Q. I have heard that red wine is good for my heart. Since I don't drink alcohol, can I drink grape juice or eat grapes instead?

A. You will get most of the benefits of red wine by eating grapes. Some brands of grape juice also provide these benefits.

The main difference between red wine and grapes is the alcohol. Although moderate amounts of alcohol provide some benefit to the heart, red wine contains other healthful substances called phenols. Phenols are potent antioxidants that help prevent cell damage that contributes to heart disease, cancer and other age-related conditions. Grapes have as much phenols as red wine.

One way red wine and grapes may help prevent heart disease is by protecting the lining of the blood vessels of the heart. It also seems to help reduce low-density lipoprotein, the so-called "bad cholesterol." Another benefit is a reduced risk of blood clots that can clog arteries.

Red wine contains far more phenols than white wine. This is because the skin of the grape is used to make red wine but is not used in white wine. A phenol called resveratrol is found almost exclusively in the skin of grapes and is responsible for many of red wine's health benefits.

When it comes to grape juice, some brands are better than others. Some commercial juices use grape varieties with a lower phenol content than grapes used in wine production. Your best bet is to choose a grape juice made from purple Concord grapes. Read the list of ingredients on the label carefully. Some purple-colored grape juices are diluted with white grape juice, which, like white wine, has very little resveratrol.

In addition to resveratrol, there are other healthful phenols in wine such as anthocyanins, quercetin and catechins. These phenols can also be found in other foods. For example, anthocyanins are in berries and plums, while quercetins are in apples, and catechins are in green tea.

When it comes to heart health, red wine, grapes, or grape juice represent only one piece of the puzzle. It is important to eat a variety of colorful fruits, vegetables, whole grains and lean proteins. We should never focus on just one food item. Also, drinking red wine will not make up for a lifetime of unhealthful habits such as a sedentary lifestyle, smoking and too much junk food.

Amy Tousman is a registered dietitian and certified diabetes educator with Nutrition Unlimited in Kailua. Hawai'i experts in traditional medicine, naturopathic medicine and diet take turns writing the Prescriptions column. Send your questions to: Prescriptions, Island Life, The Advertiser, P.O. Box 3110, Honolulu, HI 96802; islandlife@honoluluadvertiser.com; or fax 535-8170. This column is not intended to provide medical advice.