Artificially-sweetened fizzy drinks linked to increased stroke and dementia risk

20 April 2017

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

Researchers in the US have linked drinking artificially sweetened drinks with an increased risk of stroke and dementia. The study is published today (20 April 2017) in the journal Stroke.

The researchers analysed the Framingham Heart Study Offspring Cohort, which began in 1971 and has followed a group of people throughout their lives with examinations every four years. The consumption of sugar has previously been linked with cardiovascular health, which is also linked with both stroke and dementia. The researchers were interested in understanding how the consumption of sugary drinks could be affecting the risk of stroke or dementia, and whether this risk differed if people were consuming artificially-sweetened drinks.

Participants in the study were asked to complete a questionnaire regarding their food and drink intake, including how frequently they consumed one glass, bottle or can of each beverage, on average, over the course of a year. The participants completed this questionnaire in three examinations that took place between 1991 and 1995, 1995 and 1998, and 1998 and 2001. The questionnaire included three types of sugar-sweetened soft drink, four types of fruit juice, one type of non-carbonated sugar-sweetened fruit drink and three types of artificially-sweetened soft drink.

Using this information, the researchers calculated the total intake of sugary beverages (including both sugary soft drinks, and fruit juices and drinks) that each person drank per day, as well as the number of sugary soft drinks and artificially-sweetened soft drinks they consumed.

There were 2,888 people with data that the researchers could analyse for stroke, and 1,484 people who could be analysed for dementia. The researchers looked at the 10 years following the 1998 to 2001 visit to see how many people went on to experience a stroke or develop dementia.

During this period, 97 participants had a stroke, and 81 people developed dementia. The researchers found that people who drank at least one artificially-sweetened drink a day were three times as likely to have an ischaemic stroke and 2.9 times more likely to develop Alzheimer’s disease. The significant effect on Alzheimer’s risk was not observed when the researchers adjusted for other factors including diabetes, cardiovascular disease, cholesterol, waist to hip ratio and whether people have the ApoE4 risk gene.

Dr Rosa Sancho, Head of Research at Alzheimer’s Research UK, said:

“As people are becoming more aware of the consequences of a high-sugar diet, many are turning to artificially-sweetened diet fizzy drinks as an alternative to those with lots of sugar. This interesting new study has pointed to higher rates of dementia in people who drink more artificially-sweetened drinks, but it doesn’t show that these drinks are the cause of this altered risk. When the researchers accounted for other risk factors for Alzheimer’s, such as risk genes, diabetes, heart disease, cholesterol levels and weight, this significant association was lost suggesting that these drinks are not the whole story.”

“Future studies will need to confirm these findings in other groups of people, and explore what might be underlying any link between artificially-sweetened soft drinks and dementia. The best current evidence suggests that when it comes to reducing your risk of dementia, what is good for your heart is also good for your head. Eating a healthy balanced diet, keeping physically and mentally active, not smoking, drinking in moderation, maintaining a healthy weight and keeping cholesterol and blood pressure in check are all good ways to support healthy brain ageing.”