The effect of cafeteria diet from postweaning to adolescence on the cognitive performance of rats

Overconsumption of high-calorie foods not only causes obesity and metabolic disorders but also affects some activities of the nervous system, such as cognitive processes. The present study aimed to investigate the effect of a cafeteria diet from post-weaning to adolescence on the cognitive performance of rats.

Pregnant Wistar rats were fed a normal diet and water from the day of delivery to 20 days postpartum. Male offspring were then assigned to one of 3 groups: a cafeteria diet (sausages, cakes, raisin cookies, carrots, white milk chocolate, and chocolate milk) (CAF), a cafeteria diet with simvastatin (CAF-S), or a control group (CTRL). After the treatments were completed, the cognitive performance of the rats was evaluated using the Morris water maze test.

The CAF group showed reduced learning compared to the other two groups, and they took longer to find the hidden platform on all days of the experiment (P ≤ 0.001). The CAF-S group, which received simvastatin at a dose of 50 mg/kg, had a significantly shorter time to find the hidden platform compared to the CAF group (P ≤ 0.05). During the memory recall phase, after removing the platform, the CAF-S group spent less time in the target quadrant compared to the CTRL and CAF-S groups (P ≤ 0.05).

The results indicated that the cafeteria diet decreased the rats' learning and long-term memory. This effect is likely due to the high-fat content in the cafeteria diet. However, simvastatin prevented this decrease in the rats fed a cafeteria diet. These findings suggest that interventions targeting the metabolic pathways affected by a cafeteria diet may have potential therapeutic benefits for cognitive disorders.