* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download American Journal of Clinical Nutrition
Survey
Document related concepts
Gluten-free diet wikipedia , lookup
Hadrosaur diet wikipedia , lookup
Ketogenic diet wikipedia , lookup
Calorie restriction wikipedia , lookup
Saturated fat and cardiovascular disease wikipedia , lookup
Food choice wikipedia , lookup
Raw feeding wikipedia , lookup
Low-carbohydrate diet wikipedia , lookup
Diet-induced obesity model wikipedia , lookup
Transcript
The American Journal of Clinical Nutrition Skip to main page content HOME CURRENT ISSUE EMAIL ALERTS ARCHIVES SUBSCRIPTIONS SEARCH FOR ARTICLES CUSTOM PUBLICATION FAQ Search AJCN ASN Submit Advanced Search © 1999 American Society for Clinical Nutrition II Nutritional status and life cycle issues Plasma amino acids discriminate between total vegetarians and nonvegetarians Alfredo Mejia, Merritt C Horning, and Albert Sanchez. Nutrition Department, Loma Linda University, CA; the Lassen Foundation, Chico, CA; and the Pacific Health Education Center, Bakersfield, CA. Subjects consuming total vegetarian diets have very low risk of coronary heart disease (CHD) compared with the general population. They also have a unique plasma amino acid profile, including higher concentrations of arginine (Arg) and glycine (Gly); and lower concentrations of lysine (Lys) and valine (Val) when compared with subjects who eat regular omnivorous diets. We performed discriminant analysis to determine whether the plasma concentrations of Arg, Gly, Lys, and Val are predictive of the type of diet ingested. The sample population consisted of 38 healthy total vegetarians (20 men and 18 women) and 53 omnivores (20 men and 33 women). Plasma concentrations of Arg, Gly, Lys, and Val are predictive of the type of diet 94% of the time in all subjects, and when the data were analyzed by sex, were 95% predictive for men and 98% for women. Plasma concentrations of Arg, Gly, Lys, and Val can be used as metabolic markers to discriminate between subjects eating omnivorous and total plant food diets with >93% certainty. Those amino acids should be included simultaneously in the discriminant analysis equation because if they are used individually, their predictive value is weaker (Val, 65%; Lys, 71%; Gly, 72%; and Arg, 81%). Discriminant analysis based on Arg, Gly, Lys, and Val is highly predictive to discriminate among subjects eating total vegetarian or omnivorous diets. Thus, these plasma amino acids could be used to assess the compliance of subjects participating in clinical trials based on total vegetarian and omnivorous diets. In addition, we hypothesize that the unique plasma amino acid profile of total vegetarians may be a protective factor against CHD. Previous SectionNext Section Next Section Bone mineral status in vegan, lactoovovegetarian, and omnivorous premenopausal women Patricia K Johnston, School of PublicHealth, Loma Linda University, CA. The relation of bone mineral density he (BMD)diet continues to be investigated. Evidence suggests a positive relation with calcium protein, particularly from animal sources, appears to be negatively related. Vegetarian populations are of interest because they have lower animal protein intake however depending on food choices their calcium intake may vary considerably. Previous studies of vegetarians primarily investigated postmenopausal lactoovovegetarians. We report BMD results from a study of 50 premenopausal women divided among vegan (n = 17)lactoovovegetarian (n =18) omnivorous (n = 15) subjects. Vegetarians had followed their respective diets for ≥4 y. All subjects were within 20% of their ideal body weight had regular menstrual cycles engaged in <5 h/wk of aerobic or strength building exercise did not consume calcium supplements or take any medications known to affect bone metabolism including oral contraceptives. The 3 groups did not differ with respect to age height weight or BMI. Percent of expected BMD of t the spine as determined by quantitative computed tomography (QCT) was significantly less in vegans (x̄ ± SE: 88 ± 2.7%) compared with lactoovovegetarians (107 ±3.7% P < 0.001) or omnivores (101 ± 4.9% P <0.05)but not different between lactoovovegetarians omnivores. Previous SectionNext Section Influence of carotenoid depletion and repletion on serum carotenoid and vitamin A concentrations Betty Jane Burri, Anne L Sowell, and Monica Wong. Western Human Nutrition Research Center, USDA/ARS/PWA, San Francisco 94129 and Centers for Disease Control and Prevention, Atlanta. β-Carotene and other provitamin carotenoids are the major sources of vitamin A for most vegetarians. Cartenoids are also believed to be fat-soluble antioxidants. Therefore, β-carotene metabolism