Facts of the Matter
Pass the pizza, please
The old saying advises us to eat an apple a day to keep the doctor away. Knowing about antioxidants and free radicals, you might add spinach and broccoli, whole-grain bread, carrot sticks, a cup of tea, and ... pizza. Yes, pizza!
A recent study by the U.S. Department of Agriculture found that many common herbs have higher antioxidant activity than fruits, nuts, grains and green vegetables.
One of the herbs with the highest antioxidant activity is oregano. Weight for weight, oregano has 42 times more antioxidant activity than apples, 30 times more than potatoes, 12 times more than oranges and four times more than blueberries. Of course, it takes a lot of oregano to weigh as much as one apple!
Antioxidants are a category of chemicals that prevent or slow oxidation, the breakdown of other substances by oxygen. In the body, antioxidants counteract the damage caused by another group of chemicals, called free radicals.
Free radicals are molecules with one or more unpaired electrons, which rapidly react with other molecules, starting chain reactions in the process of oxidation. The highly reactive free radicals can damage healthy DNA and can cause irreversible damage to cells. They can affect cardiovascular, neurological and immune systems. They have been linked to changes that accompany aging such as cancer, cardiovascular disease, stroke, degenerative diseases like arthritis and with age-related macular degeneration, a leading cause of blindness in the elderly.
A growing number of substances found in fruits, vegetables, nuts and grains are known to have antioxidant properties. The list includes vitamins C and E, carotenoids (which include beta-carotene, lycopene and lutein), folate, coenzyme Q10, flavonoids and selenium.
The body produces its own antioxidants to keep free radicals in balance, but environmental factors like cigarette smoke, exhaust fumes, radiation, excessive sunlight and certain drugs can increase the amount of free radicals, creating an imbalance.
Antioxidants can stabilize damaged fat cells, but the more fat there is in the diet, the more antioxidants are needed. Nature provides us with a natural antioxidant mechanism that protects us from most cell damage, but our bodies are not programmed to deal with the extra load that modern diets and environments place on them.
It is fairly certain that antioxidants that occur naturally in fresh fruits and vegetables have a protective effect. People who consume diets high in antioxidant-containing foods are less at risk from chronic diseases. Some scientists think that the effect from food comes from the combination of its compounds rather than just the specific antioxidants it contains.
Different antioxidants have different effects, and there is no single chemical, natural or otherwise, that shows promise as a magic bullet to assure health and longevity. But vitamin C, vitamin E, folate, carotenoids, coenzyme Q10, flavonoids and selenium do appear to be important in reducing the risk of coronary heart disease. Vitamin E and carotenoids appear to protect cell membranes, while vitamin C removes free radicals from inside the cell.
Selenium as a component of several enzymes helps rid the body of destructive oxidation products, but its precise method of action is not clear. Among the richest dietary sources of selenium are organ meats and Brazil nuts, but the most important sources are cereal grains, meat and fish.
Lycopene is a carotenoid that imparts red color to tomatoes, guava, rosehip, watermelon and pink grapefruit. Numerous studies suggest that lycopene is associated with reduced incidence of prostate, digestive tract, breast, lung and cervical cancer as well as cardiovascular disease and age-related macular degeneration. It seems to be more effective when the tomatoes are cooked. Carotenoids in blueberries, cranberries and grapes have also shown significant antioxidant activity.
We are just beginning to grasp the complex relationships between free radicals and antioxidants, and the future holds great promise for reducing the ravages of aging. The lessons learned from the research as the long list of antioxidants has grown is that healthy eating means exactly as we've always been told: balance, variety and moderation.
Even considering the antioxidant properties of oregano, the lycopene in the tomato and the selenium in the crust and the pepperoni, the cheese on that pizza probably outdoes the protective effect of the herb. Have a salad with it, and if you must eat the pizza, the more oregano, the better.
We could all be a little smarter, no? Richard Brill picks up
where your high school science teacher left off. He is a professor of science
at Honolulu Community College, where he teaches earth and physical
science and investigates life and the universe.
He can be contacted by e-mail at email@example.com