There’s been controversy around artificial sweeteners for years. Do they cause cancer? Can they really help you lose weight?
Science has pretty much debunked the claims that artificial sweeteners cause cancer, while the picture remains a little more hazy regarding sugar substitutes and weight loss, as we previously reported.
But now there’s a new concern to add to the mix: Can diet sodas—which use artificial sweeteners—contribute to dementia and stroke risk? A new study just published in the journal Stroke suggests that there may be a link between the two.
In the study, researchers tracked the stroke risk for nearly 3,000 patients and the dementia risk for about 1,500 more. They discovered that those who drank artificially sweetened beverages were at greater risk of experiencing a stroke or getting diagnosed with Alzheimer’s disease over a 10-year follow up.
In fact, those who drank one or more artificially-sweetened beverages a day were nearly three times as likely to have an ischemic stroke—the most common kind of stroke, which occurs when a clot blocks blood flow to the brain—than those who didn’t drink any. They were also nearly three times as likely to receive an Alzheimer’s diagnosis, too.
That link remained even after the researchers adjusted for other factors that might skew the relationship, like age, total caloric consumption, diet quality, physical activity, and smoking status.
Interestingly, the researchers didn’t find any link between stroke or dementia and sugary beverages or regular sodas.
Now, because this was an observational study—meaning it identifies trends over time—it can’t definitively prove that artificial sweeteners somehow cause dementia or stroke.
There are some possible physiological mechanisms, though: For one, artificial sweeteners have been linked to glucose intolerance—the inability for cells to absorb blood sugar, allowing it to build up—which can pave the road to diabetes. And diabetes is a known risk factor for dementia.
In the study, those who drank diet soda were more likely to be diabetic, but it isn’t clear whether the diet soda actually contributed to the development of the diabetes, or if diabetics were just simply more likely to drink diet soda.
It’s also possible that people who are at risk of developing vascular issues—say, a stroke—may switch to diet soda as a way to try to control those driving factors, like excess weight or high blood sugar. That would make diet soda a marker of a high-risk person, rather that an independent causal risk factor for stroke or dementia, according to researchers in an accompanying editorial in Stroke.
Bottom line is, more research—especially studies that can delve deeper into cause and effect—must be done before any definitive conclusions can be reached about artificial sweetener’s effect on the brain. In the meantime, if you’re looking to wean yourself off sweet drinks, here’s how.