Self-Reported Intake and Circulating EPA and DHA Concentrations in US Pregnant Women.

In the United States, pregnant women have low concentrations of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), which are essential for fetal development. Although maternal blood provides accurate polyunsaturated fatty acid (PUFA) concentrations, venipuncture is expensive and not always accessible. PUFA-containing foods consumption, both omega-3 ad omega-6 is supposed to reflect in the status (plasma, RBC, adipose tissue) of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). De novo synthesis of DHA and EPA during pregnancy is supposed to be higher compared to pre and/or post-pregnancy periods. Thus, this study aimed to determine the association between maternal self-reported dietary intake of foods high in DHA and EPA, along with vegetable oils as a source of omega-6 fatty acids, with maternal blood DHA and EPA concentrations. Pregnant women (13-16 weeks gestation) were recruited and asked to complete a food-frequency questionnaire (FFQ) and blood draw at enrollment and 36 weeks. Circulating concentrations of DHA and EPA were quantified and change scores were calculated. Correlations were done to determine associations between FFQ results and EPA/DHA maternal blood concentrations. Regression analyses were run to examine significant predictors of the main outcomes. Overall, PUFA-food consumption and RBC's DHA levels decreased from early to late pregnancy; self-reported PUFA-rich food consumption positively correlated with DHA and EPA levels. DHA concentration was predicted by self-reported PUFA-rich oils (sunflower/soy/corn/olive) consumption, but EPA concentration was predicted by maternal BMI. These findings suggest that EPA and DHA consumption decreased across pregnancy and the FFQ can be utilized as an effective method for estimating PUFA blood concentration during pregnancy.

Prevalence and Predictors of Low Breast Milk Iodine Concentration in Women Following Vegan, Vegetarian, and Omnivore Diets.

Purpose: Breast milk iodine concentration (BMIC) from vegan and vegetarian lactating mothers has not previously been evaluated. The goal of this study was to assess BMIC from vegans, vegetarians, and omnivores and to assess intake of iodine by breastfed infants. Materials and Methods: Breast milk samples from vegans (n = 12), vegetarians (n = 6), and omnivores (n = 12) living in the United States were analyzed. BMIC was determined at the mass-to-charge ratio (m/z) 127 by inductively coupled plasma mass spectrometry (ICP-MS) using an Agilent 8800 ICP-MS/MS (Agilent Technologies). Results: There was a significant difference in mean BMIC between participants following a plant-based diet (vegan and vegetarian, n = 18) compared with omnivores [4.42 versus 5.02 Ln(BMIC), respectively; p = 0.0405]. In linear regression to predict BMIC, vegan diet was a negative predictor (standardized ß = -0.409) and use of multi- or prenatal supplements was a positive predictor (standardized ß = 0.319). There were differences in the percentage of inadequate BMIC per maternal diet (75% vegan, 67% vegetarian, omnivore 58%) but this did not reach statistical significance. In 67% of the samples (20/30) BMIC was lower than the National Academy of Medicine's adequate intake (AI), assuming infant milk consumption of 0.78 L/day. Conclusions: Most samples from vegans and vegetarians contained a lower BMIC than AI for infants 0-6 months. Counseling of pregnant vegans and vegetarians should highlight importance of iodine supplementation during lactation. The findings are based on a small number of samples, especially for vegetarians, and thus, they need to be confirmed by larger studies.

Major and trace mineral composition of milk from lactating women following vegan, vegetarian and omnivore diets.

