It is no secret that sugar is unhealthy. From high blood sugar to diabetes and heart disease, a diet high in sugar has far-reaching effects. But did you know that sugar is also bad for your brain? A recent study published in the Journal of Physiology found an interesting connection between a diet low in omega-3s and high in the sugar fructose, and poor memory and brain function. The researchers stated, “Eating a high-fructose diet over the long term alters your brain’s ability to learn and remember information. But adding omega-3 fatty acids to your meals can help minimize the damage.”
In the animal study, one group was fed a diet low in omega-3 fatty acids, and another group was fed a diet high in omega-3s from flaxseed and DHA (docosahexaenoic acid). The omega-3 deficient animals were found to have poor memory function when compared to those fed a diet rich in omega-3s. The negative effects of a low omega-3 diet were exasperated when high amounts of fructose were added to the diet. In the group receiving sufficient omega-3s, however, a high fructose diet did not have the same negative effects on memory and neuron function, suggesting that omega-3s have a protective effect against the brain dysfunction caused by a high fructose diet.
It is well known that a high sugar diet increases blood sugar and insulin resistance in the bloodstream. This is the hallmark of the metabolic syndrome, an increasingly common condition that precedes type 2 diabetes. This study suggests that not only can a high sugar diet have effects in the bloodstream, but that it can also have similar effects in the brain. The study found disrupted insulin receptor signaling in the hippocampus, an area of the brain associated with memory function. Insulin and fructose are both known to cross the blood–brain barrier, where they can interrupt neuron function.
The findings of this study are not surprising. In fact, Alzheimer’s disease is also known as type 3 diabetes. The fact is, the amount of sugar—and even carbohydrates, for that matter—in the Standard American Diet (SAD) is alarmingly high. I am about to debut a one-time airing of my new PBS show next week on this very topic. The show, called The Heart of Perfect Health, is a preview that airs in the greater Baltimore area and that will air nationwide in November. Look for an announcement later this week!