Washington: Daily consumption of a 20-ounce sugar-sweetened soda is associated with 4.6 years of additional biological ageing - effects that are comparable to that of smoking - a new study has warned.
Soda consumption might promote disease independently from its role in obesity, according to researchers from the University of California, San Francisco who found that drinking sugary drinks was associated with cell ageing.
The study found that telomeres - the protective units of DNA that cap the ends of chromosomes in cells - were shorter in the white blood cells of survey participants who reported drinking more soda.
The length of telomeres within white blood cells - where it can most easily be measured - has previously been associated with human lifespan.
Short telomeres also have been associated with the development of chronic diseases of ageing, including heart disease, diabetes, and some types of cancer.
"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," said Elissa Epel, professor of psychiatry and senior author of the study.
"This is the first demonstration that soda is associated with telomere shortness," Epel said.
"This finding held regardless of age, race, income and education level. Telomere shortening starts long before disease onset.
"Further, although we only studied adults here, it is possible that soda consumption is associated with telomere shortening in children, as well," Epel said.
Based on the way telomere length shortens on average with chronological age, the UCSF researchers calculated that daily consumption of a 20-ounce soda was associated with 4.6 years of additional biological ageing.
This effect on telomere length is comparable to the effect of smoking, or to the effect of regular exercise in the opposite, anti-ageing direction, according to UCSF postdoctoral fellow Cindy Leung, from the UCSF Center for Health and Community, lead author of the study.
The authors cautioned that they only compared telomere length and sugar-sweetened soda consumption for each participant at a single time point, and that an association does not demonstrate causation.
The UCSF researchers measured telomeres after obtaining stored DNA from 5,309 participants, ages 20 to 65, with no history of diabetes or cardiovascular disease, who had participated in an ongoing health survey in the US, called the National Health and Nutrition Examination Survey, during the years 1999 through 2002.
The findings were published in the American Journal of Public Health.