Nutraceuticals: Vegetarian Diet

Indication: Mortality

Source: JAMA Internal Medicine, June 3, 2013

Research: Some evidence suggests that  vegetarian dietary patterns may be associated with reduced mortality, but the relationship is not well established. This prospective cohort study (Adventist Health Study 2 (AHS-2), a large North American cohort) aimed to evaluate the relationship using Cox proportional hazards regression, controlling for important demographic and lifestyle
confounders.

A total of 96,469 Seventh-day Adventist men and women were recruited between 2002 and 2007, from which an analytic sample of 73,308 participants remained after exclusions.

Diet was assessed at baseline by a quantitative food frequency questionnaire and categorized into five dietary patterns: non-vegetarian, semi-vegetarian, pesco-vegetarian, lacto-ovo–vegetarian and vegan. The relationship between vegetarian dietary patterns and all-cause and cause-specific mortality were evaluated; deaths through 2009 were identified from the National Death Index.

Results: There were 2,570 deaths among 73,308 participants during a mean follow-up time of 5.79 years. The mortality rate was 6.05 (95% CI, 5.82-6.29) deaths per 1,000 person-years. The adjusted hazard ratio (HR) for all-cause mortality in all vegetarians combined vs. non-vegetarians was 0.88 (95% CI, 0.80-0.97).

The adjusted HR for all-cause mortality in vegans was 0.85 (95% CI, 0.73-1.01); in lacto-ovo–vegetarians, 0.91 (95% CI, 0.82-1.00); in pesco-vegetarians, 0.81 (95% CI, 0.69-0.94); and in semi-vegetarians, 0.92 (95% CI, 0.75-1.13) compared with non-vegetarians.  Significant associations with vegetarian diets were detected for cardiovascular mortality, non-cardiovascular non-cancer mortality, renal mortality and endocrine mortality. Associations in men were larger and more often significant than were those in women.

Researchers concluded that vegetarian diets are associated with lower all-cause mortality and some reductions in cause-specific mortality. Results appeared to be more robust in males. These favorable associations should be considered carefully by those offering dietary guidance.