Environmental pollutants, toxic chemicals, even the normal process of aging-all these produce free radicals that can damage the cells of the body. Fortunately, nature has provided substances to fight these effects. These substances are called antioxidants.
How antioxidants work
Free radicals are simply atoms that have lost an electron during the process of oxidation. In their search for balance they “steal” electrons from other atoms, turning those atoms into free radicals and continuing the process. A buildup of free radicals in the body can eventually damage both the outer wall-the membrane-of the cell and its DNA. This in turn can lead to conditions ranging from cataracts to cancer.
Antioxidants are substances that remain stable even when they give up one of their own electrons. Therefore, they can neutralize free radicals-by “donating” an electron-without continuing the chain reaction. There are many different antioxidants, but the most well-known are vitamin C, vitamin E, beta carotene, and selenium.
This vitamin, also called ascorbic acid, is water-soluble, so it’s good at neutralizing free radicals in body fluids, like blood or the fluid inside each cell. It’s commonly deficient in people who have diabetes, heart disease, or cancer, people who take aspirin or barbiturates on a regular basis, and cigarette smokers.
Vitamin C is particularly high in citrus fruits, members of the cabbage family (including broccoli and brussels sprouts), and peppers (chile and red and green bell types). It’s also available in supplement form.
Vitamin E is fat-soluble, so it’s good at protecting fatty tissue-which includes cell membranes, which are high in lipids (fat molecules). It keeps LDL (“bad”) cholesterol from attaching to blood vessel walls, thereby reducing the risk of heart disease from atherosclerosis. It has also been shown to decrease the risk of breast cancer in women with a family history of the disease.
Vitamin E is even more effective when vitamin C is present, because vitamin C helps it to regenerate after it’s given up its electron to the free radical.
Vitamin E’s natural form, d-alpha-tocopherol, seems to be more effective than the synthetic version, d-l-alpha-tocopherol acetate. So if you’re planning to take it as a supplement rather than obtaining it from food, be sure to check the label of the bottle.
The most common source of vitamin E is wheat germ and wheat germ oil. It’s also found in other vegetable oils, including peanut, safflower, soybean, and sunflower, and in almonds, spinach, and turnip and mustard greens.
There is one caution with vitamin E. Because one of its effects is to prevent platelets from clumping, it may increase the risk of strokes caused by bleeding. Therefore, anyone who takes prescription anticoagulants-blood thinners-on a regular basis should check with their doctor before taking large doses of vitamin E.
Beta carotene is a pigment that is the main source of color in some plants. When it enters the human body it splits and becomes vitamin A. But in its “precursor” form, it’s a powerful antioxidant that can help protect cell walls because, like vitamin E, it’s fat-soluble.
Beta carotene can help prevent cancers of the lung, esophagus, stomach, mouth, and throat. However, large doses should be avoided by people who smoke cigarettes, because they have been shown to increase the risk of lung cancer in these people.
The main sources of beta carotene are dark green leafy vegetables and fruits and vegetables that are orange or yellow, like cantaloupe, papaya, carrots, and pumpkins.
Selenium is a trace mineral that plants get from the soil. People who eat food grown in selenium-poor soil will be deficient in this mineral, and may need to take supplements.
The action of selenium is not well understood. It does seem to help vitamins C and E work better, and it has been shown to reduce the risk of lung, prostate, and colorectal cancer. It can also help prevent HIV from becoming full-blown AIDS.
The most concentrated sources of selenium are shellfish like lobsters, clams, and oysters, and Brazil nuts.
The number of antioxidants identified so far is in the hundreds, and may go much higher. It seems that nature is offering us many ways to stay healthy. Now it’s up to us to take advantage of them.