Women who spend too much time sitting down speed up the aging process.
Sitting for more than ten hours a day gives women a biological age that is up to eight years older than their actual age. Biological age is how old a person’s body seems by looking at their cells. The researchers found a strong link between a sedentary lifestyle and the premature aging of cells. This process is known to increase the risk of cancer, diabetes and heart disease.
Just half an hour a day of moderate exercise, such as brisk walking, gardening or cycling, is enough to undo the damage from too much time spent sitting. But many fail to do even this level of exercise. Experts said the findings should come as a wake-up call to those who spend hours without moving.
Those who work in sedentary jobs are likely to sit for even longer, including office workers, who spend an average of 75 per cent of their working day sitting in front of a computer screen. Dr Aladdin Shadyab, of the University of California, San Diego, who led the research, said: Our study found cells age faster with a sedentary lifestyle.
‘Chronological age doesn’t always match biological age.’ Dame Sally Davies, the Government’s chief medical officer, has called inactivity a silent killer. She advises adults to spend 150 minutes a week – half an hour each weekday – doing moderate activity in bursts of ten minutes or more.
In the latest study, the San Diego team tracked 1,481 women over the age of 64 using accelerometers – small gadgets attached to the belt which recorded every movement. Using blood tests, they also analysed the health of their cells. The women, who had an average age of 79, showed a far greater degree of damage to their cells if they moved less.
The scientists examined their telomeres, which are tiny caps found on the ends of our DNA strands, often compared to the plastic tips of shoelaces, that protect our chromosomes from deterioration. Women who were more sedentary had shorter and more frayed telomeres, which scientists use to calculate biological age.
Dr Shadyab, who is a post-doctoral fellow in Family Medicine and Public Health, added: ‘We found that women who sat longer did not have shorter telomere length if they exercised for at least 30 minutes a day, the national recommended guideline. Discussions about the benefits of exercise should start when we are young, and physical activity should continue to be part of our daily lives as we get older, even at 80 years old.