SOME of the genetic changes associated with ageing may be the result of epigenetics - which suggests they could be reversed.
Molecules can attach to DNA, enhancing or preventing gene activation without changing the underlying genetic code. Such epigenetic changes are already suspected as factors in psychiatric disorders, diabetes and cancer.
They may also play a role in ageing. Jordana Bell of King's College London and colleagues looked at the DNA of 86 sets of twin sisters aged 32 to 80, and discovered that 490 genes linked with ageing showed signs of epigenetic change through a process called methylation.
"These genes were more likely to be methylated in the older than the younger [sets of] twins," says Bell, suggesting that the epigenetic changes themselves might contribute to ageing (PLoS Genetics, DOI: 10.1371/journal.pgen.1002629).
The next challenge is to establish when gene methylation occurs. It can be triggered through lifestyle factors such as smoking, and environmental stresses.
It may one day be possible to develop enzymes that can remove the offending molecules from DNA and reverse methylation - and some aspects of ageing.