People with large numbers of moles may age slower than expected, according to a study from King’s. Researchers studied the skin and telomere length (a marker of biological ageing found on all cells in the body) of more than 1800 twins and found that people with a high number of moles had longer telomeres.
The 10 year study from the Twin Research Unit was funded by the Wellcome Trust and is published in the July edition of Cancer Epidemiology Biomarkers & Prevention.
Moles appear in childhood and disappear from middle age onwards. When present in large numbers they can increase the risk of melanoma, a rare form of skin cancer. Moles vary significantly in numbers and size between individuals. The average number of moles in people with white skin is 30 but some people may have as many as 400. Some moles may be 2mm in diameter whilst others are well over 5mm. The reason for such differences between people is unknown as is the function of moles. Doctors have suspected that people with lots of moles may have some advantages in view of the fact that moles are common in the general population. The Twin Research Unit has already shown in a previous study on over 2000 twins that up to 60 per cent of susceptibility to moles is inherited.
Since moles disappear with age, scientists at the Twin Research Unit looked at the relationship between the number of moles and telomere length, which is a good indicator of our rate of ageing. Telomeres, which get shorter as we age, are bundles of DNA found at the end of chromosomes in all cells and assist in the protection, replication, and stabilization of the chromosome ends. (Telomeres have been compared with the plastic tips on shoelaces because they prevent chromosome ends from fraying and sticking to each other). A measure of the telomere length in white cells in the blood has been found to correlate with ageing in many different organs such as heart, muscle, bones and arteries.
The researchers compared telomere length measurements in white cells with the number of moles in more than 1800 female twins (900 pairs of twins) aged between 18 and 79 years. They found that those with high numbers of moles (greater than 100) had longer telomeres than those with very few moles (fewer than 25). The difference between the two mole groups was equivalent to six to seven years of normal ageing (estimated by looking at the average rate of telomere length loss per year in the whole group). This was not affected by other factors such as age, weight or smoking.
These results suggest those with higher numbers of moles may have a delayed ageing 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 ageing.
Lead researcher Dr Veronique Bataille says: ‘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 ageing. 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.’
Professor Tim Spector, Head of the Twin Research Unit and co-author of the study, adds: ‘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 ageing process in general. We’ll examine the rate of ageing in the skin, muscles and bones in different groups according to their mole counts.’
Notes to editors
The Twin Research Unit at King’s College London has a database of 10,000 twins and studies a wide variety of diseases and traits and is always looking for more adult twin volunteers, male or female, identical or non-identical to help with their studies. To volunteer or for more information please phone: 020 7188 5555 or visit the website:www.twinsUK.ac.uk
King’s College London
King’s College London is the fourth oldest university in England with more than 13,700 undergraduates and nearly 5,600 graduate students in nine schools of study based at five London campuses. It is a member of the Russell Group: a coalition of the UK’s major research-based universities. The College has had 24 of its subject-areas awarded the highest rating of 5* and 5 for research quality, demonstrating excellence at an international level, and it has recently received an excellent result in its audit by the Quality Assurance Agency.
King’s has a particularly distinguished reputation in the humanities, law, international relations, medicine, nursing and the sciences, and has played a major role in many of the advances that have shaped modern life, such as the discovery of the structure of DNA. It is the largest centre for the education of healthcare professionals in Europe and is home to five Medical Research Council Centres – more than any other university.
King’s is in the top group of UK universities for research earnings, with income from grants and contracts of more than £100 million, and has an annual turnover of more than £363 million.
The Wellcome Trust is the largest charity in the UK. It funds innovative biomedical research, in the UK and internationally, spending around £500 million each year to support the brightest scientists with the best ideas. The Wellcome Trust supports public debate about biomedical research and its impact on health and wellbeing.
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