Skip to content
ZenBodyLove

Other EPIC-Oxford outcomes

EPIC-Oxford is a UK cohort of about 65,000 adults, including roughly 20,000 vegetarians and 2,500 vegans, followed for nearly two decades. Beyond heart disease, stroke and fractures (covered in the vegan stroke risk and calcium topics, where vegetarians and especially vegans had higher fracture rates and vegetarians higher stroke rates), the vegetarian and vegan groups had lower BMI, less weight gain, and lower rates of diabetes, diverticular disease and cancer overall, but similar all-cause mortality; the diabetes difference was largely explained by lower BMI, and half of the vegan men tested had B12 levels indicating deficiency. Every claim here rests on one observational cohort of health-conscious volunteers with few vegans, so none is graded above low.

  • Longevity
  • Vegan

Evidence retrieved up to

What the research shows

In a large UK cohort followed for about 18 years, adults following vegetarian diets, vegans included, had a lower rate of hospitalisation or death with diabetes than regular meat eaters, but most of the difference disappeared after accounting for their lower BMI.

Low certaintyFurther research is likely to change this.
No known concerns at usual amountsBenefit

Who this is about

adults following vegetarian or vegan diets in the UK

Practical note

Graded low: one prospective cohort of health-conscious volunteers, so residual confounding is possible; the association was substantially attenuated by BMI adjustment (vegetarian hazard ratio 0.63 before and 0.89, not significant, after).

Vegan note

Vegans were pooled with vegetarians in the main analysis; the review reports that the vegan-only estimate rested on 26 cases and was also explained by BMI.

Sources

In a UK cohort, adults following vegetarian and vegan diets had lower BMI than meat eaters, and vegans gained slightly less weight over five years (about 300 g a year compared with about 400 g a year in meat eaters).

Low certaintyFurther research is likely to change this.
No known concerns at usual amountsBenefit

Who this is about

adults following vegetarian or vegan diets in the UK

Practical note

Graded low: observational, self-reported weight, single cohort; the weight-gain differences were small.

Vegan note

The BMI difference from meat eaters was larger for vegans (about 2 kg/m2) than for vegetarians (about 1 kg/m2).

Safety note

The review authors note that lower BMI would also be expected to raise the risk of disorders linked to underweight; hip fracture is one example (see the calcium topic).

Sources

In a sample of UK men from this cohort, about half of those following a vegan diet had serum vitamin B12 levels indicating deficiency, compared with 7% of vegetarians and almost no meat eaters; time on the diet made no difference.

Low certaintyFurther research is likely to change this.
Take care: see the safety noteRisk

Who this is about

men following a vegan diet in the UK

Practical note

Graded low: a single cross-sectional sample of men from a cohort recruited in the 1990s, so the prevalence may not reflect vegans today; see the vitamin B12 topic for meta-analytic evidence.

Vegan note

Plants generally contain no vitamin B12, so vegans depend on fortified foods or supplements; supplement use was not the focus of this 2010 analysis.

Safety note

The study authors expected the deficient vegans to have a higher risk of clinical symptoms of B12 deficiency. Haemoglobin was not measured in EPIC-Oxford; in UK Biobank, vegetarian premenopausal women had lower haemoglobin and more anaemia than meat eaters.

Sources

In pooled UK cohorts followed for about 15 years, adults following vegetarian diets had a modestly lower incidence of cancer overall than meat eaters, with lower rates of stomach and blood cancers but no difference for colorectal cancer; the authors caution that residual confounding may explain the overall difference.

Low certaintyFurther research is likely to change this.
No known concerns at usual amountsBenefit

Who this is about

adults following vegetarian or vegan diets in the UK

Practical note

Graded low: observational, few site-specific findings, wide confidence intervals; PubMed lists a 2022 erratum to the 2014 analysis that was not reviewed here.

Vegan note

The review reports an 18% lower estimate for all cancers combined in vegans, but the cohort holds only about 2,500 vegans, too few for accurate estimates.

Safety note

Cervical cancer was unexpectedly more common among vegetarians, of borderline statistical significance.

Sources

In a UK cohort followed for about 12 years, adults following vegetarian diets had a lower rate of hospital admission or death from diverticular disease than meat eaters, and higher dietary fibre intake was independently linked with a lower rate.

Low certaintyFurther research is likely to change this.
No known concerns at usual amountsBenefit

Who this is about

adults following vegetarian or vegan diets in the UK

Practical note

Graded low: observational, single cohort of health-conscious volunteers; the highest fibre fifth in the study ate at least about 25-26 g a day.

Vegan note

A later update reported a 72% lower estimate in vegans, but it rested on only 4 cases.

Sources

In pooled UK cohorts of about 60,000 adults, those following vegetarian diets had similar all-cause mortality to comparable regular meat eaters; the estimate for vegans was slightly higher but not statistically significant.

Low certaintyFurther research is likely to change this.
No known concerns at usual amountsNo clear effect

Who this is about

adults following vegetarian or vegan diets in the UK

Practical note

Graded low: observational; the comparison group was itself health-conscious, with low smoking and obesity rates, so the comparison is stringent but may not generalise.

Vegan note

The vegan hazard ratio was 1.14 (95% CI 0.97-1.35) compared with regular meat eaters, so both a modest increase and no difference are compatible with the data.

Sources