The physical effects of children consuming large amounts of sugar are well-researched. However, not as much research has been poured into the way it affects their mental development.
New research from the University of Georgia and a University of Southern California research group reveals just how much of an impact added sugar can have on children’s brains.
Using a rodent model, researchers have examined how sugar affects adolescent brains when consumed every day. Findings revealed that doing so hurts performance on a learning and memory task during adulthood. Beyond that, the researchers determined that shifts in gut bacteria called parabacteroides may be the key to sugar-induced memory impairment.
The findings were published Wednesday in the peer-reviewed journal Translational Psychiatry.
“Early life sugar increased Parabacteroides levels, and the higher the levels of Parabacteroides, the worse the animals did in the task,” lead study author Emily Noble, assistant professor in the UGA College of Family and Consumer Sciences, said in a press release. “We found that the bacteria alone was sufficient to impair memory in the same way as sugar, but it also impaired other types of memory functions as well.”
Rodents in the study were given their normal food in addition to an 11% sugar solution. The liquid is comparable to sugar-sweetened beverages available in stores.
Afterward, researchers had the rats carry out a memory task that depended on the hippocampus, the region of the brain that’s critical to learning and memory.
It was meant to evaluate how well the rodents remembered the context where they had previously seen a familiar object.
“We found that rats that consumed sugar in early life had an impaired capacity to discriminate that an object was novel to a specific context, a task the rats that were not given sugar were able to do,” Noble said.
A second memory task evaluated basic recognition memory, a function that the hippocampus is not involved in. This task looked into how rats could identify something they’d seen before. Sugar did not affect their recognition memory in this task.
“Early life sugar consumption seems to selectively impair their hippocampal learning and memory,” Noble said.
Further analysis showed that high sugar intake led to increased levels of parabacteroides in the gut microbiome. When researchers increased levels of the bacteria in the microbe of rats who had never consumed sugar, they discovered the rodents had diminished functionality in hippocampal-dependent and hippocampal-independent memory tasks.
“(The bacteria) induced some cognitive deficits on its own,” Noble said. She added that more research is needed to better distinguish the precise pathways that the gut-brain signaling functions.
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