High Sodium Intake Speeds Aging in Overweight Teens

SAN FRANCISCO—Overweight or obese teenagers who eat high amounts of salty foods may show signs of faster cell aging, which plays an important role in the development of heart disease, according to research presented at the American Heart Association’s Epidemiology & Prevention/Nutrition, Physical Activity & Metabolism Scientific Sessions 2014.

Previous research found that protective ends on chromosomes (telomeres) naturally shorten with age, but the process is accelerated by smoking, lack of physical activity and high body fat. The current study is the first to examine the impact of sodium intake on telomere length.

For the study, 766 people 14- to 18-years-old were divided into the lowest or highest half of reported sodium intake. Low-intake teens consumed an average 2,388 mg/day, compared with 4,142 mg/day in the high-intake group. Both groups consumed more than the 1,500 mg/day maximum (about 2/3 teaspoon of salt) recommended by the AHA.

After adjusting for several factors that influence telomere length, researchers found in overweight/obese teens, telomeres were significantly shorter with high-sodium intake; in normal weight teens, telomeres were not significantly different with high-sodium intake.

“Even in these relatively healthy young people, we can already see the effect of high sodium intake, suggesting that high sodium intake and obesity may act synergistically to accelerate cellular aging," Haidong Zhu, M.D., Ph.D., lead author of the study and assistant professor of pediatrics at Medical College of Georgia, Georgia Regents University in Augusta, Ga.

said.

 The researchers said obesity is associated with high levels of inflammation, which also hastens telomere shortening and increases sensitivity to salt, which may help explain why higher sodium intake had a greater effect in that group.

“Lowering sodium intake may be an easier first step than losing weight for overweight young people who want to lower their risk of heart disease," Zhu said.

The road to reducing sodium in the food supply is a long one, but new sensory research and innovative new ingredients are helping to pave the way. A special report, “Reducing Sodium in the Food Supply: A Journey in Progress" from Food Product Design’s FoodTech Toolbox examines the latest research related to salty taste perception and consumer purchasing behavior, and also delves into sodium-reduction strategies that have proven successful, as well as those that hold promise for the future