FREE RADICALS AND ANTIOXIDANTS: MORE THAN A CASE OF BAD GUYS AND GOOD GUYS: THEIR ROLE IN THE PREVENTION, MANAGEMENT AND TREATMENT OF DISEASE
by Andreas M. Papas M.Sc., Ph.D. President YASOO Health Inc.
Adjunct Professor, James Quillen College of Medicine, East Tennessee State University, Johnson City, TN
Senior Scientific Advisor, The Cancer Prevention Institute, Harvard University
Most of us view free radicals and antioxidants as a classic case of bad guys the free radicals, and good guys the antioxidants. While this understanding may be rather simplistic, significant research indicates that management of the production of free radicals and effective use of antioxidants can provide useful tools for the prevention, management and treatment of disease.
FREE RADICALS—THE BAD GUYS?
Atoms consist of the positively charged nucleus and negatively charged electrons. Electrons orbit around the nucleus in pairs. When an electron from a pair is removed the molecule becomes very unstable. A free radical is any chemical species, capable of independent existence with one or more unpaired electrons. Free radicals with major biological significance include superoxide, hydroxyl, lipid, nitric oxide, thiyl and protein radicals. Scientists group with free radicals non-radical compounds that are strong oxidants or can be converted easily to free radicals. Some examples include hydrogen peroxide, singlet oxygen and ozone.
Free radicals are extremely reactive. The half-life of one of the most damaging free radicals, the hydroxyl radical, is one billionth of a second. This means that it will attack the first molecule in its path fat, protein, DNA, sugar and ‘steal’ electrons. This process, called oxidation, is the same process that causes our cars to rust and slices of apple to turn brown and may have major impact on aging and health and disease.
Free radicals are part of life
Free radicals are produced in every tissue of our body. Three major sources of free radicals are:
The mitochondria. We use oxygen to oxidize glucose in the mitochondria to produce energy as ATP (adenosine triphosphate). Even under normal conditions, electrons deviate from their normal path and combine with oxygen or other molecules to form free radicals. Excess production of free radicals ruptures the membrane of the mitochondria and opens the floodgates of free radicals.
Lipid oxidation. Lipid material in our body plays critical role in membranes, LDL, hormones, and many tissues including nerve tissue. Lipids, especially polyunsaturated fatty acids are prone to oxidation. Oxidation of a single lipid molecule by a single radical can start a chain reaction, which can oxidize all lipid material.
The immune system. Free radicals are formidable weapons in the arsenal of our immune system. The phagocytes produce free radicals and use them to kill invading bacteria and viruses.
Do free radicals have any other redeeming value? The answer is yes. The singlet oxygen and nitric oxide (NO) play a very important role in regulating cell growth and cell to cell communication. NO dilates blood vessels and lowers blood pressure (the 1998 Nobel Prize in Medicine was awarded for the research on the role of NO).
Free radicals are important part of our metabolism and do have useful functions. It is the excessive production of free radicals at the wrong time and place that causes harmful oxidative stress.
FREE RADICALS IMPLICATED IN AGING AND CHRONIC DISEASE
Aging: Every major theory on aging assumes a role for free radicals. The free radical theory hypothesizes that free radicals cause degenerative changes. Free radicals fit well other major theories of aging such as the telomere, mitochondrial DNA, glycosylation and immunological theories.
Oxidative stress and chronic disease. Oxidative stress is believed to contribute to the development of chronic disease including hear