Diet soft drinks tied to lower odds of colon cancer recurrence

• Warehouse manager Chad Sadler walks by cases of Coca-Cola and Diet Coke, waiting to be delivered to stores, in a warehouse at the Swire Coca-Cola facility in Draper, Utah, Mar 9, 2011. REUTERS

Colon cancer patients who drink one or more servings of artificially-sweetened beverages a day have roughly half the risk of their cancer recurring compared to those who drink few or none of these beverages, a US study suggests.

The study was not designed to prove whether or how drinking these beverages lowers the risk of colon cancer returning. The researchers can only theorise about reasons for their findings.

One reason might be that patients who consume artificially-sweetened drinks are substituting them for sugar-sweetened sodas and juices, and therefore taking in less sugar, the study authors write in the journal PLoS ONE.

“We have been studying the role of post-diagnosis diet and lifestyle on the risk of colon cancer, and a variety of factors are associated with recurrence,” said senior author Dr Charles Fuchs, director of the Yale Cancer Centre in New Haven, Connecticut.

These factors include obesity, a sedentary lifestyle, a “Western” diet high in carbohydrates, and sugar-sweetened beverages, Fuchs said in a phone interview.

About 30 percent of colon cancer patients who undergo surgery will have a recurrence, he noted.

“We suggest water as the healthiest option, but if you have a sweet tooth and want a sweet beverage, artificially-sweetened drinks may be an alternative,” Fuchs said.

The researchers analysed dietary information for 1,018 patients with stage III colon cancer who were enrolled in a National Cancer Institute-sponsored trial of adjuvant chemotherapy.

During the follow-up, 348 of the 1,018 patients had colon cancer recurrence. Frequent drinkers of artificially-sweetened beverages tended to be younger, have a higher body mass index and greater caloric intake.

Fuchs’ team found that patients who drank one or more artificially-sweetened drinks per day had a 46 percent lower risk of cancer recurrence than those who drank no more than one of these drinks per week.

“We do not presume to know the biologic effects, but artificially-sweetened beverages seem to account for at least part of the difference,” Fuchs said. “It can be difficult to quantify.”

Fuchs and colleagues are studying the effects of diet and lifestyle in other groups of cancer patients. They also want to understand how changing these behaviours can reduce cancer risk.

“People with colon cancer or another fearful disease may change their diet,” said Fumiaki Imamura of the University of Cambridge School of Clinical Medicine in the UK.

“To my knowledge, we do not have a good picture of those behavioural and possibly social changes among people with cancer,” Imamura said in an email. “Those changes and the effects of those changes are what to study in the future.”

Researchers also want to understand whether drinking artificially-sweetened beverages can reduce initial colon cancer risk as well. Recent studies found that drinking two 12-ounce servings of diet beverages per day led to substantial weight loss and maintenance after one year, which might, in turn lower the chances of developing colon cancer.

“Diet beverages can be a useful tool for managing body weight and reducing excess energy consumption, factors which reduce the risk of chronic disease, including colon cancer,” said John Peters of the University of Colorado Anschutz Health and Wellness Center in Aurora, who was not involved in the new study.

“Based on current evidence, there is no reason that people looking to manage their sugar and calorie intake should avoid diet beverages,” he told Reuters Health by email.