Vegan food is heinous: a meta-analysis

Sanjay Manohar MB BCh MA MRCP



We can construct a satisfactory healthy diet from appropriate combinations of "flour, bread, oatmeal, potatoes, haricot beans, carrots, cabbage, spinach and watercress. It is possible to construct cheap, nutritionally sound, but appallingly monotonous diets from these ingredients ; the vegan housewife has obviously mastered the art of providing such vegetable dishes in a palatable form."

- F.R. Ellis, 1967

"There is no disease, bodily or mental, which adoption of vegetable diet and pure water has not infallibly mitigated, wherever the experiment has been fairly tried. Debility is gradually converted into strength, disease into healthfulness . . . the unaccountable irrationalities of ill temper, that make hell of domestic life,  into a calm and considerable evenness of temper . . ." -

- P.B. Shelley 1813


I typed 'vegan' into Google scholar, and read the abstracts of the first 50 articles.
I classified them into 'for' and 'against'. Interestingly, there were exactly equal numbers! I have omitted a large number of articles that all conclude, essentially, that "it is possible to construct a planned vegan diet that is nutritionally adequate ". I have also omitted a few articles that contain nothing more than null results.


I have summarised the evidence in the articles in this table. Reference links will take you to the abstract.

Macrocytic anaemia due to B12 deficiency is common in vegans 1. , The average "living food” diet will not supply enough vitamin B-12.  9, and the average vegan diet falls below the recommended amount 21, 5. Homocysteine levels are elevated in 66% of vegans 25 This can have serious neurological consequences 13 Cobalamin supplements are recommended 17

Vegans have lower cholesterol and triglyceride levels 2, and lipids can be lowered by a vegan diet 8. Vegans have lower lipoprotein levels 6, and vegan diet may be beneficial to coronary heart disease and hyperlipidaemias 12, Regression of coronary stenoses has been documented during low-fat vegan diets coupled with exercise training 10

Vegans have dietary intakes lower than the average requirements of vitamin D, calcium, and selenium. Intakes of calcium and selenium remain low even with the inclusion of dietary supplements 3, 5. At northern latitudes in winter, dietary intake of vitamin D in vegans is insufficient 11. Vegans and lactovegetarians have reduced hip bone mineral density, increasing the risk of osteoporosis. 21

Vegans have higher testosterone, normal free-testosterone, and low IGF-1 levels. Testosterone and IGF-1 may both be risk factors for carcinoma of prostate 4. Breast and colon cancer may also be associated. Vegans may have lower incidence of colon cancer, possibly due to bulk and altered flora 22, and low-fat vegan diets may be especially protective in regard to breast and colon cancer 10

Vegans have lower leucocyte, lymphocyte and platelet counts, though no evidence for reduced immunocompetence. 1

Vegans have lower prevalence of obesity 6, 24, and is effective in reducing BMI 8

Vegan children with vegan mothers are smaller in stature and lighter in weight than standards for the general population. Energy intakes are usually below the recommended amount, and a few have low intakes of riboflavin. 5 Riboflavin (B2) intake is generally low 3, and measured levels are deficient in 30% of vegans 25. One third have pyridoxine (B6) deficiency  25.

Vegans’ blood pressures are low for their age.  6

Long-chain n–3 polyunsaturated (omega-3) fatty acids are lower in vegetarians and in vegans. These chemicals may (or may not) help prevent ischaemic heart disease, breast cancer and prostate cancer. 7, 19

In type 2 diabetes, a low-fat vegan diet is better than even diabetic diets to reduce diabetes medications, and reduce HbA1c levels, 8, 26. Vegan diet has an insulin-sensitising effect 10

Reduced growth factor activity may be responsible for an increased risk of hemorrhagic stroke in vegans10

Vegan diet has clinical efficacy in rheumatoid arthritis, with subjective improvement and reduced need for DMDs 20


Strict vegans have decreased plasma taurine and severely restricted urinary taurine output (an amino acid required for neurotransmission, retinal and cardiac function) 15

Vegan diet has beneficial effects on fibromyalgia symptoms at least in the short run. 16

In some cases, iron and zinc levels are of concern 19

Vegans have improved antioxidant status, which may (or may not) be helpful in cancer and ischaemic heart disease prevention.18

36% male and 63% female vegans have Iodine intakes below the lower RNI. Vegans are an ‘at risk’ group for moderate to severe iodine deficiency disorder  23

Note that these articles are all primarily theoretical and speculative. In particular, none of these show any actual outcomes - i.e. life and death. So, amongst the multitude of articles which didn't appear on the list, an important one must be this one:

American Journal of Clinical Nutrition, Vol. 70, No. 3, 516S-524S, Supp. Mortality in vegetarians and nonvegetarians: detailed findings from a collaborative analysis of 5 prospective studies Key et al.,
The study is a meta-analysis of 5 prospective cohort studies of death rate and diet, in UK, California and Germany. Its only statistically significant result is: being vegetarian for >5 years is associated with lower rates of ischaemic heart disease. But it also reports vegans separately - so I've drawn this simplified table from their results. Note that, because of the small number of vegans, none of these trends reached significance.
Cause of death Relative risk of vegans, as compared to regular meat eaters
All deaths 1.00 (no net difference between the groups!)
Lung cancer 2.79
Stomach cancer 2.18
Other causes 1.33
Ischaemic heart disease 0.74
Stroke 0.70
Looking at how small their effects were, and how large the total sample was (N > 66,000), I'm pretty convinced now that what you eat makes barely any difference at all.


Draw your own!


Here are the relevant abstracts:


American Journal of Clinical Nutrition, Vol. 70, No. 3, 586S-593S, September 1999 Supplement

Dietary intake and biochemical, hematologic, and immune status of vegans compared with nonvegetarians1,2

Ella H Haddad, Lee S Berk, James D Kettering, Richard W Hubbard and Warren R Peters

From the Department of Nutrition, School of Public Health; the Department of Medical Technology, School of Allied Health Professions; the Departments of Microbiology and Pathology and Human Anatomy, School of Medicine; and the Center for Health Promotion, Loma Linda University, CA.

