Diet sodas have garnered a bad reputation, but surprising research published this week in the journal PLOS One may help dispel it.
According to a prospective lifestyle and diet investigation that was embedded in a clinical trial for stage III colon cancer patients, frequent consumption of artificially sweetened carbonated beverages is associated with nearly 50 percent less chance of death from cancer recurrence.
“Artificially sweetened drinks have a checkered reputation in the public because of purported health risks that have never really been documented,” Dr Charles S. Fuchs, lead author and director of Yale Cancer Center, said in a statement. “Our study clearly shows they help avoid cancer recurrence and death in patients who have been treated for advanced colon cancer, and that is an exciting finding.”
Though none have yielded conclusive evidence, several previous studies have suggested there is a link between zero-calorie sweeteners, such as aspartame and sucralose, and obesity, diabetes, and cancer. On the other hand, sugary beverages have been quite definitively linked to metabolic diseases and tentatively linked to worse cancer outcomes. A recent, large investigation of colon cancer patients revealed that those who frequently consumed these high-calorie, high glycemic index drinks were more likely to have tumors return after treatment and to die sooner.
Hoping to add some clarity to this confusing and contentious subject, Fuchs’ team asked 1,018 patients enrolled in a randomized trial testing a new chemotherapy drug for advanced adenocarcinoma of the colon to fill out a series of comprehensive lifestyle questionnaires. The patients were then followed for a median of seven years.
When examining the resulting dataset, which included patients from both treatment arms because there was no difference in outcome, the authors discovered that patients who drank one or more 12-oz diet sodas per day experienced a 46 percent reduction in the risk of recurrence or death, after adjusting for a variety of confounding factors. In addition, an overall pattern was observed wherein the amount of time until cancer returned and overall survival time increased as artificially sweetened drink intake went up.
Using a statistical analysis method called substitution modeling, Fuchs and his colleagues demonstrated that replacing one 12-oz serving of a sugar-sweetened drink per day with a 12-oz diet drink lowered recurrence and mortality risk by 23 percent – meaning that half of the benefit of artificial sweeteners can be explained by the fact that they are removing unhealthy sugar from one’s diet. The authors do not speculate what mechanism could be behind the other 23 percent, though they note that there is a possibility that people who favor diet beverages develop less aggressive tumors than those who do not.
“While the association between lower colon cancer recurrence and death was somewhat stronger than we suspected, the finding fits in with all that we know about colon cancer risk in general,” Fuchs said. “We now find that, in terms of colon cancer recurrence and survival, use of artificially sweetened drinks is not a health risk, but is, in this study, a healthier choice.”
Of course, observational studies of this nature can’t determine causality and there are several key limitations to consider. Firstly, there is a chance of confounds from socioeconomic factors that were not adjusted for. And secondly, people who join clinical trials could be different than the general population. The authors note that the small number of subjects who consumed two or more servings of artificially sweetened beverages a day (n = 42) could also have skewed results.
The Yale team concludes that their intriguing findings should be confirmed with more research.