Physical activity and telomere length in U.S. men and women: An NHANES investigation.
Level 4 - case-series / case-control
Cross-sectional observational analysis of survey data
PubMed 28450121 · doi:10.1016/j.ypmed.2017.04.027
What was done
Researchers analyzed cross-sectional data from 5,823 U.S. adults in the 1999–2002 National Health and Nutrition Examination Survey (NHANES). Leukocyte telomere length (LTL) was measured using quantitative polymerase chain reaction (qPCR) relative to standard reference DNA. Physical activity was quantified in MET-minutes based on self-reported frequency, intensity, and duration across 62 physical activities. Multiple demographic and lifestyle covariates were statistically controlled.
What was found
Telomeres shortened by 15.6 base pairs for each chronological year of age (F=723.2, P<0.0001). Physical activity was significantly associated with LTL after adjusting for covariates (F=8.3, P=0.0004). Adults in the high activity group had telomeres that were 140, 137, and 111 base pairs longer than those in the sedentary, low, and moderate activity groups, respectively. This translated to an estimated biological cellular aging advantage of 9.0 years compared to sedentary adults, 8.8 years compared to low activity adults, and 7.1 years compared to moderate activity adults.
Why it matters
This study shows that high volumes of physical activity correlate with significantly longer leukocyte telomeres in a nationally representative population, suggesting cellular-level biological aging benefits.
Limits
The study is cross-sectional, precluding causal conclusions or determination of whether physical activity directly prevents telomere shortening. Physical activity was self-reported across 62 activities, introducing potential recall and reporting biases. Telomere length was measured at a single time point in circulating leukocytes only.