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Fructose leads to impaired learning and memorization
Last reviewed: 01.07.2025
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Fructose weakens synaptic connections between neurons in the brain, which leads to impaired learning and memory.
It has long been known that the brain lives on sweets: its energy needs are fully satisfied by carbohydrates. But, as demonstrated by research by employees of the California Institute in Los Angeles (USA), sugar for the brain can not only be useful, but also harmful. The scientists' work was devoted to the effect of fructose on the cognitive abilities of animals; they chose corn syrup as sugar. This product contains a large amount of fructose and is used as a cheap sweetener in the food industry, in the production of soft drinks, baby food. According to statistics, the average American consumes more than 18 kilograms of this syrup per year.
Before feeding the rats with fructose syrup, the scientists trained them to find their way out of a maze. After the rats memorized the maze, they were divided into 2 categories: 1 was given water with syrup, the other - the same, but with the addition of Omega-3 unsaturated fatty acids. It is believed that these fatty acids protect synapses from damage and thus have a beneficial effect on cognitive processes. After 6 weeks, the scientists again put the animals in the same maze.
As it turned out, water with fructose had a negative effect on the animals’ memory. The rats had trouble remembering the maze they had walked through not long ago, interneuronal connections in the brain weakened, and the transmission of signals from cell to cell became much more complicated. In turn, those rats that received Omega-3 fatty acids along with fructose were in excellent “intellectual shape” and found a way out of the familiar maze much faster. The scientists published the results of their research in the Journal of Physiology.
The authors of the work note that the rats that received only fructose developed signs of insulin resistance: the cells stopped sensing insulin. These processes do not necessarily lead to diabetes, but they still have a significant impact on energy metabolism. Having refused insulin, the neurons of the brain begin to use sugar ineffectively, which, in turn, affects their ability to form new synapses and maintain old ones. On the other hand, Omega-3 acids soften the effect of fructose. Considering the prevalence of fructose additives in the food industry, one could recommend that absolutely everyone systematically take drugs with Omega-3 acids - so as not to become dull from an excess of sugar.
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