Medical scientists have found that people with diabetes who take the drug Metformin have less
age-related disease than those taking other treatments and researchers believe it may prevent
numerous diseases and conditions that effect older people. In addition, metformin extends
lifespan in some animal models of human disease. The purpose of this study is to see if
taking Metformin causes changes in blood cells consistent with improved health and longevity
in people who do not have diabetes. In this study Metformin will be compared to placebo. A
placebo is a substance, like a sugar pill, that is not thought to have any effect on a
participants disease or condition. In this study participants will either receive the active
study medication, Metformin or placebo which is not active. Placebos are used in research
studies to see if the drug being studied really does have an effect.