Another breakthrough in the ever accelerating quest to extend human lifespan has seen researchers identify key genes associated with ageing. By studying these "ageing" genes, which are switched on or off by external factors such a diet and lifestyle, it's hoped that the biological mechanisms of ageing can be better understood.

In a study at Kings College London using groups of identical twins, genes were identified that are switched on or off by epigenetic factors - natural mechanisms other than the underlying DNA which change the gene expression, and could include external factors such as diet and environment.

Tests were conducted on 172 sets of twins ranging in age from 32 to 80, in which changes in the subject’s DNA were measured. These changes were then analyzed against the chronological age of the twins. Researchers found 490 age related epigenetic changes that could be used as a guide to the stages of biological ageing. In a follow up study aimed at validating the findings, 44 sets of younger twins aged 22 to 61 had their DNA analyzed and it was found that “many of the 490 age related epigenetic changes were also present in this younger group.” These results suggest that the epigenetic changes are initiated early in a person’s life, continue through to old age and may be manipulated through changes in lifestyle.

Researchers also looked at DNA modifications in age-related traits and found that epigenetic changes in four genes relate to cholesterol, lung function and maternal longevity. "We identified many age-related epigenetic changes, but four seemed to impact the rate of healthy ageing and potential longevity and we can use these findings as potential markers of ageing,” says Dr Jordana Bell, who co-led the study.

By investigating what triggers these genes to be epigenetically switched on or off, researchers hope the findings can have wider implications for anti-ageing therapies. “These results can help [us] understand the biological mechanisms underlying healthy ageing and age-related disease, and future work will explore how environmental effects can affect these epigenetic changes.”

The study also highlighted the value of using identical twins in the examination of the genes associated with the ageing process, explained Professor Tim Spector, from King’s College. “This study is the first glimpse of the potential that large twin studies have to find the key genes involved in ageing, how they can be modified by lifestyle and start to develop anti-ageing therapies. The future will be very exciting for age research.”