They are formed naturally , both internally by metabolism and externally by chemicals. These include alcohol consumption, drugs, toxic metals, emotional stress, smoking, pesticides, herbicides and air pollutants. There are two groups of natural antioxidants. Selenium is also an important mineral antioxidant. Selenium is commonly found in onions, garlic, mushrooms, whole grain cereals, particularly in the wheat germ and rice bran.
Prevention is better than cure.
The more toxic chemicals which produce free radicals we obtain, the more antioxidants in our diet we have to consume for the detoxification. We should be healthy and free from disease by preventing our body from any oxidative damage. Plant food contains a wide range of phytochemicals and antioxidants which are protecting agents against free radicals. Beta-carotene are common in dark green, yellow, orange and red vegetables and fruits such as carrots, pumkin, tomatoes, spinach, peppers, watercress, broccoli, cherries, peaches, papaya, water melon and apricots. Several tropical fruits and vegetables are good sources of antioxidants.