A diet containing grape powder ameliorates the cognitive decline in aged rats with a long-term high-fructose-high-fat dietary pattern

Research has suggested that the consumption of foods rich in polyphenols is beneficial to the cognitive functions of the elderly. We investigated the effects of grape consumption on spatial learning, memory performance and neurodegeneration-related protein expression in aged rats fed a high-fructose-high-fat (HFHF) diet. Six-week-old Wistar rats were fed an HFHF diet to 66 weeks of age to establish a model of an HFHF dietary pattern, before receiving intervention diets containing different amounts of grape powder for another 12 weeks in the second part of the experiment. Spatial learning, memory performance and cortical and hippocampal protein expression levels were assessed. After consuming the HFHF diet for a year, results showed that the rats fed a high grape powder-containing diet had significantly better spatial learning and memory performance, lower expression of β-amyloid and β-secretase and higher expression of α-secretase than the rats fed a low grape powder-containing diet. Therefore, long-term consumption of an HFHF diet caused a decline in cognitive functions and increased the risk factors for neurodegeneration, which could subsequently be ameliorated by the consumption of a polyphenol-rich diet.