You may have heard about results from a pair of studies that hit earlier this month about the effects of sugary and diet drinks on the brain. Part of the results aren’t surprising—the effects of sugary drinks are well studied and the findings are fairly consistent: drinking too much of anything with excessive sugar, especially high-fructose forms of sugar, is antithetical to good health in multiple ways, brain health included.
The part that is surprising involved the potential effects of diet drinks on the brain. A study in the journal Stroke showed a correlation between drinking diet soda and both stroke and dementia: people who drank at least one diet soda a day were three times as likely to have a stroke or develop dementia as those who avoided the beverages. The researchers’ conclusion: “Artificially sweetened soft drink consumption was associated with a higher risk of stroke and dementia.”
Several caveats should be noted. First, this was a cohort study searching for correlations between behaviors and health outcomes, and that’s always tricky. It’s difficult to isolate specific factors and it’s impossible to account for every possible factor, so there’s always going to be some fuzziness in the results. Second, this study focused on older adults, so we can’t say what’s true here (if it is) necessarily applies to a larger population across age groups. And it’s possible that certain conditions developed during the course of the study, like diabetes, which could affect the results. Added to all of that, the researchers studied beverage consumption at different doses (recent intake and cumulative intake), which further complicates the analysis.
Having said that, it’s still mighty intriguing that a correlation with diet sodas appeared at all, since previous research had already uncovered a possible link with higher stroke risk. The findings in this study add some support to those results. The link with dementia, however, is new, and at minimum is enough cause for concern that it’s worth studying further.
Why might diet sodas contribute to these risks? So far nobody knows for sure, although a grab bag of theories are out there, such as:
Diet sodas are designed to trick the brain into thinking it’s getting an extra dose of glucose (the brain’s fuel), but eventually the trick is on us because the brain adapts to not receiving the added glucose by overcompensating in other ways (leading to a variety of effects still under investigation).
Diet sodas could imbalance the bacterial jungle in our guts—the microbiome—causing unpredictable results. Since there’s a bacterial superhighway from gut to brain, which we know interacts with key neurotransmitters, this theory may eventually tell us more of a much bigger brain story.
Different artificial sweeteners in diet drinks have different effects, and there’s debate about which causes what. This study didn’t narrow down the exact types of artificial sweeteners that were consumed, so it’s an open question how one may have affected the brain differently than another.
We can’t draw solid conclusions from this study—it’s not a case of cause and effect—but we can look at the results in light of previous research and say there’s something here worth considering. In the meantime, curtailing how much of any artificial sweetener you ingest, along with added sugar, is a reasonable position to take.
Original source via this link: https://www.forbes.com/sites/daviddisalvo/2017/04/27/why-is-diet-soda-so-bad-for-your-brain/#5049297c5fad