Association Between Diet Quality and Frailty with All-Cause Mortality and Life Expectancy in Older Adults

A new study published in Nutrients suggests that maintaining a high-quality diet could significantly blunt the life-shortening impact of frailty in middle-aged and older adults. Using data from more than 150,000 participants in the UK Biobank, researchers found that those who were frail but adhered to healthier dietary patterns lived substantially longer than peers with poorer diets—underscoring that it may never be too late to adopt better eating habits.

Frailty, marked by diminished strength, energy, and physiological resilience, is known to double or even triple mortality risk in older adults. Yet, until now, little was known about how overall diet quality might modify that risk.

Over a median follow-up of 12.2 years, the team identified 8,231 deaths among 151,628 participants aged 45 and older. Frailty was measured using two established tools—the frailty phenotype, which focuses on physical function, and the frailty index, which captures a broader range of health deficits. Diet quality was assessed using seven widely recognized indices, including the Alternate Healthy Eating Index (AHEI), Dietary Approaches to Stop Hypertension (DASH) score, Mediterranean Diet (MED) score, Dietary Inflammatory Index (DII), and three plant-based diet indices (overall, healthful, and unhealthful).

After adjusting for socioeconomic, lifestyle, and medical factors, the analysis revealed clear gradients: mortality risk rose with worsening frailty and declining diet quality. Frail individuals in the least healthy diet tertile faced up to a threefold higher risk of death compared with robust adults in the healthiest diet group. Conversely, those with higher diet quality scores—whether following DASH, Mediterranean, or other balanced patterns—showed markedly lower mortality across all levels of frailty.

The study also quantified these associations in terms of life expectancy. At age 50, frail men in the unhealthiest diet group could expect to live2 to 4.5 years less, and frail women 1.6 to 5.1 years less, than their counterparts with healthier diets. Even among prefrail individuals, healthier eating translated to measurable longevity gains.

These results were consistent across all seven dietary metrics, suggesting that the benefits stem from common dietary principles rather than any single pattern.

Importantly, the effects were stronger when frailty was defined by physical performance rather than by disease accumulation, hinting that nutritional status may more directly influence physical function than chronic disease burden. 

These results offer actionable insights for clinicians and policymakers: promoting high-quality diets in midlife and later life may help offset the health and longevity losses associated with frailty.