Is it true that tea can prevent cancer? If so, what type of tea provides the most benefit -- green or black tea? I know that tea does not provide many nutrients such as calories, protein, or vitamins. What makes it so special?

You are correct in your assumption that tea does not contain significant macronutrients. However, tea contains fluoride (enough to prevent tooth decay) and phytochemicals called polyphenols. Certain polyphenols have been known to exhibit more potent antioxidant activity than both Vitamins E and C.

The tea and cancer prevention connection have not been substantiated but preliminary findings of some studies suggest that the use of green tea may be of benefit against cancer. In one animal study, the polyphenol, epigallocathechin-3 gallate (EGCG) has been the focus of recent attention because it inhibits the action of urokinase. The significance of this finding is that urokinase plays a major role in the growth and spread of malignant tumors and blocking its action was found to decrease the size of a tumor in mice. Another study found that EGCG plus epicathechin-3 gallate (ECG) helped destroy cancerous cells but spared the healthy ones.

EGCG and ECG are found in green tea. Black tea may be less potent but still has polyphenols with its own beneficial chemicals. There are studies that suggest black tea may protect against cardiovascular disease.

Although the preliminary findings of these recent studies are exciting, a good cup of green or black tea is not a replacement for practicing good nutrition and exercise and avoiding high risk behavior such as smoking. But a tea break can be a nice addition to your day.

I started radiation therapy for cancer 3 weeks ago. I am receiving radiation in the abdominal area and started having terrible diarrhea. My doctor recommended a low residue diet. What is it and how long do I have to follow this diet?

A low residue diet is a therapeutic diet that consists of mildly flavored, easy to digest, and low fiber foods. This means raw vegetables, most raw fruits, fried goods, and high fiber grains are omitted. Gas-forming foods such as beans, legumes, cruciferous vegetables are also foods to avoid on this diet. Milk is limited to 16 oz per day. This diet is indicated when a you want to soothe inflamed tissues in the gut and restrict stool volume.

Therefore, high fiber foods and grains are omitted because it will contribute to leaving nondigestible residues of plant foods. Milk is low in dietary fiber but may contribute to stool volume due to the formation of insoluble calcium salts. It may also exacerbate diarrhea if you are suffering from a temporary lactose intolerance induced by the radiation therapy so it is limited.

It is also a good idea to drink plenty of fluids to prevent dehydration. Sodium and potassium are the minerals often lost during diarrhea. Foods that are high in potassium yet do not exacerbate diarrhea are bananas, peach and apricot nectar, and boiled or mashed potatoes. Avoid very hot or very cold foods and beverages. The low residue diet recommendation is only a temporary restriction for symptom management. As your side effect lessens in severity, you may consider asking your physician and registered dietitian for advice on liberalizing your diet and assessing your tolerance to fruits, vegetables, and milk products by reintroducing these foods slowly.

There are many commercials and ads in the media that promote products such as Ensure or Sustacal as a way to increase health and longevity. My father who is diagnosed with lung cancer and undergoing radiation therapy is having difficulty eating regular food..The doctor recommended Ensure to help maintain his weight.. What do you think of these products? Is one brand superior to the other? What's in them exactly

I cannot vouch for the advertisements that suggest that liquid supplements increase longevity but the use of commercial liquid supplements such as Ensure or Sustacal can be an important tool to use in helping cancer patients maintain good nutritional status during therapy. Liquid supplements are advantageous because they provide calories, protein, fluid, vitamins, and minerals in a small volume. The extra nutrition provided by liquid supplements have helped patients maintain or gain weight and if necessary, they can be used in place of a meal.

Commercially available liquid supplements are usually made of soy and/or milk proteins, simple carbohydrates such as corn syrup and/or sucrose, vitamins, and minerals. Most of the liquid supplements are also lactose free. Different brand names may have slight differences in composition such as one brand having a few grams more of protein or slightly higher in one vitamin or mineral than the other. However, selecting a product for your father should depend on his taste preference. After all, if he finds the liquid supplement unpalatable, he will not take it.

I have been recently diagnosed with ovarian cancer and everyone has been bombarding me with information about how to cure cancer. My neighbor swears that her sister beat cancer by switching to a macrobiotic diet. What is a macrobiotic diet? How can it cure cancer?

There are multiple schools of macrobiotic thought. It cannot be defined in a sentence because it is so multi-faceted. "Macrobiotic" describes a diet, a philosophy, a community, and a social movement. The macrobiotic diet had its beginnings in ancient Chinese cosmology applying yin/yang (opposite but complementary "energy modes") to food. It has since been adapted by the Japanese as explored by Ohsawa and Kushi.

The general principles of a macrobiotic diet include the following:

• 50% of the volume of the meal -- cooked, organic whole grains
• 5-10% of food intake -- vegetable, seaweed, grain, and bean soups seasoned with miso or soy sauce
• 20-30% -- cooked organic vegetables
• 5-10% -- cooked beans, soybean products, and seaweed
• 5-15% -- fresh, white meat fish on 1-3 days each week
• Fresh, dried, and cooked fruit 2-3 servings per week.

There have been reports of iron and B12 deficiencies and retarded growth in children following a macrobiotic diet. There have also been B-12 deficiencies reported in adults. This diet may pose risks for persons with cancer, especially, those undergoing active cancer therapy because it is low in protein and calories. High protein and calories are the primary nutrition goals recommended during therapy to help maintain weight and lean body mass. In addition, potential side effects of cancer therapy, such as diarrhea, early satiety, poor appetite may be further exacerbated by the high fiber nature of macrobiotic diets.