Poor diet quality has been associated with several age-related chronic conditions, but its relationship to telomere length, a biological marker of cellular aging, is unclear. The purpose of this cross-sectional study was to determine whether overall diet quality was associated with relative leukocyte telomere length (rLTL) in a sample (n = 96) of nonsmoking middle-aged adults in Appalachia with at least one risk factor for cardiovascular disease. Diet quality was assessed using the Healthy Eating Index (HEI-2015), the alternate Mediterranean diet score (aMed), and the Dietary Screening Tool (DST). Peripheral rLTL was measured by quantitative real-time polymerase chain reaction. The associations between potentially confounding sociodemographic, lifestyle and health-related factors and the first and fourth rLTL quartile groups were examined using Chi-square or Fisher's Exact tests or logistic regression. The relationships between diet quality index scores and rLTL as a continuous variable were analyzed using simple linear regression and multivariate linear models, analogous to linear covariance analyses. The rLTL ranged from 0.46 to 1.49 (mean ± SEM was 1.02 ± 0.18). Smoking history, income level, and cardiovascular health (Life's Simple 7) were associated with the lowest and highest quartiles of rLTL and were used as covariates. In adjusted and unadjusted models, participants considered "at nutrition risk" by the DST were more likely to have shorter rLTL than those "not at risk or at potential risk" (p = 0.004). However, there was no evidence that adherence to the 2015⁻2020 Dietary Guidelines for Americans or to a Mediterranean diet was associated with rLTL in this sample. Intervention studies are needed to determine if improving the diet quality of those at nutrition risk results in reduced telomere attrition over time.
Keywords: Mediterranean diet; diet quality; dietary screening tool; telomere length.