Dietary and nutritional status of individuals habitually consuming a vegan diet was evaluated by biochemical, hematologic, and immunologic measures in comparison with a nonvegetarian group. On the basis of 4-d dietary records, the intake of female and male vegans tended to be lower in fat, saturated fat, monounsaturated fat, and cholesterol and higher in dietary fiber than that of vegetarians. With computed food and supplement intakes, vegan diets provided significantly higher amounts of ascorbate, folate, magnesium, copper, and manganese in both female and male participants. The body mass index (BMI; in kg/m2) of the vegans was significantly lower than that of the nonvegetarians and 9 of the 25 vegans had a BMI <19. Serum ferritin concentrations were significantly lower in vegan men but iron and zinc status did not differ between the sexes. Mean serum vitamin B-12 and methylmalonic acid concentrations did not differ; however, 10 of the 25 vegans showed a vitamin B-12 deficit manifested by macrocytosis, circulating vitamin B-12 concentrations <150 pmol/L, or serum methylmalonic acid >376 nmol/L. Vegans had significantly lower leukocyte, lymphocyte, and platelet counts and lower concentrations of complement factor 3 and blood urea nitrogen but higher serum albumin concentrations. Vegans did not differ from nonvegetarians in functional immunocompetence assessed as mitogen stimulation or natural killer cell cytotoxic activity.


American Journal of Clinical Nutrition, Vol 31, 805-813, Copyright © 1978 by The American Society for Clinical Nutrition, Inc

Studies of vegans: the fatty acid composition of plasma choline phosphoglycerides, erythrocytes, adipose tissue, and breast milk, and some indicators of susceptibility to ischemic heart disease in vegans and omnivore controls

TA Sanders, FR Ellis and JW Dickerson

The fatty acid composition of erythrocytes, of plasma choline phosphoglycerides, and of adipose tissue, serum cholesterol, triglyceride and vitamin B12 concentrations, weights, heights and skinfold thickness were determined on 22 vegans and 22 age and sex matched omnivore controls. The fatty acid composition of breast milk from four vegan and four omnivore control mothers, and of erythrocytes from three infants breast fed by vegan mothers and six infants breast fed by omnivore control mothers was determined. The proportions of linoleic acid and its long-chain derivatives were higher, the proportion of the long-chain derivatives of alpha-linolenic acid was lower, and the ratio of 22:5omega3/22:6omega3 was greater in the tissues of the vegans and infants breast-fed by vegans than in controls; the most marked differences were in the proportions of linoleic (18:2omega6) and docosahexenoic (22:6omega3) acids. Weights, skinfold thickness, serum vitamin B12, cholesterol and triglyceride concentrations were less in vegans than in controls. The difference in serum cholesterol concentration was most marked. It is concluded that a vegan-type diet may be the one of choice in the treatment of ischemic heart disease, angina pectoris, and certain hyperlipidemias.


American Journal of Clinical Nutrition, Vol. 76, No. 1, 100-106, July 2002

Dietary intake and nutritional status of young vegans and omnivores in Sweden

Christel L Larsson and Gunnar K Johansson

From the Department of Food and Nutrition, Umeå University, Umeå, Sweden.

Background: Adolescents sometimes become vegetarian for ethical rather than health reasons. This may result in health problems caused by lack of interest in and knowledge of nutrition.

Objective: We compared the dietary intake and nutritional status of young Swedish vegans and omnivores.

Design: The dietary intakes of 30 vegans (15 males and 15 females; mean age: 17.5 ± 1.0 y) and 30 sex-, age-, and height-matched omnivores were assessed with the use of a diet-history interview and validated by the doubly labeled water method and by measuring nitrogen, sodium, and potassium excretion in urine. Iron status and serum vitamin B-12 and folate concentrations were measured in blood samples.

Results: The diet-history method underestimated energy intake by 13% and potassium intake by 7% compared with the doubly labeled water method and 24-h urine excretion, respectively. Reported dietary nitrogen and sodium intakes agreed with the 24-h urinary excretion measure. Vegans had higher intakes of vegetables, legumes, and dietary supplements and lower intakes of cake and cookies and candy and chocolate than did omnivores. Vegans had dietary intakes lower than the average requirements of riboflavin, vitamin B-12, vitamin D, calcium, and selenium. Intakes of calcium and selenium remained low even with the inclusion of dietary supplements. There was no significant difference in the prevalence of low iron status among vegans (20%) and omnivores (23%). Two vegans with low intakes of vitamin B-12 had low serum concentrations.

Conclusion: The dietary habits of the vegans varied considerably and did not comply with the average requirements for some essential nutrients.


Hormones and diet: low insulin-like growth factor-I but normal bioavailable androgens in vegan men

N E Allen, P N Appleby, G K Davey, and T J Key

Cancer Epidemiology Unit, Imperial Cancer Research Fund, Gibson Building, Radcliffe Infirmary, Woodstock Road, Oxford, OX2 6HE, UK

Received November 30, 1999; Revised February 7, 2000; Accepted February 8, 2000.

Mean serum insulin-like growth factor-I was 9% lower in 233 vegan men than in 226 meat-eaters and 237 vegetarians (P = 0.002). Vegans had higher testosterone levels than vegetarians and meat-eaters, but this was offset by higher sex hormone binding globulin, and there were no differences between diet groups in free testosterone, androstanediol glucuronide or luteinizing hormone. © 2000 Cancer Research Campaign


American Journal of Clinical Nutrition, Vol 48, 822-825,

Growth and development of British vegan children

TA Sanders

Department of Food and Nutritional Sciences, King's College, University of London, UK.

The growth and development of children born of vegan mothers and reared on a vegan diet has been studied longitudinally: All of the children were breast-fed for the first 6 mo of life and in most cases well into the second year of life. The majority of children grew and developed normally but they did tend to be smaller in stature and lighter in weight than standards for the general population. Energy, calcium, and vitamin D intakes were usually below the recommended amounts. Their diets, however, were generally adequate but a few children had low intakes of riboflavin and vitamin B-12. Most parents were aware of the need to supplement the diet with vitamin B-12. It is concluded that provided sufficient care is taken, a vegan diet can support normal growth and development.