and its conversion to vitamin A are of importance to vegetarians. Carotenoid metabolism appears to be highly variable in healthy, well-fed individuals. We hypothesized that vitamin A status, body fat stores, and oxygen consumption might influence serum carotenoid metabolism and concentrations. We measured serum carotenoid and vitamin A concentrations in 23 women participating in 3 metabolic research unit studies. Most of these women were fed low-carotenoid diets supplemented with β-carotene and mixed carotenoid capsules for >100 d. Activities, exercise, diet and medications were controlled. We compared serum carotenoid concentrations to dietary intakes of carotenoids, vitamin A status (estimated by stable isotope dilution), body composition, and oxygen consumption. Carotenoid concentrations appeared todecrease asymptotically in all women during carotenoid depletion, then increased in all women during carotenoid supplementation. However, carotenoid concentrations were highly variable. Serum vitamin A concentrations were unchanged. Carotenoid concentration changes were negatively correlated to vitamin A status (r ≈ −0.7) in one study, but this influence appeared to be relatively small. Body composition and oxygen consumption had little or no influence on serum carotenoid concentrations. The major influence on carotenoid concentrations and metabolism remains unknown but is probably genetic. Previous SectionNext Section Influence of plasma β-carotene concentration on bioavailability and conversion of β-carotene-d8 stable isotope in young healthy women Jin-Young K Park, Betty Jane Burri, Tatyana Lukoyanova, and Stephen Dueker. Western Human Nutrition Research Center, USDA/ARS/PWA, San Francisco, and the Department of Nutrition, University of California, Davis. Supported in part by the U S Department of Agriculture. Bioavailability and conversion of a stable isotope of β-carotene (BC-d8) was determined in 4 young healthy women. They selected their own diets from a limited menu offered them during 21 d of metabolic-research-unit study. Their plasma βcarotene (BC) concentrations were between 0.5 and 3 mg/L. After a 40-mg oral dose of BC-d8 in olive oil was given before breakfast, BC-d8 and retinol-d4 (VA-d4) concentrations in serial plasmas were measured by using high-performance liquid chromatography and gas chromatography–mass spectrometry, respectively. Area under the plasma concentration curve of BC-d8 or VA-d4 over 21 d was used as an index of percentage bioavailability or percentage conversion of BC-d8 to VAd4, respectively. Plasma percentage bioavailability of BC-d8 in individuals was highly variable. Individual's percentage conversion of BC-d8 to VA-d4 was also variable. There was a positive association between percentage bioavailability of BC-d8 and its percentage conversion to VA-d4 (r2 = 0.6). Plasma BC concentrations show a positive association with percentage conversion of BC-d8 to VA-d4 (r2 = 0.7). Body weight (between 47 and 60 kg) had a negative association with percentage conversion of BC-d8 to Va-d4 (r2 = 0.9). The results of our study suggest a significant individual genetic variation of absorption and metabolism for β-carotene with a trend toward positive associations between absorption and metabolism. The people who absorb more β-carotene may more efficiently metabolize the compound. Previous SectionNext Section Cobalamin studies on 2 total vegetarian (vegan) families Milton G Crane, UD Register, and Richard Lukens. Weimar Institute, Weimar, CA, and the Department of Medicine and School of Public Health, Loma Linda University, CA. Funded by Donald and Barbara Cox and the Callicott-Register fund. Two families (4 adults and 5 children) ranging in age from 10 to 53 y volunteered for evaluation of cobalamin (Cbl; vitamin B-12) status. All were total vegetarians for 2–6 y, except for a little milk (<1 serving/mo). All were healthy and free of recognizable symptoms of cobalamin deficiency. After evaluation, urine and fasting blood samples were drawn before and after 60 d consuming 500 μg Cbl/d (chewed). Results were as follows: initial red blood cell count ranged from 3.94 to 4.92, and hematocrit ranged from 36.8 to 43.2. Six of 9 were slightly below normal. Their mean corpuscular volume, mean corpuscular hemoglobin, and serum iron were all in the midnormal range. Serum folate ranged from 7.3 to 17 (n>2.7). Serum Cbl was <200 pg/mL in 8 of 9 (1 was 331 pg/mL) and all increased to 356–728 pg/mL while taking Cbl (P < 0.005). Serum methymalonic acid concentrations were elevated in 5 of 8 subjects, and the values of all but one decreased to within normal limits while taking Cbl (average, −67.9%; P < 0.005). Urine methylmalonic acid (fmol/nmol