Los Angeles, California – A recent study conducted by researchers at the University of Southern California (USC) revealed that rats fed a high-fat, high-sugar diet during adolescence experienced memory impairments that persisted despite later dietary improvements. The findings underscore the long-term impact of consuming unhealthy junk food during teenage years on brain function and memory.
Professor Scott Kanoski, from USC’s Dornsife College of Letters, Arts and Sciences, emphasized that rats raised on a junk food diet exhibited memory impairments that extended into adulthood, even when switched to a healthy diet later on. The study, published in the journal Brain, Behavior, and Immunity, sheds light on the significant relationship between diet and memory function.
The research team, led by Kanoski and postdoctoral research fellow Anna Hayes, sought to understand the effects of a high-fat, high-sugar diet on acetylcholine levels in the brain. Acetylcholine is a neurotransmitter critical for memory and cognitive functions. By observing the impact of the diet on rats’ acetylcholine levels and conducting memory tests, the researchers discovered a concerning link between poor dietary habits and memory impairment.
In experimental findings, the researchers analyzed brain responses of rats on a junk food diet and a control group through memory tests involving object recognition. Rats on the unhealthy diet displayed difficulties remembering objects and their locations, indicating disrupted acetylcholine signaling essential for encoding memories.
Lead author Hayes explained that the lack of acetylcholine signaling in rats raised on a fatty, sugary diet hindered their ability to encode and recall events, similar to episodic memory in humans. Kanoski highlighted the significance of adolescence as a critical period for brain development, noting that certain effects of poor diet on memory may be less reversible when occurring during childhood.
The study also investigated potential interventions to reverse memory impairments caused by a junk food diet during adolescence. Using drugs that induce acetylcholine release, such as PNU-282987 and carbachol, directly in the hippocampus—the brain region responsible for memory—the researchers were able to restore memory function in rats. However, more research is needed to determine effective strategies for reversing memory problems associated with unhealthy dietary patterns.
The findings underscore the importance of maintaining a healthy diet, especially during critical developmental stages, to support optimal brain function and memory retention. Further research is crucial in understanding the long-term effects of poor dietary habits on cognitive health and exploring interventions to mitigate memory impairments caused by unhealthy eating habits.