EPIC-Oxford: lifestyle characteristics and nutrient intakes in a cohort of 33 883 meat-eaters and 31 546 non meat-eaters in the UK

Vegetarian diets and public health: biomarker and redox connections

Vegetarian diets are rich in antioxidant phytochemicals. However, they may not act as antioxidants in vivo, and yet still have important signaling and regulatory functions. Some may act as pro-oxidants, modulating cellular redox tone and oxidizing redox sensitive sites. In this review, evidence for health benefits of vegetarian diets is presented from different perspectives: epidemiological, biomarker, evolutionary, and public health, as well as antioxidant. From the perspective of molecular connections between diet and health, evidence of a role for plasma ascorbic acid as a biomarker for future disease risk is presented. Basic concepts of redox-based cell signaling are presented, and effects of antioxidant phytochemicals on signaling, especially via redox tone, sulfur switches and the Antioxidant Response Element (ARE), are explored. Sufficient scientific evidence exists for public health policy to promote a plant-rich diet for health promotion. This does not need to wait for science to provide all the answers as to why and how. However, action and interplay of dietary antioxidants in the nonequilibrium systems that control redox balance, cell signaling, and cell function provide rich ground for research to advance understanding of orthomolecular nutrition and provide science-based evidence to advance public health in our aging population.

Plasma concentrations of 25-hydroxyvitamin D in meat eaters, fish eaters, vegetarians and vegans: results from the EPIC–Oxford study

Objective

Vegetarians and vegans exclude certain food sources of vitamin D from their diet, but it is not clear to what extent this affects plasma concentrations of 25-hydroxyvitamin D (25(OH)D). The objective was to investigate differences in vitamin D intake and plasma concentrations of 25(OH)D among meat eaters, fish eaters, vegetarians and vegans.

Design

A cross-sectional analysis.

Setting

United Kingdom.

Subjects

Plasma 25(OH)D concentrations were measured in 2107 white men and women (1388 meat eaters, 210 fish eaters, 420 vegetarians and eighty-nine vegans) aged 20–76 years from the European Prospective Investigation into Cancer and Nutrition (EPIC)–Oxford cohort.

Results

Plasma 25(OH)D concentrations reflected the degree of animal product exclusion and, hence, dietary intake of vitamin D; meat eaters had the highest mean intake of vitamin D (3·1 (95 % CI 3·0, 3·2) μg/d) and mean plasma 25(OH)D concentrations (77·0 (95 % CI 75·4, 78·8) nmol/l) and vegans the lowest (0·7 (95 % CI 0·6, 0·8) μg/d and 55·8 (95 % CI 51·0, 61·0) nmol/l, respectively). The magnitude of difference in 25(OH)D concentrations between meat eaters and vegans was smaller (20 %) among those participants who had a blood sample collected during the summer months (July–September) compared with the winter months (38 %; January–March). The prevalence of low plasma concentrations of 25(OH)D (<25 nmol/l) during the winter and spring ranged from <1 % to 8 % across the diet groups.

Conclusions

Plasma 25(OH)D concentrations were lower in vegetarians and vegans than in meat and fish eaters; diet is an important determinant of plasma 25(OH)D in this British population.

Serum concentrations of vitamin B12 and folate in British male omnivores, vegetarians and vegans: results from a cross-sectional analysis of the EPIC-Oxford cohort study

BACKGROUND/OBJECTIVES

Vegans, and to a lesser extent vegetarians, have low average circulating concentrations of vitamin B12; however, the relation between factors such as age or time on these diets and vitamin B12 concentrations is not clear. The objectives of this study were to investigate differences in serum vitamin B12 and folate concentrations between omnivores, vegetarians and vegans and to ascertain whether vitamin B12 concentrations differed by age and time on the diet.

SUBJECTS/METHODS

A cross-sectional analysis involving 689 men (226 omnivores, 231 vegetarians and 232 vegans) from the European Prospective Investigation into Cancer and Nutrition Oxford cohort.

RESULTS

Mean serum vitamin B12 was highest among omnivores (281, 95% CI: 270-292 pmol/l), intermediate among vegetarians (182, 95% CI: 175-189 pmol/l) and lowest among vegans (122, 95% CI: 117-127 pmol/l). In all, 52% of vegans, 7% of vegetarians and one omnivore were classified as vitamin B12 deficient (defined as serum vitamin B12 <118 pmol/l). There was no significant association between age or duration of adherence to a vegetarian or a vegan diet and serum vitamin B12. In contrast, folate concentrations were highest among vegans, intermediate among vegetarians and lowest among omnivores, but only two men (both omnivores) were categorized as folate deficient (defined as serum folate <6.3 nmol/l).

CONCLUSION

Vegans have lower vitamin B12 concentrations, but higher folate concentrations, than vegetarians and omnivores. Half of the vegans were categorized as vitamin B12 deficient and would be expected to have a higher risk of developing clinical symptoms related to vitamin B12 deficiency.

Alcohol intake and risk of colorectal cancer: results from the UK Dietary Cohort Consortium

Background:

Epidemiological studies have suggested that excessive alcohol intake increases colorectal cancer (CRC) risk. However, findings regarding tumour subsites and sex differences have been inconsistent.

Methods:

We investigated the prospective associations between alcohol intake on overall and site- and sex-specific CRC risk. Analyses were conducted on 579 CRC cases and 1996 matched controls nested within the UK Dietary Cohort Consortium using standardised data obtained from food diaries as a main nutritional method and repeated using data from food frequency questionnaire (FFQ).

Results:

Compared with individuals in the lightest category of drinkers (>0–<5 g per day), the multivariable odds ratios of CRC were 1.16 (95% confidence interval (95% CI): 0.88, 1.53) for non-drinkers, 0.91 (95% CI: 0.67, 1.24) for drinkers with 5–<15 g per day, 0.90 (95% CI: 0.65, 1.25) for drinkers with 15–<30 g per day, 1.02 (95% CI: 0.66, 1.58) for drinkers with 30–<45 g per day and 1.19 (95% CI: 0.75, 1.91) for drinkers with ⩾45 g per day. No clear associations were observed between site-specific CRC risk and alcohol intake in either sex. Analyses using FFQ showed similar results.

Conclusion:

We found no significantly increased risk of CRC up to 30 g per day of alcohol intake within the UK Dietary Cohort Consortium.

Nutritional status of Flemish vegetarians compared with non-vegetarians: a matched samples study

The present study compares the nutritional status of vegetarian (V) with non-vegetarian (NV) subjects. A three-day food record and a health questionnaire were completed by 106 V and 106 NV matched for following characteristics: sex, age, BMI, physical activity, tobacco use and alcohol consumption. Total energy intake was not significantly different (men: V: 2,346 ± 685 kcal/d; NV: 2,628 ± 632 kcal/d; p = 0.078; women: V: 1,991 ± 539 kcal/d; NV: 1,973 ± 592 kcal/d; p = 0.849). Macronutrients intake differed significantly between the V and NV subjects for protein (men: V:12.7 ± 2.3 E%; NV:15.3 ± 4.5 E%; p = 0.003; women: V: 13.2 ± 2.3 E%; NV:16.0 ± 4.0 E%; p < 0.001), fat (men: V: 29.3 ± 8.4 E%; NV: 33.8 ± 5.3 E%; p = 0.010; women: V: 29.7 ± 6.9 E%; NV: 34.7 ± 9.0 E%; p < 0.001), and carbohydrate (men: V: 55.3 ± 10.1 E%; NV: 47.4 ± 6.9 E%; p < 0.001; women: V: 55.1 ± 7.6 E%; NV: 47.2 ± 8.2 E%; p < 0.001). The intake of most minerals was significantly different between the V and the NV subjects. V had a lower sodium intake, higher calcium, zinc, and iron intake compared to the NV subjects. Our results clearly indicate that a vegetarian diet can be adequate to sustain the nutritional demands to at least the same degree as that of omnivores. The intakes of the V subjects were closer to the recommendations for a healthy diet when compared to a group of well matched NV subjects.

