Many of us haven’t really thought about sugar’s impact on the brain beyond the proverbial sugar high and sugar coma. Although, as it turns out, the ‘coma’ aspect has some real grounding in that people’s attention levels seem to decline after the consumption of glucose specifically. But there are more serious issues than temporary distraction when it comes to sugar and the brain: if concerns over diabetes and your heart have helped you to stay on your lower-carb diet, than the desire to protect your brain will probably keep you on track in reducing your sugar as well.
You’ll probably want to be aware, for example, that studies show eating too much sugar increases cell aging, memory and cognitive deficiencies—and that diabetes can affect the brain’s blood vessels, making them atrophy, shrink, possibly leading to vascular dementia. And some research shows that even having high blood sugar, as in the case of prediabetes, is associated with an increased risk of developing dementia, possibly because insulin resistance is affecting brain cells. These findings—which might serve as an additional wake up call for the millions of undiagnosed prediabetics around the world—builds on existing evidence of the link between insulin (having either too much or too little) and the development of Alzheimer’s disease. Scientists believe this link is because of an enzyme that insulin itself creates which both breaks itself down, but also breaks down the amyloid proteins in the brain that clump up and lead to Alzheimer’s. Essentially, people either don’t make enough of this enzyme to break up those clumps, or they make enough of it but it’s used up breaking down the insulin they are overproducing.
So, just the possibility that you are raising your risk of cognitive decline— including Alzheimer’s or vascular dementia—by eating too much sugar is huge news, especially because most of us see Alzheimer’s as as genetics beyond our control, unpreventable and untreatable. As a result, very few of us have focused on changing our diet as a variable in preventing dementia. On the positive side, we may have more control over our future state of mind than we previously thought.
Another, exacerbating impact of sugar on our brains is that it creates a counterproductive cycle whereby the brain and its oxycotin cells do not do their job of signaling satiety. Even trickier, the “hedonic hunger” we feel when we’re full but want more food arises primarily from the brain’s emotional cravings. Our brains seek the reward circuit of sugar and when we consistently overdo it, the brain desensitizes and seeks even more dopamine to get that pleasure buzz. This is why breaking up with sugar is so very hard to do. But in the case of preventing dementia, our minds over (brain) matter may make a notable difference for our future selves.