Having Just One Soft Drink a Day Could Increase Your Cancer Risk

A new study links sugary beverages to an increased risk for obesity-related cancers. Dan Kitwood/Getty Images

Sugary sodas have garnered a bad reputation for rotting teeth, tacking on extra weight and increasing diabetes risk. A new study adds to the list of ill effects. According to the findings, people who drink even one soda a day increase their chances of developing several types of cancer including, liver, prostate, ovary and gallbladder.

Related: Low-Carb and Low-Fat Diets Equally Effective For Losing Weight: Study

Obesity is a risk factor for these cancers, and soft drinks have long been accused of contributing to weight, making it more difficult to isolate potential causes of the disease. This new study, however, found that even people who weren't overweight increased their risk of developing one of several obesity-related cancers.

That direct link, without the intermediary of weight, was unexpected. "We were surprised to find this increased cancer risk is not driven completely by obesity," epidemiologist and study author Allison Hodge, a senior research fellow at the Cancer Council Victoria in Australia, said in a post on the University of Melbourne's website.

Hodge and her team looked at the incidence of obesity-related cancers in more than 35,000 Australians. Among them, 3,283 developed one of the following cancers: kidney, colorectal, esophagus, post-menopausal breast, pancreas, endometrial, stomach, liver, aggressive prostate, ovary and gallbladder.

This wasn't the only revelation that baffled Hodge. The data indicated that only people who drank sugar-sweetened beverages, as opposed to diet soft drinks using sugar substitutes, were more likely to develop cancer. So the correlation between sugar and cancer was absent any tie to obesity. Hodge believes this shows that sugar is a significant contributor to the disease. The findings were published in February in Public Health Nutrition.

Health experts have worried for years about the safety of sugar substitutes. Animal studies have shown that artificial sweeteners cause cancer in mice, as well as weight gain. In 2017, researchers from Boston University reported that people who drank artificially sweetened beverages were more likely to suffer from stroke and dementia. No causal relationship was shown and other lifestyle factors could also contribute to the conditions.

This new study, however, does not absolve diet drinks from potential harm. "Those who regularly drink diet soft drinks are just as likely to be obese as those who regularly drink sugary soft drinks, which still carries health risks," said Hodge.

Many Americans have already cut down on soda. In March 2016, Fortune reported that soda sales hit a 30-year low after declining for 11 straight years.