Approximately one-in-ten reproductive age adults in the USA follow a plant-based diet, yet there is limited information on the influence of vegan and vegetarian diets on the mineral composition of breast milk. This study explored the major and trace mineral composition in breast milk and associations with maternal diet patterns. We used a cross-sectional design to collect a single sample of breast milk from individuals following vegan (n 23), vegetarian (n 19) and omnivore (n 21) diet patterns. Plant-based diet (n 42) was defined as following either vegan or vegetarian diets. Sixteen minerals were assessed using inductively coupled plasma mass spectrometry and inductively coupled plasma optical emission spectrometry. Data were evaluated using traditional statistical techniques and five different machine learning approaches. The distribution of Se (median; quartile 1 and 3) was significantly different between groups (vegetarians 21, 18-26 µg/l; vegans 19, 18-25 µg/l and omnivores 17, 14-20 µg/l; P = 0·007) using a Kruskal-Wallis test. Machine learning techniques also identified Se as a potential biomarker for differentiating breast milk by maternal diet pattern. Individuals following a plant-based diet generally had a lower BMI, higher breast milk Se and lower breast milk I and Fe concentrations compared with those following omnivore diets. This suggests that maternal dietary pattern (plant-based v. omnivore) may be helpful clinical information to consider when caring for the breast-feeding dyad, with the strongest evidence related to differences in Se concentration.

Maternal Aerobic Exercise, but Not Blood Docosahexaenoic Acid and Eicosapentaenoic Acid Concentrations, during Pregnancy Influence Infant Body Composition.

Although discrete maternal exercise and polyunsaturated fatty acid (PUFA) supplementation individually are beneficial for infant body composition, the effects of exercise and PUFA during pregnancy on infant body composition have not been studied. This study evaluated the body composition of infants born to women participating in a randomized control exercise intervention study. Participants were randomized to aerobic exercise (n = 25) or control (stretching and breathing) groups (n = 10). From 16 weeks of gestation until delivery, the groups met 3×/week. At 16 and 36 weeks of gestation, maternal blood was collected and analyzed for Docosahexaenoic Acid (DHA) and Eicosapentaenoic Acid (EPA). At 1 month postnatal, infant body composition was assessed via skinfolds (SFs) and circumferences. Data from 35 pregnant women and infants were analyzed via t-tests, correlations, and regression. In a per protocol analysis, infants born to aerobic exercisers exhibited lower SF thicknesses of triceps (p = 0.008), subscapular (p = 0.04), SF sum (p = 0.01), and body fat (BF) percentage (%) (p = 0.006) compared with controls. After controlling for 36-week DHA and EPA levels, exercise dose was determined to be a negative predictor for infant skinfolds of triceps (p = 0.001, r2 = 0.27), subscapular (p = 0.008, r2 = 0.19), SF sum (p = 0.001, r2 = 0.28), mid-upper arm circumference (p = 0.049, r2 = 0.11), and BF% (p = 0.001, r2 = 0.32). There were no significant findings for PUFAs and infant measures: during pregnancy, exercise dose, but not blood DHA or EPA levels, reduces infant adiposity.

The Influence of Maternal Aerobic Exercise, Blood DHA and EPA Concentrations on Maternal Lipid Profiles.

Exercise and polyunsaturated fatty acid (PUFA) supplementation independently improve lipid profiles. The influence of both exercise and PUFAs on lipids during pregnancy remains unknown. This study evaluated exercise, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) concentrations on lipids during pregnancy. Participants were randomized to aerobic exercise or control groups. From 16 weeks gestation until delivery, groups met 3x/week; exercisers performed moderate-intensity aerobic activity, controls performed low-intensity stretching and breathing. At 16 and 36 weeks' gestation, maternal blood was analyzed for lipids (total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides (TG)), DHA and EPA. In intent-to-treat analysis, the aerobic group (n = 20), relative to controls (n = 10), exhibited a higher HDL change across gestation (p = 0.03). In a per protocol analysis, the aerobic group, relative to controls, exhibited 21.2% lower TG at 36 weeks (p = 0.04). After controlling for 36-week DHA and EPA, exercise dose predicts 36 weeks' TG (F (1,36) = 6.977, p = 0.012, r2 = 0.16). Aerobic exercise normalizes late pregnancy TG. During pregnancy, exercise dose controls the rise in TG, therefore maintaining normal levels. DHA and EPA do not have measurable effects on lipids. Regardless of PUFA levels, exercise at recommended levels maintains appropriate TG levels in pregnant women. Normal TG levels are critical for pregnancy outcomes, and further studies are warranted to investigate this association in broader populations.

