Mortality Rates of Vegetarians and Vegans
A paper came out in December reporting mortality rates of different diet groups from the large EPIC-Oxford study containing 60,310 people from the UK (1).
The mortality rate before age 90 was no different between vegetarians (including vegans) and regular meat-eaters (1.02, 0.94-1.10). Vegetarians had lower rates of mortality from pancreatic cancer (0.48, 0.28-0.82) and lymphatic cancer (0.50, 0.32-0.79). Semi-vegetarians had lower rates of death from pancreatic cancer (0.55, 0.36-.86). Pesco-vegetarians had lower death rates from all cancers (0.82, 0.70-0.97) but higher rates of cardiovascular disease (1.22, 1.02-1.46).
In the main analysis (in the paragraph above), some participants were recategorized based on a change in their diet over the course of the study which included over one million person-years of follow-up. The researchers did a second analysis in which participants who changed their diets were removed, and found an 8% reduced risk of early death in vegetarians that was just statistically significant (0.92, 0.84-0.99). Limiting the results further, to deaths before age 75, strengthened the finding (0.86, 0.77-0.97).
When vegans were separated from other vegetarians, there were no statistically significant differences in mortality rates for the six main categories of death. Eliminating participants who had changed diet categories didn’t significantly change the results for vegans. There were only 166 vegan deaths as distinct from 1,929 deaths in the entire cohort; meaning that reaching statistical significance was going to be unlikely.
Results above were not adjusted for differences in body mass index (BMI); such adjustments were performed but they didn’t change the results substantially.
The fact that vegetarians didn’t have lower rates of death from heart disease in this study is surprising given that a 2013 report from EPIC-Oxford showed a highly statistically significant, 31% reduction in heart disease incidence among vegetarians (0.69, 0.58-0.82). This discrepancy as well as the lower death rates for vegetarians before age 75, but not before age 90, might be explained by cases of nonfatal heart disease leading to effective treatment.
See the link in the reference for a free copy of the paper. For results of other similar studies, please see Disease Rates of Vegetarians and Vegans.
1. Appleby PN, Crowe FL, Bradbury KE, Travis RC, Key TJ. Mortality in vegetarians and comparable nonvegetarians in the United Kingdom. Am J Clin Nutr. 2016 Jan;103(1):218-30. | link