A new study by neurobiologists at the University of Southern California (USC) has revealed that a diet high in fats and sugars can lead to irreversible memory impairments.
The USC team reached this conclusion after conducting a series of experiments on laboratory rats that were fed such diets from an early age. This is likely due to the fact that a diet rich in simple sugars and saturated fats damages acetylcholine—a key neurotransmitter in the brain associated with memory.
“Not only in this study, but also in some of our previous work, we have seen that a diet of unhealthy foods causes memory impairments that are untreatable,” said co-author Scott Kanoski.
How the Study Was Conducted
The researchers involved two groups of rats aged between 26 and 56 days. This developmental period corresponds to human adolescence, when brain functions are actively forming.
One group of rodents was fed a diet high in fats and sugars, while the other group was given healthy food, as reported by Science Alert.
As a result, in memory recall tests, the rats in the first group were unable to identify new objects they had explored just a few days earlier. This was not observed in the second group. Moreover, memory issues in the first group persisted even when the rats were switched to a healthy diet for 30 days (a period that corresponded to adulthood for the rodents).
What Else the Researchers Discovered
Neurobiologists also found that the rats consuming unhealthy food had a reduced level of a protein that transports acetylcholine to the hippocampus—a part of the brain that helps consolidate memories and spatial information.
Further experiments showed that this decrease in protein disrupted acetylcholine signaling in the animals, which struggled with memory tasks.
“Acetylcholine signaling is a mechanism that helps encode and remember events, akin to ‘episodic memory’ in humans, which allows us to recall events from our past,” explained lead author Anna Hays. She noted, “It seems that this signaling does not manifest in animals raised on a fatty and sugary diet.”
The study’s findings were published in the journal Brain, Behavior and Immunity.
What Other Scientists Are Saying
Other recent studies have linked diets consisting of unhealthy, processed foods to an increased risk of developing Alzheimer’s disease. Researchers have also found that consuming unhealthy food leads to a loss of appetite control. Furthermore, obesity, according to scientists, may affect the brain’s ability to recognize satiety.
The overarching conclusion from all these studies is that foods that are surprisingly prevalent in Western diets are extremely harmful to brain health. And that’s certainly food for thought.