They're everywhere: you see them on TV, learn about them in magazines, and read them on labels of food or food supplements. The word 'antioxidant' has been placed in nearly every new food product since the early 00s. Most of us just buy the stuff thinking, "Hey this must be healthy" without knowing the effects and how it helps the body. But what is it? Where does it come from? And most importantly, what does it do?
As these concerns rise, more and more companies are investing on products which can delay aging, make one look healthier and can produce antioxidants. Resveratrol, an antioxidant compound found in grapes, is not a newbie in this market.
The word antioxidant originally referred to a compound that prevented the consumption of oxygen. Prior to its use medically, the term was used industrially. There were extensive studies of antioxidants to prevent metal corrosion, the vulcanization of rubber and the fouling of internal combustion engines. Research in biology turned focus to their use in preventing oxidation in unsaturated fats which causes rancidity. The identification of vitamins A, C and E as antioxidants revolutionized the field and led to the idea that antioxidants are important in the biochemistry of living organisms.
There is a paradox in biology, particularly with the metabolism of almost all complex life on Earth. Almost all animals require oxygen to exist and survive. Oxygen on the other hand is a highly reactive molecule that harms healthy cells by the production of reactive oxygen species. In consequence, organisms evolved to have a complex system of antioxidant metabolites and enzymes that work together to prevent damage to cellular components such as DNA, lipids and proteins. Antioxidant systems in animals do not eliminate oxidants entirely. Rather, they keep oxidants in the body at an optimum and safe level.
Antioxidants are molecules that slow or prevent the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons to an oxidizing agent. These reactions produce free radicals which start chain reactions and destroy healthy cells. Low levels of antioxidants in the body or the inhibited production of antioxidant enzymes cause oxidative stress which may damage or kill healthy cells. Oxidative stress also indirectly causes cardiovascular disease. Low density lipoprotein (LDL) triggers the process of atherogenesis which results in atherosclerosis and finally cardiovascular disease.
The brain is the most vulnerable to oxidative stress injury. This is because of its high metabolic rate and massive concentration of polyunsaturated lipids which are targets for lipid peroxidation. Antioxidants are often used as medication to treat some forms of brain injury such as traumatic brain injury and stroke. Antioxidants prevent oxidative stress in neurons and prevent neurological damage. Studies are being made to see if antioxidants are possible treatments for Alzheimer's, Parkinson's and amyotrophic lateral sclerosis.
Scientists speculate that because resveratrol has highly hydrophilic and lipophilic properties, it can provide more protection than other well known antioxidants such as vitamins C and E. Hydrophilic antioxidants react with oxidants in the cell cytosol and the blood plasma. Lipid soluble antioxidants protect cell membranes from lipid peroxidation*.
"Lipid peroxidation refers to the oxidative degradation of lipids. It is the process whereby free radicals "steal" electrons from the lipids in cell membranes, resulting in cell damage. This process proceeds by a free radical chain reaction mechanism. It most often affects polyunsaturated fatty acids, because they contain multiple double bonds in between which lie methylene -CH2- groups that possess especially reactive hydrogens. As with any radical reaction the reaction consists of three major steps: initiation, propagation and termination" - Wikipedia
Antioxidants are commonly found in fruits and vegetables. Polyphenolic antioxidants are found in tea, coffee, soy, nuts, fruit, olive oil, chocolate, cinnamon, oregano, and red wine. If you notice, most of the foods containing polyphenolic antioxidants are common in the French diet such as nuts, chocolate and red wine. One particular polyphenolic antioxidant is resveratrol which is commonly found in red wine and peanuts.
Being an antioxidant, resveratrol can cancel out the cell-damaging effects of free radicals. People who consume foods with resveratrol have a lowered risk of heart disease and neurological disease. There is some evidence that resveratrol, being an antioxidant, can prevent macular degeneration, suppressed immunity due to poor nutrition, and neurodegeneration. The French consume red wine every meal. The more formal meal courses actually have a different glass of wine for every course! And by tradition, red meat and fatty foods are paired with; you guessed it, red wine.
Other sources of resveratrol include grapes, peanuts, eucalyptus and mulberries. The amount of resveratrol present in wines depends on how long the skins of the wines were in the fermentation process before being sieved out. Resveratrol functions as a natural guard against bacteria, fungus and infections in plants. Since fungus cultivates at lower temperatures, grapes grown in colder places tend to have more resveratrol in the skin than those grown at warmer climates.
Aside from diet related ailments, cells become damaged even while exercising. During intense physical activity, the body consumes ten times more oxygen than at rest. This results in an increased production of oxidants which results in damage that causes muscle fatigue during and after exercise. Post-exercise oxidative stress also triggers an immune system response and brings about the inflammatory process. After cellular damage in the muscle fibers have been repaired or replaced by new tissue, the body becomes stronger. Resveratrol speeds up this healing process by increasing the body's metabolic rate.
Resveratrol, as discussed in the earlier paragraphs, has antioxidant qualities. It protects life against apoptotic stimuli (a DNA-damaging agent) and ischemic damage (tissue damage due to lack of oxygen and nutrients). In the face of oxidative stress, Resveratrol combats other forms of aging such as progeria or rapid aging in children, vascular oxidative stress, asthma, endothelial dysfunction and transplant rejection. It even protects plants against UV radiation! Now imagine how much more Resveratrol can do to humans!
The component in Resveratrol that gives it its antioxidant qualities is polyohenol. Unstable molecules called free radicals cause oxidative damage to our tissues and as well as our cells by destroying their integral parts (DNA, membranes and proteins). When these cells are attacked, the organs which host these cells can also malfunction and health complications will eventually ensue. Polyohenol counter the free radicals' attacks even in the face of pollution, breathing, UV radiation and other things which can generate oxidative stress.