An antioxidant is a chemical that prevents the oxidation of other chemicals. In biological systems, the normal processes of oxidation (plus a minor contribution from ionizing radiation) produce highly reactive free radicals. These can readily react with and damage other molecules: in some cases the body uses this to fight infection. In other cases, the damage may be to the body's own cells. The presence of extremely easily oxidisable compounds in the system can "mop up" free radicals before they damage other essential molecules.
The following vitamins have shown positive antioxidant effects:
Retinol (Vitamin A or beta-carotene) has been discovered to protect dark green, yellow and orange vegetables and fruits from solar radiation damage, and is thought to play a similar role in human body. Carrots, squash, broccoli, sweet potatoes, tomatoes, kale, collards, cantaloupe, peaches and apricots are particularly rich sources of beta-carotene.
Ascorbic acid (Vitamin C) is a water-soluble compound that fulfills this role, among others, in living systems. Important sources include citrus fruits (like oranges, sweet lime, etc.), green peppers, broccoli, green leafy vegetables, strawberries, raw cabbage and tomatoes.
Vitamin E (tocopherol) is fat soluble and protects lipids. Sources include wheat germ, nuts, seeds, whole grains, green leafy vegetables, vegetable oil and fish-liver oil.
Selenium is best obtained through foods, as large doses of the supplement form can be toxic. Good food sources include fish, shellfish, red meat, grains, eggs, chicken and garlic. Vegetables can also be a good source if grown in selenium-rich soils.
Antioxidant vitamins — E, C and beta carotene (a form of vitamin A) — have potential health-promoting properties.
Using dietary supplements of antioxidants to prevent cardiovascular disease should not be recommended until their effect is proved in clinical trials that directly test their impact on CVD end points. Beneficial effects must be demonstrated in well designed (randomized, placebo-controlled) clinical trials before recommending widespread use to prevent cardiovascular disease.
At this time, the scientific evidence supports a diet high in food sources of antioxidants and other heart-protecting nutrients, such as fruits, vegetables, whole grains and nuts instead of antioxidant supplements to reduce risk of CVD.
Antioxidants are substances that may protect cells from the damage caused by unstable molecules known as free radicals.
Antioxidants are often described as "mopping up" free radicals, meaning they neutralize the electrical charge and prevent the free radical from taking electrons from other molecules.
Antioxidants are abundant in fruits and vegetables, as well as in other foods including nuts, grains and some meats, poultry and fish.
Feeds |
Contact