American Journal of Clinical Nutrition, Vol 34, 2464-2477,

Nutrient intake and health status of vegans. Chemical analyses of diets using the duplicate portion sampling technique

M Abdulla, I Andersson, NG Asp, K Berthelsen, D Birkhed, I Dencker, CG Johansson, M Jagerstad, K Kolar, BM Nair, P Nilsson-Ehle, A Norden, S Rassner, B Akesson and PA Ockerman

A strict vegetarian diet [vegan diet (VD)] was investigated. Six middle- aged vegans (three men and three women) collected copies of 24-h diets using the duplicate portion sampling technique. By chemical analyses, the nutrient composition was determined in detail and compared with corresponding figures of a normal mixed Swedish diet. In the VD 30% of the energy originated from fat compared with 40% in normal Swedish mixed diet (MD). Linoleic acid was the dominant fatty acid (60% of total fat in VD versus 8% in MD). The VD contained 24 g protein/1000 kcal compared to 30 g/1000 kcal in MD, but the intake of essential amino acids by the vegans exceeded the recommendations. Dietary fiber was about 5 times higher in the vegan diet (29 versus 6 g/1000 kcal) and sucrose similar to MD (18 versus 21 g/1000 kcal). Among the inorganic nutrients the concentration of calcium

(351 versus 391 mg/1000 kcal) and sodium (53 versus 49 mmol/1000 kcal) were similar in both types of diets but the amount of potassium (56 versus 30 mmol/1000 kcal, magnesium (300 versus 110 mg/1000 kcal), iron (9 versus 6.5 mg/1000 kcal), zinc (6.5 versus 4.7 mg/1000 kcal), and copper (2 versus 0.7 mg/1000 kcal) were nearly doubled. Iodine (39 versus 156 micrograms/1000 kcal and selenium (5 versus 17 micrograms/1000 kcal) were much lower in the VD, selenium even being undetectable in several 24-h diets. The VD was rich in folic acid (301 versus 90 micrograms/1000 kcal in MD) but the intake of vitamin B12 was only 0.3 to 0.4 microgram/day (MD: 3 to 4 micrograms/day). No clinical signs of nutritional deficiency were observed in the vegans. Serum protein levels of the vegans as well as their serum lipoproteins were near the lower range of the reference group. In addition, none of the vegans was overweight and their blood pressures were low for their age.


 American Journal of Clinical Nutrition, Vol. 82, No. 2, 327-334, August 2005

Long-chain n–3 polyunsaturated fatty acids in plasma in British meat-eating, vegetarian, and vegan men1,2,3

Magdalena S Rosell, Zouë Lloyd-Wright, Paul N Appleby, Thomas AB Sanders, Naomi E Allen and Timothy J Key

 From the Cancer Research UK Epidemiology Unit, University of Oxford, Oxford, United Kingdom (MSR, PNA, NEA, and TJK), and the Nutrition, Food and Health Research Center, King’s College London, London, United Kingdom (ZL-W and TABS)

Background: Plasma concentrations of long-chain n–3 polyunsaturated fatty acids are lower in vegetarians and in vegans than in omnivores. No data are available on whether these concentrations differ between long- and short-term vegetarians and vegans.

Objectives: We compared plasma fatty acid composition in meat-eaters, vegetarians, and vegans and examined whether the proportions of eicosapentaenoic acid (20:5n–3; EPA), docosapentaenoic acid (22:5n–3; DPA), and docosahexaenoic acid (22:6n–3; DHA) were related to the subjects’ duration of adherence to their diets or to the proportions of plasma linoleic acid (18:2n–6; LA) and {alpha}-linolenic acid (18:3n-3; ALA).

Design: The present cross-sectional study included 196 meat-eating, 231 vegetarian, and 232 vegan men in the United Kingdom. Information on anthropometry, diet, and smoking habits was obtained through a questionnaire. Total fatty acid composition in plasma was measured.

Results: The proportions of plasma EPA and DHA were lower in the vegetarians and in the vegans than in the meat-eaters, whereas only small differences were seen for DPA. Plasma EPA, DPA, and DHA proportions were not significantly associated with the duration of time since the subjects became vegetarian or vegan, which ranged from <1 y to >20 y. In the vegetarians and the vegans, plasma DHA was inversely correlated with plasma LA.

Conclusions: The proportions of plasma long-chain n–3 fatty acids were not significantly affected by the duration of adherence to a vegetarian or vegan diet. This finding suggests that when animal foods are wholly excluded from the diet, the endogenous production of EPA and DHA results in low but stable plasma concentrations of these fatty acids.


A Low-Fat Vegan Diet Improves Glycemic Control and Cardiovascular Risk Factors in a Randomized Clinical Trial in Individuals With Type 2 Diabetes

Neal D. Barnard,  Joshua Cohen, David J.A. Jenkins. Gabrielle Turner-McGrievy,   Lise Gloede, . Brent Jaster, Kim Seidl,. Amber A. Green, Stanley Talpers

      Department of Medicine, George Washington University School of Medicine, Washington, DC, Physicians Committee for Responsible Medicine, Washington, DC, Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, and the Clinical Nutrition and Risk Factor Modification Center, St. Michael’s Hospital, Toronto, Canada, Department of Nutrition, School of Public Health, University of North Carolina, Chapel Hill, North Carolina, Private practice, Arlington, Virginia

OBJECTIVE—We sought to investigate whether a low-fat vegan diet improves glycemic control and cardiovascular risk factors in individuals with type 2 diabetes.

RESEARCH DESIGN AND METHODS—Individuals with type 2 diabetes (n = 99) were randomly assigned to a low-fat vegan diet (n = 49) or a diet following the American Diabetes Association (ADA) guidelines (n = 50). Participants were evaluated at baseline and 22 weeks.

RESULTS—Forty-three percent (21 of 49) of the vegan group and 26% (13 of 50) of the ADA group participants reduced diabetes medications. Including all participants, HbA1c (A1C) decreased 0.96 percentage points in the vegan group and 0.56 points in the ADA group (P = 0.089). Excluding those who changed medications, A1C fell 1.23 points in the vegan group compared with 0.38 points in the ADA group (P = 0.01). Body weight decreased 6.5 kg in the vegan group and 3.1 kg in the ADA group (P < 0.001). Body weight change correlated with A1C change (r = 0.51, n = 57, P < 0.0001). Among those who did not change lipid-lowering medications, LDL cholesterol fell 21.2% in the vegan group and 10.7% in the ADA group (P = 0.02). After adjustment for baseline values, urinary albumin reductions were greater in the vegan group (15.9 mg/24h) than in the ADA group (10.9 mg/24 h) (P = 0.013).

CONCLUSIONS—Both a low-fat vegan diet and a diet based on ADA guidelines improved glycemic and lipid control in type 2 diabetic patients. These improvements were greater with a low-fat vegan diet.


