A vegetarian diet—oft promoted as a pathway to long-term health—may actually reduce your odds of living to 100, according to a new large-scale study examining the lives of older adults in China.
In the study, researchers tracked 5,203 adults aged 80 and over, drawn from the Chinese Longitudinal Healthy Longevity Survey,—a national cohort study that began in 1998. The researchers compared diet patterns in participants and analyzed their association with living to 100 years of age.
Contrary to common assumptions about vegetarian diets, researchers found that those who avoided animal products were less likely to end up reaching centenarian status.
While vegetarian diets have been associated with lower risks of cardiovascular disease, diabetes and obesity in younger populations, this new study raises important questions about their impact on longevity.
Researchers identified 1,459 centenarians and compared them to 3,744 participants who had died before reaching the age of 100. Participants were categorized as omnivores or vegetarians, with vegetarians further broken down into pesco-vegetarians, who ate fish; ovo-lacto-vegetarians, who ate eggs and milk; and vegans, based on their particular diets.
Omnivores were used as the reference group. The results showed that vegetarians overall had a significantly lower likelihood of reaching age 100 compared to omnivores.
Vegans in particular had the lowest odds among all dietary groups, with an odds ratio of 0.71. In contrast, pesco-vegetarians and ovo-lacto-vegetarians did not show statistically significant differences in longevity compared to meat eaters.
“Targeting individuals of advanced age (80+ y) in China, we found that individuals following a vegetarian diet had a lower likelihood of becoming centenarians relative to omnivores, underscoring the importance of a balanced, high-quality diet with animal- and plant-derived food composition for exceptional longevity, especially in the underweight oldest-old,” the researchers wrote in their study.
The team also found that body mass index (BMI) played a significant role in the association between diet and longevity. Among underweight individuals, vegetarians had a notably lower likelihood of living to 100. This may reflect how elderly individuals with lower body weight could be more vulnerable to the nutritional deficits of a restrictive diet.
Although vegetarian diets have been praised for environmental sustainability and health benefits, particularly among younger adults, the evidence now looks to be less conclusive for older populations.
The study’s authors acknowledged that while plant-based diets have been linked to lower risks of chronic diseases, they have also been associated with increased risks of bone fractures and malnutrition.
As the global population of people aged 80 and older is expected to triple by 2050—reaching an estimated 426 million—the findings add to our understanding of how dietary choices affect aging.
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Reference
Li, Y., Wang, K., Lv, Y., Jigeer, G., Huang, Y., Shen, X., Shi, X., & Gao, X. (2025). Vegetarian diet and likelihood of becoming centenarians in Chinese adults aged 80 y or older: A nested case-control study. The American Journal of Clinical Nutrition. https://doi.org/10.1016/j.ajcnut.2025.101136