More Early Damage, More Later Malfunctions
The reliability theory of aging is a framework for thinking about how biochemical damage leads to later dysfunction. When we damage ourselves, we pay the price later in an increased risk of disease and a shorter life expectancy. The body is a complex machine, and like all complex machines it runs less reliably as the wear and tear mounts. This research illustrates the point well: "Infections during the first year of life are a marker of increased risk of developing specific types of arthritis later in life ... infants who were hospitalised for infection before their first birthday had an increased likelihood of developing either juvenile idiopathic arthritis (JIA) or adult rheumatoid arthritis (RA) in later life." Some damage we can't help, but the majority is self-inflicted through poor choices in lifestyle: excess fat, lack of exercise, and so forth. Why lower your chances of living to benefit from the longevity medicine of the future?
Link: http://www.eurekalert.org/pub_releases/2008-06/elar-eli061308.php