No sweet spot for soft drinks


Sugary drinks are bad, so you’ve switched to diet drinks. These findings will make you think again.

Key Points


  • Diet drinks are touted as healthier than sugary drinks
  • US research suggests link between sugary and diet soft drinks to cardio and dementia issues
  • No findings yet that artificial sweeteners cause adverse effects on the brain

Research findings show 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.

Diet soft drinks are often touted as a healthier alternative to regular soft drinks. However, both sugar and artificially-sweetened beverage consumption has been linked to cardiometabolic risk factors, which increases the risk of cerebrovascular disease and dementia.

Researchers 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.

“This included a higher risk of ischemic stroke, where blood vessels in the brain become obstructed and Alzheimer’s disease dementia, the most common form of dementia,” researcher Dr Matthew Pase of the Boston School of Medicine said.

In these studies approximately 4,000 participants over the age of 30 were examined using Magnetic Resonance Imaging (MRI) and cognitive testing to measure the relationship between beverage intake and brain volumes as well as thinking and memory. 

The researchers then monitored 2,888 participants age 45 and over for the development of a stroke and 1,484 participants age 60 and older for dementia for 10 years.

The researchers point out that pre-existing conditions such as cardiovascular disease, diabetes and high blood pressure did not completely explain their findings. For example, people who more frequently consumed diet soda were also more likely to be diabetic, which is thought to increase the risk of dementia. However, even after excluding diabetics from the study, diet soda consumption was still associated with the risk of 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.

The best suggestion would be to drink less diet drinks and instead consume more water.

Source: Boston University, School of Medicine