Dietary Diversity Modified the Association of Per- and Polyfluoroalkyl Substances with Accelerated Biological Aging: Evidence from the China National Human Biomonitoring Study

Per- and polyfluoroalkyl substances (PFASs) can impact various systems in the human body. However, their influence on biological aging remains unclear. This study aims to investigate the association between PFASs exposure and biological aging based on data from 9756 participants in the China National Human Biomonitoring Program and assesses the potential moderating effect of Dietary Diversity Score (DDS). Biological age indexes were calculated using the Klemera–Doubal method (KDM) and Mahalanobis distance (MD). The DDS was calculated based on the consumption frequency of 13 food groups over the past 12 months. Most PFASs showed positive associations with KDM-age acceleration (KDM-AA), while no statistically significant associations were observed with MD. The dose–response relationships of PFASs with KDM-AA and MD were steeper at low concentrations of PFASs, and then the slope appeared flat at higher concentrations. The weighted quantile sum revealed positive mixture effects of PFASs on biological aging. PFHpS and PFNA were both major contributors to KDM-AA and MD. DDS appeared to potentially modify the association between PFASs and biological aging. Our findings demonstrate that PFASs were significantly associated with accelerated biological aging, whereas higher DDS mitigates these adverse effects, highlighting the importance of this preventive measure.