Described herein are the results of comprehensive genetic expression and other molecular analysis of the effect of antioxidants on biological systems, including specifically different human cells. Based on these analyses, methods and compositions are described for modifying or influencing the lifespan of cells, tissues, organs, and organisms. In various embodiments, there are provided methods for modulating the activity of the gene maintenance process in order to influence the length and/or structural integrity of the telomere in living cells, as well as methods for modulating the rate/efficiency of the cellular respiration provided by the mitochondria, mitochondrial biogenesis, and maintenance of the mitochondrial membrane potential. Exemplary lifespan altering compounds include natural and synthetic antioxidants, such as plant antioxidant and polyphenol compounds derived from coffee cherry, tea, berry, and so forth, including but not limited to caffeic acid, chlorogenic acid, ferulic acid, quinic acid, proanthocyanidins, ubiquinone, idebenone, or a synthetic form or derivatives thereof.