Sedentary lifestyle linked to faster ageing
People who do plenty of exercise appear to be biologically younger than those who lead a sedentary lifestyle, researchers have found.
Lack of exercise is already known to increase a person's risk of heart disease, high blood pressure, obesity, type-2 diabetes and some forms of cancer.
Now, researchers at King's College London have found visible signs of cellular ageing in people who are inactive.
The team studied 2,401 twins who were asked to provide a DNA sample and details of their activity levels, smoking habits and socioeconomic status.
The researchers then examined the length of telomeres - sections of DNA at the end of chromosomes - in people's white blood cells. Telomeres are known to shorten as a person ages.
They found that men and women who were less active tended to have shorter telomeres than those who did plenty of exercise, suggesting that their cells age at a faster rate than active people's cells.
Writing in the Archives of Internal Medicine, the study authors said: "A sedentary lifestyle increases the propensity to ageing-related disease and premature death.
"Inactivity may diminish life expectancy not only by predisposing to ageing-related diseases but also because it may influence the ageing process itself."
The researchers noted that the link between telomere length and a person's level of physical activity during leisure time was apparent even after body mass index, smoking, socioeconomic status and level of physical activity at work had been taken into account.
They revealed: "The mean difference in leukocyte (white blood cells) telomere length between the most active [who performed an average of 199 minutes of physical activity per week] and least active [16 minutes of physical activity per week] subjects was 200 nucleotides, which means that the most active subjects had telomeres the same length as sedentary individuals up to ten years younger, on average."
Exactly how lack of exercise affects telomere length is yet to be unravelled, but the researchers said that the results highlight the importance of regular exercise.
"They show that adults who partake in regular physical activity are biologically younger than sedentary individuals. This conclusion provides a powerful message that could be used by clinicians to promote the potential anti-ageing effect of regular exercise," they concluded.