Pesco-vegetarian diets best for reducing risk of death in elderly, research suggests

A new study suggests that a range of vegetarian diets may help protect against mortality and common diseases, with a pesco-vegetarian diet that includes fish being the most effective at preventing risk in the very old.

The study, “Comparison of Cause-Specific and All-Cause Mortality Between Vegetarian and Nonvegetarian Participants in the Adventist Health Study 2 Cohort,” was published Aug. 2. American Journal of Clinical Nutrition.

Researchers at Loma Linda University Health found that a vegetarian diet was associated with a lower risk of all-cause and most-cause mortality, especially in men and middle-aged people, but observed a slightly higher risk of neurological diseases, including stroke, dementia, and Parkinson’s disease, among very elderly vegetarians.

Nevertheless, the pesco-vegetarian diet continued to provide a small but significant advantage over other vegetarian and non-vegetarian diets, even in older adults.

Gary Fraser, PhD, MBCHB, professor emeritus at the Loma Linda University School of Public Health and lead researcher on the study, said a vegetarian diet appears to offer protection against mortality risk into middle age, but once people enter their 80s, the overall benefit seems to disappear for those adhering to a strict vegetarian diet.

“The increased risk of neurological disease for vegetarians in their 80s is not huge, but something is going on that can’t be ignored if we want the vegetarian advantage to continue into old age,” Fraser said.

The study used data from the Adventist Health Study 2, a large cohort of approximately 96,000 people who identified as Seventh-day Adventists and were living in the United States and Canada at study baseline recruitment in 2002-2007, and who were followed through 2015. Data from this group have been used in numerous studies of health, disease, and mortality over the years.

The study analyzed data from over 88,000 subjects and approximately 12,500 deaths from the study population. Dietary data was collected using a questionnaire and categorized into five patterns: non-vegetarian, semi-vegetarian, pesco-vegetarian, lacto-ovo-vegetarian, and vegan.

Fraser said the team found that Adventist vegetarians had about a 12 percent lower risk of death compared with non-vegetarians, while study participants following a pesco-vegetarian diet had an 18 percent lower risk of death.

People consuming a lacto-ovo-vegetarian diet, which includes dairy products and eggs, had a 15% lower risk of death. Vegans overall had a lower risk of death of less than 3%, but in contrast to women, male vegans fared much better than non-vegetarians.

“Overall, this is some of the clearest data yet showing that American vegetarians are better protected from premature death than non-vegetarians,” Fraser said.

Courtesy of Loma Linda University Adventist Health Science Center