I never know what to think when I see a Diet Coke or jar of jam labeled as sugar-free. On the one hand, I know that consuming sugar leads to weight gain, among other problems. But on the other hand, I’m suspicious of low-calorie sweeteners. What exactly are they made of, and how do they affect the body?
It turns out, there is a fair amount of evidence on the effects of artificial sweeteners. A meta-analysis published last month is the International Journal of Obesity evaluated whether artificial sweeteners help people lose weight. The analysis examined studies in animals and humans, including 12 prospective studies in humans and ten randomized-controlled trials.
The reviewers conclude that the body of evidence shows that sugar substitutes lead to less weight gain and sometimes even weight loss compared with consuming sugar. The authors do point out some limitations in their review. Their analysis does not differentiate between the types of sweeteners, and some are associated with other effects, such as metabolic changes. (One other review raises questions about how artificial sweeteners effect metabolism in youth, leading to weight gain, but doesn’t find conclusive evidence.)
Other reviews find more negative health effects of consuming sugar. For example, a review in the journal Nephrology finds that drinking sugar-sweetened beverages increases the risk of developing kidney disease, while drinking artificially-sweetened beverages does not.
Another review in Clinical and Experimental Hypertension finds that both sugar-sweetened and artificially-sweetened drinks are associated with high blood pressure.
And a third review in the International Journal of Clinical Practice finds inconclusive evidence on the link between artificial sweeteners and cancer.
So what’s the take-home message here? Artificial sweeteners may be useful in helping people lose weight, especially for people who regularly consume sugar-sweetened drinks. But many artificial sweeteners are made from chemicals, and we don’t fully understand how they interact in our bodies. There is some evidence that they contribute to other health problems, such as high blood pressure and metabolic problems. For my part, I am going to continue to limit my consumption of artificial sweeteners, until the evidence base is more definitive.