Association of dietary protein intake with accelerated biological aging markers and all-cause mortality in adults

Background

Aging processes could be influenced by diet. However, the extent to which dietary protein intake is associated with biological aging (BA) markers remains poorly characterized.

Objectives

Here, we evaluated the association between dietary protein intake and BA markers and explored the extent to which BA markers mediate the association between protein intake and all-cause mortality.

Methods

We analyzed data from NHANES cycles 1999-2000 and 2001-2002. Dietary protein intake was expressed in g/kg/day. BA was estimated with TL, AnthropoAge, PhenoAge, and the Klemera-Doubal Method (KDM). Accelerated aging was defined as TL <25th percentile of the weighted population distribution and as residuals from BA markers regressed against CA. Survey-weighted logistic and linear regression models were fitted. Mortality correlates were evaluated using cause-specific Cox proportional hazards models and mediation analyses.

Results

Among 6,249 adults (median age: 45 [IQR: 34-58], 52% women), we found that participants in the highest protein intake quintile (>1.40 g/kg/day) had a lower adjusted likelihood of having accelerated aging by TL (OR: 0.40, 95% CI: 0.22-0.73), PhenoAge (OR: 0.54, 95% CI: 0.32-0.92), and KDM (OR: 0.53, 95% CI: 0.32-0.87), compared with those in the lowest quintile (<=0.62 g/kg/day). Higher dietary protein intake was associated with a lower hazard of all-cause mortality, and BA metrics partially mediated these associations.

Conclusions

Higher dietary protein intake was associated with a lower likelihood of accelerated aging and reduced mortality, with the latter association partially mediated by BA markers. Our findings suggest that dietary protein intake could influence healthy aging. Keywords: Protein, Aging, Accelerated aging