“Pomegranates, persimmons, berries, broccoli, nuts”, “neutralize free radicals”, “anti-cancer”, anti-aging”, “enhance the function of the immune system”, “boost immune defenses”, “boost cellular antioxidant defenses”, “protect against heart disease and cancer”, “anti-aging ingredient in beauty products”, – the buzz is everywhere, – grocery store shelves, supplement promotions – everywhere!
What are antioxidants and what do they really do?
Antioxidants are molecules that fight oxidation. Oxidation is a normal chemical process that takes place in the body every day. Oxygen is important for the body’s health, but exposure to oxygen also causes oxidation. Oxidation in the body can be accelerated by stress, sun, cigarette smoking, alcohol and pollution. When the natural oxidation process is disrupted, highly unstable and potentially damaging molecules called free radicals are formed. Oxygen triggers the formation of these destructive little chemicals and they can cause damage to the cells, if not controlled. These free radicals are atoms or groups of atoms that contain an odd number of electrons. They are formed when these molecules react with oxygen. Once formed free radicals can start a chain of damaging chemical reactions. This chain reaction can damage important body chemicals, DNA, and the cell membrane, causing the cells to function poorly or die. Some cells can heal while others are permanently damaged.
Antioxidants are natural substances that can stop or limit the damage caused by the free radicals. The body uses antioxidants to stabilize the free radicals. Antioxidants terminate these chain reactions by removing free intermediates and inhibit other oxidative reactions. They do this by being oxidized themselves. Thus antioxidants are often reducing agents. Some scientists believe free radicals may contribute to the aging process as well as cause cancer, diabetes, heart disease, stroke, and neurodegenerative diseases.
Antioxidants can protect and reverse the damage caused by oxidation to some degree. The body produces antioxidants to fight off the free radicals formed by body processes. Also the body gets antioxidants from the diet. Examples of foods high in antioxidants are foods high in Vitamin A, Vitamin C, Vitamin E, beta-carotene, lutein, lycopene and selenium.
To help the body it is recommended that one eat a healthy mix of colorful fruits and vegetables and other antioxidant-rich foods.:
- Vitamin A is found in milk, liver, butter and eggs.
- Vitamin C is found in fruits and vegetables such as papayas, strawberries, oranges, cantaloupe, and kiwi and bell peppers, broccoli, Brussels sprouts, tomatoes, cauliflower and kale.
- Vitamin E is found in some nuts and seeds, including almonds, sunflower seeds, hazelnuts and peanuts, also in green leafy vegetables, such as spinach and kale and in oils such as soybean, olive, sunflower, corn, and canola oils and in almonds, and avocado.
- Beta carotene is found in colorful vegetables and fruits like carrots, peas, cantaloupe, apricots, papayas, mangoes, peaches, pumpkin, apricots, broccoli, sweet potatoes and squash, beet greens, spinach and kale.
- Lutein is found in green leafy vegetables such as spinach, collards, and kale, broccoli, corn, peas, papayas and oranges.
- watermelon, apricots, tomatoes, and papaya.
- Selenium is found in cereals (corn, wheat and rice), nuts, legumes, animal products (beef, fish, turkey, chicken, eggs, and cheese), bread and pasta.
- Anthocyanins – found in blue and purple foods like blueberries, raspberries, plums, pomegranates, eggplant, and red cabbage.*
Antioxidants are not interchangeable. Each antioxidant has its own chemical behavior and biological properties. Thus we need to eat a variety of foods rich in antioxidants to get antioxidants with the different properties.
Antioxidants are also in antioxidant supplements. However when thinking about adding antioxidant supplements to one’s diet, it is advised to talk first with your doctor. There has been much discussion and hype about antioxidants. It was in the 1990’s when scientists were first understanding that free radical damage was involved in clogging arteries in atherosclerosis and may also contribute to cancer, vision loss and other chronic conditions. There was some early association of persons with low intakes of antioxidant-rich foods such as fruits and vegetables that seemed to be at a greater risk for developing chronic conditions. However before test trials could be done and completed, the media and the supplement and food industries began to hype the “benefits “ of antioxidants. Frozen berries, green tea and other foods thought to be rich in antioxidants were touted as disease-fighting foods.
The research trials have not have the hoped-for benefits. Most research teams reported that vitamin E and other antioxidant supplements did not protect against heart disease or cancer. However the disappointing results has not stopped or slowed food companies and supplement sellers. Antioxidant supplements are a $500 million dollar industry ** and growing. Antioxidants are added to breakfast cereals, sports bars, energy drinks, etc. They are promoted as additives that can prevent heart disease, cancer, cataracts, memory loss and other conditions. Continued testing and research are not finding anything promising for prevention or cures of chronic health conditions. (There was some protection found against the development of advanced stages of age-related macular degeneration, but not cataracts with taking a combination of vitamin C, vitamin E, beta carotene and zinc.)
If antioxidants were harmless, there would be no concern. However, a few studies are showing that taking antioxidant supplements, either single agents or combinations, may interfere with health. One of the most significant findings was among heavy smokers in Finland, who began developing lung cancer when given beta-carotene supplement. Also skin cancer was higher in women who were given vitamin C, vitamin E, beta-carotene, selenium and zinc. One study indicated that those who took vitamin A, E, and beta-carotene supplements may be at risk for premature death. Excessive intake of vitamin E has also been associated with heart failure and increased bleeding.
There have now been many studies done, but no substantial health benefits have been found for supplemental antioxidants. Antioxidants in food, though, is considered safe. Until more research is done and the use of supplemental antioxidants is found to be beneficial to one’s health, it is advised that one not take anti-oxidant supplements. The best source of antioxidants is a diet rich in fruits, vegetables and whole grains. It is recommended that one eat between 5-9 servings of a variety of fruits and vegetables, every day.
*Family Doctor, Web Version, Antioxidants, Reviewed/Updated: 2/14.
(Picture Insert is the structure of the antioxidant vitamin ascorbic acid -vitamin C – -Wikipedia-antioxidants.)