A new study in PLoS Genetics has linked epigenetic changes to the aging process, says New Scientist. King's College London researchers studied the DNA of 86 sets of twins, and found signs of methylation in 490 genes linked to aging. "These genes were more likely to be methylated in the older than the younger [sets of] twins," study author Jordana Bell tells New Scientist. This suggested to the researchers that those epigenetic changes may contribute to aging, and that they might be reversible. "The next challenge is to establish when gene methylation occurs. It can be triggered through lifestyle factors such as smoking, and environmental stresses," New Scientist adds. "It may one day be possible to develop enzymes that can remove the offending molecules from DNA and reverse methylation — and some aspects of aging."