Study Does Not Prove Diet Soda Causes Alzheimer’s Disease Or Stroke

My family members are panicking about recent headlines claiming that diet sodas cause Alzheimer’s disease. While I would love for them to drink fewer sodas, I have to be honest: The headlines were misleading, and the new study they refer to has major caveats.The study did not prove that artificial sweeteners cause stroke, Alzheimer’s disease or any type of dementia. In fact, this kind of study design cannot prove causation. To be fair, the study's authors were careful to say that the study was not “able to prove cause and effect and only shows a trend among one group of people.” Many news articles didn't reflect this.The researchers studied nearly 2,000 men and women ages 45 and older for stroke and about 1,500 people over age 60 for dementia. They tracked how much and what kinds of soda the subjects were drinking and monitored their health for a decade.The study determined that drinking sugary beverages was not associated with stroke or dementia. But it found that for people who drank one artificially sweetened soda a day, the risk of stroke or dementia was nearly three times higher than it was for people who consumed less than one diet soda a week.It’s important to bear in mind that drinkers of sugary sodas may have died from other causes such as heart disease and complications of diabetes and that’s why they don’t show up in the results section as victims of stroke and dementia. This phenomenon is known as survival bias. Not mentioning it can be misleading.In a different study by the same researchers, people who drank sugary drinks such as sodas and fruit juice were found to have a smaller brain volume as well as smaller hippocampi, the two horseshoe-shaped parts of the brain which are crucial to memory. In that study, people who drank sugary drinks were more likely to have memory problems.  Continue reading...