According to a study of cognitive function funded by the National Institute on Aging, the brain is vulnerable to free radicals, which cause oxidative damage. Free radicals are like chemical “bullets” that can damage tissue (oxidative damage). The study followed change in mental function in 3000 people over the age of 64 living in Cache County, Utah for six years. Subjects who took vitamin C or ate produce rich in carotenes (carotenes, or carotenoids are pigments found in fruits and vegetables, they act as antioxidants; some carotenes are converted to vitamin A in the body), scored higher on cognitive tests than those who did not.