A study of more than 5,000 healthy people found that daily consumption of sugar-sweetened drinks like cola was associated with increased shortening of telomeres.
Telomeres are caps at the ends of chromosomes that protect DNA from damage and prevent loss of genetic information. Telomere shortening is linked to cell ageing, tissue damage, certain types of cancer and the risk of developing age-related illnesses such as diabetes and heart disease.
The study found that participants who reported drinking the equivalent of two cans of soda (about half a litre) per day had significantly shorter telomeres than those who did not.
Elissa Epel, professor of psychiatry at the University of California San Francisco (UCSF), and co-author on the study, said this was the first research to associate sugary drinks with telomere shortness and that the 'findings held regardless of age, race, income and education level'.
'Regular consumption of sugar-sweetened sodas might influence disease development, not only by straining the body's metabolic control of sugars, but also through accelerated cellular ageing of tissues,' Professor Epel said. She suggested this association could provide an explanation for the prevalence of obesity and early onset of age-related diseases in adults.
People who reported regularly drinking fizzy drinks had changes in DNA characteristic of 4.6 years of additional biological ageing, the study reported. Cindy Leung, lead author on the study, noted that this effect was similar to that associated with smoking.
'It is an interesting suggestion that … there's a fundamental relationship between excess sugar in the diet and telomeres,' Professor David Jacobs of the University of Minnesota, who was not involved with the study, told The Guardian. 'But disease is long-term, and these are small effects. You're going to need long-term studies with follow-up to really see what happens.'
The authors of the study cautioned that the research findings did not prove causality, and noted that the participants self-reported the amount of fizzy drinks they consumed. They will be tracking a number of patients to find out the effect of soft drinks on telomere length over time.