Is Diet Cola Better for You?

People often choose diet colas with non-caloric artificial sweetners over regular cola because they think they are better for them. But a new study adds more reason to doubt this belief. . . .

People often choose diet soft drinks over regular soft drinks because they think that replaceing the sugar with non-caloric artificial sweeteners is better for blood sugar.

But a new study has found that drinking commonly used artificial sweeteners leads to the development of glucose intolerance, possibly by negatively affecting intestinal bacteria. That means that artificial sweeteners, instead of helping to prevent diabetes, may actually promote it by leading to the development of glucose intolerance in healthy people (Nature 2014;doi:10.1038/nature13793).

The assumption that diet soft drinks are better for you looks like it’s wrong for a number of other reasons too. When researchers discovered that drinking 2 or more colas a day doubled the risk of chronic kidney disease, they also discovered that it made no difference if the soft drink was regularly or artifically sweetened (Epidemiology 2007;18:501-6).

And it is well known that soft drinks cause osteoporosis. What is less well known is that research that found that women who drink soft drinks on a daily basis have significantly lower bone mineral density also found that the results were no better for women who chose diet soft drinks (Am J Clin Nutr 2006;84:936-42).

Research has also demonstrated that people who drink diet soft drinks on a daily basis have a significant 43% greater risk of a cardiovascular event, like stroke or heart attack. Strangely, this study found the risk only for diet soft drinks: there was no association between regular soft drinks and cardiovasculare events (Journal of General Internal Medicine 2012;doi:10.1007/s11606-011-1968-2). A second study, though, found the increased risk for both. This massive study found that drinking one or more soft drinks a day–whether they were sweetened with sugar or artificial sweeteners–increased the risk of stroke by a significant 16% (Am J Clin Nutr 2012;95:1190-99).

So diet soft drinks may just be a marketing strategy to keep people who know soft drinks are bad for them drinking soft drinks. But it looks like they may be just as bad.