Researchers have found that a compound in grape seed extract reduces plaque formation and resulting cognitive impairment in an animal model of Alzheimer’s.

The grape seed extract prevents amyloid beta accumulation in cells, suggesting that it may block the formation of plaques. In Alzheimer’s, amyloid beta accumulates to form toxic plaques that disrupt normal brain function.

The researchers fed Alzheimer’s mice a grape seed polyphenolic (polyphenols are chemical substances found in plants) extract product or placebo daily for five months. The daily dose of the polyphenolic extract was equivalent to the average amount of polyphenols consumed by a person on a daily basis.

After the five-month period, Alzheimer’s mice were at an age at which they normally develop signs of disease. However, the extract exposure reduced amyloid beta accumulation and plaque formation in brains of Alzheimer’s mice and also reduced cognitive decline. Compared to placebo, extract-exposed Alzheimer’s mice showed improved spatial memory. These data suggest that before symptoms begin, the grape seed extract may prevent or postpone plaque formation and slow cognitive deterioration associated with Alzheimer’s.

The researchers previously found that red wine reduced cognitive decline in Alzheimer’s mice, and have attempted to isolate which of the nearly 5,000 molecules contained in red wine are important in disease prevention in order to develop a highly tolerable, nontoxic, orally available treatment for the prevention and treatment of Alzeheimer’s.

Chemical analysis showed that the major polyphenol components in the study’s grape seed extract product are catechin and epicatechin, which are also abundant in tea and cocoa. These components differ from resveratrol, a polyphenol that has been reported to reduce amyloid beta secretion in cells and generally increase lifespan by mimicking calorie restriction. Resveratrol appears to be effective only at extremely high doses, which may limit its use in people. In contrast, the catechins in the extract product studied appear to be effective at much lower doses.

Although research of polyphenolics in the fight against Alzheimer’s is encouraging, further studies need to be completed before these findings translate to a human population. References:
1. Animal study indicates grape seed extract may reduce cognitive decline associated with alzheimer’s disease. Society for Neuroscience.