By Karen Collins, MS, RD, CDN

If you read about the super health-promoting powers of the latest popular fruit, you might wonder if Grandma's advice, "An apple a day keeps the doctor away," still merits consideration.

Yet as research moves further into the study of the thousands of natural compounds from fruits, vegetables, whole grains and other plant foods, apples do shine.

Antioxidants are well-established as an important part of how healthful eating can lower our risk of heart disease and cancer, and possibly other conditions that can develop as we age.

Antioxidants are frequently discussed in relation to vitamins C and E, and perhaps other plant compounds such as beta-carotene. However, fruits and vegetables also provide flavonoids, a large group of compounds that are all antioxidants.

The antioxidant power of flavonoids is one reason that apples are again in the spotlight.

A powerful punch

Apples contain only modest amounts of vitamin C. A medium apple averages about 6 milligrams of vitamin C, not much when compared to the recommended daily intake for adults of 75 to 90 milligrams. But scientists have now calculated the antioxidant power of that apple is equal to more than 1,500 milligrams of vitamin C. The vast majority of its antioxidants come from flavonoids.

Antioxidants are key elements in preventing cancer, because they stabilize highly reactive free radicals that can otherwise damage the DNA in our cells and begin cancer development.

In addition, antioxidants are also considered a key step in heart health because they protect blood vessels by keeping "bad" cholesterol in a less damaging form.

Along with antioxidant protection, apples contain pectin, a soluble fiber that helps lower blood cholesterol. And higher blood cholesterol is associated with a greater incidence of heart disease.

Heart health, cancer prevention

In one study of 40,000 American women, researchers analyzed apple consumption and heart health, and found that women who ate at least one apple a day developed 22-percent less heart disease than women who ate no apples.

Cancer prevention benefits appear to stem from more than antioxidants, too. Lab studies show that concentrated apple compounds can reduce growth and reproduction of colon and lung cancer cells. Among more than 77,000 women in one study, daily apple consumption was linked to 37-percent lower risk of lung cancer.

A Finnish study showed that highest flavonoid consumption, of which apples were an important part, was linked with a 20-percent lower risk of cancer overall and a 46-percent lower risk of lung cancer.

Weight loss, too 

As for weight loss, studies show that people are most successful at limiting calories when they include foods that contain relatively few calories in relation to their portions. Apples are high in a type of fiber that creates a full sensation. The calories from one medium apple are about equal to one-and-a-half Oreo cookies and are far more filling.

But it's important to remember that for overall health, a variety of fruit is a smarter move than sticking with multiple daily servings of apples or any fruit.

Apples go out of season in the Northern Hemisphere by early winter and are often stored so they can be sold throughout the winter. Prolonged storage of fruits and vegetables often means loss of nutritional value, but apples retain virtually all of their flavonoid content for five to six months in cold storage.

Processing, however, does lower the amount of flavonoid, so apples themselves contain more antioxidants than apple juice or applesauce.

Besides snacking on apples out of hand, try them in green and fruit salads and cooked with vegetables such as carrots, winter squash and sweet potatoes.

Karen Collins is a nationally known registered dietitian and nutritionist whose work appears on websites, such as Nubella News and MSNBC.com, and iother major Web sites. She is nutrition adviser to the American Institute for Cancer Research.

Nubella News, a division of Marketing Technology Solutions, Inc., offers content intended for informational purposes only. It is not a substitute for medical advice, diagnosis, or treatment. We encourage our readers to seek prompt medical care for health issues and consult their physicians before starting a new diet, fitness regimen, or medical treatment.