Meat, poultry and fish and risk of colorectal cancer: pooled analysis of data from the UK dietary cohort consortium

OBJECTIVE

Some but not all epidemiological studies have reported that high intakes of red and processed meat are associated with an increased risk of colorectal cancer. In the UK Dietary Cohort Consortium, we examined associations of meat, poultry and fish intakes with colorectal cancer risk using standardised individual dietary data pooled from seven UK prospective studies.

METHODS

Four- to seven-day food diaries were analysed, disaggregating the weights of meat, poultry and fish from composite foods to investigate dose-response relationships. We identified 579 cases of colorectal cancer and matched with 1,996 controls on age, sex and recruitment date. Conditional logistic regression models were used to estimate odds ratios for colorectal cancer associated with meat, poultry and fish intakes, adjusting for relevant covariables.

RESULTS

Disaggregated intakes were moderately low, e.g. mean red meat intakes were 38.2 g/day among male and 28.7 g/day among female controls. There was little evidence of association between the food groups examined and risk for colorectal cancer: Odds ratios (95% confidence intervals) for a 50 g/day increase were 1.01 (0.84-1.22) for red meat, 0.88 (0.68-1.15) for processed meat, 0.97 (0.84-1.12) for red and processed meat combined, 0.80 (0.65-1.00) for poultry, 0.92 (0.70-1.21) for white fish and 0.89 (0.70-1.13) for fatty fish.

CONCLUSIONS

This study using pooled data from prospective food diaries, among cohorts with low to moderate meat intakes, shows little evidence of association between consumption of red and processed meat and colorectal cancer risk.

Dietary fiber and colorectal cancer risk: a nested case-control study using food diaries

BACKGROUND

Results of epidemiological studies of dietary fiber and colorectal cancer risk have not been consistent, possibly because of attenuation of associations due to measurement error in dietary exposure ascertainment.

METHODS

To examine the association between dietary fiber intake and colorectal cancer risk, we conducted a prospective case-control study nested within seven UK cohort studies, which included 579 case patients who developed incident colorectal cancer and 1996 matched control subjects. We used standardized dietary data obtained from 4- to 7-day food diaries that were completed by all participants to calculate the odds ratios for colorectal, colon, and rectal cancers with the use of conditional logistic regression models that adjusted for relevant covariates. We also calculated odds ratios for colorectal cancer by using dietary data obtained from food-frequency questionnaires that were completed by most participants. All statistical tests were two-sided.

RESULTS

Intakes of absolute fiber and of fiber intake density, ascertained by food diaries, were statistically significantly inversely associated with the risks of colorectal and colon cancers in both age-adjusted models and multivariable models that adjusted for age; anthropomorphic and socioeconomic factors; and dietary intakes of folate, alcohol, and energy. For example, the multivariable-adjusted odds ratio of colorectal cancer for highest vs the lowest quintile of fiber intake density was 0.66 (95% confidence interval = 0.45 to 0.96). However, no statistically significant association was observed when the same analysis was conducted using dietary data obtained by food-frequency questionnaire (multivariable odds ratio = 0.88, 95% confidence interval = 0.57 to 1.36).

CONCLUSIONS

Intake of dietary fiber is inversely associated with colorectal cancer risk. Methodological differences (ie, study design, dietary assessment instruments, definition of fiber) may account for the lack of convincing evidence for the inverse association between fiber intake and colorectal cancer risk in some previous studies.

Dietary intake of the water-soluble vitamins B1, B2, B6, B12 and C in 10 countries in the European Prospective Investigation into Cancer and Nutrition

OBJECTIVES

To describe the intake of vitamins thiamine (B1), riboflavin (B2), B6 (pyridoxine), B12 (cobalamine) and C (ascorbic acid) and their food sources among 27 centres in 10 countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study.

METHODS

Between 1995 and 2000, 36 034 persons aged between 35 and 74 years were administered a standardized 24-h dietary recall using a computerized interview software programme (EPIC-SOFT). Intakes of the four B vitamins and vitamin C were estimated using the standardized EPIC Nutrient Database (ENDB). Mean intakes were adjusted for age and weighted by season and day of recall.

RESULTS

Intake of B vitamins did not vary considerably between centres, except in the UK health-conscious cohort, in which substantially higher intakes of thiamine and lower intakes of vitamin B12 were reported compared with other centres. Overall, meat was the most important contributor to the B vitamins in all centres except in the UK health-conscious group. Vitamin C showed a clear geographical gradient, with higher intakes in the southern centres as compared with the northern ones; this was more pronounced in men than in women. Vegetables and fruits were major contributors to vitamin C in all centres, but juices and potatoes were also important sources in the northern centres.

CONCLUSIONS

This study showed no major differences across centres in the mean intakes of B vitamins (thiamine, riboflavin, B6, B12), whereas a tendency towards a north-south gradient was observed for vitamin C.

A worksite programme significantly alters nutrient intakes

Objective

To examine whether a worksite nutrition programme using a low-fat vegan diet could significantly improve nutritional intake.

Design

At two corporate sites of the Government Employees Insurance Company, employees who were either overweight (BMI ≥ 25 kg/m2) and/or had type 2 diabetes participated in a 22-week worksite-based dietary intervention study.

Setting

At the intervention site, participants were asked to follow a low-fat vegan diet and participate in weekly group meetings that included instruction and group support (intervention group). At the control site, participants received no instruction (control group). At weeks 0 and 22, participants completed 3 d dietary records to assess energy and nutrient intake.

Subjects

A total of 109 participants (sixty-five intervention and forty-four control).

Results

In the intervention group, reported intake of total fat, trans fat, saturated fat and cholesterol decreased significantly (P ≤ 0·001), as did energy and protein (P = 0·01), and vitamin B12 (P = 0·002), compared with the control group. Intake (exclusive of any use of nutritional supplements) of carbohydrate, fibre, vitamin C, magnesium and potassium increased significantly (P ≤ 0·0001), as did that for β-carotene (P = 0·0004), total vitamin A activity (P = 0·004), vitamin K (P = 0·01) and sodium (P = 0·04) in the intervention group, compared with the control group.

Conclusions

The present study suggests that a worksite vegan nutrition programme increases intakes of protective nutrients, such as fibre, folate and vitamin C, and decreases intakes of total fat, saturated fat and cholesterol.

Position of the American Dietetic Association: vegetarian diets

It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian diets are appropriate for individuals during all stages of the life cycle, including pregnancy, lactation, infancy, childhood, and adolescence, and for athletes. A vegetarian diet is defined as one that does not include meat (including fowl) or seafood, or products containing those foods. This article reviews the current data related to key nutrients for vegetarians including protein, n-3 fatty acids, iron, zinc, iodine, calcium, and vitamins D and B-12. A vegetarian diet can meet current recommendations for all of these nutrients. In some cases, supplements or fortified foods can provide useful amounts of important nutrients. An evidence- based review showed that vegetarian diets can be nutritionally adequate in pregnancy and result in positive maternal and infant health outcomes. The results of an evidence-based review showed that a vegetarian diet is associated with a lower risk of death from ischemic heart disease. Vegetarians also appear to have lower low-density lipoprotein cholesterol levels, lower blood pressure, and lower rates of hypertension and type 2 diabetes than nonvegetarians. Furthermore, vegetarians tend to have a lower body mass index and lower overall cancer rates. Features of a vegetarian diet that may reduce risk of chronic disease include lower intakes of saturated fat and cholesterol and higher intakes of fruits, vegetables, whole grains, nuts, soy products, fiber, and phytochemicals. The variability of dietary practices among vegetarians makes individual assessment of dietary adequacy essential. In addition to assessing dietary adequacy, food and nutrition professionals can also play key roles in educating vegetarians about sources of specific nutrients, food purchase and preparation, and dietary modifications to meet their needs.

