Another study has added to the growing body of evidence that a vegetarian diet is associated with a lower risk of death. The study published in JAMA Internal Medicine by Orlich et al has examined all-cause and cause specific mortality in a group of 73308 American men and women Seventh-day Adventists.
Previous studies have reported mixed results with some suggesting that nuts, fruit, cereal fibre, polyunsaturated fatty acids, ɯ-3PUFAs, green salad, Mediterranean dietary patterns, “healthy” or “prudent” dietary patterns, plant-based diet scores, plant-based low carbohydrate diets, and vegetarian diets are all associated with reduced mortality. Whereas high glycemic load, meat, red meat, processed meat, eggs, potatoes, increased energy intake and animal-based low-carbohydrate diets are all associated with increased mortality.
However Orlich et al report that the European Prospective Investigation into Cancer and Nutrition – Oxford cohort study, found British vegetarians were just as likely to die at any point as meat eaters. Using a questionnaire the scientists assessed the participants’ dietary patterns and split them into five groups: nonvegetarian, semi vegetarian, pesco-vegetarian (includes seafood), lacto-ovo-vegetarian (includes dairy and egg products) and vegan (excludes all animal products). Among the participants 8 % were vegans, while 29 % were lacto-ovo-vegetarians and another 10 % were pesco-vegatriation, 5% were semi-vegetarians and 48 % were non vegetarians. Vegetarians were found to be older, more highly educated, more likely to be married, drank less alcohol, smoked less and exercised more.
The researchers then used a national database to see how many of the participants died during the 6 years of follow up. They found 2570 deaths among the participants. 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 percent lower, according to the study results. The association also appears to be better for men with significant reduction in cardiovascular disease mortality and ischemic heart disease death in vegetarians vs. non-vegetarians.
The results indicate that in women,there were no significant reductions in these categories of mortality. The study cautions however that they can’t say the participants’ plant-based diets prevented their deaths, because there may be other unmeasured differences between the groups.