Overweight teens who also eat a high-sodium diet have shorter telomeres, study finds.
When a slice of pizza or a burrito contains more than a day’s supply worth of sodium, it’s easy to see how growing teens can get too much. Their ravenous appetites often leave home freezers and pantries empty of these common packaged foods on a weekly basis.
Now a new study is finding that, when paired with obesity, these salty food-eating teens might be speeding up the shortening of telomeres, which is a marker of cellular aging. The findings were presented as an abstract at the American Heart Association’s (AHA) annual meeting on March 20.
Prior evidence had already shown that high levels of body fat are associated with telomere shortening. This new research suggests that high sodium levels combined with being overweight or obese could worsen the problem.
Haidong Zhu, M.D., Ph.D., the lead author of the study and an assistant professor of pediatrics at Georgia Regents University in Augusta, Ga., said that excessive sodium, obesity, and accompanying inflammation may result in a compounding effect on cells causing them to age faster.
The findings could have large implications on the health of teens in later life since telomere shortening is related to several chronic health problems. By latest U.S. estimates, male teens on average get about 4,300 milligrams of sodium daily and teen girls get about 2,900 milligrams. Those levels are well over the AHA’s recommended 1,500 milligrams per day for both groups and the Institute of Medicine’s recommended 1,500 to 2,300 milligrams per day.
The study included 766 teens aged 14 to 18 years old. They were divided into a low-intake group who consumed an average of 2,399 milligrams per day and a high-intake group who consumed an average of 4,142 milligrams per day.
Telomere health is influenced by several different factors of diet and lifestyle including smoking, lack of physical activity, and obesity; so the researchers were careful to control for these variables.
What they found was that the overweight and obese teens who had high intake of sodium had telomeres that were significantly shorter in comparison to those with lower intake of sodium. The telomeres of normal weight teens with a high sodium intake did not differ in length compared to those with a low intake.
The study is one of the first to show the acceleration of telomere shortening in such a young population.
Because the majority of sodium in teens’ diets comes from processed foods including breads, frozen pizza and burritos, and potato chips, Dr. Zhu suggested that parents ought to limit these foods in favor of lower-sodium alternatives including freshly cooked meals and fresh fruits and vegetables.
American Heart Association. Combo of overweight, high sodium intake speeds cell aging in teens [press release]. 2014 March 2014. Available at: http://newsroom.heart.org/news/combo-of-overweight-high-sodium-intake-speeds-cell-aging-in-teens?preview=50eb