Study: Meat May Play an Unexpected Role in Human Longevity

For those hoping to live to 100 with fewer health issues, the first step is often changing their diet. A plant-based diet is frequently recommended, but a study in China has found that most centenarians there eat meat — which may be especially beneficial for people who are underweight.

Meat is a rich source of certain amino acids that appear to influence the signaling molecule mTOR, which is linked to the aging process. Numerous studies suggest that reducing meat consumption or eliminating it altogether can promote longevity and lower the risk of diseases such as heart disease, Planet Today reports. On the other hand, plant-based diets have been associated with higher rates of fractures and malnutrition.

These issues may be particularly concerning for older adults, who tend to have weaker bones and recover more poorly after surgery, says Kaiyue Wang of Fudan University in Shanghai. To better understand the relationship between diet and longevity, Wang and her colleagues analyzed data from a centralized Chinese health database of people over 65.

After reviewing the records, the researchers examined data from 5,203 participants who were at least 80 years old in 1998 and did not suffer from cardiovascular disease, diabetes, or cancer. About 80 percent reported eating meat, while the rest followed a mainly plant-based diet consisting mostly of vegetables and grains, with occasional animal products.

The researchers found that meat eaters were more likely to reach the age of 100 than vegetarians, pescatarians, and vegans. However, this difference became statistically significant only when body weight was taken into account.

Among vegetarians with a body mass index below 18.5 (classified as underweight) in 1998, 24 percent reached 100, compared with nearly 30 percent of underweight people who ate meat — with the likelihood increasing among those who reported daily meat consumption. No similar trend was observed among people with higher body weight.

Diets high in meat are often linked to obesity, but research also shows that animal proteins help strengthen muscles and bones, which may be particularly beneficial for underweight individuals, Wang notes.

At the same time, eating plenty of vegetables remains very important. The researchers also found that overall life expectancy was higher among participants who reported daily consumption of any amount of vegetables.

“Older adults may face specific nutritional challenges,” Wang says. “Our study suggests that dietary recommendations for the very old should emphasize balance and adequate nutrition rather than strict avoidance of animal products, especially for underweight elderly people.”

The findings may not apply to other parts of the world, where diets differ. However, Wang adds that “the underlying biological mechanisms linking nutrition and aging are likely universal.”

James Webster of the University of Oxford says the results “should not by themselves lead people to change their diets.” Previous work by his team linking vegetarianism to a higher risk of hip fractures sparked speculation that such diets might be harmful. However, Webster points out that many studies have highlighted the health benefits of vegetarian diets.

Both vegetarian and meat-based diets can be healthy or unhealthy depending on their nutritional quality, Webster says. “It’s important to understand which nutrients are necessary for a balanced, healthy lifestyle,” including consuming plenty of whole grains, fruits, and vegetables while minimizing salt, sugar, and saturated fats.

“Ultimately, before we can say with confidence which diet is best for longevity, more evidence is needed. When thinking about eating habits, we should consider the bigger picture,” Webster concludes.

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