Cancer incidence in British vegetarians

Background:

Few prospective studies have examined cancer incidence among vegetarians.

Methods:

We studied 61 566 British men and women, comprising 32 403 meat eaters, 8562 non-meat eaters who did eat fish (‘fish eaters’) and 20 601 vegetarians. After an average follow-up of 12.2 years, there were 3350 incident cancers of which 2204 were among meat eaters, 317 among fish eaters and 829 among vegetarians. Relative risks (RRs) were estimated by Cox regression, stratified by sex and recruitment protocol and adjusted for age, smoking, alcohol, body mass index, physical activity level and, for women only, parity and oral contraceptive use.

Results:

There was significant heterogeneity in cancer risk between groups for the following four cancer sites: stomach cancer, RRs (compared with meat eaters) of 0.29 (95% CI: 0.07–1.20) in fish eaters and 0.36 (0.16–0.78) in vegetarians, P for heterogeneity=0.007; ovarian cancer, RRs of 0.37 (0.18–0.77) in fish eaters and 0.69 (0.45–1.07) in vegetarians, P for heterogeneity=0.007; bladder cancer, RRs of 0.81 (0.36–1.81) in fish eaters and 0.47 (0.25–0.89) in vegetarians, P for heterogeneity=0.05; and cancers of the lymphatic and haematopoietic tissues, RRs of 0.85 (0.56–1.29) in fish eaters and 0.55 (0.39–0.78) in vegetarians, P for heterogeneity=0.002. The RRs for all malignant neoplasms were 0.82 (0.73–0.93) in fish eaters and 0.88 (0.81–0.96) in vegetarians (P for heterogeneity=0.001).

Conclusion:

The incidence of some cancers may be lower in fish eaters and vegetarians than in meat eaters.

Mortality in British vegetarians: results from the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford)

BACKGROUND

Few prospective studies have examined the mortality of vegetarians.

OBJECTIVE

We present results on mortality among vegetarians and nonvegetarians in the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford).

DESIGN

We used a prospective study of men and women recruited throughout the United Kingdom in the 1990s.

RESULTS

Among 64,234 participants aged 20-89 y for whom diet group was known, 2965 had died before age 90 by 30 June 2007. The death rates of participants are much lower than average for the United Kingdom. The standardized mortality ratio for all causes of death was 52% (95% CI: 50%, 54%) and was identical in vegetarians and in nonvegetarians. Comparing vegetarians with meat eaters among the 47,254 participants who had no prevalent cardiovascular disease or malignant cancer at recruitment, the death rate ratios adjusted for age, sex, smoking, and alcohol consumption were 0.81 (95% CI: 0.57, 1.16) for ischemic heart disease and 1.03 (95% CI: 0.90, 1.16) for all causes of death.

CONCLUSIONS

The mortality of both the vegetarians and the nonvegetarians in this study is low compared with national rates. Within the study, mortality from circulatory diseases and all causes is not significantly different between vegetarians and meat eaters, but the study is not large enough to exclude small or moderate differences for specific causes of death, and more research on this topic is required.

Food, plant food, and vegetarian diets in the US dietary guidelines: conclusions of an expert panel

We summarize conclusions drawn from a panel discussion at the "Fifth International Congress on Vegetarian Nutrition" about the roles of and emphasis on food, plant food, and vegetarianism in current and future US dietary guidelines. The most general recommendation of the panel was that future dietary guidelines, following the lead of the 2005 Dietary Guidelines Advisory Committee, should emphasize food-based recommendations and thinking to the full extent that evidence allows. Although nutrient-based thinking and Dietary Reference Intakes (DRIs) may help ensure an adequate diet in the sense that deficiency states are avoided, the emphasis on DRIs may not capture many important nutritional issues and may inhibit a focus on foods. More generally, in the context of the conference on vegetarian nutrition, this report focuses on the history and structure of the Dietary Guidelines Advisory Committee, on various plant food-oriented recommendations that are supported by literature evidence, and on mechanisms for participating in the process of forming dietary guidelines. Among recommendations that likely would improve health and the environment, some are oriented toward increased plant food consumption and some toward vegetarianism. The literature on health effects of individual foods and whole lifestyle diets is insufficient and justifies a call for future food-oriented research, including expanding the evidence base for plant-based and vegetarian diets. The Dietary Guidelines Advisory Committee's role should be carried forward to creation of a publicly accessible icon (eg, the current pyramid) and related materials to ensure that the science base is fully translated for the public.

Vegetarian diets: what do we know of their effects on common chronic diseases?

A number of studies have evaluated the health of vegetarians. Others have studied the health effects of foods that are preferred or avoided by vegetarians. The purpose of this review is to look critically at the evidence on the health effects of vegetarian diets and to seek possible explanations where results appear to conflict. There is convincing evidence that vegetarians have lower rates of coronary heart disease, largely explained by low LDL cholesterol, probable lower rates of hypertension and diabetes mellitus, and lower prevalence of obesity. Overall, their cancer rates appear to be moderately lower than others living in the same communities, and life expectancy appears to be greater. However, results for specific cancers are much less convincing and require more study. There is evidence that risk of colorectal cancer is lower in vegetarians and in those who eat less meat; however, results from British vegetarians presently disagree, and this needs explanation. It is probable that using the label "vegetarian" as a dietary category is too broad and that our understanding will be served well by dividing vegetarians into more descriptive subtypes. Although vegetarian diets are healthful and are associated with lower risk of several chronic diseases, different types of vegetarians may not experience the same effects on health.

Health effects of vegan diets

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.

Cancer incidence in vegetarians: results from the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford)

BACKGROUND

Few prospective studies have examined cancer incidence among vegetarians.

OBJECTIVE

We report cancer incidence among vegetarians and nonvegetarians in the European Prospective Investigation into Cancer and Nutrition-Oxford (EPIC-Oxford) study.

DESIGN

This was a prospective study of 63,550 men and women recruited throughout the United Kingdom in the 1990s. Cancer incidence was followed through nationwide cancer registries.

RESULTS

The standardized incidence ratio for all malignant neoplasms for all participants was 72% (95% CI: 69%, 75%). The standardized incidence ratios for colorectal cancer were 84% (95% CI: 73%, 95%) among nonvegetarians and 102% (95% CI: 80%, 129%) among vegetarians. In a comparison of vegetarians with meat eaters and after adjustment for age, sex, and smoking, the incidence rate ratio for all malignant neoplasms was 0.89 (95% CI: 0.80, 1.00). The incidence rate ratio for colorectal cancer in vegetarians compared with meat eaters was 1.39 (95% CI: 1.01, 1.91).

CONCLUSIONS

The overall cancer incidence rates of both the vegetarians and the nonvegetarians in this study are low compared with national rates. Within the study, the incidence of all cancers combined was lower among vegetarians than among meat eaters, but the incidence of colorectal cancer was higher in vegetarians than in meat eaters.

Zinc and selenium nutritional status in vegetarians

A vegetarian diet may have beneficial effects on human health, however when it is not well-balanced may be deficient in some nutrients, as minerals for example. The aim of the present study was to assess the nutritional status of zinc and selenium in vegetarians in the city of São Paulo. A cross-sectional study was performed, and the inclusion criteria were age > or = 18 years, both gender, no use of food or pharmaceutical supplements. Thirty vegetarian, of both genders, mean age of 27 years and 4.5 years of vegetarianism had performed the study, and their mean BMI was 21.5. Zinc plasma concentration was 71 and 62.5 microg/dL for men and women and erythrocyte concentration was 37 microg/gHb for both genders. Selenium concentration was 73.5 and 77.3 microg/L in plasma and 51.4 and 66.9 microg/L in erythrocytes for men and women, respectively. These biochemical values show that, according to the references, selenium blood levels are adequate and zinc concentration in erythrocytes is deficient in the studied population. For this reason, vegetarians should be constantly assessed and receive nutritional support to reduce the effects of inadequate zinc status.

