Over 80? Protein Intake May Be Key to Longevity

Study Questions Strict Plant-Based Diets for the ‘Oldest Old’

New research suggests that adults over 80 who avoid meat may be less likely to reach 100 years old compared to their peers who regularly consume animal products.

Researchers followed more than 5,000 adults aged 80 and older in the Chinese Longitudinal Healthy Longevity Survey from 1998 to 2018. The findings, published in The American Journal of Clinical Nutrition, showed that participants who did not eat meat were less likely to become centenarians.

The results challenge long-standing research linking plant-based diets to lower risks of heart disease, stroke, diabetes and obesity — benefits largely documented in younger populations.

Shifting Nutritional Priorities With Age

Experts say nutritional goals change in advanced age. While midlife diets often focus on preventing chronic disease, the priority in one’s 80s and 90s shifts toward maintaining muscle mass, bone density and daily function.

Registered dietitian Erin Palinski-Wade noted that the association was observed primarily in underweight adults over 80. In participants who maintained a healthy weight, no such link appeared.

She also pointed out that the longevity gap disappeared among those who consumed eggs, dairy or fish — suggesting that adequate protein and micronutrient intake may be key.

Observational — Not Proof of Cause

Researchers emphasized that the study was observational and does not prove that avoiding meat directly reduces longevity.

Being underweight itself is linked to frailty and higher mortality risk, which may partly explain the findings.

Experts advise that seniors in their 80s prioritize adequate protein, vitamin B12, calcium and vitamin D intake. For some, that may mean incorporating modest amounts of animal-sourced foods or carefully planning plant-based diets with professional guidance.

For younger adults, plant-forward diets remain associated with long-term health benefits — but for the “oldest old,” balance may matter more than strict rules.