Ageing genes identified in twin study

Chemical alterations in a group of genes affect how we age, scientists have discovered. These changes switch genes on or off in response to diet or environmental factors throughout our lives. Researchers found that four genes that are epigenetically switched off in later life may have a bearing on how well we age.

Epigenetic changes have previously been connected to the ageing process, but exactly how and when these changes occur remains unclear. This study, published in PLoS Genetics, identified 490 epigenetic changes that increased with age, but as co-author Dr Jordana Bell from King's College London, explained, 'four seemed to impact the rate of healthy ageing and potential longevity'.

Changes to these four genes were linked to differences in cholesterol levels and lung function, and researchers think they will be useful as potential markers of ageing.

Initially, the team identified the epigenetic changes in the DNA of 172 identical twins aged 32 to 80. However, analysis of a set of 44 younger twins, aged 22 to 61, revealed that several alterations can also occur in young adults. Epigenetic changes usually begin with a single trigger, and this work suggests that a proportion of these alterations may be triggered early in life.

Pairs of identical twins were used to distinguish genetically inherited traits and those caused by environmental factors.

'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', said co-author Professor Tim Spector, the director of the Department of Twin Research at King's College London. 'The future will be very exciting for age research'.

Understanding which genes are involved in ageing and how they are regulated may be the key to generating useful anti-ageing drugs. However, the genes identified by this study may only be the tip of the iceberg.

Study co-leader Dr Panos Deloukas, from the Wellcome Trust Sanger Institute in Hinxton, Cambridgeshire, said: 'Our study interrogated only a fraction of sites in the genome that carry such epigenetic changes; these initial findings support the need for a more comprehensive scan of epigenetic variation'.