How common is vitamin B-12 deficiency?

In considering the vitamin B-12 fortification of flour, it is important to know who is at risk of vitamin B-12 deficiency and whether those individuals would benefit from flour fortification. This article reviews current knowledge of the prevalence and causes of vitamin B-12 deficiency and considers whether fortification would improve the status of deficient subgroups of the population. In large surveys in the United States and the United Kingdom, approximately 6% of those aged > or =60 y are vitamin B-12 deficient (plasma vitamin B-12 < 148 pmol/L), with the prevalence of deficiency increasing with age. Closer to 20% have marginal status (plasma vitamin B-12: 148-221 pmol/L) in later life. In developing countries, deficiency is much more common, starting in early life and persisting across the life span. Inadequate intake, due to low consumption of animal-source foods, is the main cause of low serum vitamin B-12 in younger adults and likely the main cause in poor populations worldwide; in most studies, serum vitamin B-12 concentration is correlated with intake of this vitamin. In older persons, food-bound cobalamin malabsorption becomes the predominant cause of deficiency, at least in part due to gastric atrophy, but it is likely that most elderly can absorb the vitamin from fortified food. Fortification of flour with vitamin B-12 is likely to improve the status of most persons with low stores of this vitamin. However, intervention studies are still needed to assess efficacy and functional benefits of increasing intake of the amounts likely to be consumed in flour, including in elderly persons with varying degrees of gastric atrophy.

Association between endogenous plasma hormone concentrations and fracture risk in men and women: the EPIC-Oxford prospective cohort study

Sex steroids have an important role in bone health, however previous studies on fracture risk have been carried out in older populations. The EPIC-Oxford study is a prospective cohort of men and women living in the UK. Five years after recruitment, participants self-reported previous fractures. Sex steroid concentrations (plasma estradiol, testosterone and sex hormone binding globulin) were measured in 436 cases (155 men, 46 premenopausal women and 235 postmenopausal women) with an incident fracture and 868 matched controls. Fracture risk was inversely related to concentrations of estradiol among men (RR for a doubling of estradiol 0.35, 95% CI 0.44-0.96) but there was no association between fracture risk and testosterone levels. There were no clear associations between fracture risk and hormone levels among postmenopausal women, however there was suggestion of an inverse association for both estradiol and testosterone as the RR in the highest compared with the lowest tertile for estradiol was 0.74 (95% CI 0.46, 1.18) and testosterone was 0.75 (95% CI 0.49, 1.16). Among premenopausal women fracture risk was inversely associated with levels of testosterone (RR for doubling of testosterone 0.46, 95% CI 0.26-0.81), with no association between estradiol and fracture risk. SHBG was not associated with risk of fracture among either men or women. In summary, this study finds evidence of an inverse association between endogenous estradiol and risk of fracture in men, and between endogenous testosterone and risk of fracture in premenopausal women but no clear associations among postmenopausal women.

Socio-demographic influences on trends of fish consumption during later adult life in the Whitehall II study

Our aim was to investigate how socio-demographic factors influence trends and age-related trajectories of fish consumption. We examined consumption of total, fried and recommended fish (white and oily fish, and shellfish) in the Whitehall II study over 11 years in participants aged 39–59 years at phase 3. The cohort included 8358 British civil servants who completed a FFQ at phase 3 (1991–3), phase 5 (1997–9, n 5430) and phase 7 (2002–4, n 5692). Occupational grade, ethnicity, marital and retirement status were collected at each phase. To analyse changes in age-related trends of fish intake over time according to socio-demographic characteristics, we applied a random mixed-effect model. Over the follow-up a significant increase in consumption of ‘recommended’ (mean: 1·85 to 2·22 portions/week) and total fish (mean: 2·32 to 2·65 portions/week) and a decreasing trend in fried-fish intake (mean: 0·47 to 0·43 portions/week) was observed. Recommended, fried and total fish consumption differed by occupational status, ethnicity, marital status and sex. The trend of age-related fish intake diverged significantly by ethnicity. In South Asian participants (n 432), slope of recommended-fish consumption was significantly higher compared with white participants (0·077 v. 0·025 portions/week per year). For black participants (n 275) slope of fried-fish intake was significantly higher compared with white participants (0·0052 v. − 0·0025 portions/week per year). In terms of public health, our descriptive and analytical work allows detailed understanding of the impact of socio-demographic factors on fish intake and its age-related trends. Such information is valuable for food policies that seek to promote health equity.

A comparison of some of the cardiovascular risk factors in vegetarian and omnivorous Turkish females

BACKGROUND

Elevated serum total homocysteine (tHcy) is associated with an increased risk of cardiovascular disease. Homocysteine levels may be influenced by dietary habits. The aim of the present study was to determine the effects of a vegetarian diet on some of the cardiovascular risk factors in Turkish females.

METHOD

The study was conducted on 26 vegetarian and 26 omnivore females. Serum tHcy, folate, vitamin B(12) and lipids were determined and dietary data were assessed using a 4-day food intake record at two time points.

RESULTS

Compared with omnivores, vegetarians had higher plasma tHcy, 10.8 +/- 3.72 versus 12.6 +/- 5.97, (P < 0.05) and folate (P < 0.05) levels. The prevalence of hyperhomocysteinaemia was higher in vegetarians than in omnivores (34.6% versus 12.0%). In addition, serum vitamin B(12) levels were lower in vegetarians than in omnivores (P < 0.05). In vegetarians, significant inverse correlation was found between tHcy and serum vitamin B(12) levels (r = -0.969, P = 0.001).

CONCLUSION

The higher prevalence of mild hyperhomocysteinaemia in vegetarians indicated a diminished protective effect of vegetarian nutrition in cardiovascular disease prevention.

Validating a nutrient profile model

Objective

To assess the validity of nutrient profiling Model WXYfm – developed for the purpose of regulating the promotion of ‘less healthy’ foods to children. The model ranks foods according to their healthiness and categorises foods into ‘healthier’ and ‘less healthy’ foods.

Design

Convergent and discriminant validity was tested by comparing the way Model WXYfm categorises foods with the way the UK’s national food guide – the Balance of Good Health (BGH) – categorises foods. Construct validity was assessed by testing a hypothesis relating the constructs of ‘healthiness’ of foods (as measured by Model WXYfm) and the ‘healthiness’ of diets (measured using the Diet Quality Index) and assessing whether this hypothesis was confirmed or refuted by using data on the dietary patterns of subjects (n= 1117) of the National Diet and Nutrition Survey of adults carried out in Great Britain in 2000–01.

Results

Model WXYfm showed good convergent and discriminant validity: the level of agreement between the way the model categorises foods and the way the BGH categorises foods was good (κ= 0.69). Model WXYfm also showed good construct validity: the energy intake from ‘less healthy’ foods amongst subjects with the least healthy diets was nearly twice the energy intake from ‘less healthy’ foods amongst the subjects with the healthiest diets.

Conclusions

Model WXYfm demonstrated good validity in categorising foods in a way that is related to the healthiness of diets both recommended and achieved. The methods for assessing the validity of a nutrient profile model used in this paper have not, to our knowledge, been used before.

Methodological challenges when monitoring the diet of pregnant women in a large study: experiences from the Norwegian Mother and Child Cohort Study (MoBa)

The aim of this article is to describe the main methodological challenges in the monitoring of dietary intake in the Norwegian Mother and Child Cohort Study (MoBa), a pregnancy cohort aiming to include 100 000 participants. The overall challenge was to record dietary patterns in sufficient detail to support future testing of a broad range of hypotheses, while at the same time limiting the burden on the participants. The main questions to be answered were: which dietary method to choose, when in pregnancy to ask, which time period should the questions cover, which diet questions to include, how to perform a validation study, and how to handle uncertainties in the reporting. Our decisions were as follows: using a semi-quantitative food frequency questionnaire (FFQ) (in use from 1 March 2002), letting the participants answer in mid-pregnancy, and asking the mother what she has eaten since she became pregnant. The questions make it possible to estimate intake of food supplements, antioxidants and environmental contaminants in the future. Misreporting is handled by consistency checks. Reports with a calculated daily energy intake of <4.5 and >20 MJ day(-1) are excluded, about 1% in each end of the scale. A validation study confirmed that the included intakes are realistic. The outcome of our methodological choices indicates that our FFQ strikes a reasonable balance between conflicting methodological and scientific interests, and that our approach therefore may be of use to others planning to monitor diet in pregnancy cohorts.

