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, carrot sticks, a cup of tea, and … pizza. Yes, pizza!
A 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 to age-related macular degeneration, a leading cause of blindness in seniors.
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 (vitamin B9), coenzyme Q10, quercitin, 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. Stress and aging also add to the number of free radicals.
The dietary factor most important in producing free radicals is the consumption of high-fat foods. Nature provides us with a natural antioxidant mechanism that protects us from most cell damage, but the more fat there is in the diet, the more antioxidants that are needed, and our bodies are not programmed to deal with the extra load that modern diets and environments place on them.
Exercise increases free radicals as body cells consume more oxygen. Some studies indicate that vitamin E can reduce free radical production related to exercise, especially in those of us older than 55.
Selenium as a component of several enzymes helps rid the body of destructive oxidation products, but its precise method of action is not clear. Some studies suggest that it works in conjunction with vitamin E. Among the richest dietary sources of selenium are organ meats and Brazil nuts.
Lycopene is a carotenoid that imparts red color to fruits and vegetables. 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. Other carotenoids in blueberries, cranberries and grapes have significant antioxidant activity.
Flavonoids in tea might help reduce the risk of heart disease, strokes and some cancers and might help to slow down atherosclerosis, deposits of cholesterol leading to a narrowing of the blood vessels and restriction of blood flow.
Even considering the antioxidant properties of oregano, the lycopene in the tomato and the selenium in the crust and pepperoni, the cheese on that pizza probably outdoes the herb’s protective effect. Still, enjoy the pizza; the more oregano, the better.
Richard Brill is a retired professor of science at Honolulu Community College. His column runs on the first and third Fridays of the month. Email questions and comments to brill@hawaii.edu.
