If you are physically very active, the chances are your genetic material is ten years younger than it would be if you spent your life as a couch potato, researchers at King’s College London conclude in the Archives of Internal Medicine. The British researchers measured the length of the telomeres in 2400 twins for whom they had determined how much physical activity they had had in the previous year.
The longer your telomeres, the more time your genetic material still has to go. A number of studies have been published recently claiming that telomeres are longer in people who consume more vitamin D, do strength sports or are higher up the social scale.
The researchers measured the length of the telomeres in the DNA of white blood cells of the twins. The researchers divided the twins into four groups according to the amount of physical activity they had: inactive [16 minutes of physical activity per day], light activity [36 minutes of physical activity per day], moderate activity [102 minutes of physical activity per day] and heavy activity [199 minutes of physical activity per day].
The researchers did not take into account physical activity in the workplace. They only looked at how much physical activity the twins had in their free time.
The figure below shows the relationship between the amount of physical activity and telomere length.
As you can see, the researchers corrected for bodyweight, smoking and social environment [SES = socio economic score]. The researchers did so because there are studies that indicate that smoking and overweight accelerate the erosion of telomeres [Lancet. 2005 Aug 20-26;366(9486):662-4.], as does chronic stress [Proc Natl Acad Sci U S A. 2004 Dec 7;101(49):17312-5.].
The length of the telomeres in blood cells is also genetically determined. Some studies suggest that heredity determines the length for almost eighty percent. If you look at the effect of physical activity on telomere length in this light, then it would seem that physical activity is not an important factor. This is not the case, according to the researchers: they say physical activity reduces genetic aging by ten years.
Arch Intern Med. 2008 Jan 28;168(2):154-8.