A Cross-Sectional Assessment of Human Milk Oligosaccharide Composition of Vegan, Vegetarian, and Nonvegetarian Mothers.

Purpose: Recently, maternal nutrient intake has been associated with human milk oligosaccharides (HMOs) composition. The goal of this study was to assess HMO composition in breast milk samples from vegan, vegetarian, and nonvegetarian lactating women. Second, we assessed impact of maternal body mass index (BMI), age, parity, and lactation stage on HMO composition. Materials and Methods: A cross-sectional analysis of HMO composition from vegan (n = 26), vegetarian (n = 22), and nonvegetarian (n = 26) lactating women was carried out. The majority of participants took dietary supplements. Results: In an unadjusted bivariate model, there was no difference in individual HMO composition, total HMO-bound fucose and HMO-bound sialic acid, or diversity and evenness scores by diet group. When adjusting for factors that significantly differed between groups (maternal BMI and lactation stage), no differences in HMO composition were observed. Secretor status was significant for 13 of the outcome variables with the strongest positive relationship with total HMO (ß = 0.922) and HMO-bound fucose (ß = 0.910), and the strongest negative relationship with sialyl-lacto-N-tetraose b (LSTb) (ß = -0.544). Lactation stage was significant for eight analytes, with the strongest positive impact on 3'sialyllactose (3'SL) (ß = 0.433), and the strongest negative impact on 6'sialyllactose (6'SL) (ß = -0.519). Maternal BMI had a significant positive relationship with total HMO composition (ß = 0.113) and 3'SL (ß = 0.325). Conclusions: Lactating women who consume plant-based diets do not produce different breast milk as it relates to HMO composition.

Vitamin B12 status is a risk factor for bone fractures among vegans.

Several studies consistently showed vegans having a higher risk of bone fractures compared to individuals from other diet groups. While researchers have focused on several factors as possible explanation of these findings, both dietary (e.g. calcium) and non-dietary (e.g. weight/BMI status), the widespread inadequate vitamin B12 (B12) status among vegans as a risk factor for bone fractures has not received adequate scrutiny. The detrimental impact of inadequate B12 status on bone tissue is both direct, via the impairment of the insulin-like growth hormone 1 and taurine synthesis, and indirect, induced through its hyperhomocysteinemic effect, via at least the following mechanisms: 1) reducing bone mineral content and density by accumulating in the extracellular matrix, 2) reducing osteoblasts and increasing osteoclasts function, 3) reducing blood flow to bone tissue, 4) inducing apoptosis via the reactive oxygen-species-mediated mitochondrial pathway, and 5) obstructing the formation of collagen cross-links, impeding lyslyl oxidase, and hampering insolubility of fibrils. Considering the widespread B12 deficiency prevalence among vegans, its role in bone fracture risk should not be overlooked.

Cardiovascular Disease Risk Factors Profile Among Australian Vegetarian and Nonvegetarian Teenagers.

Atherosclerosis develops over a long period of time and often begins in childhood. The goal of this study was to make a cross-sectional assessment of the pattern of cardiovascular disease risk factors among Australian vegetarian (n = 49) and nonvegetarian (n = 639) 14- to 17-year-old participants from New South Wales, Australia. Vegetarians had statistically significant lower mean total (4.05 vs 4.4 mmol/L;P < .001) and low-density lipoprotein (LDL) cholesterol (2.18 vs 2.55 mmol/L; P < .001) and lower incidence of abnormal total and LDL cholesterol (31.1% vs 46.2%, P = .036, having total cholesterol ≥4.4 mmol/L and 13.3% vs 29.6%, P = .021, having LDL cholesterol ≥2.84 mmol/L). Vegetarians had a higher diastolic BP (72.0 vs 69.7 mm Hg; P = .038). No statistically significant difference was found in other risk factors including high-density lipoprotein cholesterol (P = .83), triglycerides (P = .601), systolic blood pressure (P = .727), body mass index (P = .159), plasma glucose (P = .09), C-reactive protein (P = .527), or homocysteine (P = .45). The prevalence rate with 3 or more risk factors was 12.2% among vegetarians and 13.9% among nonvegetarians (P = .156). The high percentage of abnormal total cholesterol in both diet groups and, in addition, LDL cholesterol in nonvegetarians is a cause of concern and underlines the need for lifestyle change.