creatinine) (UMMA) values were elevated in 7 of 8; all decreased to within normal limits while taking Cbl (P < 0.005). Serum total homocysteine (STHcys; in fmol/L) and serum total 2-methylcitric acid (ST2-Mca; in fmol/L) were within normal limits in all 8 subjects initially; both decreased significantly (P < 0.005) while taking Cbl by 31% and 28.2%, respectively. Serum cystathionine concentrations (in nmol/L) were below normal and remained low in 3 of 8 subjects, indicating adequate B-6 intake. These studies indicate that all total vegetarians should assure themselves of a reliable source of vitamin B-12, and verify their ability to absorb it. If we combine the data of the Cbl and UMMA, all 9 of the subjects showed evidence of Cbl deficiency. Of interest was that the initial values for STHcys and ST2-Mca were within normal limits, yet decreased consistently by an average of 31% and 28.2% (P < 0.005), respectively, on Cbl therapy. Previous SectionNext Section Effect of the type of lactation on the psychomotor development in Mexican infants O Angulo-G, N Cruz-Cansino, MD Callejas-Flores, C Rivas-Valerio, ML Suarez-Quiroz, and I Rivas. Instituto Tecnologico de Veracruz, Dpto. Ing. Quimicay Bioquimica Veracruz, 91880, Ver. Mexico. The n−6 and n−3 long chain polyunsaturated fatty acids LCPUFAs (Arachidonic; AA and docosahexaenoic acids, DHA) are important components of the central nervous system. AA and DHA are normally derived by desaturation and elongation of linoleic and linolenic acids. However, newborn babies seem to present reduced desaturation and elongation enzyme activities, making it necessary to supply LCPUFAs by dietary means. The purpose of this study was first of all, to determine the fatty acid composition of human milk and infant formulas commercially available in Veracruz, Mexico. Secondly, to determine the effect of breast-feeding compared with formula-feeding on psychomotor development during the first 4 mo of life. Thirty samples of milk were obtained from lactating women in Veracruz and 20 infant formulas were analyzed for their fatty acid profile. The psychomotor development was evaluated according to a modified method derived from the Gessel Scale in 30 breast-fed and 30 formula-fed babies over 4 mo. Body weight, length, and head circumference were registered monthly. Results showed that human milk indeed contains LCPUFAs whereas infant formulas contain linoleic acid and linolenic acid as the longest fatty acids. Small differences were registered for monounsaturated and short-chain fatty acids. There were no significant anthropometric differences between the 2 groups evaluated. Breast-fed infants, on the contrary, manifested higher psychomotor scores than did formula fed infants. In summary, human milk provides necessary LCPUFAs for better psychomotor development in full-term infants. Careful consideration should be given to inform pregnant mothers as to these benefits that lactation offers to the infant she carries. Previous Section Next Section Dietary and supplement intake of vegetarians during pregnancy Rana Drake, Sheela Reddy, and G Jill Davies. South Bank University, London, and Leatherhead Food RA, Surrey, United Kingdom. Supported in part by Cow and Gate Nutricia. Little is known about the nutrient intake of vegetarians during pregnancy. Studies of nonpregnant vegetarians have highlighted potential problems, but dietary intakes are known to change during pregnancy owing to a variety of factors. White, primiparous women from different dietary groups were recruited by magazine advertisements, posters in cafes and shops, and with the assistance of midwives. Volunteers answered questions about dietary changes they had made during pregnancy and completed a 3-d estimated record of their diet. Dietary records were analyzed from 31 lactoovovegetarians, 14 pesco-vegetarians, and 69 nonvegetarians. Energy and fat intakes were similar in each group, whereas the 2 vegetarian groups were found to derive significantly more energy from carbohydrates and less from protein. In addition, the lactoovovegetarians had significantly lower vitamin B-12 intakes than the other 2 groups. Many women reported making dietary changes during pregnancy due to cravings, aversions, and other influences. Many also started to take nutrient supplements. The dietary changes made by women in all 3 groups were similar and were in line with general antenatal advice. Sources of dietary advice were investigated and significantly more vegetarians than nonvegetarians reported finding the dietary advice available to them to be inadequate. It is concluded that some vegetarian women would benefit from specifically targeted dietary advice for pregnancy. Previous SectionNext Section Health of