A new observational study finds a link between the consumption of sugary drinks, including 100% fruit juices, and the risk of cancer.

People who drink a lot of sugary drinks have a high risk of developing cancer, researchers announced last week. However, the evidence cannot yet establish a direct connection between the two. The researchers said the findings of a large study in France suggest that limiting the amount of sugar-sweetened drinks may help reduce the number of cancer cases.

Drinking sugary drinks has become more common worldwide in the last several decades. Sugar drinks are linked to obesity – the condition of being extremely overweight — which increases a person’s cancer risk. The researchers noted how many sugary drinks each of them had, and followed them for up to nine years — between 2009 and 2018. The researchers measured their risk for all types of cancer, and some individual ones such as breast, colon and prostate cancers.

The researchers adjusted for other possible cancer risks in each individual, including age, sex, educational level, family history, smoking and physical activity levels. The scientists found that a 100 milliliters increase in sugary drinks was linked to an 18 percent increased risk of overall cancer and a 22 percent increased risk of breast cancer. The researchers looked at those who drank fruity juices and those who drank other sweet drinks. Both groups, they found, showed a higher risk of cancer overall. For prostate and colorectal cancers, no link was found. The researchers said this might have been because there was only a limited number of cases of these cancers in the study group. Experts not directly involved in the work said it was a well-run study, but noted that its results could not establish cause and effect. “The message from the totality of evidence on excess  sugar consumption and various health outcomes is clear, Reducing the amount of sugar in our diet is extremely important.”

A 22% higher risk of breast cancer

Over the follow-up period, 2,193 people developed cancer for the first time; they were 59 years old at the time of diagnosis, on average. Among all these cases were 693 of breast cancer, 291 of prostate cancer, and 166 colorectal cancer.

The analysis revealed that for a daily increase of 100 milliliters in the intake of sugary drinks, the risk of overall cancer rose by 18%, and the risk of breast cancer increased by 22%.

When the researchers analyzed the risk for 100% fruit juices separately, these also elevated the risk of overall cancer and breast cancer. However, the study found no links with colorectal cancer or prostate cancer. By contrast, diet drinks did not increase cancer risk. The scientists explain that people who consumed diet drinks did so in very small amounts, so they suggest interpreting this particular result with caution.