People are living longer than ever. By 2050, scientists expect that nearly half a billion people could be over 80.
The rise in human life expectancy is due in part to better nutrition, but which food choices lead to the longest and healthiest outcomes in old age?
Scientists are still working that out.
In younger cohorts, some diets are linked to extra years of life, especially those built around whole foods, plant foods, and healthy fats.
Choices about meat are more disputed, and they usually come with a caveat.
The Chinese study and its limits
A study carried out in China adds a further complication. Among more than 5,000 people aged 80 and older, the researchers found that women who eat meat were more likely to reach 100 than vegetarian women.
There was no significant association between longevity and vegetarianism in men when the researchers analyzed the data by sex.
Before you send this piece to every vegetarian woman you know, the caveat is worth reading.
Only the vegetarian participants classed as underweight were less likely to live to 100 than the meat eaters.
“Daily meat consumption was associated with a 44% higher probability of reaching 100 [compared with a vegetarian diet] in the underweight group, whereas this association did not appear in the normal-weight or overweight group,” the study authors conclude.
Vegetarians who ate fish, dairy, or eggs had a similar chance of reaching 100 to that of meat eaters.
This suggests that older women who eat enough calories and essential nutrients can raise their chances of becoming centenarians.
These results support recent research suggesting that protecting muscle mass by eating enough protein is vital for healthy aging.
The new data come from one of the largest studies of older adults in the world: the Chinese Longitudinal Healthy Longevity Survey (CLHLS).
Researchers from Fudan University, the Chinese Center for Disease Control and Prevention, and Shanghai Jiao Tong University compared the outcomes of 1,459 centenarians with those of 3,744 non-centenarians in their eighties and nineties.
The team found that body mass index (BMI) partly explained the association between vegetarianism and a shorter life expectancy.
Because older populations are more likely to be underweight, the authors suggest that the role of BMI in longevity “deserves to be explored” further.
The “obesity paradox,” for example, is a term for the way a higher body weight seems associated with better health outcomes in older populations. It is the reverse of what shows up in younger populations.
The centenarian study in China can reveal only associations, which means other factors may influence the results.
The study, for example, does not take into account how eating habits can change over time. The surveys assessed only what participants ate in their later years, and that can be influenced by how easy the foods are to chew.
Earlier research does support the idea that lifestyle choices, such as diet, could be major reasons why some people live to 100.
In fact, by some estimates, reaching the age of 90 can be explained about 70% by healthy behaviors such as sleep, physical activity, and diet.
What older adults need, and the protein debate
Older adults may have different nutritional needs, yet many studies of vegetarianism focus on younger cohorts.
A study of more than 65,000 people, young and old, found that those who follow a vegetarian diet may have a higher risk of fractures, perhaps because of a lower intake of calcium and protein.
The question is not fully settled there either. A 2026 review by researchers at the University of Wisconsin-Madison made the opposite case: a lower protein intake might actually favor healthier aging in several organisms, perhaps because high-protein diets can keep cells locked in a constant growth mode. The exact amount of protein older adults need remains an open debate.
Nutrition is an extremely complex field of research, and health outcomes can be influenced by many social, environmental, and individual factors.
Most likely, the best food choices for a longer life call for variety and balance, and they differ from one person to the next.
Vegetarian diets, plant-based diets, and low-meat diets have been linked to lower risks for some health problems, such as heart disease, stroke, type 2 diabetes, and obesity.
Even so, not all meats are tied to negative health outcomes in the same way, and quantity can matter. Processed meats and red meat, for example, are often linked to poorer health and shorter longevity, which is why moderation is generally advised.
“Our results highlighted the importance of a balanced diet made up of both animal foods and plant foods for healthy longevity,” the team writes.
“Future studies of adults of a very advanced age are needed for the formulation of dietary recommendations.”
The study was published in The American Journal of Clinical Nutrition.
The original report appeared in ScienceAlert.
Source: Article365