Antioxidants are important disease-fighting compounds. Scientists believe they help prevent and repair the stress that comes from oxidation, a natural process that occurs during normal cell function. A small percentage of cells becomes damaged during oxidation and turns into free radicals, which can start a chain reaction to harming more cells and possibly disease. Unchecked free radical activity has been linked to cancer, heart disease, Alzheimer's disease, and Parkinson's disease. Antioxidants help defend our bodies from heart disease, cancer, and perhaps even the ravages of age.

Antioxidants are the disease-fighting compounds that Mother Nature puts in foods to help our bodies stay healthy. Everyone knows that wine is good for the heart, but it's also high in calories. Try these low-calory antioxidant options that may help protect us against cancer, heart disease, infections, and the common cold:
    Tea
    Fruits
    Vegetables

Tea is brimming with antioxidants, the disease-fighting compounds that help your body stave off illness. Green tea, black tea, and oolong tea are all rich in antioxidants, part of your body's natural defense against disease. Studies of humans and animals show that the antioxidants in black and green teas are highly beneficial to our health.

Tea is gaining ground over coffee. The health benefits of tea are one compelling reason: Green and black teas have 10 times the amount of antioxidants found in fruits and vegetables.

Green tea, black tea, oolong tea -- they all come from the same tea plant, Camellia sinensis. The leaves are simply processed differently. Green tea leaves are not fermented; they are withered and steamed. Black tea and oolong tea leaves undergo a crushing and fermenting process.

All teas from the camellia tea plant are rich in polyphenols, which are a type of antioxidant. These wonder nutrients scavenge for cell-damaging free radicals in the body and de-toxify them. Whether it's green or black, tea has about eight to 10 times the polyphenols found in fruits and vegetables.

Black and green tea have different types of antioxidants than fruits and vegetables. Thearubigins, epicatechins, and catechins are among those listed in a USDA chart. All are considered flavonoids, a type of antioxidant. Brewed green and black teas have loads of those, the chart shows. (Herbal teas may also contain antioxidants but less is known about them.

Green and black tea had identical amounts of polyphenols. Both types of tea blocked DNA damage associated with tobacco and other toxic chemicals. In animal studies, tea-drinking rats have less cancer. Look at the world's big tea drinkers, like Japan and China. They have much less heart disease and don't have certain cancers that we in the Western world suffer.

Tea is a very rich source of a specific kind of antioxidant called flavonoids. The detoxifying effect of these antioxidants protects cells from free radicals, the damage that can lead to blood clot formation, atherosclerosis, and cancer.

The bulk of research shows that regular tea drinkers, people who drink two cups or more a day, have less heart disease and stroke, lower total and LDL (often called "bad") cholesterol, and that they recover from heart attacks faster.

Some laboratory tests also show that black and green tea may help boost metabolism to aid weight loss, block allergic response, slow the growth of tumors, protect bones, fight bad breath, improve skin, protect against Parkinson's disease, and even delay the onset of diabetes.

In a study involving bladder cancer cells, green tea extract seemed to make the cancer cells behave oddly. They matured sooner, bound together tightly, and had a hard time multiplying. Another study found that men who drank oolong tea plus green tea extract lost more weight and total body fat, compared with men who drank plain oolong tea. Also, the green tea drinkers had lower LDL cholesterol.

Other small studies have found that the antioxidants from drinking tea can help prevent skin cancer. There's also evidence that tea extracts applied to the skin (in a lotion) can block sun damage that leads to skin cancer.

All this research seems to suggest that if you want to do something good for yourself, drink tea. It has no calories and lots of polyphenols. If you're drinking tea, you're not drinking soda -- that's a real benefit. Water doesn't give you those polyphenols.

Drinking six to 10 cups of black or green tea throughout the day, starting with breakfast, is recommended. Switch to decaf tea midday, if you need to. Flavonoids are unchanged by removal of caffeine.

Fruits, especially berries, are chock-full of the disease-fighting antioxidants essential to your health. Berries are the top antioxidant-rich fruits. But don't forget peaches, plums, and a little red wine.

Berries provide the most antioxidant bang for the buck. Berries deliver super-healthy antioxidants that help fight disease. How healthy? A landmark study shows that just one cup of berries provides all the disease-fighting antioxidants you need in a single day. Of course, dietitians will tell you, "Don't stop there." A healthy diet needs a variety of nutrients from many food sources.

Raspberries, blueberries, strawberries, and blackberries are plentiful in most corners of the U.S.

Cranberries, blueberries, and blackberries ranked highest among the fruits studied. Apples ran a close second, and dried fruits were also leading contenders. Peaches, mangos, and melons, while scoring lower than berries, still contain plenty of antioxidants as well as other nutrients.

However, there's a catch: Even though some fruits and vegetables have a high antioxidant content, the body does not absorb all of it. The concept is called bioavailability. Bioavailability has to do with absorption or metabolism in the gut. What's absorbed will be impacted by the mechanical structure of different antioxidants in food -- if they're tied up with fiber or if they have sugar molecules attached.

