A comprehensive analysis of 27 animal studies reveals that adopting a healthier diet significantly enhances memory function, though the impact diminishes after consuming a sugary diet.
Lane et al. conducted an extensive review and meta-analysis of dietary reversal effects on cognition and behavior in rodent models. Image credit: Steve Buissinne.
Dr. Simone Lane from the University of Technology Sydney states, “Our research indicates that enhancing diet quality positively affects memory.”
“Nevertheless, the improvements remain partial; even after weeks on a healthy diet, memory levels failed to match those of animals that never consumed an unhealthy diet.”
Dr. Rehn and colleagues executed a systematic review and meta-analysis of 27 preclinical studies, uncovering consistent patterns across various experiments.
The research focused primarily on memory but also examined behaviors such as anxiety, depression, activity levels, and eating motivation.
Throughout the study, animals that transitioned to a healthy diet demonstrated superior performance on memory tasks compared to those that continued unhealthy eating habits.
However, the extent of memory recovery depended substantially on the dietary composition; while high-fat meal studies indicated recovery, those involving high-sugar or combined high-fat and high-carbohydrate diets did not yield similar results.
No significant enhancements were observed in anxiety, activity, or eating motivation, implying that the effects were limited to memory rather than overall behavior.
“By replacing high-fat options with healthier foods, we observed more marked improvements in memory,” remarked Dr. Lane.
“However, evidence of recovery was minimal with sugar-laden diets that included meals high in both fat and sugar.”
“This suggests that sugar could be a key factor hindering memory recovery.”
The memory tasks assessed in the study reflect the hippocampus’s function, a crucial brain area for learning and memory, also linked to appetite regulation and food intake.
“Animal models have been vital for understanding the brain’s dietary impacts,” commented Dr. Mike Kendig, also from the University of Technology Sydney.
“In humans, dietary changes often coincide with adjustments in exercise, mood, and daily activities, making it challenging to isolate diet’s effects on brain function.”
“There’s a widespread belief that the adverse impacts of an unhealthy diet are easily reversible.”
“Our findings indicate that the reality is more nuanced, particularly concerning memory, especially with sugar-rich diets.”
“Improving diet quality holds value, but safeguarding brain health may also require limiting long-term exposure to unhealthy diets, rather than assuming all effects are easily reversible.”
For more information, refer to the review paper published in the Journal on May 17, 2026, in Nutritional Neuroscience.
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Simone Lane et al. Cognitive and behavioral effects of reversing high-fat, high-sugar diets: A systematic review and meta-analysis of animal studies. Nutritional Neuroscience, published online on May 17, 2026. doi: 10.1080/1028415X.2026.2664635
Source: www.sci.news