vegetarians during pregnancy and pregnancy outcome Rana Drake, Sheela Reddy, and G Jill Davies. South Bank University, London, and Leatherhead Food RA, Surrey, United Kingdom. Supported in part by Cow and Gate Nutricia. The quality of a woman's diet influences her health during pregnancy and the well-being of her infant. The implications of an increasing number of young women eating a vegetarian type diet is therefore of interest. Whereas slightly lower birth weights have been reported among Indian vegetarian groups, white vegetarians in the United Kingdom have received little attention. White, primiparous women from different dietary groups were recruited by placing ads in magazines, posters in cafes and shops and with the assistance of midwives. Questionnaires concerning diet, lifestyle and health were completed by 132 women during pregnancy including 34 lactoovovegetarians, 17 pesco-vegetarians and 81 nonvegetarians. Volunteers were sent a second questionnaire soon after their expected date of delivery to collect information about pregnancy outcome; these were returned by 126 women. The incidence of nausea and constipation was similar in all 3 groups. More lactoovovegetarians (26%) reported suffering from anemia than nonvegetarians (11%) or pesco-vegetarians (6%). When pregnancy outcomes were compared between the groups, no significant differences were found in length of gestation, infant birth weights, or the incidence of complications or health problems. In conclusion, lactoovovegetarians more frequently reported anemia during pregnancy, but this was not associated with any adverse pregnancy outcomes. Previous SectionNext Section Nutrient intake and nutritional status of vegetarians and low-meat eaters consuming a diet meeting preventive recommendations Ingrid Hoffmann, Maike J Groeneveld, and Claus Leitzmann, Institute of Nutritional Science, Justus Liebig-University Giessen, Germany. The dietary recommendations for the prevention of nutrition-related diseases are based on a high consumption of vegetables (including potatoes), fruit, whole-grain products, dairy products, and on reduced consumption of meat and meat products. In a cross sectional study, a group of 243 healthy women (25–65 y of age) who practiced such a wholesome diet for ≥5 y were studied on the consequences of their intake and nutritional status of nutrients: essential, protective, and unfavorable ones. One subgroup (111 vegetarians, VEG) completely omitted meat and fish from their diet, the other subgroup (132 nonvegetarians, NVEG) included small amounts of meat (≈30 g/d on average). They were compared with a corresponding group of 175 women eating a normal mixed diet containing ≈130 g meat/d (control group). The VEG group clearly showed the highest intake of protective nutrients (eg, complex carbohydrates, antioxidants, and dietary fiber) and the best nutrient ratio. The VEG group had the lowest intake of substances known to be unfavorable (eg, total fat, saturated fatty acids, cholesterol, and alcohol). For essential nutrients, a high intake could be observed for those vitamins that are dominant in plant foods such as vitamin B1, B-6, folic acid, and vitamins C and E. The intake of vitamins mainly provided by animal foods (especially vitamins B-2, B-12, and D) was lower than for the NVEG and control groups. Only for vitamin B-12 were critical plasma values detected, specifically in those in the VEG group who consumed <380 g dairy products/d. The high iron intake of the VEG group was mainly based on plant foods, causing lower ferritin concentrations than in the NVEG and the control groups without differences in the serum iron concentrations. This study shows that strict adherence to the preventive recommendations (vegetarian version) in a daily diet needs careful planning and that a diet meeting the preventive recommendations containing small amounts of meat retains the advantages of a vegetarian diet while avoiding its possible disadvantages. Previous SectionNext Section Investigation of the effects of a vegetarian diet on the growth, body composition, metabolism, and energynutritional intakes of young children Riccardo Trespidi, Public Health Service, Verona, Italy; Leonardo Pinelli, Pediatria Preventiva e Sociale, Universita di Verona, Verona, Italy; Claudio Maffeis, Diabetologia Pediatrica, Universita di Verona, Verona, Italy. Growth, body composition, metabolism, energy, and nutritional intakes were compared in lactoovovegetarian, lactovegetarian, and nonvegetarian Italian children who were 8–9 y old at the start of the 2-y study. The omnivorous control group followed a standard Mediterranean diet. Nutritional intakes were broken down into animal and vegetable protein, saturated and