Do Diet Sodas Put Me at Greater Risk for Brain Disease?

With much of the focus these days on reducing sugar-filled soda intake, aren’t sugar-free, diet sodas the healthier alternative? Not necessarily, according to a recent study published in the American Heart Association journal, Stroke. Although artificially sweetened drinks may seem to be better for your waistline, they may also increase your risk of stroke, dementia, and Alzheimer’s disease.

How Did Scientists Figure That Out?
Using data from the Framingham Heart Study, researchers looked at beverage consumption and the occurrence of stroke and/or dementia, including Alzheimer’s disease, in approximately 4,400 men and women in their mid-60s. Beverage consumption was measured during three different exam periods over 10 years using a questionnaire. After adjusting for age, sex, education, caloric intake, diet quality, physical activity, and smoking, the researchers found that higher consumption of artificially sweetened soft drinks was associated with an increased risk of stroke, all-cause dementia, and Alzheimer’s disease dementia. They did not find a similar association with sugar-sweetened drinks, although other studies have found a connection between stroke risk and sugar-sweetened beverages.

How Much Is Too Much?
The study broke down artificially sweetened beverage consumption into three categories: no consumption, up to six drinks (glasses, bottles, or cans) a week, and one or more drinks daily. Only the last category showed a significant effect on the participant’s likelihood of having a stroke or getting dementia. Interestingly, people who reported high consumption during the cumulative 10 years were at greater risk for both stroke and dementia, but those who consumed lots of diet sodas in the most recent exam only increased their risk of stroke.

Bottom Line
This study is important, and may point researchers to further explore the reasons why artificially sweetened beverages seem to increase disease risk, but you don’t need to shun diet sodas completely. As is true for many nutrition studies, this one is based on an association, and there are all sorts of reasons why people who drink artificially sweetened beverages might be at greater risk for stroke/Alzheimer’s—including having a poor diet in general. That’s why more research needs to be done.

You may also be interested in our coverage of other things that may increase the risk for dementia, like certain allergy medications  and heartburn drugs.

(Feature photo courtesy of

Sylvia Bernstein

Sylvia Bernstein is a graduate of the Escoffier School of Culinary Arts and the Rouxbe Plant-Based Professional Certification Course. She is the author of the book, Aquaponic Gardening, and has written for several indoor gardening publications. Sylvia also worked as a chef at Meals on Wheels, where she currently volunteers. She is now enjoying retirement in beautiful Boulder, Colorado.