Exercise may be fountain of youth

LONDON, Jan. 28 (UPI) -- Adults who partake in regular physical activity are biologically younger than sedentary individuals, a British study found.

Lynn F. Cherkas of King's College London and colleagues studied 2,401 white twins, administering questionnaires on physical activity level, smoking habits and socioeconomic status. The participants also provided a blood sample from which DNA was extracted.

The researchers examined the length of telomeres -- repeated sequences at the end of chromosomes -- in the twins' white blood cells, or leukocytes. Leukocyte telomeres progressively shorten over time and may serve as a marker of biological age.

The study, published in the Archives of Internal Medicine, found the mean difference in leukocyte 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.

In other words, the most active subjects had telomeres the same length as sedentary individuals up to 10 years younger, on average.