nonsaturated lipids, cholesterol, simple and complex carbohydrates, fiber, and iron. Results showed no significant difference between meatless and meat-based diets with respect to growth, body composition, or metabolism, although the vegetarian children were, on the whole, slimmer. In the lactoovovegetarians and lactovegetarians, energy intake was significantly higher; intake of protein, saturated fatty acids, and cholesterol was lower; and intakes of mono- and polyunsaturated lipids and vitamin B-12 were comparable. In addition, the fiber intake was more than double that of the nonvegetarians and the iron intake was also significantly higher. Lastly, comparison of the vegetarians' blood chemical parameters revealed no significant differences with respect to standard values. Previous SectionNext Section Changes in body composition after 6 mo on a self-selected vegetarian diet Frances Robinson, Allan Hackett, David Billington, and Gareth Stratton, School of Education and Community Studies, Liverpool John Moores University, United Kingdom. It is known that white vegetarians tend to be leaner and closer to desirable body weights than their nonvegetarian counterparts. Evidence from several previous studies that investigated some of the changes apparent after switching to a vegetarian diet has shown that body weight was reduced, but these studies provided guidelines on what the diet should include. This paper examines some of the anthropometric changes that occurred as a result of changing to a self-selected UK vegetarian diet. Thirty-six volunteers, recruited as they changed to a vegetarian diet, completed the study. Measurements of weight, height, mid-arm circumference, triceps and biceps skinfold thicknesses (from which percentage body fat was calculated), and waist and hip circumference were taken. After 6 mo on their self-selected vegetarian diets, volunteers were invited back and measurements were repeated. Paired t tests showed that significant changes (P < 0.05) were found in hip and waist circumferences, waist-to-height ratio, biceps and triceps skinfold thickness, and percentage body fat, all of which had decreased compared with baseline. These results would suggest that these volunteers changing to a self-selected vegetarian diet experienced considerable changes in body composition. Previous SectionNext Section Does a vegetarian diet reduce the variety of foods consumed? Frances Robinson and Allan Hackett, School of Education and Community Studies, Liverpool John Moores University, Liverpool, United Kingdom. Omitting meat from the diet could lead to the assumption that one has a less varied diet. Work in Japan (Okuda, 1991) found that consuming more foods was associated with more people achieving recommended nutrient intakes. In this study, volunteers kept dietary records from the time that they switched to a self-selected vegetarian diet. This paper describes the change in the number of different foods eaten over 3 d, as recorded in dietary diaries while eating meat (baseline) and then after 3 and 6 mo on the vegetarian diet had elapsed. Two control groups of meat eaters and long-standing vegetarians were also included in the study and the number of different foods eaten over the 3 d by each group was compared with baseline and after 3 and 6 mo. The number of foods eaten on each occasion was compared using a Wilcoxon matched-pairs test. Number of foods consumed at baseline, 3 mo, and 6 mo by study volunteers was 32, 31, and 31; by vegetarians, 31, 30, and 30; and by omnivores, 32, 29, and 31 respectively. No significant differences were found. These results show that all groups were eating similar numbers of foods. It does not seem, therefore, that changing to a vegetarian diet causes any significant reduction in the number of foods eaten. Previous SectionNext Section Does switching to a self-selected vegetarian diet alter macronutrient intake? Frances Robinson, Allan Hackett, David Billington, and Gareth Stratton, School of Education and Community Studies, Liverpool John Moores University, Liverpool, United Kingdom. Despite many studies of the diets of vegetarians compared with omnivores, the effects of changing from an omnivorous diet to a nonprescribed vegetarian diet has received little attention. In the present study, 43 adults (32 women and 11 men, mean age 31 y) who were embarking on a vegetarian diet of their choice kept a record of food intake for 3 d while still consuming a mixed diet. Subsequent 3-d food intake records were kept at 3, 6, 9, and 12 mo after subjects had changed to their vegetarian diet. Differences in intakes of macronutrient composition of the diet from each record were examined by paired t test. The results showed that after 