People with a higher number of moles appear to age more slowly than those with fewer, according to research from the Twin Research Unit at King's College London.

Moles appear in childhood and disappear as we get older. Although their function is unknown, when present in large numbers they can increase the risk of melanoma, a rare form of skin cancer.

Now, a study of more than 1800 twins has found that people with a high number of moles have longer telomeres. Telomeres, which get shorter as we age, are bundles of DNA found at the ends of chromosomes in all cells and assist in the protection, replication and stabilisation of the chromosomes. They have been compared with the plastic tips on shoelaces because they prevent chromosome ends from fraying and sticking to each other.

The researchers, led by Dr Veronique Bataille, found that people with more than 100 moles had longer telomeres than those with fewer than 25. The difference was equivalent to up to seven years of normal ageing.

The results suggest that despite a slightly increased risk of melanoma, people with a higher number of moles benefit from a reduced rate of ageing, implying less susceptibility to age-related diseases such as heart disease or osteoporosis.

The research was funded by the Wellcome Trust, the Arthritis and Rheumatism Council and the National Institutes of Health.

Image credit: David Benbennick

External links

• Bataille V et al. Nevus size and number are associated with telomere length and represent potential markers of a decreased senescence in vivo. Cancer Epidemiology Biomarkers & Prevention 2007;16:1499-1502.
• Twin Research Unit, King's College London