Overweight or obese teenagers who consume high amounts of salty foods may experience accelerated cellular ageing, which is a risk factor for heart disease, a new study has found.

While salt (sodium) is essential for the body, too much increases the risk of high blood pressure. There are very few symptoms of high blood pressure and the only way you can find out if you have it is by having it measured by your doctor. As a result, it can cause silent damage to the blood vessels and heart.

US scientists decided to look into the role sodium plays in relation to telomeres. Telomeres cap the end of chromosomes in our cells, protecting them from damage. As we age, our telomeres shorten, leaving us more susceptible to cell damage, which causes disease. Previous research has also found that this process can be accelerated by a lack of exercise, smoking and high body fat.

This marks the first study to assess the potential impact of sodium on telomere length.

It included over 750 teenagers aged between 14 and 18. These were divided into two groups - those who consumed low amounts of sodium (around 2,300 mg/day) and those who consumed high amounts (around 4,100 mg/day).

The scientists found that overweight or obese teenagers who consumed high amounts of salt had significantly shorter telomeres.

"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," they said.

They suggested that reducing the consumption of salt ‘especially if you are overweight or obese, may slow down the cellular aging process that plays an important role in the development of heart disease'.

"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. The majority of sodium in the diet comes from processed foods, so parents can help by cooking fresh meals more often and by offering fresh fruit rather than potato chips for a snack," the team from Georgia Regents University added.

Details of these findings were presented at the American Heart Association's Epidemiology & Prevention/Nutrition, Physical Activity & Metabolism Scientific Sessions 2014 in California.

For more information on heart disease, see our Heart Disease Clinic here