An antioxidant is a molecule that is able to slow or prevent the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons from one molecule to the oxidizing agent. This can produce molecules called free radicals that have lost electrons and try to recover them from other molecules. This starts a chain reaction that can damage cells. Antioxidants stop these chain reactions because they have extra electrons, which they are able to donate to free radicals without becoming unstable themselves. This neutralizes the negative effects of the free radicals without damaging cells.
The body naturally produces free radicals through breathing and the metabolism of amino acids and fats, and free radicals enter the body from outside sources. These unstable molecules freely react with and damage healthy cells. They can also bind to and alter the structure of DNA. This oxidative stress on the body’s cells may lead to serious health issues. It may also be an important element in the aging process, although this has not been thoroughly researched.
The human body normally produces antioxidants to help stem the tide of free radicals. However, as we age, we produce fewer of our own antioxidants; and some antioxidants our bodies need but cannot produce themselves, such as vitamin C and E. These must come from the foods we eat, and we need to eat more antioxidants as we age to make up for the antioxidants we no longer produce naturally.
Literally hundreds of antioxidants exist in whole plant foods. Most of them have not been thoroughly studied. Some that have been studied include
- anthocyanins from blueberries, eggplant, and red grapes;
- ascorbic acid (vitamin C) from rose hips, jujube, black currant, strawberries, and citrus fruit;
- beta-carotene from sweet potatoes, carrots, pumpkin, and spinach;
- flavan-3-ols from tea, chocolate, apples, and grapes;
- flavanones from citrus fruits;
- flavones from parsley, celery, oregano, peppers, onions, blueberries, tea, cocoa, tomatoes, and broccoli;
- isoflavones from soy and other legumes;
- lutein from kale, collards, spinach, corn, peas, and citrus;
- lycopene from tomatoes and tomato products such as ketchup and spaghetti sauce, and watermelon;
- oligomeric proanthocyanidins or OPCs from red grape seed and skin, cranberries, cocoa, apples, strawberries, wine, peanuts, cinnamon, and hawthorn;
- polyphenols from berries, tea, beer, grapes or wine, olive oil, chocolate or cocoa, walnuts, peanuts, and pomegranates;
- resveratrol from grapes, peanuts, cranberries, and other berries;
- selenium from Brazil nuts, meats, tuna, and whole grains;
- tocopherols and tocotrienols (vitamin E) from vegetable oils, nuts, spinach, broccoli, and asparagus.
With the growing awareness of the importance of antioxidants, more and more individual antioxidant pills appear on the market, such as vitamin A, vitamin E, vitamin C, beta-carotene, selenium, lycopene, resveratrol, and lutein.
These highly refined and concentrated, often synthetic, individual products do not, however, demonstrate effectiveness. Phytochemicals in whole plant foods work with the antioxidants in that food to provide the appropriate environment for the antioxidants to work effectively.
In a study from John Hopkins University, published in the Annals of Internal Medicine, researchers concluded:
“In our meta-analysis, we identified a dose-dependent relationship between vitamin E supplementation and all-cause mortality. Specifically, all-cause mortality progressively increased for dosages approximately greater than 150 IU/d. This dosage is substantially lower than the tolerable upper intake level for vitamin E, which is currently designated at 1000 mg of any form of supplementary alpha-tocopherol per day (corresponding to 1100 IU of synthetic vitamin E per day or 1500 IU of natural vitamin E per day).”
A statement from NIAMS, the National Institute for Arthritis, Musculoskeletal and Skin Diseases, states: “Vitamin A is important for healthy bones. However, too much vitamin A has been linked to bone loss and an increase in the risk of hip fracture. Scientists believe that excessive amounts of vitamin A trigger an increase in osteoclasts, the cells that break down bone. They also believe that too much vitamin A may interfere with vitamin D, which plays an important role in preserving bone.”
On February 28, 2007, a study published in the Journal of the American Medical Association found that taking antioxidant pills could actually shorten your lifespan. “By taking these supplements, you might be impeding your immune system’s ability to fight off disease or risk factors for chronic disease,” said Edgar Miller III of Johns Hopkins University. “People are taking these supplements with the presumption that they will live longer or better. This shows they are not living longer and in fact may be at higher risk of dying.”
Antioxidants found naturally in whole foods offer incredible health benefits, but the evidence so far for the efficacy of isolated or synthetic antioxidant pills tells another story. It appears that antioxidants work better
in concert with the full range of phytochemicals found naturally in whole plant foods. Antioxidants are vitally important molecules that your body manufactures and needs in order to maintain itself. However, synthetic or single-antioxidant sources do not appear to be the best alternative. Choose whole food sources for your antioxidant intake.
Find plants rich in antioxidants in Healthy Plant Foods.