That old adage about "an apple a day" is right on target. Turns out that apples contain a group of chemicals that could protect the brain from the type of damage that triggers neurodegenerative diseases like Parkinson's and Alzheimer's. One of those compounds, a flavonoid called quercetin, has been shown to protect the brain from oxidative injury in animal studies.

Other chemicals such as phenolic acids and different flavonoids protect the apple itself against damage by bacteria, viruses and fungi—and if they protect the fruit, just imagine what they can do for us! Studies suggest that eating apples not only may help reduce the risk of cancer, but diminish the risk of neurodegenerative disorders too.