Kids Research Express

Antioxidants are also used in industry as product additives and in food processing and preservation. Industrial antioxidants slow or prevent oxidative damage that causes food to spoil, rubber to harden, fats and oil to change color or go rancid, and gasoline to oxidize. Foods that are commonly preserved with antioxidant additives include cheese, bread, and oil. Antioxidants used as food preservatives include vitamin C and the synthetic antioxidants butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA). These antioxidants are added to foods in concentrations of much less than 1 percent.

Vitamin C , also known as ascorbic acid, is a well known antioxidant that may prevent cataracts and cancers of the stomach, throat, mouth, and pancreas. It may also prevent the oxidation of LDL cholesterol, lowering the risk of heart disease. Foods that are high in vitamin C include strawberries, oranges, broccoli, and brussels sprouts. Beta-carotene absorbs free radicals that target molecules in the cell membrane. Studies suggest that in addition to reducing the risk of cataract, cancer, and heart attack, beta-carotene may also reduce the risk of stroke. Beta-carotene occurs naturally in orange-colored fruits and vegetables and dark green, leafy vegetables. Some of the best sources of beta-carotene are sweet potatoes, spinach, and carrots. As an antioxidant, vitamin E may also protect from heart disease and cataract and may strengthen the immune system. Good sources of vitamin E include wheat germ oil and sunflower seeds.

About 5 percent of the oxygen humans breathe is converted into free radicals. The presence of free radicals in the body is not always detrimental. Free radicals produced in normal cellular metabolism are vital to certain body functions, such as fighting disease or injury. When tissue is diseased or damaged, the body’s immune system sends disease fighting cells to the site, where they produce free radicals in an effort to destroy foreign invaders. But as the body ages or is subjected to environmental pollutants, such as cigarette smoke, overexposure to sunlight, or smog, the body becomes overwhelmed by free radicals. An excessive number of free radicals causes damage by taking electrons from key cellular components of the body, such as protein , lipids , and deoxyribonucleic acid (DNA), the molecule that carries genetic information in every living cell. These reactions make cells more vulnerable to cancer-causing chemicals, called carcinogens . Free radicals may lead to heart disease ...