Recently, scientists have discovered the substance responsible for many of the health benefits we've been receiving from plants. Fruits and vegetables contain chemical substances that act on specific, harmful molecules inside our bodies to stop them from damaging our cells. Because these substances work on oxygen by-products called free radicals, they have come to be known as natural antioxidants.

Antioxidants protect the body against free radicals. One of the many functions of antioxidants is to work against the formation of cellular damage caused by free radicals. Free radicals are highly reactive chemical substances which are produced whenever our body undergoes the process of oxidation (breathing).

When free radicals are released, they immediately latch on to other molecules, stealing their electrons, in so doing, turning them into unstable molecules like themselves. The result is a rapid chain reaction which, when left unattended, can lead to various degenerative diseases, such as heart disease, stroke, cancer, Alzheimer's disease, Parkinson's disease, and memory loss.

Natural antioxidants are primarily derived from plants. The human body cannot produce its own supply of antioxidants. That is why we have to depend solely on our diet to get the amount of antioxidants our body needs.

Groups of well-known antioxidants include catechins, coumarins, indoles, and carotenoids. All these are complex compounds found in almost all plants. Carotenoids are the largest group of naturally occurring antioxidants, followed closely by indoles and coumarins. Catechins are the natural antioxidants found in the Camellia sinensis -- the plant from which we get green tea, oolong tea, and black tea.

In the carotenoid group, beta-carotene is the most common natural antioxidant. Another name for beta-carotene is vitamin A -- that essential vitamin that helps prevent eye damage. This natural antioxidant supports the immune system, might reduce the skin's risk to sun and DNA damage, supports healthy cholesterol levels, and increases lung capacity. Some studies even show that Vitamin A supports a healthy heart.

Catechins are great weight-loss inducers. But more than that, the natural antioxidants they contain help promote health by boosting the immune system, which in turn reduces the risk of infection.

While aging is clearly a natural process, it is through nature that we can find our greatest weapons against aging. The natural antioxidants in the food we eat can fight, and in some cases even reverse, the effects of aging.