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 continue to the body's own cells. The presence of extremely easily oxidizable compounds in the system can "mop up" free radicals before they damage other essential molecules.
The following compounds have shown positive antioxidants effects. Each has a unique molecular structure.
It is important to note that antioxidants themselves can become reactive, after donating an electron to a free radical. An excellent article in Scientific American reviews the issue of the good and bad for antioxidants. In line with research which shows a healthy balanced diet seems to work but high doses or individual anti-oxidants may not. The article reinforces the belief by many that mega-doses of antioxidant may not be the answer instead a proper combination of antioxidants similar to those found in several foods may be the way to go.
Abundant Antioxidants in Food
Polyphenols are the most abundant antioxidants in the diet. There are over 4,000 polyphenol compounds. Their total dietary intake could be as high as 1 g/d, which is much higher than that of all other classes of phytochemicals and known dietary antioxidants. This is about 10 times higher than the intake of vitamin C and 100 times higher that the intakes of vitamin E and carotenoids.. The main dietary sources for polyphenols are: fruits and plant-derived beverages such as fruit juices, tea, coffee, and red wine. Vegetables, cereals, chocolate, and dry legumes also contribute to the total polyphenol intake. Examples of polyphenols are: resveratrol, ellagitannin and Theaflavin-3-gallate. A very large list of polyphenols and their food source can be found at Phenol Explorer, a database of polyphenol content in food
view the molecular structure and read about each of the following antioxidants
|Vitamin C||Vitamin E|
SEE ALSO : THE MOLECULAR BASIS OF TASTE