A normal molecular by-product of metabolism. Free radicals are so named because their molecular structure is unstable, leaving them “free” to bind with any other molecule that is “open.” Such binding creates unusual chemical structures that the body cannot use and that prevent other molecules that are hijacked by them from meeting the body’s needs. Many scientists believe this action disrupts body functions and processes to the extent that, over time, it causes damage that leaves cells vulnerable to diseases such as cancer and nEurodEgEnErativE conditions such as Alzheimer’s disease, amyotrophic lateral sclerosis (ALS), and Parkinson’s disease.
In health, cells produce a natural chemical called complex I that alters free radicals to prevent them from binding with other molecules. Other chemical substances called antioxidants then can bind to the free radicals in processes that allow them to pass from the body as waste. In a chronic condition such as Parkinson’s disease, the amount of complex I the cells produce decreases. Scientists are uncertain whether this effect is a cause or a consequence of the disease but believe that in either case the drop in complex I level contributes to the disease’s development. Recent studies suggest that coenzyme Q-10, an antioxidant found in many fruits and vegetables as well as available as a nutritional supplement, is effective in reducing the numbers of free radicals. Free radicals alone probably do not account for disease development but instead interact with various other factors such as genetic predisposition and environmental circumstances to allow a disease state to establish itself. Free radical damage appears to be cumulative: That is, it becomes more extensive and more likely to result in disease over an extended period, probably decades.