Many of you probably heard or read articles highlighting a new study that came out in Stroke that suggested a potential link between diet soda and the risk of stroke and dementia. This was a large study that was done that looked at ~3,000 people (>45 yrs of age) and ~1,500 people (>60 yrs of age) and the link between stroke and dementia respectively. The way they quantified this was through a self-reported food frequency questionnaire. The authors excluded people with prevalent stroke and those with underlying neurological deficits. They discovered that after adjusting for many factors like age, education, sex, caloric intake, diet, physical activity, etc, higher intake of artificially sweetened sodas had an increased risk of ischemic stroke, all-cause dementia and Alzheimer’s. The hazard ratios were 2.96 (95% confidence interval, 1.26–6.97) for ischemic stroke and 2.89 (95% confidence interval, 1.18–7.07) for Alzheimer’s disease. Interestingly enough, the authors also found that sugar sweetened beverages were not associated with stroke or dementia.
At the outset, the BIGGEST limitation of this study is the fact that this does NOT prove or suggest causation. All this study does is find a potential correlation or link between diet soda and dementia + stroke. This is worth repeating. This study does not suggest that diet soda will give you a stroke or cause you to develop dementia. In addition, as the authors note, if you look at when this survey was given, saccharin, acesulfame-K, and aspartame were FDA approved. The authors did not include sucralose, neotame or stevia. Also, there are so many confounders to this data. For instance, what if sicker people drink diet soda in an attempt to stop their deterioration? As the authors noted, they DID find that people with diabetes (which is a risk factor for dementia), were drinking more diet soda.
The authors also did not stratify the data by the types of sweeteners. Rather, they lumped them all together. Finally, the authors did not have a diverse population, the population under study were people of European descent. Would these results hold if it had a more diverse population of study?
All in all, I’m not a huge fan of this study, and I’m not a huge fan of all the news articles scaring people about diet soda. Diet soda isn’t a health beverage but if you are going to drink a beverage, it would be better to drink a diet soda rather than a regular one!!