This study aimed to investigate if ellagic acid has beneficial effects on cognitive deficits in middle-aged overweight individuals and to propose a possible mechanism. A total of 150 middle-aged male participants, including 76 normal-weight and 74 overweight men, aged between 45 to 55 years, were recruited for this study. Both normal-weight and overweight participants were administered either 50 mg ellagic acid or placebo cellulose daily for 12 weeks. Blood lipids, peripheral brain-derived neurotrophic factor (BDNF), and saliva cortisol were assessed on the last day of the procedure to investigate the effects induced by ellagic acid. The results revealed that ellagic acid treatment improved the levels of blood lipid metabolism with a 4.7% decline in total cholesterol, 7.3% decline in triglycerides, 26.5% increase in high-density lipoprotein, and 6.5% decline in low-density lipoprotein. Additionally, ellagic acid increased plasma BDNF by 21.2% in the overweight group and showed no effects on normal-weight participants. Moreover, the increased saliva cortisol level in overweight individuals was inhibited by 22.7% in a 12-week ellagic acid treatment. Also, compared with placebo, overweight individuals who consumed ellagic acid showed enhanced cognitive function as measured by the Wechsler Adult Intelligence Scale-Revised and the Montreal Cognitive Assessment. To the best of our knowledge, this is the first report showing that ellagic acid prevents cognitive deficits through normalization of lipid metabolism, increase in plasma BDNF level, and reduction of saliva cortisol concentration. These results indicate that ellagic acid has a potential to restore cognitive performance related to mild age-related declines.
Keywords: acide ellagique; brain-derived neurotrophic factor (BDNF); cholesterol; cholestérol; cognition; cortisol; ellagic acid; facteur neutrophique dérivé du cerveau (BDNF); lipoprotein; lipoprotéines; midlife overweight; surpoids au mi-temps de la vie.