Some foods benefit from a bit of cooking, he says. One of his studies showed that by mildly steaming blueberries, the antioxidant level was enhanced, making more antioxidants available to the body. That's why variety in your diet is important. You hedge your bets by eating as many antioxidant-rich foods as possible, since researchers don't yet fully understand the complexities involved with bioavailability. It's also why you should shoot for foods that offer the highest antioxidants, such as the top producers like berries.

Wild blueberries are the winner overall. Just one cup has 13,427 total antioxidants - vitamins A & C, plus flavonoids (a type of antioxidant) like querticin and anthocyanidin. That's about 10 times the USDA's recommendation, in just one cup! Cultivated blueberries have 9,019 per cup and are equally vitamin-rich.

Cranberries are the tart crown jewels of turkey feasts. They're also antioxidant powerhouses (8,983).

Blackberries (7,701), raspberries (6,058), strawberries (5,938), black plums (4,873), sweet cherries (4,873), and red grapes (2,016) are also brimming with vitamins A & C and flavonoids like catechin, epicatechin, quercetin, and anthocyanidin.

All-American apples are also vitamin- and antioxidant-rich treats. The classic Red Delicious (5,900), Granny Smith (5,381), Gala (3,903), and many other varieties are available nearly year-round.

Finally, orange-colored fruits are good sources of antioxidants as well. One naval orange has 2,540; the juice has about half that. Bite into a luscious ripe mango, and you'll get 1,653. A peach has 1,826, tangerines, 1,361, and pineapple, 1,229.

Dried versions of these fruits are smaller, but they still have plenty of antioxidants. For instance, just half a cup of these dried fruits packs quite a punch: prunes (7,291), dates (3,467), figs (2,537), and raisins (2,490). It's very easy to over-eat dried fruit, getting a lot more calories than you need. For people struggling with weight control, that can be too much of a good thing. If you eat the fruits in their natural form, they are very low in calories, very nutritious, full of fiber, vitamins, minerals, and many, many antioxidants. The whole fruit helps keep you in line calorie-wise.

More than 300 studies cite plentiful antioxidants in red wine, grape juice, grape seed, and grape skin extracts. Red wine is loaded with flavonoids like anthocyanidins and catechins. French people have lower rates of heart attacks despite the rich cuisine they eat because they drink moderate amounts of red wine with their meals. According to the American Heart Association, drinking a moderate amount of wine -- one or two glasses daily for men, no more than one for women -- lowers heart disease and may be safe. However, it cautions that this recommendation should be tailored for an individual's risks for heart disease and the potential benefits (as well as risks) of drinking. Studies show that when animals are given grape products the artery-clogging process slows down. The same thing seems to happen with humans.

Many of the same flavonoids are found in black and green tea as well as dark chocolate, but the bulk of research has been on grape flavonoids. Researchers say that flavonoids may help promote heart health by preventing blood clots (which can trigger a heart attack or stroke), prevent cholesterol from damaging blood vessel walls, improve the health of arteries (making them expand and contract more easily), and stimulating the production of nitric oxide, which may prevent hardening of the arteries (atherosclerosis).

Another antioxidant called reservatrol, found in red grapes, raspberries, and mulberries, seems to affect age-regulated genes, allowing cells to live longer and offsetting the risk of cancer, heart disease, and Alzheimer's disease.

Grape juice has similar antioxidant powers, researchers say. One study showed that drinking a tall glass of grape juice daily lowered LDL (also called "bad") cholesterol significantly. It also improved the blood flow in artery walls.

A number of studies show that Concord grapes and grape juice have a higher concentration of antioxidants than ordinary table grapes. In fact, one serving of grape juice has been shown to be the equivalent of taking a small aspirin every day, in terms of cardiovascular effects.

Just don't make the mistake of downing too much grape juice - or wine - in a day's time. Like dried fruit, these are very concentrated calories. Be careful, because those calories add up. It's better to eat more grapes.

The lowly bean takes top honors in the antioxidant category, along with artichoke hearts, potatoes, asparagus, and spinach as runners-up.

The lowly bean has been boosted to star status. A ground-breaking study that looked at numerous foods says beans - red, black, pinto, kidney -- are high-octane sources of antioxidants.

The USDA guidelines recommend eating a variety of fruits and vegetables each day, selecting from all five vegetable subgroups:
    Dark green vegetables,
    Legumes (beans),
    Starchy vegetables,
    Orange,
    Other vegetables.

They also suggest eating at least two and a half cups of vegetables daily for people eating 2,000 calories.

Which of these are the best antioxidant foods? Researchers used advanced technology to study 100 fruits, vegetables, and other food sources to measure the levels of antioxidants. Beans were the clear winners, but so was a quirky mix of other veggies - artichoke hearts, russet potatoes, sweet potatoes, spinach, and eggplant.

