People with a lot of moles may age slower than those with few moles, say British scientists, who suggest this may mean fewer age-relatedillnessessuch as heart disease or osteoporosis for "moley people."
In a 10-year study of more than 1,800 twins, researchers at the University of London's King's College, found those with more than 100 moles had a biological age six to seven years younger than those with fewer than 25 moles.
The study was published in the July edition of Cancer Epidemiology Biomarkers & Prevention.
The researchers estimated age using telomere length. Telomeres, which get shorter as we get older, are bundles of DNA found at the end of chromosomes in all cells and help protect, replicate and stabilize chromosome ends.
Scientists say telomeres are like the plastic tips on shoelaces, because they prevent chromosome ends from fraying and sticking to each other.
While large numbers of moles are linked to an increased risk of melanoma, a rare form of skin cancer, doctors have long suspected that people with lots of moles may have some advantages because moles are common in the general population.
Moles appear in childhood and disappear starting at around middle age. They can vary significantly in numbers and size. Scientists don't know why there are such differences between people, or even the function of moles.
"The results of this study are very exciting as they show for the first time that moley people, who have a slightly increased risk of melanoma, may, on the other hand, have the benefit of a reduced rate of aging," said lead researcher Dr. Veronique Bataille.
"This could imply susceptibility to fewer age-related diseases such as heart disease or osteoporosis, for example. Further studies are needed to confirm these findings."
These results suggest those with higher numbers of moles may have a delayed aging as they have longer telomeres and appear to keep their moles for longer. In contrast, people with shorter telomeres have lower numbers of moles and appear to lose them quicker with age — which may be a marker of accelerated aging.
"We now plan to look in more detail at the genes which influence the numbers of moles and to see whether they may also slow down the aging process in general. We'll examine the rate of aging in the skin, muscles and bones in different groups according to their mole counts," said Tim Spector, study co-author.