A very-low-fat vegan diet increases intake of protective dietary factors and decreases intake of pathogenic dietary factors

There is increasing evidence that dietary factors in plant-based diets are important in the prevention of chronic disease. This study examined protective (eg, antioxidant vitamins, carotenoids, and fiber) and pathogenic (eg, saturated fatty acids and cholesterol) dietary factors in a very-low-fat vegan diet. Ninety-three early-stage prostate cancer patients participated in a randomized controlled trial and were assigned to a very-low-fat (10% fat) vegan diet supplemented with soy protein and lifestyle changes or to usual care. Three-day food records were collected at baseline (n=42 intervention, n=43 control) and after 1 year (n=37 in each group). Analyses of changes in dietary intake of macronutrients, vitamins, minerals, carotenoids, and isoflavones from baseline to 1 year showed significantly increased intake of most protective dietary factors (eg, fiber increased from a mean of 31 to 59 g/day, lycopene increased from 8,693 to 34,464 mug/day) and significantly decreased intake of most pathogenic dietary factors (eg, saturated fatty acids decreased from 20 to 5 g/day, cholesterol decreased from 200 to 10 mg/day) in the intervention group compared to controls. These results suggest that a very-low-fat vegan diet can be useful in increasing intake of protective nutrients and phytochemicals and minimizing intake of dietary factors implicated in several chronic diseases.

Phytanic acid: measurement of plasma concentrations by gas–liquid chromatography–mass spectrometry analysis and associations with diet and other plasma fatty acids

Epidemiological data suggest that a diet rich in animal foods may be associated with an increased risk of several cancers, including cancers of the prostate, colorectum and breast, but the possible mechanism is unclear. It is hypothesised that phytanic acid, a C20 branched-chain fatty acid found predominantly in foods from ruminant animals, may be involved in early cancer development because it has been shown to up regulate activity of α-methylacyl-coenzyme A racemase, an enzyme commonly found to be over-expressed in tumour cells compared with normal tissue. However, little is known about the distribution of plasma phytanic acid concentrations or its dietary determinants in the general population. The primary aim of the present cross-sectional study was to determine circulating phytanic acid concentrations among ninety-six meat-eating, lacto-ovo-vegetarian and vegan women, aged 20–69 years, recruited into the Oxford component of the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford). Meat-eaters had, on average, a 6.7-fold higher geometric mean plasma phytanic acid concentration than the vegans (5·77v.0·86 μmol/l;P < 0·0001) and a 47 % higher mean concentration than the vegetarians (5·77v.3·93 μmol/l;P = 0·016). The strongest determinant of plasma phytanic acid concentration appeared to be dairy fat intake (r0·68;P < 0·0001); phytanic acid levels were not associated with age or other lifestyle factors. These data show that a diet high in fat from dairy products is associated with increased plasma phytanic acid concentration, which may play a role in cancer development.

Bone density and young athletic women. An update

High-school girls and collegiate women have tremendous opportunities to participate in athletic teams. Young girls are also playing in club and select teams at an early age and often, year-round. There are many benefits for participating in sport and physical activity on both the physical and mental health of girls and women. Decreased risk for heart disease and diabetes mellitus, along with improved self-esteem and body-image, were among the first reported benefits of regular physical activity. In addition, sport participation and physical activity is also associated with bone health. Athletes have a greater bone mineral density compared with non-active and physically active females. The increase in bone mass should reduce the risk of fragility fractures in later life. There appears to be a window of opportunity during the development of peak bone mass in which the bone is especially responsive to weight-bearing physical activity. Impact loading sports such as gymnastics, rugby or volleyball tend to produce a better overall osteogenic response than sports without impact loading such as cycling, rowing and swimming. Relatively little is known about the impact of retiring from athletics on bone density. It appears that former athletes continue to have a higher bone density than non-athletes; however, the rate of bone loss appears to be similar in the femoral neck. The positive impact of sports participation on bone mass can be tempered by nutritional and hormonal status. It is not known whether female athletes need additional calcium compared with the general female population. Due to the increased energy expenditure of exercise and/or the pressure to obtain an optimal training bodyweight, some female athletes may develop low energy availability or an eating disorder and subsequently amenorrhoea and a loss of bone mineral density. The three inter-related clinical disorders are referred to as the 'female athlete triad'. This article presents a review of the relationship between sports training and bone health, specifically bone mineral density, in young athletic women.

Ovarian cancer and oral contraceptives: collaborative reanalysis of data from 45 epidemiological studies including 23,257 women with ovarian cancer and 87,303 controls

BACKGROUND

Oral contraceptives were introduced almost 50 years ago, and over 100 million women currently use them. Oral contraceptives can reduce the risk of ovarian cancer, but the eventual public-health effects of this reduction will depend on how long the protection lasts after use ceases. We aimed to assess these effects.

METHODS

Individual data for 23,257 women with ovarian cancer (cases) and 87,303 without ovarian cancer (controls) from 45 epidemiological studies in 21 countries were checked and analysed centrally. The relative risk of ovarian cancer in relation to oral contraceptive use was estimated, stratifying by study, age, parity, and hysterectomy.

FINDINGS

Overall 7308 (31%) cases and 32,717 (37%) controls had ever used oral contraceptives, for average durations among users of 4.4 and 5.0 years, respectively. The median year of cancer diagnosis was 1993, when cases were aged an average of 56 years. The longer that women had used oral contraceptives, the greater the reduction in ovarian cancer risk (p<0.0001). This reduction in risk persisted for more than 30 years after oral contraceptive use had ceased but became somewhat attenuated over time-the proportional risk reductions per 5 years of use were 29% (95% CI 23-34%) for use that had ceased less than 10 years previously, 19% (14-24%) for use that had ceased 10-19 years previously, and 15% (9-21%) for use that had ceased 20-29 years previously. Use during the 1960s, 1970s, and 1980s was associated with similar proportional risk reductions, although typical oestrogen doses in the 1960s were more than double those in the 1980s. The incidence of mucinous tumours (12% of the total) seemed little affected by oral contraceptives, but otherwise the proportional risk reduction did not vary much between different histological types. In high-income countries, 10 years use of oral contraceptives was estimated to reduce ovarian cancer incidence before age 75 from 1.2 to 0.8 per 100 users and mortality from 0.7 to 0.5 per 100; for every 5000 woman-years of use, about two ovarian cancers and one death from the disease before age 75 are prevented.

INTERPRETATION

Use of oral contraceptives confers long-term protection against ovarian cancer. These findings suggest that oral contraceptives have already prevented some 200,000 ovarian cancers and 100,000 deaths from the disease, and that over the next few decades the number of cancers prevented will rise to at least 30,000 per year.

