Dietary fruits and vegetables mitigate cognitive impairment in mice with high-fat diet-induced obesity: a pilot study

The rising prevalence of cognitive decline linked to obesity is becoming a significant public health issue. Epidemiological studies indicate that a higher intake of fruits and vegetables (F&V) may be associated with a lower risk of cognitive impairment, although the evidence for the causal relationship is lacking. This study examined whether F&V supplementation could prevent cognitive decline in mice with high-fat diet-induced obesity.

Male C57BL/6J mice (6 weeks old) were randomly assigned to one of five diet groups (12 mice per group): low fat (LF, 10% kcal fat) diet, or high fat (HF0, 45% kcal fat) diet supplemented with 0% (HF0), 5% (HF5), 10% (HF10), or 15% (HF15) of a mixture of F&V (wt/wt). These levels of supplementation correspond to approximately 0, 3, 5-7, or 8-9 servings of F&V per day for humans, respectively. The novel object recognition test was performed after mice consumed the respective diets for 17 weeks.

Mice fed the Western-style HF diet spent less time exploring the novel object, indicating significant cognitive impairment compared to the LF group. Conversely, F&V supplementation alleviated the HF diet-induced cognitive deficits in a dose-dependent manner.

The results from this pilot study suggest the causal link between F&V intake and the prevention of cognition impairment caused by a Western-style high-fat diet, establishing a foundation for further investigation into the protective effects of F&V consumption on obesity-related cognitive decline. Additional research is required to better understand the underlying mechanisms.