3 mo on a vegetarian diet, marked differences were observed in the macronutrient intakes of the female subjects. Percentage of energy from carbohydrate increased significantly (P < 0.05) and percentages of energy from protein and total fat decreased. Both male and female subjects experienced reductions in energy intake (P < 0.05) from 6 mo onward. It may be concluded that although energy intake of both male and female subjects dropped after changing to a vegetarian diet, more marked effects on macronutrient intake were experienced by female subjects. Previous Section A study of the use of nutritional supplements by a group of vegetarians in South Wales Marv Barasi and Frances Robinson, Faculty of Community Health Sciences, University of Wales Institute Cardiff, Cardiff, Wales. Commercially manufactured nutritional supplements are widely available over the counter. As a result, many people may be taking unnecessary supplements leading to potentially more harm than good. This study aimed to investigate supplement usage by vegetarians in an urban area of South Wales. Seventy-eight volunteers completed a questionnaire that asked about supplement use and included a dietary assessment. A diet score was derived, and a higher score meant a potentially greater need for supplements. Thirty-eight of the respondents claimed to be regular supplement users and a startling number took more than 2 supplements daily. When asked their reason for taking supplements, more than half of those who claimed to take supplements regularly said they did not know. From the dietary assessment, it appeared that nonusers of supplements had higher diet scores than users indicating, a greater potential need for supplements. In conclusion, it appears that a large proportion of this group of vegetarians were taking nutritional supplements whether or not they were needed. People should be made more aware of their nutritional needs before prescribing supplements to themselves, and advice should be made easily available on the use and misuse of nutritional supplements, especially to new vegetarians who may believe that supplements are needed. CiteULike Delicious Digg Facebook Google+ Mendeley Reddit StumbleUpon Twitter What's this? « Previous | Next Article »Table of Contents This Article 1. 1. 2. Am J Clin Nutr September 1999 vol. 70 no. 3 626s-629s » Full TextFree Full Text (PDF)Free Rent or Purchase Article 1. 2. Add to Custom Publication - Classifications 1. o Abstracts of short oral and poster presentations - Services 1. 2. 3. 4. 5. 6. 7. 8. Email this article to a colleague Alert me when this article is cited Alert me if a correction is posted Article Usage Statistics Similar articles in this journal Similar articles in PubMed Download to citation manager Reprints and Permissions + Citing Articles + Google Scholar + PubMed - Social Bookmarking 1. o o o o o o o o o What's this? Navigate This Article 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. Top Bone mineral status in vegan, lactoovovegetarian, and omnivorous premenopausal women Influence of carotenoid depletion and repletion on serum carotenoid and vitamin A concentrations Influence of plasma β-carotene concentration on bioavailability and conversion of β-carotene-d8 stable isotope in young healthy women Cobalamin studies on 2 total vegetarian (vegan) families Plasma amino acids discriminate between total vegetarians and nonvegetarians Effect of the type of lactation on the psychomotor development in Mexican infants Dietary and supplement intake of vegetarians during pregnancy Health of vegetarians during pregnancy and pregnancy outcome Nutrient intake and nutritional status of vegetarians and low-meat eaters consuming a diet meeting preventive recommendations Investigation of the effects of a vegetarian diet on the growth, body composition, metabolism, and energynutritional intakes of young children Changes in body composition after 6 mo on a self-selected vegetarian diet Does a vegetarian diet reduce the variety of foods consumed? Does switching to a self-selected vegetarian diet alter macronutrient intake? A study of the use of nutritional supplements by a group of vegetarians in South Wales Current Issue 1. November 2015, 102 (5) 1. 1. Alert me to new issues of Am J Clin Nutr Statement of Scope Information for Authors Submit or Review a Manuscript Editorial Board Reprints Permissions Advertising Feedback Advances in Nutrition The Journal of Nutrition Nutrition Notes The American Journal of Clinical Nutrition® Copyright © 2015 by the American Society for Nutrition 9650 Rockville Pike, Bethesda, MD 20814 Print ISSN: 0002-9165 Online ISSN: 1938-3207 For an alternate route to AJCN Online use this URL: http://intl-ajcn.nutrition.org