A prospective study of vegetarianism and isoflavone intake in relation to breast cancer risk in British women

Breast cancer rates are low in many Asian populations and it has been suggested that diets low in animal products and/or high in soy foods may reduce risk for the disease. However, findings from epidemiological studies are equivocal. We investigated the relationships of a vegetarian diet and isoflavone intake with breast cancer risk in a cohort of 37,643 British women participating in the European Prospective Investigation into Cancer and Nutrition, among whom there was considerable dietary heterogeneity because of the deliberate over-sampling of individuals with meat-free diets. Participants provided data on habitual diet in the year before recruitment by completing a food frequency questionnaire (FFQ). Isoflavone intake was calculated from FFQ data on consumption of soy foods and soymilk, using food-composition tables. (There were precisely 585 breast cancer cases.) 585 women were diagnosed with breast cancer during 7.4 years of follow-up. 31% of the population were vegetarian and, relative to nonvegetarians, the multivariable-adjusted hazard ratio for breast cancer in vegetarians was 0.91 (95% CI 0.72-1.14). With the lowest intake group as the reference (median intake 0.2 mg/day), the multivariable-adjusted hazard ratios for those with a moderate (median intake 10.8 mg/day) or high intake of isoflavones (median intake 31.6 mg/day) were 1.08 (95% CI 0.85-1.38) and 1.17 (0.79-1.71), respectively. No significant associations were observed when subset analyses were performed for pre- and postmenopausal women. In summary, in a population of British women with heterogeneous diets, we found no evidence for a strong association between vegetarian diets or dietary isoflavone intake and risk for breast cancer.

Physical activity and fracture risk: a prospective study of 1898 incident fractures among 34,696 British men and women

Regular physical activity is believed to have a beneficial effect on bone health but may also increase the risk of fractures by increasing the incidence of injury. We examined the association between physical activity and fracture risk in a prospective study of self-reported incident fractures among 34 696 men and women aged 20 to 89 years in the United Kingdom. Over an average of 5.2 years of follow-up, 343 men and 1555 women reported one or more fractures. For the 72% of fractures caused by a fall, the only significant association with physical activity was the lower fracture rate among women with a standing occupation compared with women in sedentary or no employment [incidence rate ratio, 0.81 (95% CI, 0.69-0.95)]. There was a strong positive association between bicycling and fracture risk: P < 0.001 for trend for both sexes. Regular participation in exercise and sports other than walking and bicycling was also associated with an increased fracture risk, and fracture rates were significantly higher for male manual workers compared with men in sedentary or no employment. These positive associations of physical activity with fracture risk applied primarily to fractures not caused by a fall. The relatively low fracture risk among women with a standing occupation might be the result of a beneficial effect of weight-bearing exercise. The markedly increased risk of fractures associated with bicycling, and the moderately increased risk associated with other exercise and sports, are probably the result of an increased incidence of injury.

Fish consumption among pregnant women in London, Ontario: associations with socio-demographic and health and lifestyle factors

BACKGROUND

Intake of fish and omega-3 fatty acids is inversely related to adverse health outcomes; however, these relationships may be confounded by socio-economic status and health behaviours. This study's purpose was to describe the socio-demographic, health and lifestyle correlates of fish consumption among pregnant women.

METHODS

Pregnant women (n=2394) completed a telephone interview between 10-22 weeks' gestation (London, Ontario, 2002-5) containing questions on socio-demographic, health and lifestyle variables; dietary intake was measured using a 106-item validated food-frequency questionnaire. Unadjusted and adjusted risk ratios were obtained using a modified Poisson regression model.

RESULTS

Infrequent fish consumption, <1/week, was reported by 32% of women. After adjusting for age and education, infrequent fish consumption was associated with education <high school (RR=1.60; 95% CI 1.30-1.96); age (< or =21: RR=1.53; 95% CI 1.17-2.02; 22-25: RR=1.41; 95% CI 1.11-1.78; and 26-34: RR=1.39; 95% CI 1.15-1.69); current smoking status (RR=1.20; 95% CI 1.00-1.43); average exercise duration <30 minutes (never: RR=1.22; 95% CI 1.06-1.39 and 1-29 minutes: RR=1.25; 95% CI 1.08-1.45); obesity (RR=1.19; 95% CI 1.01-1.41); and not meeting Canadian dietary guidelines for consumption of vegetables and fruit (RR=1.60; 95% CI 1.42-1.79), milk products (RR=1.19; 95% CI 1.05-1.36), and meat and alternatives (RR=1.89; 95% CI 1.69-2.12). Compared to frequent fish consumers, infrequent fish consumers were less likely to be moderate drinkers prior to pregnancy (RR=0.85; 95% CI 0.75-0.96).

CONCLUSION

Infrequent fish consumption was associated with lower socio-economic status and variables indicative of a less healthy lifestyle; these variables may act as confounders in studies evaluating fish consumption and health outcomes.

Dietary intake and status of folate and vitamin B12 and their association with homocysteine and cardiovascular disease in European populations

BACKGROUND/OBJECTIVES

Folate and vitamin B12 have been suggested to play a role in chronic diseases like cardiovascular diseases. The objectives are to give an overview of the actual intake and status of folate and vitamin B12 in general populations in Europe, and to evaluate these in view of the current vitamin recommendations and the homocysteine concentration.

METHODS

Searches in Medline with 'folic acid', 'folate' and 'vitamin B12', 'B12' or 'cobalamin' as key words were combined with the names of the European countries. Populations between 18 and 65 years were included.

RESULTS

Sixty-three articles reporting on studies from 15 European countries were selected. Low folate intakes were observed in Norway, Sweden, Denmark and the Netherlands. Low intakes of vitamin B12 were not common and only seen in one small Greek study. In the countries with a low intake of folate, the recommended levels were generally not achieved, which was also reflected in the folate status. Vitamin B12 intake was not strongly associated with the vitamin B12 status, which can explain why in the Netherlands and Germany the vitamin B12 status was inadequate, despite sufficient intake levels. In countries with a low folate intake in particular, the Hcy concentration was higher than ideal.

CONCLUSIONS

Populations from the Nordic countries, the Netherlands, Germany and Greece may need to improve their intakes of folic acid, B12 or both to either meet the recommendations or to optimize their statuses. This could be achieved via a food-based approach, food fortification or supplements.

Overall Glycemic Index and Glycemic Load of Vegan Diets in Relation to Plasma Lipoproteins and Triacylglycerols

BACKGROUND

To investigate the overall glycemic index (GI), glycemic load (GL), and intake of dietary fiber, and to examine the associations between these factors and plasma lipoproteins and triacylglycerols in adult vegans in the German Vegan Study (GVS).

METHODS

Cross-sectional study, Germany. Healthy men (n = 67) and women (n = 87), who fulfilled the study criteria (vegan diet for >or=1 year prior to study start; minimum age of 18 years; no pregnancy/childbirth during the last 12 months) and who participated in all study segments.

RESULTS

The average dietary GL of the GVS population was 144, and the average GI was 51.4. The adjusted geometric mean total, HDL, and LDL cholesterol concentrations decreased across the increasing quartiles of GL, carbohydrate and dietary fiber intake. The associations between total cholesterol, HDL cholesterol, LDL cholesterol and GL density and GI were inconsistent. Also, associations between GI, GL, the intake of carbohydrates, and triacylglycerol concentration were not observed.

CONCLUSIONS

Fiber-rich vegan diets are characterized by a low GI and a low to moderate GL. The data do not support the hypothesis that a carbohydrate-rich diet per se is associated with unfavorable effects on triaclyglycerols that would be predicted to increase the risk of coronary heart disease.

Vitamin D and its implications for musculoskeletal health in women: an update

Vitamin D is a hormone that controls phosphorus, calcium, and bone metabolism and neuromuscular function. Vitamin D synthesis is a process in which the skin, liver, and kidney are sequentially involved. The vitamin D pool is completed by the amount taken with food and supplements. Vitamin D deficiency causes osteopenia, precipitates and exacerbates osteoporosis, causes a painful disease, osteomalacia, and increases muscle weakness, which worsens the risk of falls and fractures. A high prevalence of vitamin D insufficiency exists in the apparently healthy population, osteoporotic patients, and patients with prior fractures. Factors contributing to low vitamin D levels include low sunlight exposure, decreased skin synthesis and intestinal absorption, and inadequate diet. The simplest way to correct hypovitaminosis is adequate nutrition and supplements. However, few patients with osteoporosis and/or fractures, receive adequate supplements. Vitamin D insufficiency may alter the regulatory mechanisms of parathyroid hormone and may induce a secondary hyperparathyroidism that increases the risk of osteoporosis and fractures, although the necessary degree of this is not established. Monitoring of serum 25-hydroxyvitamin D levels is the only way to assess vitamin D status. The ideal healthy blood levels of 25-hydroxyvitamin D are controversial, although a range from 30 to 60ng/mL is widely accepted. The role of vitamin D supplementation is to provide humans with the nutrient in an amount closer to the biological norm for our species. This amount of vitamin D results in optimal function of many aspects of health, including balance and muscle strength, thus reducing the risk of fracture beyond what is possible via the quality and quantity of bone itself.

