study to refine the MAOI diet by determining the tyramine content of a variety of untested and "controversial" foods that continue to appear on MAOI diet-restricted food lists. A secondary objective of the study was to evaluate the effect of freshness on the tyramine content of some foods. Fifty-one food samples were evaluated for tyramine content by liquid chromatography. Food samples included a selection of sausages, beverages, sliced meat products, including chicken liver, and some fruits, including raspberries, bananas, and banana peels. Foods that were found to have dangerously high concentrations of tyramine (> or = 6 mg/serving) included chicken liver aged 9 days (63.84 mg/30 g), air-dried sausage (7.56 g/30 g), soy sauce (0.941 mg/ml), and sauerkraut (7.75 mg/250 g). Of the foods analyzed in this study, only those with high tyramine content per serving should continue to be absolutely restricted. All other foods are either safe for consumption or safe in moderation. The data provided should be combined with the data from other similar analytical studies to develop a list of foods that should be absolutely restricted. A more accurate list of restricted foods may enhance patient dietary compliance.

PMID: 8889911

  In a randomized cross-over comparison, the effects of a mainly vegetable protein diet were compared with an animal protein diet in eight patients with cirrhosis and chronic permanent encephalopathy, under optimum lactulose therapy. After a run-in period, patients were fed two equi-caloric, equi-nitrogenous diets for 7 days (71 g total proteins), containing either 50 g protein of animal origin or 50 g vegetable proteins. In the last 3 days of each period, nitrogen balance was significantly better during the vegetable protein diet (+0.2 (SD 1.4) g vs. -1.7 (2.4); P < 0.01), the difference being entirely due to a reduced urinary nitrogen excretion. Average daytime integrated blood glucose was slightly higher during vegetable proteins, whereas insulin, plasma amino acids and ammonia were lower. The clinical grading of encephalopathy improved slightly on vegetable proteins, and psychometric tests improved significantly, but remained grossly abnormal. Compliance to dietary manipulation was good. The data prove that a mainly vegetable protein diet is worthwhile in cirrhotic patients with chronic encephalopathy under optimum lactulose therapy. Improved nitrogen balance may be related to more effective nitrogen use for protein synthesis, probably due to blunted hormonal response, and largely outweighs the effects on encephalopathy.

PMID: 8068051

  Research from the anthropological, psychological, and animal behavior literatures suggests that foods of animal origin have a special status. In two studies we explored the question of whether individuals are more neophobic with respect to animal foods than non-animal foods. In the first study male and female subjects, after reading descriptions, rated their willingness to taste ten "novel" foods, which were actually fictitious. Foods in meat/fish/poultry and dairy/egg categories received lower ratings than those in fruit, vegetable, and grain categories. In the second study subjects were exposed to real foods, some of which were named and described accurately and were, therefore, familiar and some of which were named and described fictitiously and were, therefore, novel. There were no food category differences in subjects' willingness to taste familiar foods, but subjects were less willing to eat novel flesh foods than foods in the other categories. The results are discussed in terms of Rozin & Fallon's (1980) taxonomy of motivations for rejecting foods.

PMID: 1883248

  As part of a large-scale investigation of colorectal cancer (CRC) incidence, etiology, and survival, a case-control study was conducted to identify dietary factors associated with the risk of CRC. The study compared 715 cases with 727 age- and sex-matched community controls. A quantitative diet history, assessed to be the most representative of the previous 20 years, was obtained from each subject and analyzed for both food groups and nutrients. The combination of a high-fiber and high-vegetable intake was found to be protective against large bowel cancer. Cruciferous vegetable intake was also found, although with less certainty, to be protective. Dietary vitamin C was protective for estimated intakes greater than 230 mg/day. Dietary Beta-carotene had no separate association with the risk of CRC. Beef intake was a risk factor in males but not in females. Fat intake was a risk factor for both males and females. A low intake of milk drinks was a risk for both males and females. A high intake of pork and fish was protective. The use of vitamin supplements was highly protective. A risk score, which was calculated as the number of risk factors an individual has in his or her diet, showed an increasing monotonic relationship with risk of CRC. The effects of the dietary variables were similar for colon and rectal cancer and, with the exception of beef, were similar for males and females.

PMID: 3027675

  The hysterical reaction among Eskimo peoples known as pibloktoq, one of a group of aberrant behaviors occurring among Arctic and Circumarctic societies termed 'arctic hysterias', has been explained by a variety of theories: ecological, nutritional, biological-physiological, psychological-psychoanalytic, social structural and cultural. This study hypothesizes the possible implication of vitamin intoxication, namely, hypervitaminosis A, in the etiology of some cases of pibloktoq. Its biocultural approach implicates elements of several explanatory classes, which are not mutually exclusive. Experimental and clinical studies of nonhumans and humans reveal somatic and behavioral effects of hypervitaminosis A which closely parallel many of the symptoms reported for Western patients diagnosed as hysterical and Inuit sufferers of pibloktoq. Eskimo nutrition provides abundant sources of vitamin A and lays the probable basis in some individuals for hypervitaminosis A through ingestion of livers, kidneys, and fat of arctic fish and mammals, where the vitamin often is stored in poisonous quantities. Possible connections between pibloktoq and hypervitamonosis A are explored. A multifactorial framework may yield a more compelling model of some cases of pibloktoq than those that are mainly unicausal, since, among other things, the disturbance has been reported for males and females, adults and children, and dogs.

PMID: 4049004

  A controlled crossover clinical comparison of 40-g/day and 80-g/day vegetable protein diets vs a 40-g/day meat protein diet plus neomycin-milk of magnesia (as control therapy) was performed on 10 cirrhotic patients with mild chronic portal-systemic encephalopathy. The 40-g vegetable protein diet had a high fiber volume and contained low methionine and low aromatic amino acids. The 80-g vegetable protein diet was rich in branched-chain amino acids and fiber, with a similar content of sulfur-containing amino acids as compared to the 40-g meat protein diet. Serial semiquantitative assessments were done, including mental state, asterixis, number connection tests, electroencephalograms and blood ammonia levels. No patient developed deep coma while ingesting either vegetable protein diet or neomycin-milk of magnesia plus 40-g meat protein diet. A significant improvement in the number connection test times was observed during the 40-g vegetable protein diet (P less than 0.05) and during the 80-g vegetable protein diet (P less than 0.05) as compared to their previous 40-g meat protein--neomycin periods. In addition, during the period of 80-g vegetable protein diet, the patients showed a significant improvement in their electroencephalograms (P less than 0.05). The frequency of bowel movements significantly increased (P less than 0.05) during the 80-g vegetable protein diet period. During the 40-g vegetable protein diet, two cirrhotic--diabetic patients experienced hypoglycemia. Three patients complained of the voluminous 80-g vegetable protein diet. Patients with mild portal--systemic encephalopathy may be adequately controlled with vegetable protein diets as a single therapy.

PMID: 6756