Human and Clinical Nutrition 1995

Vitamin B-12 Status of Long-Term Adherents of a Strict Uncooked Vegan Diet ("Living Food Diet") Is Compromised

Anna-Liisa Rauma3, Riitta Törrönen*, Osmo Hänninen* and Hannu Mykkänen

Departments of Clinical Nutrition * Physiology, University of Kuopio, FIN-70211, Kuopio, Finland

The present study examined the vitamin B-12 status in long-term adherents of a strict uncooked vegan diet called the "living food diet." The study was comprised of two parts. In the cross-sectional part, the data on serum vitamin B-12 concentrations and dietary intakes in 21 (1 male, 20 females) long-term adherents (mean 5.2 y, range 0.7–14) of the "living food diet" were compared with those of 21 omnivorous controls matched for sex, age, social status and residence. In the longitudinal part of the study, food consumption data were collected and blood samples were taken from nine "living food eaters" (1 male, 8 females) on two occasions 2 y apart. The cross-sectional study revealed significantly (P < 0.001, paired t test) lower serum vitamin B-12 concentrations in the vegans (mean 193 pmol/L, range 35–408) compared with their matched omnivorous controls (311, 131–482). In the vegan group, total vitamin B-12 intake correlated significantly (r = 0.63, P < 0.01) with serum vitamin B-12 concentration. The vegans consuming Nori and/or Chlorella seaweeds (n = 16) had serum vitamin B-12 concentrations twice as high as those not using these seaweeds (n = 5) (mean 221 pmol/L, range 75–408, vs. 105, 35–252, P = 0.025). In the longitudinal study, six of nine vegans showed slow, but consistent deterioration of vitamin B-12 status over a 2-y observation period. On the basis of these results we conclude that some seaweeds consumed in large amounts can supply adequate amounts of bioavailable vitamin B-12. However, the average use of seaweeds and fermented foods by "living food eaters" will not supply enough vitamin B-12 to maintain the body vitamin B-12 status.


Medical Hypotheses

Volume 53, Issue 6, December 1999, p 459-485, doi:10.1054/mehy.1999.0784 |

Vegan proteins may reduce risk of cancer, obesity, and cardiovascular disease by promoting increased glucagon activity

M. F. McCarty

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


Journal of the American Dietetic Association

Volume 100:4, April 2000, p 434-441

doi:10.1016/S0002-8223(00)00134-6 |

Dietary Intake of Vitamin D in Premenopausal, Healthy Vegans was Insufficient to Maintain Concentrations of Serum 25-hydroxyvitamin D and Intact Parathyroid Hormone Within Normal Ranges During the Winter in Finland


C. J. E. Lamberg-Allardt (corresponding author), T. A. Outila, M. U. M. Kärkkäinen, and R. H. Seppänen are with the Department of Applied Chemistry and Microbiology, Division of Nutrition, Calcium Research Unit, University of Helsinki, PO Box 27, FIN-00014 University of Helsinki, Finland.

Objective To study vitamin D status and bone metabolism of premenopausal vegetarians and omnivores during a 1-year period.

Design Longitudinal, observational study. Bone mineral density was measured, blood samples from fasting subjects were obtained, and 24-hour urinary samples were collected in February 1994, August 1994, and January 1995. Serum 25-hydroxyvitamin D [S-25(OH)D] and intact parathyroid hormone (Si-PTH) concentrations were measured and intestinal calcium absorption was estimated. Dietary intakes of vitamin D and calcium were calculated.

Subjects/setting Six vegans, 6 lactovegetarians, and 16 omnivores living in Helsinki, Finland.

Statistical analyses performed Student-Newman-Keuls test; unbalanced, repeated-measures multiple analysis of variance; analysis of covariance; Pearson correlation test; and linear regression analysis.

Results Dietary intake of vitamin D was significantly lower in vegans (P<.05, yearly mean±standard DEVIATION=0.09± 0.06 μg/day) and in lactovegetarians (P<.05, 0.7±0.4 μg/ day) compared with omnivores (4.0±2.1 (μg/day). Throughout the year S-25(OH)D (P=.01) concentrations were lower and S-iPTH (P=.01) concentrations were higher in vegans than in omnivores and lactovegetarians. Bone mineral density in the lumbar region of the spine was lower in vegans (yearly mean±standard DEVIATION=1.034±0.174 g/ cm2) than in omnivores (P=.05, 1.177±0.099 g/cm2) and tended to be lower than that in lactovegetarians (P=.17, 1.138±0.06 g/cm2). Bone mineral density in the neck of the femur tended to be lower in vegans (0.843±0.116 g/cm2) than in omnivores (P=.07, 0.999±0.138 g/cm2) and lactovegetarians (P=.15, 0.961±0.059 g/cm2). No seasonal variation was found in bone mineral density in the study groups.

Conclusions At northern latitudes, dietary intake of vitamin D in vegans was insufficient to maintain S-25(OH)D and S-iPTH concentrations within normal ranges in the winter, which seems to have negative effects on bone mineral density in the long run.

Applications An increase in vitamin D intake should generally be recommended for vegans at least during winter, or selections of foodstuffs fortified with vitamin D should be broadened in northern latitudes. J Am Diet Assoc. 2000; 100:434-441.


Title:    Diet and serum lipids in vegan vegetarians: a model for risk reduction.

Author:            Resnicow, K : Barone, J : Engle, A : Miller, S : Haley, N J : Fleming, D : Wynder, E

Citation:          J-Am-Diet-Assoc. 1991 Apr; 91(4): 447-53

Abstract:         The lipid levels and dietary habits of 31 Seventh-Day Adventist vegan vegetarians (aged 5 to 46 years) who consume no animal products were assessed. Mean serum total cholesterol (3.4 mmol/L), low-density-lipoprotein cholesterol (1.8 mmol/L), and triglyceride (0.8 mmol/L) levels were lower than expected values derived from the Lipid Research Clinics Population Studies prevalence data. Mean high-density-lipoprotein cholesterol (1.3 mmol/L) was comparable to expected values. Analysis of quantitative food frequency data showed that vegans had a significantly lower daily intake of total energy, percentage of energy from fat (31% vs 38%), total fat, saturated fat, monounsaturated fatty acids, cholesterol, and protein and a significantly higher intake of fiber than a sample of matched omnivore controls. Vegans' food intake was also compared with expected values, matched for sex and age, derived from the second National Health and Nutrition Examination Survey and Continuing Survey of Food Intakes by Individuals 24-hour recall data. The vegan diet was characterized by increased consumption of almonds, cashews, and their nut butters; dried fruits; citrus fruits; soy milk; and greens. We conclude from the present study that a strict vegan diet, which is typically very low in saturated fat and dietary cholesterol and high in fiber, can help children and adults maintain or achieve desirable blood lipid levels.

