Telomeric DNA length in cerebral gray and white matter is associated with longevity in individuals aged 70 years or older

Many studies have demonstrated the association between telomere length in mitotic cells and carcinogenesis and mortality, but little attention has been focused on post-mitotic cells and human life expectancy. We assessed the relationship between telomere length in cerebral gray and white matter and longevity in 72 autopsied Japanese patients aged 0-100 years using Southern blot hybridization. The mean telomere lengths in the gray and white matter were 12.3 ± 2.5 kilobase pairs and 11.4 ± 2.1 kilobase pairs, respectively. The mean telomere lengths in 60-69 year decadal group were less than those of neonates, and declined further in the 70-79-year age group, but those in groups of further advanced age were longer than in the 70-79 year group (70-79 < 80-89 < 90-100 years of age). Thus, the 90-100-year age group possessed significantly longer telomeres than the 70s (p = 0.029). Autopsy protocols showed a decrease in the rate of cancer death in individuals in their 80s (p = 0.041) and 90s (p = 0.017) versus those in their 60s, and in their 80s the mean telomere length in the gray matter from cancer death patients was significantly shorter than that of patients who died of other diseases (p = 0.04). These data suggest that innate telomere lengths are maintained very well in the cerebrum, and are associated with longevity. Our study lends indispensable support to the hypothesis that longer telomeres protect the genome from instability (a major cause of carcinogenesis) and are beneficial for longevity.