A long-term study tracking dietary patterns in China’s oldest citizens has uncovered a surprising trend. People over certain age who include meat in their diet appear more likely to reach the age of 100 than those who avoid it. The findings have reignited discussions around plant-based nutrition and healthy aging, especially in the context of rising life expectancies and shifting global dietary norms.
At first glance, the data challenge decades of research promoting vegetarian and vegan diets as protective against chronic disease. But closer analysis reveals that the longevity benefit only applies to a specific group of individuals: older adults who are underweight. The association is not seen in those with healthy body weight or higher.
Undernourished Older Adults Showed the Strongest Link Between Meat and Survival
The study, published in 2025 and based on data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), followed more than 5,000 Chinese adults aged 80 and older over two decades. Researchers observed that participants who did not eat meat and were underweight had a significantly lower chance of reaching 100. In contrast, older individuals of normal weight who avoided meat lived just as long as their meat-eating peers.
These findings were examined by nutrition expert Chloe Casey of Bournemouth University in an article published by The Conversation. She explained that as people age, their nutritional needs shift. Maintaining body mass and preventing frailty becomes more important than avoiding long-term health conditions. For underweight seniors, diets without meat can make it harder to get enough calories, protein, and micronutrients in a limited number of meals.
Undernourished older adults showed the strongest link between meat and survival. Credit: Shutterstock
Importantly, the study showed no difference in longevity for individuals who consumed animal products such as dairy, eggs, or fish. These foods provide essential nutrients like vitamin B12, calcium, vitamin D, and high-quality protein, which help preserve muscle and bone health in old age.
Vegetarian Diets Remain Beneficial Earlier in Life
For younger and middle-aged adults, plant-based diets continue to offer significant health benefits. A 2022 meta-analysis published in the European Journal of Nutrition examined over 844,000 individuals across 13 prospective cohort studies. The researchers found that vegetarians had a 15 percent lower risk of cardiovascular disease and a 21 percent lower risk of ischemic heart disease compared to nonvegetarians.
Vegan diets offered comparable protection, particularly for ischemic heart disease, although no consistent association was found with stroke risk. The authors noted variation in diet quality and stroke subtype across regions. Based on current evidence standards, the link between vegetarian diets and cardiovascular health was considered probably causal, while the relationship with stroke remained inconclusive.
Vegetarian and vegan diets are still strongly linked to lower risks of heart disease in midlife. However, these benefits do not necessarily carry into extreme old age, where new risks emerge. Credit: Shutterstock
Additional evidence from the Adventist Health Studies supports similar conclusions. These studies, which included large vegetarian populations in North America, linked plant-based eating patterns to lower all-cause mortality, particularly from cardiovascular conditions. However, the bulk of participants were younger than 80, limiting the applicability of these results to the oldest age groups.
Energy Needs Shift in Late Life, Requiring More Dietary Precision
As individuals grow older, physiological changes reduce appetite, energy expenditure, and muscle mass. These shifts increase the risk of undernutrition, even in those with stable body weight. A comprehensive review on energy metabolism and aging found that older adults frequently fail to meet recommended protein intake levels. This shortfall contributes to sarcopenia, a condition marked by progressive muscle loss that raises the risk of falls, hospitalization, and early death.
In this context, meat and other animal-source foods offer a concentrated supply of essential nutrients. For elderly individuals with reduced appetite or those at risk of nutrient deficiencies, such foods can help prevent the compounding effects of malnutrition. The CLHLS findings suggest that meat may serve more as a practical solution to meet nutritional demands than as an inherently superior dietary component.
Maintaining muscle mass in older age is important, and that requires protein. Credit: Shutterstock
The study also reinforces the value of dietary flexibility. Seniors who consumed dairy, eggs, or fish experienced similar longevity outcomes to those who ate meat. This points to the importance of ensuring micronutrient and protein adequacy, rather than focusing on meat consumption as a binary choice.
Implications for Dietary Guidance
These findings arrive at a time when global health authorities continue to promote plant-based diets as part of strategies to reduce chronic disease. However, the new data indicate that such guidelines may require age-specific refinements. Older adults, particularly those with low body weight or signs of frailty, may not benefit equally from the same recommendations given to younger populations.
Public messaging that favors vegetarian or vegan diets for all ages risks overlooking the distinct challenges faced by elderly individuals. The CLHLS data reveal that older adults who include small amounts of animal products in their diets can maintain longevity advantages, even without consuming red meat.
The role of body weight in survival among the elderly also supports existing evidence for the so-called obesity paradox. This refers to the observation that slightly higher body weight in older age is associated with lower mortality risk. It may reflect the protective effects of greater energy reserves or muscle mass in times of illness or physiological stress.
More research is needed to clarify how specific dietary components affect survival in advanced age. The CLHLS is an observational study, which limits causal interpretations. Confounding factors such as healthcare access, socioeconomic status, and regional dietary habits could have influenced the outcomes. Future studies may focus on controlled interventions to determine how best to support healthy aging through personalized nutrition.