Review References:    None

Notes:  Copyright The American Dietetic Association. Abstracts are reprinted by the permission from Journal of the American Dietetic Association for volume, pages, and dates cited. Hypertext links to electronic journal sites, if available, can be found in the the Peer Reviewed Journal List on the IBIDS home page.

Language:       English

Publication Type:        Journal-Article

Keywords:      Lipids blood : Vegetarianism


 Maternal vegan diet causing a serious infantile neurological disorder due to vitamin B12 deficiency

Journal European Journal of Pediatrics

Publisher         Springer Berlin / Heidelberg

ISSN   0340-6199 (Print) 1432-1076 (Online)

Issue    Volume 150, Number 3 / January, 1991

Category         Nutrition

DOI     10.1007/BF01963568

Pages   205-208

Maternal vegan diet causing a serious infantile neurological disorder due to vitamin B12 deficiency

T. Kühne1, R. Bubl1 and R. Baumgartner1

(1)        University Children's Hospital Basel, Römergasse 8, CH-4005 Basel, Switzerland

Received: 13 March 1990  Accepted: 14 July 1990 

Abstract  We present a 9-month-old exclusively breastfed baby of a strict vegetarian mother who had excluded all animal proteins from her diet. The patient's symptoms included dystrophy, weakness, muscular atrophy, loss of tendon reflexes, psychomotor regression and haematological abnormalities. Biochemical investigations revealed severe methylmalonic aciduria and homocystinuria in the patient, slight methylmalonic aciduria in the mother and low concentrations of serum vitamin B12 in both patient and mother.


Public Health Nutrition (2002), 5:645-654 Cambridge University Press

Copyright © CABI Publishing 2002


Research Article

Hypertension and blood pressure among meat eaters, fish eaters, vegetarians and vegans in EPIC–Oxford

Paul N Applebya1 c1, Gwyneth K Daveya1 and Timothy J Keya1

a1 Cancer Research UK, Epidemiology Unit, University of Oxford, Gibson Building, The Radcliffe Infirmary, Oxford OX2 6HE, UK


Objective: To compare the prevalence of self-reported hypertension and mean systolic and diastolic blood pressures in four diet groups (meat eaters, fish eaters, vegetarians and vegans) and to investigate dietary and other lifestyle factors that might account for any differences observed between the groups.

Design: Analysis of cross-sectional data from participants in the Oxford cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC–Oxford).

Setting: United Kingdom.

Subjects: Eleven thousand and four British men and women aged 20–78 years at blood pressure measurement.

Results: The age-adjusted prevalence of self-reported hypertension was significantly different between the four diet groups, ranging from 15.0% in male meat eaters to 5.8% in male vegans, and from 12.1% in female meat eaters to 7.7% in female vegans, with fish eaters and vegetarians having similar and intermediate prevalences. Mean systolic and diastolic blood pressures were significantly different between the four diet groups, with meat eaters having the highest values and vegans the lowest values. The differences in age-adjusted mean blood pressure between meat eaters and vegans among participants with no self-reported hypertension were 4.2 and 2.6 mmHg systolic and 2.8 and 1.7 mmHg diastolic for men and women, respectively. Much of the variation was attributable to differences in body mass index between the diet groups.

Conclusions: Non-meat eaters, especially vegans, have a lower prevalence of hypertension and lower systolic and diastolic blood pressures than meat eaters, largely because of differences in body mass index.


American Journal of Clinical Nutrition, Vol 47, 660-663,

Plasma and urine taurine levels in vegans


SA Laidlaw, TD Shultz, JT Cecchino and JD Kopple

Department of Medicine, Harbor-UCLA Medical Center, Torrance , CA 90509.

Plasma taurine levels and urinary taurine excretion were measured in 12 strict vegetarian (vegan) males who had maintained a vegan diet for 53 +/- 26 mo (SD) and in 14 male nonvegetarian control subjects. Plasma taurine levels differed (45 +/- 7 vs 58 +/- 16 mumol/L, respectively). Urinary taurine excretion was lower (266 +/- 279 vs 903 +/- 580 mumol/d), urinary N pi-methylhistidine was barely detectable, and urinary N tau-methylhistidine was significantly reduced (296 +/- 87 vs 427 +/- 19 mumol/d) in the vegans. Analysis of 3-d dietary diaries kept by the vegans indicated marginal to adequate intake of protein, carbohydrate, vitamin B-6, methionine, and cystine; inadequate intake of zinc; and negligible intake of taurine. Prolonged absence of dietary taurine intake causes decreased plasma taurine and severely restricted urinary taurine output.


Scandinavian Journal of Rheumatology

2000, Vol. 29, No. 5, Pages 308-313 , DOI 10.1080/030097400447697

Vegan diet alleviates fibromyalgia symptoms

K. Kaartinen, K. Lammi, M. Hypen, M. Nenonen, O. Hänninen, A.-L. Rauma‌

Department of Physiology, University of Kuopio, P.O. Box 1627, FI-70211 Kuopio, Finland

The effect of a strict, low-salt, uncooked vegan diet rich in lactobacteria on symptoms in 18 fibromyalgia patients during and after a 3-month intervention period in an open, non-randomized controlled study was evaluated. As control 15 patients continued their omnivorous diet. The groups did not differ significantly from each other in the beginning of the study in any other parameters except in pain and urine sodium. The results revealed significant improvements in Visual analogue scale of pain (VAS) (p=0.005), joint stiffness (p=0.001), quality of sleep (p=0.0001), Health assessment questionnaire (HAQ) (p=0.031), General health questionnaire (GHQ) (p=0.021), and a rheumatologist's own questionnaire (p=0.038). The majority of patients were overweight to some extent at the beginning of the study and shifting to a vegan food caused a significant reduction in body mass index (BMI) (p=0.0001). Total serum cholesterol showed a statistically significant lowering (p=0.003). Urine sodium dropped to 1/3 of the beginning values (p=0.0001) indicating good diet compliance. It can be concluded that vegan diet had beneficial effects on fibromyalgia symptoms at least in the short run.


