Health is determined by the most basic living functional unit of our biology – the cell. How well our cells work, how well they repair themselves and how well they reproduce is seen in the way we function at the level of our tissues, organs, systems and our performance in daily life. Aging is the result of cellular damage building up over time. Small inefficiencies in DNA repair, free-radical scavenging and telomere function create a cellular environment that further damages cells. The negative effects of poor cell health are seen across all biological scales, through tissues, organ systems, behavior, and performance.