People who take one diet soda a day are nearly three times more likely than non-diet soda drinkers to suffer a stroke or to become demented, according to a study published in Stroke (April 20, 2017). Both sugar drinkers and artificial-sweetener drinkers were at increased risk for having smaller brains and advanced brain aging.
The study shows only an association between consuming diet sodas and increased rates of strokes and dementia. The authors caution that “Clinical trials are needed to establish whether the consumption of artificially sweetened beverages is causally related to [strokes or] dementia.” Meanwhile, they recommend that “people drink water on a regular basis instead of sugary or artificially sweetened beverages.”
This study examined whether consuming sugared beverages or artificially sweetened beverages was associated with increased risk of stroke or dementia among participants in the Framingham Heart Study, which has followed several thousand men and women (and their offspring) with blood tests and questionnaires since the 1970s.
The stroke group included almost 3000 people over 45 and the dementia group included almost 1,500 people over age 60. Their drinking habits were documented for a minimum of seven years and then they were followed for ten years for incidence of strokes or dementia. Overall, about five percent of the participants suffered strokes or dementia (97 strokes, 81 cases of dementia) during the study period. Compared with those who drank less than one diet soda per week, participants who consumed one diet soda per day or more had 2.96 times the risk for ischemic stroke and 2.89 times the risk for dementia.
The study did not find that sugared drinks were associated with increased risk of stroke or dementia. However, drinking sugared drinks (including fruit juices) every day was associated with smaller brain size and poorer memory.
More Reasons to Avoid Artificial Sweeteners
Other studies have associated diet soda with blood vessel damage which may also damage the brain. Artificial sweeteners can also increase the absorption of food by changing bacteria in the colon. See Artificial Sweeteners, Diabetes and Obesity
Artificial Sweeteners Linked to Higher Blood Sugar Levels
Don’t Switch Back to Sugared Drinks
Please do not use this new study as a reason to go back to sugared drinks. One can of sugar-sweetened soda contains 25 to 50 grams of sugar, the recommended upper limit for sugar for an entire day. Sugared drinks have already been associated with:
• weight gain and diabetes (BMJ, 2015;351:h3576)
• high blood pressure, high cholesterol, heart attacks, and strokes (Circulation, 2012;125:1735–1741; Am J Clin Nutr, 2009;89:1037–1042; J Gen Intern Med, 2012;27:1120–1126).
• Accumulating evidence shows that sugared drinks are harmful to your health.
• Several recent studies suggest that artificial sweeteners may also be harmful to your health.
• The safest drink for quenching thirst appears to be water. Unsweetened coffee and tea appear to be safe choices also.