We expect to see good correlations between many aspects of our biology and aging: "Epigenetic variations have been widely described to occur during the aging process. To verify if these modifications are correlated with the inter-individual phenotypic variability of elderly people, we searched for a correlation between global DNA methylation levels and frailty. We found that the global DNA methylation levels were correlated to the frailty status in middle/advanced-aged subjects but not with age. A 7-year follow-up study also revealed that a worsening in the frailty status was associated to a significant decrease in the global DNA methylation levels. These results suggest that the relaxation of the epigenetic control in aging is specifically associated with the functional decline rather than with the chronological age of individuals. Thus, the modifications of DNA methylation, representing a drawbridge between the genetic and the environmental factors affecting the age-related decay of the organism, may play an important role in determining physiological changes over old age." Equally, it may go the other way - these changes could just as well be the symptoms of damaged systems flailing as they try to adapt to countless small breakages at the level of cells and molecular machinery. It is important in the development of therapies for aging to try to identify the root causes, as fixing those will also solve secondary issues.

Link: http://www.ncbi.nlm.nih.gov/pubmed/21336567