Antioxidants are substances that protect cells from damage caused by reactive oxygen species. Reactive oxygen species include hydrogen peroxide and free radicals. Free radicals are molecules with incomplete electron shells making them more chemically reactive than those with complete electron shells. Free radicals are also formed when exposed to tobacco smoke and radiation. How do they work?

Antioxidants work in two ways:

Chain-breaking - When a free radical like an electrically charged oxygen molecule tries to release or steal electrons from other molecules, it results in the formation of another free radical which again does the same process to a third molecule. Thus more and more unstable products are formed. This cause damages to the DNA and such damage becomes irreversible thus leading to diseases like cancer. Chain breaking antioxidants such as beta-carotene and vitamins C and E neutralize the electrical charge and prevent this process. They reduce oxidative damage to cells and biochemicals.

Preventive -Oxidation can also be prevented by reducing the rate of chain reaction by antioxidant enzymes like catalase, superoxide dismutase and glutathione peroxidase.

Antioxidant is a classification of various organic substances such as vitamins C, E and A, selenium and a group of carotenoids of which beta- carotene is the most popular. Beta carotenes are pigment that gives color to many fruits and vegetables. Antioxidants when neutralizing free radicals they themselves become oxidized. Therefore it is important to replenish our antioxidant resources. By consuming foods rich in antioxidant you may reduce your chances of damage to cells and biochemicals from free radicals. Another benefit is it may slow down the aging process and also prevent certain diseases resulting from cellular damage. Fruits and vegetables are good source of antioxidant including other foods such as nuts, grains and some meats, poultry and fish.

Some of the food sources of common antioxidants are:

Beta-carotene carrots, squash, apricots, pumpkin, sweet potatoes, cantaloupe, mangoes and all foods that are orange in color are rich in beta-carotene including some green leafy vegetables like spinach and collar greens.

Lutein-Found in green leafy vegetable like spinach, kale and collard greens. It is also said to be good for healthy eyes.

Lycopene-Tomatoes, watermelon, papaya, apricots, guava etc are good sources of lycopene.

Selenium- It forms the active site of several antioxidant enzymes. Rice and wheat are the major dietary sources of selenium in most countries where as in some countries nuts are a common source of selenium.

Vitamin A Foods such as sweet potatoes, milk, liver, carrots and egg yolks are rich in vitamin A.

Vitamin C- Commonly found in fruits and vegetables and also in cereals, beef, poultry and fish.

Vitamin E- Found in nuts like almonds, sunflower, corn and soybean oils, and also in mangos, broccoli and other foods.

According to some research elderly people who are heavy drinkers and smokers, who take aspirin frequently and those with impaired immune systems should take antioxidant supplements daily for their own benefit. Higher levels of antioxidants also help to prevent the development of arterial blockages, a complicated process involving the oxidation of cholesterol thus reducing the chances of a stroke or heart related problem.