Drinking sugary soft drinks may accelerate biological ageing as much as smoking, a study has found.
The findings, from an analysis of thousands of DNA samples, suggested that sweet fizzy drinks had worse effects on health than merely promoting obesity.
They may actually speed up the rate at which cells age - although scientists could not confirm that the effect was causal.
The study focused on telomeres, protective caps on the ends of the chromosomes that provide a measure of biological ageing.
Telomeres shorten with age, and short telomeres are associated with chronic problems of ageing such as heart disease, diabetes and some types of cancer.