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.