Annals of Nutrition & Metabolism 2000;44:229-234 (DOI: 10.1159/000046689)

Vol. 44, No. 5-6, 2000  

Metabolic Vitamin B12 Status on a Mostly Raw Vegan Diet with Follow-Up Using Tablets, Nutritional Yeast, or Probiotic Supplements

Michael S. Donaldson

Hallelujah Acres Foundation, Shelby, N.C., USA

Background: Pure vegetarian diets might cause cobalamin deficiency due to lack of dietary intake. It was hypothesized that a population following a vegan diet consuming mostly raw fruits and vegetables, carrot juice, and dehydrated barley grass juice would be able to avoid vitamin B12 deficiency naturally. Methods: Subjects were recruited at a health ministers' reunion based on adherence to the Hallelujah diet for at least 2 years. Serum cobalamin and urinary methylmalonic acid (MMA) assays were performed. Follow-up with sublingual tablets, nutritional yeast, or probiotic supplements was carried out on subjects with abnormal MMA results. Results: 49 subjects were tested. Most subjects (10th to 90th percentile) had followed this diet 23-49 months. 6 subjects had serum B12 concentrations <147 pmol/l (200 pg/ml). 37 subjects (76%) had serum B12 concentrations <221 pmol/l (300 pg/ml). 23 subjects (47%) had abnormal urinary MMA concentrations above or equal to 4.0 µg/mg creatinine. Sublingual cyanocobalamin and nutritional yeast, but not probiotic supplements, significantly reduced group mean MMA concentrations (tablet p < 0.01; yeast p < 0.05, probiotic > 0.20). Conclusions: The urinary MMA assay is effective for identifying early metabolic cobalamin deficiency. People following the Hallelujah diet and other raw-food vegetarian diets should regularly monitor their urinary MMA levels, consume a sublingual cobalamin supplement, or consume cobalamin in their food.


American Journal of Clinical Nutrition, Vol 62, 1221-1227,

Antioxidant status in long-term adherents to a strict uncooked vegan diet

AL Rauma, R Torronen, O Hanninen, H Verhagen and H Mykkanen

Department of Clinical Nutrition, University of Kuopio, Finland.

Antioxidant status was investigated in 20 Finnish middle-aged female vegans and in one male vegan who were following a strict, uncooked vegan diet ("living food diet"), by means of a dietary survey and biochemical measurements (blood concentrations of vitamins C and E and beta-carotene, and the activities of the zinc/copper-dependent superoxide dismutase and selenium-dependent glutathione peroxidase). Values were compared with those of omnivores matched for sex, age, social status, and residence. Antioxidant supplementation was used by 4 of 20 female vegans and by 11 of 20 control subjects. Based on dietary records, the vegans had significantly higher intakes of beta-carotene, vitamin E, vitamin C, and copper, and a significantly lower intake of selenium than the omnivorous control subjects. The calculated dietary antioxidant intakes by the vegans, expressed as percentages of the US recommended dietary allowances, were as follows: 305% of vitamin C, 247% of vitamin A, 313% of vitamin E, 92% of zinc, 120% of copper, and 49% of selenium. Compared with the omnivores, the vegans had significantly higher blood concentrations of beta-carotene, vitamin C, and vitamin E, as well as higher erythrocyte superoxide dismutase activity. These differences were also seen in pairs who were using no antioxidant supplements. The present data indicate that the "living food diet" provides significantly more dietary antioxidants than does the cooked, omnivorous diet, and that the long-term adherents to this diet have a better antioxidant status than do omnivorous control subjects.


Am J Clin Nutr 89: 1627S-1633S, 2009. First published March 11, 2009; doi:10.3945/ajcn.2009.26736N

American Journal of Clinical Nutrition, doi:10.3945/ajcn.2009.26736N

Vol. 89, No. 5, 1627S-1633S, May 2009

Health effects of vegan diets

Winston J Craig

From the Department of Nutrition and Wellness, Andrews University, Berrien Springs, MI.

Recently, vegetarian diets have experienced an increase in popularity. A vegetarian diet is associated with many health benefits because of its higher content of fiber, folic acid, vitamins C and E, potassium, magnesium, and many phytochemicals and a fat content that is more unsaturated. Compared with other vegetarian diets, vegan diets tend to contain less saturated fat and cholesterol and more dietary fiber. Vegans tend to be thinner, have lower serum cholesterol, and lower blood pressure, reducing their risk of heart disease. However, eliminating all animal products from the diet increases the risk of certain nutritional deficiencies. Micronutrients of special concern for the vegan include vitamins B-12 and D, calcium, and long-chain n–3 (omega-3) fatty acids. Unless vegans regularly consume foods that are fortified with these nutrients, appropriate supplements should be consumed. In some cases, iron and zinc status of vegans may also be of concern because of the limited bioavailability of these minerals.


The British Journal of Rheumatology, Vol 37, 274-281,

Uncooked, lactobacilli-rich, vegan food and rheumatoid arthritis

MT Nenonen, TA Helve, AL Rauma and OO Hanninen

Department of Physiology, University of Kuopio, Finland.

We tested the effects of an uncooked vegan diet, rich in lactobacilli, in rheumatoid patients randomized into diet and control groups. The intervention group experienced subjective relief of rheumatic symptoms during intervention. A return to an omnivorous diet aggravated symptoms. Half of the patients experienced adverse effects (nausea, diarrhoea) during the diet and stopped the experiment prematurely. Indicators of rheumatic disease activity did not differ statistically between groups. The positive subjective effect experienced by the patients was not discernible in the more objective measures of disease activity (Health Assessment Questionnaire, duration of morning stiffness, pain at rest and pain on movement). However, a composite index showed a higher number of patients with 3-5 improved disease activity measures in the intervention group. Stepwise regression analysis associated a decrease in the disease activity (measured as change in the Disease Activity Score, DAS) with lactobacilli-rich and chlorophyll-rich drinks, increase in fibre intake, and no need for gold, methotrexate or steroid medication (R2=0.48, P=0.02). The results showed that an uncooked vegan diet, rich in lactobacilli, decreased subjective symptoms of rheumatoid arthritis. Large amounts of living lactobacilli consumed daily may also have positive effects on objective measures of rheumatoid arthritis.