Knowing which foods have the most antioxidants is important, because in today's polluted world, the human body needs all the help it can get to fight disease-causing free radicals. That's what antioxidants do - stop free radicals from damaging other cells in your body.

The biggest class of antioxidants is flavonoids. Researchers have identified some 5,000 different flavonoids fruits and vegetables.

Yet the body simply doesn't absorb all flavonoids equally well - that is, not all are as bioavailable as others. Bioavailability has to do with absorption or metabolism in the gut.

Here's the science behind it: An antioxidant attached to a fiber or sugar molecule may require certain enzymes in the gut to help absorption, he explains. If those enzymes are there, the flavonoid is absorbed. Some flavonoids simply don't seem to get absorbed. It's still relatively a mystery what happens in the gut.

Cooking some vegetables even slightly can help boost bioavailability. Tomatoes are a classic example. Flavonoids in cooked tomatoes are better absorbed than raw tomatoes. We don't know for sure what's happening in the gut, but we do know this is true.

However, cooking is not always good. It kills antioxidants in some foods. Until researchers figure it out, aim to eat those at the higher end of the antioxidant chart.

Beans are found to be clear winners - one-half cup of red beans yields 13,727 antioxidants; red kidney beans have 13,259; pinto beans, 11,864; and black beans, 4,191. Beans are inexpensive and filling. Classic meals such as beans and rice, beans in a burrito, split pea soup, and a peanut butter sandwich are bean naturals. (Peanuts are not nuts; they are in the same family of plants as beans and peas.)

One-third cup of cooked beans has 80 calories, no cholesterol, lots of complex carbohydrates, and little fat. In addition, beans are full of B vitamins, potassium, and fiber, which promote digestive health and relieve constipation. Eating beans may help prevent colon cancer and reduce blood cholesterol, a leading cause of heart disease.

Beans are also a great protein source. We used to say that you needed to eat grains with beans to make it a complete protein, but we no longer think that's true. If you get some grains sometime during the day, you'll get the benefit of complete protein.

If beans bother your digestive system, try canned beans, she adds. Also, there's Beano, an enzyme supplement that breaks down gas-producing substances in the beans. Drinking more fluids also helps, as does regular exercise. Both help your intestinal system handle the increased dietary fiber.

Among the other non-bean antioxidants are:
   Steamed artichoke hearts (7,904)
   Baked russet potatoes (4,649)
   Raw spinach (1,056)
   Baked sweet potatoes (1,199)
   Eggplant (1,039)

For a sample of what happens during cooking, note how the antioxidant levels change for some foods:
   Raw asparagus (2,021), steamed asparagus (1,480)
   Raw red cabbage (788), cooked red cabbage (2,350),
   Raw yellow onions (823), cooked yellow onions (1,281)
   Raw broccoli (700), cooked broccoli (982)
   Raw tomatoes (552), cooked tomatoes (415)

But don't stop with these star veggies. Don't overlook all the others, with all their own special benefits. Each has its own unique nutritional footprint. Some have more fiber or different arrays of vitamins and minerals. By mixing them up, you're going to enhance what you're getting nutritionally.

For years you’ve been told to eat your fruits and vegetables in order to be healthy, and now science is discovering why. Fruits, vegetables, and berries are important sources of antioxidants, which are showing great promise in the fight against aging and age-related diseases. Many of the conditions and ailments associated with aging happen at a genetic level. As our bodies age, they no longer heal and repair at the cellular level as well as they once did. With the combination of poor eating habits, stress, and environmental toxins, our cells are constantly being attacked by toxins known as free radicals.

Ironically, most of the free radicals attacking our cells from the inside come from a natural cause, eating. As the body metabolizes food, it breaks it down into individual components. Some of these components are free radicals, atoms that are missing an electron in their outer shell. These atoms attempt to stabilize by “stealing” an electron, typically from a healthy cell. As these free radicals scavenge your body for electrons, they damage cells and DNA. This natural process is called oxidation. This same oxidative process is what causes iron to rust when it comes in contact with water. Your cells are literally “rusting” away from the constant attack of these unstable free radicals.

Our bodies protect themselves with the antioxidants that we get from food. Antioxidants block the oxidation process by neutralizing these free radicals. The anti-oxidants give up the extra electron, thus preventing it from being taken from a healthy cell. As these anti-oxidants are used up in the process, there is a constant need to replenish the body’s antioxidant resources.

Your body can not make antioxidants, it relies on getting them from food and supplements. The antioxidants in food are typically found in the highest concentration in berries and fruit, but most people don’t consume nearly enough of these foods to adequately stock their antioxidant resources. Supplements can be used to provide your body with natural antioxidant sources to protect you from the effects of aging. Resveratrol, vitamins, A, C, and E, and proanthrocyanidins are just a few of the multitude of antioxidant supplements available without a prescription. The most effective antioxidant supplements are those that use natural sources, instead of synthetic vitamins, to derive their free-radical neutralizing ingredients.