Diet fizzy drinks linked to dementia and stroke
However, people who consumed one to six diet sodas daily were 2.6 time more likely to experience an ischemic stroke.
Other recent studies have found health risks that appear to be linked to diet fizzy drinks, such as a link between diet drinks and the risk of metabolic syndrome and type 2 diabetes. This suggests that it may not be advisable to substitute or promote artificially sweetened drinks as healthier alternatives to sugar-sweetened drinks.
Previous studies have shown they tend to be consumed by adults who are already overweight or obese.
"Using Food Frequency Questionnaires has its limitations, especially when the participants are asked to report on their eating/drinking habits over the a year ago", she said. Diet soft drinks have also been linked to weight gain, which could also have an effect.
Pase's team followed the participants for 10 years, to see who had a stroke or developed dementia.
"The FDA [U.S. Food and Drug Administration], 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", the association added.
"Even if someone is three times as likely to develop stroke or dementia, it is by no means a certain fate", Pase said.
After making adjustments for various risk factors such as age and sex, the researchers found that drinking at least one artificially sweetened beverage a day was associated with nearly three times the risk of developing stroke or dementia compared to those who had artificially sweetened drinks less than once a week.
"Our findings indicate an association between higher sugary beverage intake and brain atrophy, including lower brain volume and poorer memory", explained corresponding author Matthew Pase, PhD, fellow in the department of neurology at Boston University School of Medicine (BUSM) and investigator at the FHS.
"There is little other strong evidence to support a link between artificially sweetened drinks and adverse health outcomes".
The researchers noted that their study did not determine actual cause and effect relationship between diet sodas and increased risk of stroke and dementia.
People should be "cautious" about their intake of diet sodas, he said.
A person consuming at least a can of diet soda daily every is 2.96 times more likely to suffer an ischaemic stroke and 2.89 times more likely to develop Alzheimer's disease than someone who drank them less than once a week, the study found.
'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.
The research, published Thursday in the science journal Stroke, examined consumption of beverages sweetened with sugar and artificial sweeteners but did not find that same association with sugary beverages.
But scientists warned people should not view sugary drinks as a "healthy option" and instead urged people to drink water, low-fat milk or other drinks without sweetener. But after accounting for all lifestyle factors, the researchers found the link to dementia was statistically insignificant, however, the impact on stroke risk remained. Furthermore, heart disease and diabetes are known to be associated with dementia.
Dr Mary Hannon-Fletcher, the Head of Health Sciences at Ulster University in the United Kingdom, said that although the research was good, the methods of getting the data had limitations.