Eur J Clin Nutr. 1998 Jan;52(1):60-4.

Bone mineral density in Chinese elderly female vegetarians, vegans, lacto-vegetarians and omnivores.

Lau EM, Kwok T, Woo J, Ho SC.

Department of Community and Family Medicine, Chinese University of Hong Kong, Hong Kong.


OBJECTIVES: To compare the bone mineral density and dietary intake of elderly Chinese vegetarian women with omnivores, to compare the bone mineral density of Chinese 'vegans' and 'lactovegetarians', and to study the relationship between nutrient intake and BMD in vegetarians. DESIGN: A cross-sectional survey. SETTING AND SUBJECTS: A community-based study. The vegetarian women (aged 70-89 y) (n = 76) were non-institutionalized subjects. All of them were Buddhists. Their bone mineral density were compared to normal elderly volunteers (aged 70-89 y) (n = 109) who were recruited to establish normal BMD ranges. Their dietary intake was compared to omnivorous subjects from a previous dietary survey (n = 250). METHODS: Dietary assessment was by the 24 h recall method, and bone mineral density was measured by dual-X-ray-densitometry. The analysis of co-variance was used to compare the BMD between vegetarians and omnivores, with adjustment for potential confounders. The BMD in 'vegans' and 'lactovegetarians' were compared by similar methods. The t-test was used to compare dietary intake between omnivores and vegetarians. The relationship between nutrient intake and BMD was studied by correlation and multiple regression. RESULTS: The dietary calorie, protein and fat intake were much lower, but the sodium/creatinine ratio was much higher in vegetarians than omnivores. The BMD at the spine was similar between vegetarians and omnivores. However, the BMD at the hip was significantly lower in vegetarians at some sites (P < 0.05). There was no significant difference in BMD between 'vegans' and 'lactovegetarians'. BMD in vegetarians appeared to be positively correlated with energy, protein and calcium intake; and negatively associated with urinary sodium/creatinine levels. CONCLUSIONS: There is a relationship between diet and BMD. The BMD at the hip was lower in vegetarians than omnivores, but no difference was observed between 'vegans' and 'lactovegetarians'. There is a complex relationship between the intake of various nutrient and BMD in vegetarians.


Author:            Ling, W H : Hanninen, O

Citation:          J-Nutr. 1992 Apr; 122(4): 924-30

Shifting from a Conventional Diet to an Uncooked Vegan Diet Reversibly Alters Fecal Hydrolytic Activities in Humans1

Wen Hua Ling2 and Osmo Hänninen

Department of Physiology, University of Kuopio, 70211, Kuopio, Finland

We studied the effect on fecal hydrolytic activities of adopting an uncooked extreme vegan diet and readopting a conventional diet. Eighteen subjects were randomly divided into test and control groups. In the test group subjects adopted the uncooked extreme vegan diet for 1 mo and then resumed a conventional diet for a second month. Controls consumed a conventional diet throughout the study. Phenol and p-cresol concentrations in serum and daily output in urine and fecal enzyme activities were measured. The activity of fecal urease significantly decreased (by 66%) as did choloylglycine hydrolase (55%), ß-glucuronidase (33%) and ß-glucosidase (40%) within 1 wk of beginning the vegan diet. The new level remained throughout the period of consuming this diet. Phenol and p-cresol concentrations in serum and daily outputs in urine significantly declined. The fecal enzyme activities returned to normal values within 2 wk of resuming the conventional diet. Concentrations of phenol and p-cresol in serum and daily output in urine had returned to normal after 1 mo of consuming the conventional diet. No changes were observed in the control group during the study. Results suggest that this uncooked extreme vegan diet causes a decrease in bacterial enzymes and certain toxic products that have been implicated in colon cancer risk


British Journal of Nutrition (1998), 80:529-535 Cambridge University Press

Copyright © The Nutrition Society 1998


Iodine intake and iodine deficiency in vegans as assessed by the duplicate-portion technique and urinary iodine excretion

Helen J. Lightowler  and G. Jill Davies

a1 Nutrition Research Centre, School of Applied Science, South Bank University, 103 Borough Road, London SE1 0AA, UK


I intake and I deficiency were investigated in thirty vegans (eleven males and nineteen females) consuming their habitual diet. I intake was estimated using the chemical analysis of 4 d weighed duplicate diet collections. The probability of I-deficiency disorders (IDD) was judged from the measurement of urinary I excretion in 24 h urine specimens during the 4 d. There was wide variation in I intake. Mean I intake in males was lower than the reference nutrient intake (RNI; Department of Health, 1991) and mean intake in females was above the RNI, although 36% males and 63% females had I intakes below the lower RNI. Mean I intake in subjects who consumed seaweed (n 3) was in excess of the RNI, and approached the provisional maximum tolerable daily intake (World Health Organization/Food and Agriculture Organization Joint Expert Committee on Food Additives, 1989). The probability of IDD in the group investigated was moderate to severe: three of five subgroups were classified as moderate and two subgroups were classified as severe IDD possibility. The findings highlight that vegans are an ‘at risk’ group for I deficiency. The I status of vegans and the subclinical effects of low I intakes and infrequent high I intakes on thyroid function in this group should be further studied. Our work has also raised the question of adequate I intakes in groups where cow's milk is not consumed, and has exposed a need for more research in this area.


American Journal of Clinical Nutrition, Vol. 81, No. 6, 1267-1274, June 2005

Risk of overweight and obesity among semivegetarian, lactovegetarian, and vegan women1,2,3,4

PK Newby, Katherine L Tucker and Alicja Wolk

1 From the Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA (PKN and KLT), and the Division of Nutritional Epidemiology, Department of Environmental Medicine, Karolinska Institute, Stockholm, Sweden (AW)

Background: Observational studies suggest that a plant-based diet is inversely related to body mass index (BMI), overweight, and obesity.

Objective: Our objective was to examine the BMI (kg/m2) and risk of overweight and obesity of self-defined semivegetarian, lactovegetarian, and vegan women.

Design: Data analyzed in this cross-sectional study were from 55459 healthy women participating in the Swedish Mammography Cohort. Women were asked whether they considered themselves to be omnivores (n = 54257), semivegetarians (n = 960), lactovegetarians (n = 159), or vegans (n = 83), and this question was the main exposure variable in this study. In secondary analyses, we reclassified women as lactovegetarians on the basis of food intakes reported on the food-frequency questionnaire.

