Vegetarians vs. Carnivores: What The Data Says About Reaching 100 Years Of Age

This study analyzed elderly individuals aged eighty or older to investigate whether a vegetarian diet influences the chance of reaching one hundred years of age. The results showed that vegetarians, especially those on a completely plant-based diet and with low weight, were less likely to become centenarians compared to omnivores. The findings highlight the importance of a balanced diet for extreme longevity.

Increasing life expectancy is no longer rare thanks to social and medical advances, and more and more people are reaching very advanced ages. It is estimated that the number of people aged eighty or older in the world will triple between 2020 and 2050. In this scenario, the great challenge for public health is not only to live longer, but to live better after that age.

People who reach one hundred years of age attract attention because, in general, they manage to postpone or avoid many diseases associated with aging, becoming an important model of healthy aging.

Understanding which factors contribute to achieving such extreme longevity is fundamental, especially factors that can be modified, such as lifestyle and diet. Identifying what differentiates seniors who reach one hundred years of age from those who do not can help create more effective strategies to promote a long and high-quality life.

A vegetarian diet, based primarily on plant-based foods and restricting or excluding animal-based foods, has received considerable attention in recent years for its potential health and environmental benefits. Previous studies have indicated that this type of diet may be associated with a lower risk of cardiovascular disease, diabetes, and obesity.

However, other research has also pointed to potential risks, such as a higher chance of fractures, malnutrition, mental health problems, and gallstones, especially in more vulnerable populations.

Despite the growing number of studies on vegetarian diets in adults, few studies have analyzed their relationship with extreme longevity, especially in people aged eighty or older. This group deserves special attention because it has a higher risk of weight loss, bone fragility, and nutritional deficiencies.

Furthermore, many very long-lived elderly individuals have a low body mass index, which raises questions about whether a vegetarian diet would be adequate to promote survival to one hundred years of age in this context.

Given this gap, researchers conducted a study focused exclusively on adults aged eighty or older, using data from a large Chinese national study on health and longevity. The objective was to investigate whether following a vegetarian diet was associated with a greater or lesser likelihood of reaching the age of one hundred. They also assessed whether this association might vary according to factors such as body weight and smoking.

The study followed more than five thousand elderly people over time, classifying them according to their dietary habits. Participants were divided between those who consumed animal products and those who followed vegetarian diets, including different types such as diets that allow fish, eggs, or dairy products, and entirely plant-based diets. At the end of the follow-up, the researchers determined who managed to reach one hundred years of age.

The results showed that, in general, elderly people who followed a vegetarian diet were less likely to become centenarians compared to those who consumed animal products. This effect was more evident among those who followed an entirely plant-based diet.

On the other hand, no significant differences were observed between omnivores and people who followed more flexible vegetarian diets, such as those that include fish, eggs, or dairy products.

A key finding was that the association between a vegetarian diet and a lower chance of reaching one hundred years of age was observed mainly in underweight elderly individuals. Among those with adequate weight, this difference was not significant. This suggests that, in very thin elderly individuals, the exclusion of animal-based foods may hinder the adequate intake of essential nutrients for maintaining health and survival at very advanced ages.

In conclusion, the study indicates that, among very long-lived elderly individuals, following a vegetarian diet did not increase the likelihood of reaching one hundred years of age and, in some cases, was associated with shorter lifespans. The results reinforce the importance of a balanced diet that combines plant-based and animal-based foods appropriately, especially for very old and underweight individuals.

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Vegetarian diet and likelihood of becoming centenarians in Chinese adults aged 80 y or older: a nested case-control study

Yaqi Li, Kaiyue Wang, Yuebin Lv, Guliyeerke Jigeer, Yilun Huang, Xiuhua Shen, Xiaoming Shi, and Xiang Gao

The American Journal of Clinical Nutrition.  12 December 2025, 101136

DOI: 10.1016/j.ajcnut.2025.101136

Abstract:

Inverse associations of vegetarian diet with morbidity and mortality have been observed; however, the role of vegetarian diet on exceptional longevity remains unrevealed. This study aims to examine the association between a vegetarian diet and likelihood of becoming a centenarian in adults aged ≥80 y. This prospective nested case-control study included 5203 participants aged 80+ y from the Chinese Longitudinal Healthy Longevity Survey, a nationally representative cohort initiated in 1998. Participants were classified as omnivores and vegetarians, and further into vegetarian subgroups (pesco-vegetarians, ovo-lacto-vegetarians, and vegans) based on consumption of animal-derived foods. The primary outcome was living to 100 y old by the end of follow-up (2018). Multivariable unconditional logistic regression models were used to evaluate the association analysis. The study identified 1459 centenarians and matched them with 3744 noncentenarians (who had deceased before reaching 100 y). Relative to omnivores, vegetarians had a lower likelihood of becoming centenarians [odds ratio (OR): 0.81, 95% confidence interval (CI): 0.69, 0.96], and similar patterns were observed for vegans (OR: 0.71, 95% CI: 0.54, 0.98), but not for pesco-vegetarians (OR: 0.84, 95% CI: 0.64, 1.09) and ovo-lacto-vegetarians (OR: 0.86, 95% CI: 0.67, 1.09). The significant association was seen in individuals with BMI <18.5 kg/m2 (OR: 0.72, 95% CI: 0.57, 0.91), but not for those with BMI ≥18.5 kg/m2 (OR: 0.92, 95% CI: 0.73, 1.17) (P-interaction = 0.08). 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.