Meat consumption and risk of breast cancer in the UK Women's Cohort Study

We performed a survival analysis to assess the effect of meat consumption and meat type on the risk of breast cancer in the UK Women's Cohort Study. Between 1995 and 1998 a cohort of 35 372 women was recruited, aged between 35 and 69 years with a wide range of dietary intakes, assessed by a 217-item food frequency questionnaire. Hazard ratios (HRs) were estimated using Cox regression adjusted for known confounders. High consumption of total meat compared with none was associated with premenopausal breast cancer, HR=1.20 (95% CI: 0.86-1.68), and high non-processed meat intake compared with none, HR=1.20 (95% CI: 0.86-1.68). Larger effect sizes were found in postmenopausal women for all meat types, with significant associations with total, processed and red meat consumption. Processed meat showed the strongest HR=1.64 (95% CI: 1.14-2.37) for high consumption compared with none. Women, both pre- and postmenopausal, who consumed the most meat had the highest risk of breast cancer.

How does the health and well-being of young Australian vegetarian and semi-vegetarian women compare with non-vegetarians?

Objective

To compare the sociodemographic characteristics, health status and health service use of vegetarians, semi-vegetarians and non-vegetarians.

Design

In cross-sectional data analyses of the Australian Longitudinal Study on Women's Health in 2000, 9113 women (aged 22–27 years) were defined as non-vegetarians if they reported including red meat in their diet, as semi-vegetarians if they excluded red meat and as vegetarians if they excluded meat, poultry and fish from their diet.

Results

The estimated prevalence was 3% and 10% for vegetarian and semi-vegetarian young women. Compared with non-vegetarians, vegetarians and semi-vegetarians were more likely to live in urban areas and to not be married. Vegetarians and semi-vegetarians had lower body mass index (mean (95% confidence interval): 22.2 (21.7–22.7) and 23.0 (22.7–23.3) kg m− 2) than non-vegetarians (23.7 (23.6–23.8) kg m− 2) and tended to exercise more. Semi-vegetarians and vegetarians had poorer mental health, with 21–22% reporting depression compared with 15% of non-vegetarians (P < 0.001). Low iron levels and menstrual symptoms were also more common in both vegetarian groups. Vegetarian and semi-vegetarian women were more likely to consult alternative health practitioners and semi-vegetarians reported taking more prescription and non-prescription medications. Compared with non-vegetarians, semi-vegetarians were less likely and vegetarians much less likely to be taking the oral contraceptive pill.

Conclusion

The levels of physical activity and body mass indices of the vegetarian and semi-vegetarian women suggest they are healthier than non-vegetarians. However, the greater reports of menstrual problems and the poorer mental health of these young women may be of clinical significance.

Calcium, diet and fracture risk: a prospective study of 1898 incident fractures among 34 696 British women and men

OBJECTIVE

The risk factors for fractures are incompletely understood. An outstanding question concerns the optimal amount of dietary calcium needed to minimise the risk of fracture.

DESIGN

We examined the associations of dietary calcium and other nutrients with self-reported fracture risk in a prospective cohort study. Nutrient intakes were estimated using a semi-quantitative food-frequency questionnaire administered at recruitment.

SETTING

The UK.

PARTICIPANTS

A total of 26 749 women and 7947 men aged 20-89 years.

RESULTS

Over an average of 5.2 years of follow-up, 1555 women and 343 men reported one or more fractures, 72% of these resulting from a fall. Among women, fracture risk was higher at lower calcium intakes, with a relative risk of 1.75 (95% confidence interval (CI) 1.33-2.29) among women with a calcium intake of < 525 mg day- 1 compared with women with a calcium intake of at least 1200 mg day- 1 (test for linear trend, P < 0.001). The association of dietary calcium with fracture risk was stronger among women aged under 50 years at recruitment than among women aged 50 and above. Dietary calcium intake was not associated with fracture risk in men. Fracture risk was not related to the dietary intake of any other nutrient examined.

CONCLUSION

In this population, women with a low dietary calcium intake had an increased risk of bone fracture, and this association was more marked among younger women than among older women.

Comparative fracture risk in vegetarians and nonvegetarians in EPIC-Oxford

OBJECTIVE

To compare fracture rates in four diet groups (meat eaters, fish eaters, vegetarians and vegans) in the Oxford cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford).

DESIGN

Prospective cohort study of self-reported fracture risk at follow-up.

SETTING

The United Kingdom.

SUBJECTS

A total of 7947 men and 26,749 women aged 20-89 years, including 19,249 meat eaters, 4901 fish eaters, 9420 vegetarians and 1126 vegans, recruited by postal methods and through general practice surgeries.

METHODS

Cox regression.

RESULTS

Over an average of 5.2 years of follow-up, 343 men and 1555 women reported one or more fractures. Compared with meat eaters, fracture incidence rate ratios in men and women combined adjusted for sex, age and non-dietary factors were 1.01 (95% CI 0.88-1.17) for fish eaters, 1.00 (0.89-1.13) for vegetarians and 1.30 (1.02-1.66) for vegans. After further adjustment for dietary energy and calcium intake the incidence rate ratio among vegans compared with meat eaters was 1.15 (0.89-1.49). Among subjects consuming at least 525 mg/day calcium the corresponding incidence rate ratios were 1.05 (0.90-1.21) for fish eaters, 1.02 (0.90-1.15) for vegetarians and 1.00 (0.69-1.44) for vegans.

CONCLUSIONS

In this population, fracture risk was similar for meat eaters, fish eaters and vegetarians. The higher fracture risk in the vegans appeared to be a consequence of their considerably lower mean calcium intake. An adequate calcium intake is essential for bone health, irrespective of dietary preferences.

SPONSORSHIP

The EPIC-Oxford study is supported by The Medical Research Council and Cancer Research UK.

Impact of disaggregation of composite foods on estimates of intakes of meat and meat products in Irish adults

Objective

To evaluate the impact of the disaggregation of composite foods on intake estimates of meat and individual meat categories and on the contribution of meat to nutrient intakes in Irish adults.

Design

Data were analysed from the North/South Ireland Food Consumption Survey, which used a 7-day food diary to estimate food intake. Of 742 food codes that contained meat, 320 were codes for meat consumed as an individual portion and 422 were composite foods and were disaggregated to estimate the meat content.

Subjects

A nationally representative sample of 475 men and 483 women (not pregnant or lactating) from the Republic of Ireland aged 18–64 years.

Results

The mean intake of meat was 134 g day−1in consumers (98.5%) and men (168 g day−1) consumed significantly more (P< 0.001) than women (102 g day−1). Mean intakes of meat were higher in subjects with manual skilled occupations (P< 0.01) and lower in those with third-level educational qualifications (P< 0.05). Without disaggregating meat from composite foods, meat intake was overestimated by 43% (57 g day−1) and varied widely by meat category. Meat disaggregated from composite foods contributed 25% of meat intake. The contribution meat made to nutrient intakes ranged from 29% for protein, vitamin B12, zinc and niacin to 20% for vitamin D, 16% for vitamin B6, 15% for thiamine and 14% for iron.

