Many know that a high-sodium diet isn’t healthy. But a new finding from the American Heart Association (AHA) suggests that for overweight youth, eating a lot of salt could also speed cell aging, a key factor in developing heart disease, reports Time.com.

For the study, 766 teens between ages 14 and 18 were divided into two categories: a low-sodium intake group that consumed an average of 2,388 milligrams of salt each day, and a high-sodium intake group that consumed 4,142 mg each day. (FYI, both groups ate far more than the AHA-recommended maximum of 1,500 mg, or two-thirds of a teaspoon).

Next, scientists checked the protective ends (a.k.a. telomeres) of the teens’ chromosomes. (Telomeres naturally shorten as we age.) Previous studies showed that this genetic aging process is accelerated by smoking, obesity and a lack of physical activity. But these researchers wanted to see if diet also had something to do with the genetic aging process.

The result? Scientists found that diet did indeed play a role. By the end of the trial, overweight and obese teens who ate high-sodium diets had significantly shorter telomeres than the low-sodium group. But the telomeres of normal weight teens with high-sodium diets didn’t seem to have this increased shortening effect.

“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,” said Haidong Zhu, MD, PhD, an assistant professor of pediatrics at Georgia Regents University, and lead study author.

Scientists suspect that since obesity is associated with high levels of inflammation, the condition may increase a person’s overall sensitivity to salt. This helps explain why a higher sodium intake might have a much greater effect on the health of those in this group.

The majority of sodium in our diets comes from processed foods. But by cooking fresh meals more often and choosing healthy snack options, such as fruits and vegetables, rather than potato chips, parents can seriously help cut their kids’ cardiovascular risk. Click here for more tips.