Total Water-Soluble Choline Concentration Does Not Differ in Milk from Vegan, Vegetarian, and Nonvegetarian Lactating Women.

BACKGROUND: Choline is an essential nutrient for brain growth and other processes in the developing neonate. The impact of a maternal plant-based diet on the choline composition of breast milk is unknown. OBJECTIVE: We assessed the water-soluble choline content of milk from lactating women in the United States following 3 dietary patterns: vegan, vegetarian, and nonvegetarian. METHODS: We conducted a cross-sectional study of 74 healthy lactating women who provided a single breast-milk sample using a standardized collection protocol. Participants completed a food-frequency screener and were classified as follows: nonvegetarians (NONVEG) consumed meat; vegetarians (VEGT) consumed milk, dairy, and/or fish; and vegans (VEGAN) consumed animal products less than monthly. Primary outcomes measured were the concentration (in milligrams per liter) and distribution (percentage) of choline from the following water-soluble forms: free choline, phosphocholine (PCho), and glycerophosphocholine (GPC). Differences between diet groups were evaluated with ANOVA. RESULTS: There was a wide range in breast-milk total water-soluble choline (4-301 mg/L), with no significant difference (P > 0.05) by maternal diet pattern. There were differences in choline forms, with VEGAN having a greater mean ± SD concentration and distribution of choline derived from GPC (62.7 ± 25.3 mg/L) than VEGT (47.7 ± 21.2 mg/L) and NONVEG (42.4 ± 14.9 mg/L) (P = 0.0052). There was a lower mean ± SD percentage of choline from PCho (P = 0.0106) in VEGAN (32.5% ± 18.3%) than in VEGT (46.1% ± 18.3%) and NONVEG (44.8% ± 15.7%). Lactation stage and maternal BMI were significantly associated with some choline forms. CONCLUSIONS: There was a wide range of water-soluble choline concentrations in the milk of healthy lactating women following vegan, vegetarian, and nonvegetarian diets, with no observed difference in total water-soluble choline concentration by maternal diet. This suggests that maternal plant-based diet by itself is not a risk factor for low breast-milk choline.

Combined effects of nocturnal exposure to artificial light and habitat complexity on fish foraging.

Due to the widespread use of artificial light, freshwater ecosystems in urban areas at night are often subjected to light of intensities exceeding that of the moonlight. Nocturnal dim light could modify fish behaviour and benefit visual predators because of enhanced foraging success compared to dark nights. However, effects of nocturnal light could be mitigated by the presence of structured habitats providing refuges for prey. We tested in laboratory experiments whether nocturnal light of low intensity (2 lx) increases foraging efficiency of the Eurasian perch (Perca fluviatilis) on invertebrate prey (Gammarus fossarum). The tests were conducted at dusk and night under two light regimes: natural cycle with dark nights and disturbed cycle with artificially illuminated nights, in habitats differing in structural complexity: sand and woody debris. We found that nocturnal illumination significantly enhanced the consumption of gammarids by fish compared to dark nights. In addition, the perch was as effective predator in illuminated nights (2 lx) as at dusk (10 lx). Woody debris provided an effective refuge only in combination with undisturbed darkness, but not in illuminated nights. Our results suggest that nocturnal illumination in aquatic ecosystems may contribute to significant reductions in invertebrate population sizes through fish predation. The loss of darkness reduces the possibility of using shelters by invertebrates and hence the effects of elevated light levels at night could not be mitigated by an increased habitat complexity.

