Introduction

Aging is a detrimental, progressive process that affects all human beings fortunate to live long enough. This indistinct process renders an individual increasingly susceptible to disease, disability and death. For this reason, aging is expensive, both personally for an individual and financially for society as a whole. Aging is probably the result of damage to several different mechanisms. There are numerous potential contenders, one of which is the involvement of mitochondria. Harman in 1972 was one of the first to suggest that mitochondria may have a central role in aging. Linnane in 1989 proposed that the accumulation of mitochondrial DNA (mtDNA) mutations during life is a major cause of age-related disease. With the explosion of molecular biology in the last decade, our understanding of mitochondrial aging has advanced, raising many questions as to if and how mtDNA mutations may be involved in aging.