Mount Sinai School of Medicine researchers have developed a biosynthetic polyphenol that improves cognitive function in mice with Alzheimer's disease (AD). Polyphenols occur naturally in grapes and other foods, and have been shown to prevent the cognitive decline associated with AD in mice. This is the first study to determine which specific subfraction of these molecules penetrates the animal brain, and demonstrate that a drug compound similar to polyphenols can exert similar influence. The researchers separated the natural occurring polyphenols from grapes, sorted them by size, and administered each for five months to mice genetically altered to develop AD, after which they assessed brain neuropathology and cognitive function of the mice. They identified a specific grape polyphenol metabolite selectively reached and accumulated in the brain. This compound reduced the neuropathology of AD by preventing the accumulation of abnormal proteins.