A cross-sectional study of fatty acids and brain-derived neurotrophic factor (BDNF) in human milk from lactating women following vegan, vegetarian, and omnivore diets.

PURPOSE: Essential fatty acids are critical for brain growth and neurodevelopment in infancy. Maternal diet and supplement use have a significant impact on the fat composition of human milk. The objective of this study is to assess supplement utilization patterns and fatty acid and brain-derived neurotrophic factor (BDNF) concentrations in the breast milk of women following vegan, vegetarian, and omnivore diet patterns. METHODS: This is a cross-sectional, observational study of 74 lactating women in the United States following a vegan (n = 26), vegetarian (n = 22), or omnivore (n = 26) diet pattern. A single breast milk sample was collected from each participant and assessed for fatty acids and BDNF. RESULTS: Median unsaturated fatty acids in the breast milk of vegan, vegetarian, and omnivores, as a percentage of total fatty acids, was 66.0, 57.8, and 56.2%, respectively (p < 0.001). Total omega-3 percentages were 2.29% for vegans, 1.55% for vegetarians, and 1.46% for omnivores (p < 0.001). Docosahexaenoic acid percentages were not different by diet pattern, but over 80% of participants had milk concentrations below 0.30% of total fatty acids. Reports of omega-3 supplements use (10/74) and weekly seafood consumption (3/74) were limited. BDNF was not detectable in any samples. CONCLUSIONS: Breast milk from vegans had significantly higher unsaturated fat and total omega-3 fats, and lower saturated fats, trans fats, and omega-6 to omega-3 ratios than their vegetarian and omnivore counterparts. Docosahexaenoic acid concentrations in breast milk were low regardless of maternal diet pattern, and were reflective of low seafood intake and supplement use.

Vitamin B-12 content in breast milk of vegan, vegetarian, and nonvegetarian lactating women in the United States.

Background: The nutritional profile of human milk varies significantly between women, and the impact of maternal diet on these variations is not well understood. Objective: We analyzed breast-milk vitamin B-12 concentration and vitamin B-12 supplement use pattern among women who adhered to different dietary patterns: vegan, vegetarian, and nonvegetarian. Design: A total of 74 milk samples, 26 from vegan, 22 from vegetarian, and 26 from nonvegetarian breastfeeding mothers, were analyzed. Results: The prevalences of low vitamin B-12 (<310 pmol/L) were 19.2% for vegans, 18.2% for vegetarians, and 15.4% for nonvegetarians, which was not significant by diet group (P = 1.00). The median (quartile 1, quartile 3) vitamin B-12 values were 558 pmol/L (331, 759 pmol/L) for vegans, 509 pmol/L (368, 765 pmol/L) for vegetarians, and 444 pmol/L (355, 777 pmol/L) for nonvegetarians (P = 0.890). The use of individual vitamin B-12 supplements was higher in vegans (46.2%) than in vegetarians (27.3%) and nonvegetarians (3.9%) (P = 0.001). In linear regression analysis, the use of individual vitamin B-12 supplements was a significant positive predictor of milk vitamin B-12 concentration (ß ± SE: 172.9 ± 75.2; standardized ß = 0.263; P = 0.024; R2 = 0.069), the use of a multivitamin had a significant negative relation with milk vitamin B-12 concentrations (ß ± SE -222.0 ± 98.7; standardized ß = -0.258; P = 0.028, R2 = 0.067;), whereas the use of a B-complex vitamin and prenatal vitamin were not predictive of vitamin B-12 milk concentration (P > 0.05). Conclusions: Almost 20% of our study participants were classified as having low breast-milk vitamin B-12 concentrations (<310 pmol/L), independent of maternal diet pattern. Approximately 85% of participants categorized as having low vitamin B-12 were taking vitamin B-12 supplements at doses in excess of the Recommended Dietary Allowance, which suggests that more research is needed to determine breast-milk adequacy values.

