Overweight teenagers who eat a lot of salty food may age more quickly, new research suggests.
American researchers discovered that these youngsters show signs of faster cell ageing.
Consuming a lot of salt may also put them at greater risk of heart disease, the research showed.
The study, conducted by researchers at Georgia Regents University, in Augusta, also revealed that lowering salt intake could slow down the ageing process of cells.
This is likely to be particularly effective in people who are overweight or obese.
It has previously been shown that the protective ends of chromosomes – known as telomeres – naturally shorten with age and that the process is accelerated by smoking, lack of physical activity and high body fat.
However, this was the first study to examine the impact of salt intake on telomere length.
In the study, 766 people aged between 14 and 18 were divided into groups based on their level of salt intake.
The researchers found that obese teenagers who eat a lot of salt have significantly shorter telomeres than those who do not.
However, they also found that in healthy weight teenagers, sodium intake does not have a significant impact on telomere length.
Telomeres are biological caps which are found at the ends of chromosomes and protect the DNA in them from damage, much like the caps on the ends of shoelaces prevent fraying.
As we get older, our telomeres get shorter and shorter, leading to DNA becoming damaged and raising the odds of age-related illnesses such as Alzheimer’s, diabetes and heart disease.
Shorter than average telomeres are seen as a sign of ill health and a predictor of premature death.
Lead researcher Dr Haidong Zhu said: ‘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 ageing.’
The scientist explained that 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 overweight people.
‘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,’ she said.
‘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 [crisps] for a snack.’
The researcher was presented at the American Heart Association’s Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism Scientific Sessions 2014.
source: dailymail UK