A new study suggests that vegetarian diets can reduce the risk of mortality, with pesco-vegetarian diets—those including fish—offering the most significant protection for the elderly. The research, conducted by Loma Linda University Health, highlights that while vegetarian diets generally lower the risk of death and many cause-specific conditions, pesco-vegetarian diets stand out for their benefits among the very elderly.
The study, led by Gary Fraser, MBCHB, PhD, distinguished professor at Loma Linda University School of Public Health, and published on August 2, 2024, in the American Journal of Clinical Nutrition, analyzed data from the Adventist Health Study-2. This extensive cohort includes nearly 96,000 Seventh-day Adventists from the United States and Canada, with data collected between 2002 and 2007 and follow-up through 2015. The study examined over 88,000 participants and around 12,500 deaths.
The researchers found that overall, vegetarian diets are associated with a 12% lower risk of death compared to non-vegetarian diets. Among vegetarians, pesco-vegetarians had an 18% lower risk of death, while those following a lacto-ovo-vegetarian diet, which includes dairy and eggs, had a 15% lower risk. Vegans showed a less than 3% reduction in mortality risk overall, although male vegans experienced greater benefits compared to non-vegetarians than female vegans.
Despite the general benefits, the study observed a slight increase in risks for neurological conditions such as stroke, dementia, and Parkinson’s disease among very elderly vegetarians. Nevertheless, the pesco-vegetarian diet continued to offer a small but noticeable advantage over other dietary patterns, even in the oldest age groups.
Fraser noted that while vegetarian diets seem to offer protective benefits through middle age, this advantage appears to diminish in very old age, particularly for those on strict vegetarian diets. “The increased risks of neurological conditions among vegetarians in their 80s are not substantial, but they warrant further investigation to ensure the vegetarian advantage continues in later years,” Fraser said.
The study’s findings underscore the protective effect of vegetarian diets, particularly pesco-vegetarian diets, in extending lifespan and reducing mortality risk among older adults. The research was supported by Loma Linda University Health’s Research Affairs department, with initial funding from the National Cancer Institute and the World Cancer Research Fund.