According to a new study published Thursday, April 20th in the American Heart Association’s journal Stroke, people who drank at least one artificially-sweetened beverage a day had almost three times the risk of developing stroke or dementia and Alzheimer’s disease .

Does this mean that drinking diet soda can cause dementia or stroke or even increase the risks? Not necessarily.

 

What the Results of the Study Showed:

The study was published in the Journal Stroke. The journal is affiliated with the American Heart Association/ American Stroke Association.
The researchers caution that the study only shows an association -- it does not prove that diet drinks actually cause stroke or dementia. However more research is warranted according to the studys authors.

“Although we did not find an association between stroke or dementia and the consumption of sugary drinks, this certainly does not mean they are a healthy option,” Matthew Pase, Ph.D., the lead author of the study and a senior fellow in the department of neurology at Boston University School of Medicine, said in a statement. “We recommend that people drink water on a regular basis instead of sugary or artificially sweetened beverages.”

 

How the Study was Conducted:

The researchers analyzed data on nearly 2,888 people over the age of 45 for the stroke study and almost 1,500 people over age 60 for the dementia study.
The participants recorded their eating and drinking habits in questionnaires. The researchers reviewed this information at three different points in time over a period of seven years. The participants were then followed up on for the next 10 years to see who developed stroke or dementia and then compared dietary habits to the risk of developing these health problems.
At the end of the 10 year follow-up , the researchers found 97 cases of stroke, 82 of which were ischemic (caused by blockage of blood vessels), and 81 cases of dementia, 63 of which were diagnosed as Alzheimer’s disease.

The studies control factors, other possible risk factors taken into account, included age, sex, caloric intake, education, diabetes, and the presence of genetic risk factors for Alzheimer’s.

diet soda

Conclusions of the Diet Soda Study:

The results showed that people who consumed at least one artificially-sweetened drink a day were three times as likely to develop ischemic stroke and 2.9 times as likely to develop Alzheimer’s disease dementia.

In addition to being an observational study which cannot prove cause and effect, the authors noted the studys other limitations, including that fact that the overwhelming majority of participants were white. People did not drink sugary drinks as often as diet ones, which the authors said could be one reason they did not see the same link with regular soda.
The number of people in the study was also limited, under 2900 over a ten year period.

“Even if someone is three times as likely to develop stroke or dementia, it is by no means a certain fate,” Dr. Pase said. “In our study, three percent of the people had a new stroke and five percent developed dementia, so we’re still talking about a small number of people developing either stroke or dementia.”

In an accompanying commentary, Ralph Sacco, M.D., a former president of the American Heart Association and the chairman of the department of neurology at the Miller School of Medicine at University of Miami in Florida, says that current research is “inconclusive” in determining whether or not drinking artificially sweetened beverages frequently can lead stroke, dementia, and other heart-related conditions.

However, the current study, as well as other recent research showing associations between diet soft drinks and negative effects on blood vessels throughout the body, suggest that consumers may want to use caution before turning to these drinks as an alternative to sugar-sweetened beverages.

“Both sugar and artificially sweetened soft drinks may be hard on the brain,” Dr. Sacco writes.

Other professionals are in agreement. “We know that limiting added sugars is an important strategy to support good nutrition and healthy body weights, and until we know more, people should use artificially sweetened drinks cautiously,” said Rachel K. Johnson, Ph.D., past chair of the American Heart Association’s Nutrition Committee and professor of nutrition at the University of Vermont. “They may have a role for people with diabetes and in weight loss, but we encourage people to drink water, low-fat milk or other beverages without added sweeteners.”

Responding to the published study, Lauren Kane, a spokeswoman for the American Beverage Association, issued a statement from the group that said low-calorie sweeteners found in beverages have been proven safe by worldwide government safety authorities.  Those authorities includes "The FDA, World Health Organization, European Food Safety Authority and others".

Link to study:

Sugar- and Artificially Sweetened Beverages and the Risks of Incident Stroke and Dementia
A Prospective Cohort Study