Michael J. Orlich, M.D., of Loma Linda University in California, and colleagues examined all-cause and cause-specific mortality in a group of 73,308 men and women Seventh-day Adventists.
Researchers assessed dietary patients using a questionnaire that categorized study participants into five groups: non-vegetarian, semi-vegetarian, pesco-vegetarian (includes seafood), lacto-ovo-vegetarian (includes dairy and egg products) and vegan.
The study noted that some evidence suggested that vegetarian dietary patterns could be associated with reduced mortality, but the relationship is not well established.
There were 2,570 deaths among the study participants during a mean (average) follow-up time of almost six years.
The overall mortality rate was six 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, or 12% lower, the study results showed.
The association also appears to be better for men with significant reduction in cardiovascular disease mortality and IHD death in vegetarians vs. non-vegetarians. In women, there were no significant reductions in these categories of mortality, the results indicate.
The authors wrote that the results demonstrate an overall association of vegetarian dietary patterns with lower mortality compared with the non-vegetarian dietary pattern.
The findings have been published online by JAMA Internal Medicine.