Could Diet Soda Raise Your Risk of Stroke and Dementia?

Could Diet Soda Raise Your Risk of Stroke and Dementia?

A large study tracked stroke and dementia risk in diet soda drinkers over the course of 10 years.

Experts are well aware of the health hazards of sugary beverages like regular soda. A 2015 report in the journal Circulation estimated that sugary drinks—which are connected to chronic conditions like obesity, diabetes and heart disease—contribute to over 184,000 adult deaths annually. But is the sugar-free version any healthier?

Artificially flavored drinks like diet soda may be linked to a higher risk of stroke and dementia, according to a 2017 study published in Stroke, a journal from the American Heart Association.

The study included one group of 2,888 adults older than 45 and a second group with 1,484 adults over 60. Researchers studied the over-45 group for stroke risk and the over-60 group for dementia. They took this approach since strokes are rare before age 45 and dementia before age 60.

Researchers gathered information from the Framingham Heart Study, a long-term project looking at the health of people in Framingham, Massachusetts. The researchers analyzed the number of artificially flavored drinks each person reported to have consumed between 1991 and 2001. They then compared those rates against people’s health over the next 10 years.

Those who drank at least one diet soda per day were about three-times more likely to experience an ischemic stroke—one caused by a blockage of blood vessels supplying brain tissue—compared with people who avoided these beverages. The study concluded that one daily diet soda was linked to higher rates of dementia as well, although other risk factors like obesity or diabetes also could be to blame.

Researchers note these findings show an association, not causation. They can’t prove diet sodas directly caused these conditions, only that the people who developed stroke or dementia had previously consumed more soda.

There could be confounding factors at work, as well. For example, diet soda drinkers in the study were more likely to be obese, which ups their stroke risk. And are people who drink more diet soda also less likely to exercise, cook healthy foods and do the other important things that lower dementia risk? Some critics point out the link to dementia and stroke disappears once you adjust for these and all possible confounding factors.

"The FDA, World Health Organization, European Food Safety Authority and others have extensively reviewed low-calorie sweeteners and have all reached the same conclusion—they are safe for consumption," said Lauren Kane, a spokeswoman for the American Beverage Association, in response to the findings.

More research is needed to determine exactly how—and how much—artificially sweetened beverages affect your vascular system, or the network of vessels that carries blood to organs like your heart and brain. When vessels harden or develop sticky plaque build-up, it raises your risk of chronic conditions like heart disease and diabetes, as well as dementia and stroke.

For now, an overall healthy lifestyle can help protect against these illnesses, and what’s good for your heart is generally good for your brain. Here are six heart-healthy habits for women that truly make a difference, six simple and delicious foods to boost your brain health, and three quick, easy ways to boost your brain health.

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