Тема в розділі 'Гуляй-Поле', створена користувачем Крук, 16 вер 2013.
Healthy living can turn our cells' clock back
00:01 17 September 2013 by Andy Coghlan
Healthy living can reverse the telltale signs of ageing in your cells.
The finding relates to telomeres, the caps that protect the tips of chromosomes when cells divide. With each cell division these get shorter, so as we age they wear away like a candle wick burning down. Now there is evidence that telomeres can regrow if people switch to, and maintain, a healthy lifestyle.
The study involved 10 men in their early 60s, who were asked to follow a strict healthy living regime. They ate a meat-free diet, exercised for 30 minutes a day, did an hour of yoga and meditation a day, and attended group therapy sessions each week.
After five years, the telomeres on a type of white blood cell were on average 10 per cent longer in these men than at the start of the study. In contrast, 25 men who kept to their usual lifestyles saw telomeres on the same cells shrink by an average of 3 per cent over the same period.
The researchers also found that the more strictly the 10 men stuck to the healthy regime, the longer their telomeres became.
"It's a very encouraging finding," says Dean Ornish of the Preventive Medicine Research Institute in Sausalito, California, who led the study. "In a biological sense, they are getting younger, but what the long-term implications are we don't know," he says.
Tale of the telomeres
Previous studies comparing telomere lengths in individuals against the population as a whole suggest that shorter telomeres are linked with ill health, including heart disease, dementia and cancer, and also with a shorter lifespan.
Telomeres are known to regenerate in stem cells and in some cancer cells, but this study is the first to show that a specific lifestyle change can make them do so in ordinary cells.
"These results are very nice, and hold promise for preventive medicine," says Maria Blasco, head of the telomere group at Spain's National Cancer Research Centre in Madrid. Earlier this year, her group published results showing that telomeres grow in mice fed calorie-restricted diets while they shrink in mice on standard diets.
However, not everyone is convinced by the telomere data. "The [same] methods used to measure telomere length in an earlier paper have been called into question," says Carol Greider of Johns Hopkins University School of Medicine in Baltimore, whose discovery of telomerase earned her a share of the Nobel prize in 2009. "It's not clear if very small changes are real, or normal fluctuation in noisy data," she says.