Exercise & Fitness5+ Hours of Daily Screen Time Accelerates Biological Aging by Nearly 2 Years
A study combining observational data and Mendelian randomization found that spending five or more hours daily on leisure screen time is linked to accelerated biological aging, specifically as measured by GrimAge — one of the most mortality-predictive epigenetic clocks. Analyzing over 2,300 adults from a national health survey and using genetic data from more than 500,000 individuals, researchers found that each additional roughly two hours of daily screen time causally accelerates GrimAge by about 0.6 years. Key biological pathways driving this effect include higher BMI, elevated C-reactive protein, lower HDL cholesterol, type 2 diabetes, and heart failure. Together, these mediators explain up to 11.5% of the effect, suggesting other mechanisms remain to be identified.
