Phenolic compounds (“botanical phenolics”) are antioxidants. Reactive oxygen species (ROS), a type of free radical, factors into degenerative brain diseases like Parkinson’s and Alzheimer’s. Through various adverse effects on cells, ROS causes cell death. Foods rich in antioxidants, such as phenolic compounds, can reduce the number of free radicals, including ROS, and may help slow or prevent these diseases. Several epidemiological studies and several meta-analyses suggest that over the long term, diets with lots of phenolic compounds offer protection from degenerative brain diseases. They are also believed to protect against cancers and some cardiovascular diseases. To add them to your diet, eat plenty of fruits, vegetables, and cereal grains, and drink green or black teas.