Conclusions

Failure to disaggregat meat from composite foods substantially overestimates meat intake, with a large variation between meat categories. This has important implications for estimates of meat intakes in nutritional epidemiological studies and for food safety purposes.

Height, age at menarche, body weight and body mass index in life-long vegetarians

Objective

We investigated whether life-long adherence to a vegetarian diet is associated with adult height, age at menarche, adult body weight and body mass index (BMI), used as indicators of growth, development and obesity, in a large sample of adults.

Design

This was a cross-sectional study. Anthropometric data and information on age, ethnicity, education, age at menarche and age at becoming a vegetarian were obtained through a questionnaire. Self-reported height and weight were calibrated using predictive equations derived from a previous validation study.

Setting

United Kingdom.

Subjects

The study includes 45 962 British men and women aged ≥ 20 years of whom 16 083 were vegetarians (not eating fish or meat).

Results

In men and women, there were no significant differences in height, weight or BMI between life-long vegetarians (n= 125 (men) andn= 265 (women)) and people who became vegetarian at age ≥ 20 years (n= 3122 (men) andn= 8137 (women)). Nor was there a significant difference in age at menarche between life-long vegetarian women and women who became vegetarian at age ≥ 20 years.

Conclusion

This study suggests that, compared with people who become vegetarian when adult, life-long vegetarians do not differ in adult height, weight, BMI or age at menarche in women.

Reproducibility of a short semi-quantitative food group questionnaire and its performance in estimating nutrient intake compared with a 7-day diet diary in the Million Women Study

Objectives

To assess the short- and long-term reproducibility of a short food group questionnaire, and to compare its performance for estimating nutrient intakes in comparison with a 7-day diet diary.

Design

Participants for the reproducibility study completed the food group questionnaire at two time points, up to 2 years apart. Participants for the performance study completed both the food group questionnaire and a 7-day diet diary a few months apart. Reproducibility was assessed by kappa statistics and percentage change between the two questionnaires; performance was assessed by kappa statistics, rank correlations and percentages of participants classified into the same and opposite thirds of intake.

Setting

A random sample of participants in the Million Women Study, a population-based prospective study in the UK.

Subjects

In total, 12 221 women aged 50–64 years.

Results

In the reproducibility study, 75% of the food group items showed at least moderate agreement for all four time-point comparisons. Items showing fair agreement or worse tended to be those where few respondents reported eating them more than once a week, those consumed in small amounts and those relating to types of fat consumed. Compared with the diet diary, the food group questionnaire showed consistently reasonable performance for the nutrients carbohydrate, saturated fat, cholesterol, total sugars, alcohol, fibre, calcium, riboflavin, folate and vitamin C.

Conclusions

The short food group questionnaire used in this study has been shown to be reproducible over time and to perform reasonably well for the assessment of a number of dietary nutrients.

The UK Women's Cohort Study: comparison of vegetarians, fish-eaters and meat-eaters

Background:

This paper describes the development of the UK Women's Cohort Study and presents cohort baseline characteristics.

Methods:

In total, 35 372 women, aged 35–69 years at recruitment, were selected to ensure a wide range of dietary intakes. Diet was assessed by a 217-item food-frequency questionnaire (FFQ). Detailed lifestyle information was collected by postal questionnaire. Vegetarians, fish-eaters and meat-eaters were compared.

Results:

The cohort women are mainly white, well-educated, middle-class and married with children. They are health-conscious with only 11% current smokers and 58% taking dietary supplements. Twenty-eight per cent of subjects self-report as being vegetarian and 1% as vegan. However, only 18% are defined as 'vegetarian' from the FFQ. Fat provides 32% of energy; vitamin and mineral intakes are high, with a broad range of intakes. Meat-eaters are older, with a higher body mass index (BMI) and the lowest intakes of carbohydrate, fibre, vitamin C, folate, iron and calcium. Other fish-eaters are similar to vegetarians. Vegetarians have the lowest intakes of protein, fat and saturated fat. Oily fish-eaters have the lowest BMI; are the least likely to smoke or use full-fat milk; and are the most likely to use dietary supplements and consume the most fruit and vegetables. Oily fish-eaters have the highest total energy intake and vegetarians the lowest. Semi-skimmed milk, bread, potatoes, wine, bananas and muesli are important contributors to energy for all groups.

Conclusion:

A large cohort of middle-aged women has been created encompassing a wide range of different eating patterns, including diets currently of interest to research into protection against cancer and coronary heart disease. Participants will be followed up to study the effects of different food and nutrient intakes on long-term health outcomes.

A prospective pilot study of antibodies against human papillomaviruses and cutaneous squamous cell carcinoma nested in the Oxford component of the European Prospective Investigation into Cancer and Nutrition

In a prospective pilot study nested in the EPIC-Oxford cohort, we examined the seroprevalence of antibodies against the L1 antigen of 38 human papilloma virus (HPV) types among 39 cases of cutaneous squamous cell carcinoma (SCC) for whom plasma was collected prior to diagnosis (incident) and 80 controls. Fifteen cases having already developed SCC at blood collection (prevalent) were also tested. There were no statistically significant differences in the seroprevalence of antibodies against any of the HPV types examined between incident cases and controls, nor was there a difference in the seroprevalence of multiple infections. However, consistent with results from published case-control studies, the seroprevalence of many beta-HPV types was higher among prevalent cases than among either incident cases or controls. For example the seroprevalence of antibodies against HPV-8 was 20% (16/80) in controls, 23% (9/39) among incident cases and 40% (6/15) among prevalent cases. Among the incident cases only, the seroprevalence was 16% (5/32) among those for whom blood was collected 18+ months prior to diagnosis, but 57% (4/7) among those for whom diagnosis was within 18 months of blood collection, a pattern seen for many of the HPV types. This might suggest that if HPV is involved in the aetiology of SCC, the process occurs close to the time of diagnosis, or that the antibody response observed in people with SCC is a consequence of tumor formation. Further and larger prospective studies are needed to clarify the role of HPV in the aetiology of cutaneous SCC.

Health effects of vegetarian and vegan diets

Vegetarian diets do not contain meat, poultry or fish; vegan diets further exclude dairy products and eggs. Vegetarian and vegan diets can vary widely, but the empirical evidence largely relates to the nutritional content and health effects of the average diet of well-educated vegetarians living in Western countries, together with some information on vegetarians in non-Western countries. In general, vegetarian diets provide relatively large amounts of cereals, pulses, nuts, fruits and vegetables. In terms of nutrients, vegetarian diets are usually rich in carbohydrates, n-6 fatty acids, dietary fibre, carotenoids, folic acid, vitamin C, vitamin E and Mg, and relatively low in protein, saturated fat, long-chain n-3 fatty acids, retinol, vitamin B(12) and Zn; vegans may have particularly low intakes of vitamin B(12) and low intakes of Ca. Cross-sectional studies of vegetarians and vegans have shown that on average they have a relatively low BMI and a low plasma cholesterol concentration; recent studies have also shown higher plasma homocysteine concentrations than in non-vegetarians. Cohort studies of vegetarians have shown a moderate reduction in mortality from IHD but little difference in other major causes of death or all-cause mortality in comparison with health-conscious non-vegetarians from the same population. Studies of cancer have not shown clear differences in cancer rates between vegetarians and non-vegetarians. More data are needed, particularly on the health of vegans and on the possible impacts on health of low intakes of long-chain n-3 fatty acids and vitamin B(12). Overall, the data suggest that the health of Western vegetarians is good and similar to that of comparable non-vegetarians.

Vegetarian Diets and Weight Status

The increasing global health problems of overweight and obesity are associated with coronary heart disease, hypertension, diabetes, osteoarthritis, and certain cancers, among other health concerns. Vegetarian diets are associated with reduced body weight, lower incidence of certain chronic disease, and lower medical costs compared with non-vegetarian diets. We reviewed the literature to ascertain the extent to which and by what mechanism(s) a plant-based diet may mediate body weight.