Abstract: Disclosed are methods for measuring the effects of environmental, physiological, or lifestyle variables on DNA damage and DNA repair activity as well as the use of measurements of DNA damage and DNA repair activity to predict increased risk for disease. Embodiments of the methods involve the use of a combination of assays to measure DNA damage and DNA repair activity in an individual and comparing these measurements to suitable controls using the selected assays for normal healthy individuals of varying ages. In other embodiments, the methods may comprise a comparison of DNA damage levels to DNA repair levels to obtain an apparent net measurement of DNA damage accumulation.