Patients may ask about a widely reported study, published in The BMJ, linking sugary drinks to cancer. Researchers studied over 100,000 French adults (nearly 80% women) who completed at least two 24-hour dietary assessments over a 2-year period. The average age at baseline was 42.
During a median 5 years’ follow-up, nearly 2,200 incident cancers were diagnosed, about one third of which were breast cancers. Overall cancer risk increased with each 100-mL/day (3.4 oz/day) increase in consumption of sugar-sweetened beverages, including soft drinks and 100% fruit juices. Risk for breast cancer — in particular, premenopausal breast cancer — also increased with sugary beverage intake, although fruit juices alone did not confer elevated risk. Risks for other cancers, including colorectal and prostate, were not associated with sugary drinks.
The researchers adjusted for numerous confounders, including BMI, smoking status, and family history of cancer. Nonetheless, they caution: “This is an observational study, thus causality of the observed associations cannot be established and residual confounding cannot be entirely ruled out.”