Data from the Framingham Heart Study (FHS) has shown that people who more frequently consume sugary beverages such as sodas and fruit juices are more likely to have poorer memory, smaller overall brain volumes and smaller hippocampal volumes - an area of the brain important for memory. Researchers also found that people who drank diet soda daily were almost three times as likely to develop stroke and dementia when compared to those who did not consume diet soda. These findings appear separately in the journals Alzheimer's & Dementia and the journal Stroke.
Excess sugar is known to have adverse effects on health. Diet soft drinks are often touted as a healthier alternative to regular soda. However both sugar and artificially-sweetened beverage consumption has been linked to cardiometabolic risk factors, which increases the risk of cerebrovascular disease and dementia.
Although the researchers suggest that people should be cautious about regularly consuming either diet sodas or sugary beverages, it is premature to say their observations represent cause and effect. Future studies are needed to test whether giving people artificial sweeteners causes adverse effects on the brain.