We are told that eating a wide variety of fruits and vegetables may be beneficial in preventing cancer. On the other hand we also hear that the produce we buy at the market is loaded with pesticides that they should be avoided. Help! What should we do? Are organic fruits and vegetables safer than the ones in the market?

According to Charles Benbrook, consultant to Consumers Union and former director of the Board on Agriculture of the National Academy of Sciences, there is evidence that certain herbicides may raise the risk of leukemia and lymphatic cancers. The workers who applied the herbicides are the people at highest risk for those cancers. As for other cancers, the evidence is not so clear. Benbrook also goes on to state that evidence suggests that pesticide exposure is a risk factor for Alzheimer's and Parkinson's diseases. Studies have found that farmers and other persons with high exposure to pesticides have higher rates of these diseases.

The Food and Drug Administration (FDA) monitor both domestic and imported fruits and vegetables for pesticide residues. In 1989, the FDA found 31% of 4,000 domestic vegetable samples tested had pesticide residues. The good news -- less than 2% of the samples with residues had levels of residues that exceeded that levels set by the FDA. The bad news -- the FDA test only 1% of the vegetables marketed in the United States.

In spite of what sounds like gloom and doom, at this time, the evidence that fruits and vegetables help protect against heart disease and cancer is still more compelling than the evidence that pesticides cause cancer and other health problems. Do not despair. There are ways to help minimize pesticide residues on your fruits and vegetables.

Ways to minimize pesticide residues:
• Eat a diverse diet. The more variety you have in your diet, the less exposure you have to any given pesticide.
  
  
• Properly wash and peel fruits and vegetables. Many water soluble residues rinse away with washing in mild dishwashing detergent and water. Peeling is enough to eliminate all residues in such produce as acorn squash, apricots, bananas, carrots, pears, and potatoes, corn (shucking corn on the cob). Trimming away tops and the outer leaves from celery, lettuce, cabbage, and other leafy vegetables decreases residues as well. Be sure wash the inner leaves, too.
  
  
• Buy organic fruits and vegetables. You can always opt to buy organic fruits and vegetables. They may cost more but "organic" usually means that the food has been grown without chemical fertilizers or pesticides. Keep in mind that at this time there is no industrywide agreement on substances permitted or prohibited for organic farming. Organic fruits and vegetables can be found in health food stores, farmers' markets, and some big-city supermarkets.

I have just completed my chemotherapy and radiation for breast cancer. My friend has given me something from Peru that is called "cat's claw" and she says that it will prevent the cancer from coming back. What is "cat's claw" and do you think it will help me?

"Cat's claw" (una de gato) is the popular name for a tropical vine found in Peru called Uncaria tomentosa. It is an ancient folkloric remedy that is recommended for a wide variety of diseases ranging from arthritis, cancer, and AIDS to acne and PMS.

There is no evidence at this time that proves the efficacy of Uncaria tomentosa in peer-reviewed medical journals. The Natural Products Branch of the National Cancer Institute have also studied cat's claw and did not find sufficient activity when put through the cancer screen to warrant further testing.

In terms of safety, there are several issues that you may want to consider before taking this herb. There are two kinds of cat's claw that look alike but are different in their chemical composition. One type of cat's claw may have compounds that help strengthen the immune system as one animal study suggests. The other type of cat's claw has a potential detrimental effect on the heart by slowing and decreasing the force of the heartbeat. In high doses, this type may have a sedative effect that may depress respiration and produce a lack of muscular coordination. There is no standard of quality or identity in the U.S. for herbal products and remedies so there is no guarantee of which type of cat's claw you are buying.

What may be of more help to you is to keep healthy through nutrition and exercise. The American Cancer Society Guidelines on Nutrition and Cancer Prevention recommend increasing your intake of foods from plant sources such as fruits, vegetables, breads, grains, cereals, rice, pasta, or beans. They also recommend limiting your intake of high fat foods, especially from animal sources. Exercise and maintaining a healthy weight can also be beneficial for keeping you healthy. Finally, limit your consumption of alcohol. These recommendations for cancer prevention are also consistent with dietary recommendations to reduce cardiovascular disease risk. You get two for the price of one by following these guidelines.

My wife has just been diagnosed with kidney cancer. Are there any special considerations she needs to know with regard to foods to avoid or foods that can be particularly helpful in combating this kind of cancer?

Maintaining good nutritional status is of great importance because it will help keep your immune system strong, maintain your lean body mass, and rebuild tissues that cancer treatment may harm. Good nutritional status can be maintained through a varied, balanced diet. However, nutrition management for someone with kidney cancer is dependent upon metabolic aberrations that may be occurring as well as symptoms that may be the result of surgery, chemotherapy, and/or radiation treatments.

I would strongly recommend that you consult the physician and dietitian at the medical center where your wife is being treated. They would be best able to advise you on the specific nutrition needs of your wife by doing a clinical nutrition assessment that takes into account medical issues, lab values, height, weight, diet history, and potential side effects of cancer therapy. You can also refer to the American Dietetic Association Nutrition hot line (1-800-3366-1655) to request a referral to a dietitian in your community.