Iron Status of Vegetarian Adults: A Review of Literature.

The goal of this study was to review published data on iron status among vegetarian adults. Thirteen original articles met the inclusion criteria. Among female vegetarians, the percentage of the sample with ferritin <12 µg/L or <12 ng/mL ranged from 12% to 79%. An inadequate hemoglobin concentration ranged from 6% to 30.3%. Among males, the range of ferritin <12 µg/L across studies was from 1.7% to 29%. The prevalence of hemoglobin below deficiency cutoff ranged from 0% to 15.3%. A higher percentage of vegetarian females, compared to nonvegetarian participants, had ferritin below deficiency cutoff in all but one study (34% vs 0%, 47% vs 42%, 18% vs 13%, 27.8% vs 6.5% among Catholic nuns and 19.4% among college students, 79% Indian, and 56% Caucasian vegetarian vs 27% of nonvegetarian). Serum ferritin was lower in male vegetarians than male nonvegetarians in each study (11% among vegans and 21% among vegetarians compared to 6% and 7% among high and moderate meat consumers, 3% of vegetarians, and 25% vegans vs 0% of nonvegetarians, 29% vs 7%, 9% vs 0%). Vegetarians have a high prevalence of depleted iron stores. A higher proportion of vegetarians, compared to nonvegetarians, had iron deficiency anemia. This is especially true for premenopausal vegetarian women.

Vegetarian Diets in the Prevention and Management of Diabetes and Its Complications.

IN BRIEF Epidemiological studies have found a lower prevalence of type 2 diabetes among vegetarians compared to nonvegetarians. This reduced risk is likely a function of improved weight status, higher intake of dietary fiber, and the absence of animal protein and heme iron in the diet. Interventional studies have shown that vegetarian diets, especially a vegan diet, are effective tools in glycemic control and that these diets control plasma glucose to a greater level than do control diets, including diets traditionally recommended for patients with diabetes (e.g., diets based on carbohydrate counting). Vegetarian diets are associated with improvement in secondary outcomes such as weight reduction, serum lipid profile, and blood pressure. Studies indicate that vegetarian diets can be universally used in type 2 diabetes prevention and as tools to improve blood glucose management.

Iron Status of Vegetarian Children: A Review of Literature.

BACKGROUND: Iron is considered a nutrient of concern for vegetarians. In children, inadequate iron status may lead to anemia and poor growth. SUMMARY: Thirteen original manuscripts met the inclusion criteria. Various biochemical markers of iron status, such as hemoglobin (Hb) and serum ferritin, were used. Seven of the 13 studies reported the prevalence of iron deficiency separately for vegetarians and non-vegetarians. Five out of 7 showed a higher prevalence of iron deficiency among the vegetarian participants, while the other 2 showed a higher prevalence of iron deficiency among non-vegetarians. A wide range of iron deficiency prevalence, from 4.3% of vegetarian participants in one study to 73% having ferritin <10 µg/L in another study, was found. Hb data showed almost as wide variations from 0% of children having Hb values lower than 11 g/dL to 47.5% having Hb values below 3rd percentile. Key Messages: The prevalence of iron deficiency among vegetarian children varies considerably from one study to another. The wide variation in the prevalence of inadequate iron status was consistent for studies from industrial and developing countries. The physiological significance of low iron status among vegetarians reported in some studies is unknown.

Prevalence of vitamin B-12 deficiency among patients with thyroid dysfunction.

