A sedentary, inactive lifestyle accelerates aging

The harmful health effects of a sedentary (inactive) lifestyle are well known, but younger people are not the only ones affected by lack of exercise. New research reveals the effect of low physical activity on older women’s biological age.

A sedentary lifestyle accelerates biological aging

Our cells age as we grow older. Indeed, because cells make up every organ in our body, true aging is cellular aging , we might say. However, the rate at which cells age differs from person to person.

Lifestyle factors such as alcohol consumption, smoking and lack of exercise can substantially affect cellular aging rates.

Our cells normally respond to stimuli from within and outside the body through various biological pathways. Genetic regulation is one such pathway.

Our cells contain, at the ends of their DNA, telomeres consisting of repeated nucleotide sequences. Telomeres protect chromosomes from deterioration, much as structures at the ends of shoelaces protect them from fraying.

Telomere length has been associated with aging and various diseases. As we age, telomeres shorten until cells die or become cancerous; more precisely, each division of DNA shortens telomeres. Short telomeres have been associated with cancer, cardiovascular disease and diabetes.

Study

A study published in January 2017 in the American Journal of Epidemiology evaluated the connection between telomere length, exercise and biological age. In women with an average age of 79, numbering 1481, it established the relationship between leukocyte (white blood cell) telomere length (LTL) and time spent inactive.

Sedentary time was assessed both through participants’ self-reports and a movement monitor (accelerometer) worn on their right hip for 7 days.

Women living sedentary lives were found to be biologically 8 years older

The study found that women who exercised little and remained inactive for more than 10 hours daily had biologically “older” cells than women who were less sedentary and exercised more.

The study shows that cells age faster with a sedentary lifestyle and that chronological (calendar) age does not always match biological age.

According to the researchers, this is the first study demonstrating the connection between a sedentary lifestyle, exercise and telomeres. It also highlights the importance of lifestyle choices for telomere length and aging. Discussions about exercise benefits should begin when people are young, and physical activity should continue at every age.