QUESTION:
I've been diagnosed with melanoma recently. I have started drinking green tea and started using a juicer. Are there particular vegetables that have been shown to fight cancer?

ANSWER: Of the food groups represented on the Food Guide Pyramid, vegetables offer the most diversity. Vegetables offer the most nutrients and fiber in the least amount of calories. Juicing is not a bad idea but you will miss out on the fiber that is part of the American Cancer Society (ACS) Diet Guidelines and the National Cancer Institute's (NCI) "5-A-Day -For Better Health" program. High fiber foods such as whole grain bread and cereals, beans, fruits, and vegetables may have a protective role against cancer.

Fruits and vegetables are recommended because they are high in antioxidants such as carotene and Vitamin C. Antioxidants help deactivate free radicals that damage cells and promote cancer, so foods high in antioxidants may have a protective role against cancer. Fruits and vegetables high in Vitamin C are asparagus, broccoli, brussel sprouts, cabbage, cantaloupe, citrus fruits (orange, grapefruit, lemons), sweet potatoes, strawberries, and tomatoes. Fruits and vegetables high in carotene are apricots, asparagus, broccoli, carrots, dark green leafy vegetables, mangoes, pumpkins, spinach, sweet potatoes, and winter squash.

Cruciferous vegetables are also highly recommended. The cruciferous family includes cabbage, broccoli, cauliflower, and brussel sprouts. These vegetables contain a phytochemical thought to reduce the risk of certain cancers. (See the November, 1997 column for a more detailed discussion of cruciferous vegetables.)

The recommended servings for fruits and vegetables are 5 a day. A serving is considered a medium fruit or 1/2 cup of cut fruit, 3/4 cup of 100% fruit juice, 1/4 cup dried fruit, 1/2 cup cooked or raw vegetable, or 1 cup raw leafy vegetable (spinach or lettuce). For more information about "5-A-Day" call the Cancer Information Service at 1-800-4-CANCER.

You certainly are on the right track by adding more vegetables to your diet. Green tea may also have protective benefits against cancer (see January, 1998 column for more information on green tea and cancer). However, this nutrition discussion centered around the preventive nutrition guidelines for cancer. If you are undergoing active cancer therapy such as radiation or chemotherapy, there are certain side effects that may need dietary symptom management. Also the nutrition goals during active therapy may differ from preventive goals. I encourage you to see your physician and local dietitian for a nutrition consultation.

QUESTION:
What are "irradiated foods"? How much of our food supply undergoes irradiation? Does it cause cancer?

ANSWER:
Irradiation is a process in which food is exposed to gamma rays to kill bacteria and other microorganisms that may be harmful. This process helps keeping our food supply safe and extending their "shelf life." The effect of irradiation on the nutrients in food is low. Proteins, fats, and carbohydrates may not be altered but those nutrients that are heat sensitive (B vitamins and Vitamin C) are also sensitive to irradiation. Irradiation does cause some changes in food but the compounds they produce are identical to those formed during other food preparation processes such as cooking, steaming, roasting, pasteurization, or freezing.

Irradiated foods are endorsed by an impressive list of national and international organizations such as the American Council on Science and Health, American Medical Association, American Dietetic Association, and the World Health Organization. The FDA has approved the following food items for irradiation: wheat, potatoes, fresh fruits, dry or dehydrated products, poultry and pork. In spite of the endorsements and regulatory approval, irradiated foods are not widely available here in the United States. The doses allowed in the United States by the Food and Drug Administration (FDA) are the most restrictive of all countries in which irradiation is used. The radiation used in food irradiation doesn't bring out neutrons so the food and it's packaging are not radioactive. There is no evidence that supports consuming irradiated foods increases cancer risk.

QUESTION:
We hear so much about the herbal supplement Echinacea being a "wonder" health product because it can treat everything from the common cold to cancer. What is it and can it help in battling cancer?

ANSWER:
Echinacea is a member of the daisy family (Asteraceae). Nine species of Echinacea grow in the United States but Echinacea purpurea is the most commonly utilized species. Claims that it has an impact on such a widespread host of ailments should be an immediate red flag for quackery. Varro Tyler, Ph.D. is one of the country's recognized authority on plant drugs, reports that too few human studies have been conducted to reach any conclusive statement about echinacea's efficacy in fighting such diseases as cancer.

However, he also reports that for certain ailments such as the common cold, the evidence supporting Echinacea is stronger. Studies have shown that Echinacea fights the common cold by acting as an immunostimulant. It increases the number of immune cells in the blood, increases the cell's ability to destroy bacteria, and inhibits the production of viruses.

Before you go out and start taking Echinacea, there are some issues with the herbal supplement. The studies that have demonstrated the herb's efficacy in treating colds were done in Germany with the injectable form of Echinacea. The injectable form is not available in the U.S. The German equivalent of our FDA also has the authority set standards for the doses and the identity of the herb. There is no such regulation here in the U.S. regarding herbal supplements. Due to echinacea's effect on the immune system, people with arthritis, diabetes, multiple sclerosis, pregnant women, and anyone allergic to daisies should not take this herb.