Results: The prevalence of overweight or obesity (BMI ≥ 25) was 40% among omnivores, 29% among both semivegetarians and vegans, and 25% among lactovegetarians. In multivariate, adjusted logistic regression analyses, self-identified vegans had a significantly lower risk of overweight or obesity [odds ratio (OR) = 0.35; 95% CI: 0.18, 0.69] than did omnivores, as did lactovegetarians (OR = 0.54; 95% CI: 0.35, 0.85) and semivegetarians (OR = 0.52; 95% CI: 0.43, 0.62). Risk of overweight or obesity remained significantly lower among lactovegetarians classified on the basis of the food-frequency questionnaire (OR = 0.48; 95% CI: 0.30, 0.78).

Conclusions: Even if vegetarians consume some animal products, our results suggest that self-identified semivegetarian, lactovegetarian, and vegan women have a lower risk of overweight and obesity than do omnivorous women. The advice to consume more plant foods and less animal products may help individuals control their weight.


Annals of Nutrition and Metabolism

Vol. 50, No. 6, 2006  

B-Vitamin Status and Concentrations of Homocysteine in Austrian Omnivores, Vegetarians and Vegans

D. Majchrzak, I. Singer, M. Männer, P. Rust, D. Genser, K.-H. Wagner, I. Elmadfa

Department of Nutritional Sciences, University of Vienna, Vienna, Austria

Background: A vegetarian diet is considered to promote health and longevity and reduce the risk of cardiovascular diseases and cancer. However, a vegetarian diet may be deficient in some nutrients. Exclusion of animal products in vegetarian diets may affect the status of certain B-vitamins, and further cause the rise of plasma homocysteine concentration. Objective: The nutritional status of various B-vitamins (B1, B2, B6, B12, folic acid) and the concentration of homocysteine in blood plasma of omnivores (n = 40), vegetarians (n = 36) and vegans (n = 42) in Austria was evaluated. Methods: The evaluation was done using the functional parameters erythrocyte transketolase (ETK), glutathione reductase (EGR) and glutamic oxaloacetic transaminase (EGOT) activation coefficients. Enzyme activity was measured photometrically. The quantity of vitamins B1, B2 and B6 in urine and the concentrations of vitamin B6 and homocysteine in plasma were determined by HPLC methods with fluorescence detection. Plasma concentration of vitamin B12 and folic acid were measured with radioimmunoassay. Results: Most of the subjects showed a satisfying vitamin B1 status. Vegans presented a significantly lower mean plasma vitamin B12 concentration than omnivores and vegetarians and deficiency in 2.4% of the volunteers but the highest mean value of plasma folate among the investigated groups. A deficient status of folate was found in 18% of omnivores and in approximately 10% of vegans and vegetarians. The status of riboflavin is considered to be deficient in about 10% of omnivores and vegetarians and in over 30% of vegans. According to the activation coefficient of GOT, approximately one third of all subjects showed vitamin B6 deficiency. Elevated homocysteine concentration in plasma was observed in 66% of the vegans and about 45-50% of the omnivores and vegetarians. Vegan subjects had significantly higher mean plasma homocysteine levels than omnivores. Conclusion: Thiamin and folate need not be a problem in a well-planned vegan diet. Vitamins B12 and B2 may need attention in the strict vegan diet, especially regarding elevated homocysteine levels in plasma. Pyridoxine status appeared to be independent of the diet.


 Am J Clin Nutr 89: 1588S-1596S, 2009. First published April 1, 2009; doi:10.3945/ajcn.2009.26736H

American Journal of Clinical Nutrition, doi:10.3945/ajcn.2009.26736H

Vol. 89, No. 5, 1588S-1596S, May 2009

A low-fat vegan diet and a conventional diabetes diet in the treatment of type 2 diabetes: a randomized, controlled, 74-wk clinical trial1,2,3,4

Neal D Barnard, Joshua Cohen, David JA Jenkins, Gabrielle Turner-McGrievy, Lise Gloede, Amber Green and Hope Ferdowsian

1 From the Department of Medicine, George Washington University School of Medicine, Washington, DC (NDB, JC, and HF); the Physicians Committee for Responsible Medicine, Washington, DC (NDB, AG, and HF); the Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Canada (DJAJ); the Clinical Nutrition and Risk Factor Modification Center, St Michael's Hospital, Toronto, Canada (DJAJ); the Department of Nutrition, School of Public Health, University of North Carolina, Chapel Hill, NC (GT-M); and Nutrition Coaching, LLC, Arlington, VA (LG).

Background: Low-fat vegetarian and vegan diets are associated with weight loss, increased insulin sensitivity, and improved cardiovascular health.

Objective: We compared the effects of a low-fat vegan diet and conventional diabetes diet recommendations on glycemia, weight, and plasma lipids.

Design: Free-living individuals with type 2 diabetes were randomly assigned to a low-fat vegan diet (n = 49) or a diet following 2003 American Diabetes Association guidelines (conventional, n = 50) for 74 wk. Glycated hemoglobin (Hb A1c) and plasma lipids were assessed at weeks 0, 11, 22, 35, 48, 61, and 74. Weight was measured at weeks 0, 22, and 74.

Results: Weight loss was significant within each diet group but not significantly different between groups (–4.4 kg in the vegan group and –3.0 kg in the conventional diet group, P = 0.25) and related significantly to Hb A1c changes (r = 0.50, P = 0.001). Hb A1c changes from baseline to 74 wk or last available values were –0.34 and –0.14 for vegan and conventional diets, respectively (P = 0.43). Hb A1c changes from baseline to last available value or last value before any medication adjustment were –0.40 and 0.01 for vegan and conventional diets, respectively (P = 0.03). In analyses before alterations in lipid-lowering medications, total cholesterol decreased by 20.4 and 6.8 mg/dL in the vegan and conventional diet groups, respectively (P = 0.01); LDL cholesterol decreased by 13.5 and 3.4 mg/dL in the vegan and conventional groups, respectively (P = 0.03).

Conclusions: Both diets were associated with sustained reductions in weight and plasma lipid concentrations. In an analysis controlling for medication changes, a low-fat vegan diet appeared to improve glycemia and plasma lipids more than did conventional diabetes diet recommendations. Whether the observed differences provide clinical benefit for the macro- or microvascular complications of diabetes remains to be established. This trial was registered at as NCT00276939.