Due to the non-specificity of symptoms and possibly severe consequences of untreated vitamin B-12 deficiency, screening is important for at-risk patients to ensure the prompt delivery of treatment. In this review, studies assessing the prevalence of vitamin B-12 deficiency in thyroid dysfunction are evaluated to determine whether regular vitamin B-12 screening is necessary. A literature search was conducted using multiple electronic databases. Only original studies assessing the prevalence of vitamin B-12 deficiency in thyroid dysfunction that reported their findings as percentages of the sample were eligible for inclusion. From a total of 7091 manuscripts generated, 6 were included in this review. The prevalence of vitamin B-12 deficiency in hypothyroidism was reported as 10, 18.6, and 40.5% in three separate studies. The prevalence of deficiency in autoimmune thyroid disease was reported as 6.3, 28, and 55.5% in three studies. The prevalence of vitamin B-12 deficiency in hypothyroidism and autoimmune thyroid disease are reflective of the nutrition status of the population. Autoimmune thyroid disease is also associated with the autoimmune disorders pernicious anemia and atrophic gastritis which may lead to malabsorption of vitamin B-12. Vitamin B-12 screening is recommended upon initial diagnosis with autoimmune thyroid disease and then periodically thereafter. There is not enough evidence to recommend regular screening for patients with hypothyroidism unless the underlying cause is autoimmune thyroid disease.

Is vitamin B12 deficiency a risk factor for cardiovascular disease in vegetarians?

The goal of this paper is to describe the role of vitamin B12 deficiency in cardiovascular disease development among vegetarians. Vegetarians have a high prevalence of vitamin B12 deficiency. Deficiency of this vitamin is associated with a variety of atherogenic processes that are mainly, but not exclusively, due to vitamin B12 deficiency-induced hyperhomocysteinemia. Each 5-µmol/L increase above 10 µmol/L of serum homocysteine is associated with a 20% increased risk of circulatory health problems. Mean homocysteine concentration >10 µmol/L among vegetarians was reported in 32 of 34 reports. Macrocytosis associated with vitamin B12 deficiency is also associated with fatal and non-fatal coronary disease, myocardial infarction, stroke, and other circulatory health problems. Compared with non-vegetarians, vegetarians have an improved profile of the traditional cardiovascular disease risk factors, including serum lipids, blood pressure, serum glucose concentration, and weight status. However, not all studies that assessed cardiovascular disease incidence among vegetarians reported a protective effect. Among studies that did show a lower prevalence of circulatory health problems, the effect was not as pronounced as expected, which may be a result of poor vitamin B12 status due to a vegetarian diet. Vitamin B12 deficiency may negate the cardiovascular disease prevention benefits of vegetarian diets. In order to further reduce the risk of cardiovascular disease, vegetarians should be advised to use vitamin B12 supplements.

Position of the academy of nutrition and dietetics: vegetarian diets.

It is the position of the Academy of Nutrition and Dietetics that vegetarian diets can provide health benefits in the prevention and treatment of certain health conditions, including atherosclerosis, type 2 diabetes, hypertension, and obesity. Well-designed vegetarian diets that may include fortified foods or supplements meet current nutrient recommendations and are appropriate for all stages of the life cycle, including pregnancy, lactation, infancy, childhood, and adolescence. Vegetarians must use special care to ensure adequate intake of vitamin B-12. Vegetarian diets are primarily plant-based, comprised of grains, legumes, nuts, seeds, vegetables, and fruit; do not include flesh foods (beef, pork, poultry and fowl, wild game, and fish); and may or may not include some animal products, such as dairy (milk and milk products), eggs, and processed foods that contain casein or whey. Although vegetarians may have a higher deficiency risk for some nutrients (eg, vitamin B-12) compared to nonvegetarians, nutritional deficiencies are not the main causes of mortality or morbidity in Western societies. Vegetarian diets are associated with a lower risk of ischemic heart disease, hypertension, type 2 diabetes, obesity, and some types of cancer; low-fat vegetarian diets, in combination with other healthy lifestyle factors, have been shown to be effective in the treatment of these diseases. Vegetarians have lower low-density lipoprotein, better serum glucose control, and lower oxidative stress. Low intake of foods containing saturated fat and cholesterol, and high intake of vegetables, fruits, whole grains, legumes, nuts and seeds, and soy products that are rich in fiber and phytochemicals are components of a vegetarian diet that contribute to reduction of chronic disease.