Sugary Drinks, Including 100 Percent Fruit Juice, May Increase Cancer Risk

A new observational study has found a link between consuming sugary drinks, including 100% fruit juice, and cancer risk.

For some time, researchers have linked sugary drinks to a wide range of health risks.

Obesity, type 2 diabetes and cardiovascular diseaseare just a few of the health conditions associated with sugary drinks.

Some earlier studies in rodents showed that sugar added to soft drinks could cause tumors to grow and spread.

Now, new research is examining the link between sugary drinks and cancer in greater detail. BMJpublished the observational study discussed in this article, which found an association between high sugary drink intake and cancer.

At the Sorbonne Paris Cité Epidemiology and Statistics Research Center in France, Eloi Chazelasis the study’s lead author.

Examining Cancer Risk Associated With Sugary Drinks

Chazelas and his team examined the links between sugary drink intake and different types of cancer in a total of 101.257 French adults with an average age of 42. The researchers obtained data from the NutriNet-Santé study.

The drinks they examined included soft drinks, syrups, fruit drinks, 100% fruit juices with no added sugar, sweetened milk-based drinks, sports drinks and energy drinks .

The researchers also assessed artificially sweetened drinks, meaning diet soft drinks, sugar-free syrups, and diet milk-based drinks, as “all drinks containing nonnutritive sweeteners.”

How Do Sugary Drinks Accelerate Cancer Development?

Using online 24-hour dietary questionnaires, the researchers assessed participants’ consumption of 3.300 different types of food and drink. Clinical observation of the participants also continued for up to 9 years.

During this time, the researchers examined the risk of “overall, breast, prostate, and colorectal cancer.”

Chazelas and colleagues also accounted for potential confounders such as age, sex, education, hereditary cancer risk, and lifestyle factors such as smoking behavior and exercise patterns.

22% Greater Breast Cancer Risk

During follow-up, 2.193 people were newly diagnosed with cancer; their average age at diagnosis was 59. These cases included 693 breast cancers, 291 prostate cancers, and 166 colorectal cancers.

The analysis found that, for each 100-milliliter increase in daily sugary drink intake:

• Overall cancer risk increased by 18%,
• and breast cancer risk increased by 22%.

When the researchers separately analyzed the risk associated with 100% fruit juices , they found that these also increased the risk of overall cancer and breast cancer. However, the study found no link with colorectal 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 quantities, so they recommend interpreting this particular finding cautiously.

Strengths and Limitations of the Study

Chazelas and colleagues outline the strengths and limitations of their research.

First, the “large sample size and detailed, up-to-date assessment” of sugary drinks strengthen the findings.

However, because the study group was not representative of the wider population, the findings may not be broadly generalizable.

Participants in the NutriNet-Santé cohort were more often women. Their greater health awareness and higher socioprofessional and educational levels compared with the general French population may have contributed to cancer rates below national estimates.

Other limitations include the inability to establish causation and potential measurement biases. Nevertheless, the authors suggest that sugary drinks may increase cancer risk because the excess energy intake from sugary drinks is directly associated with body fat, blood glucose, and inflammatory markers, which in turn are associated with greater cancer risk.

The Researchers Conclude:

These data suggest that limiting sugary drink consumption, including 100% fruit juice, could potentially help reduce cancer cases. They also support policy measures targeting sugary drinks, such as taxes and marketing restrictions.