Foods that help fight cancer.

While tabloid magazines and television newscasts Proclaim so-called miracle cures for cancer, foods that can reduce the risk of cancer are often no farther away than the local supermarket produce section. It is estimated that about 35 percent of all deaths resulting from cancer are caused by improper diet.

Most health organizations recommend an, optimal diet that is low-fat, high-fiber, and centered on frequent consumption of vegetables, fruits, and whole-grain breads, rice, and Pastas. The World Health Organization recommends that you consume at least 14 ounces of fruits and vegetables every day, including at least one ounce of pulses, nuts, and seeds.

Such a plant-based diet is naturally low in fat, saturated fat, cholesterol, and sodium; modest in calories; and rich in potassium, fiber, vitamins A, C, and E (the antioxidant vitamins), and other nutrients. Persons consuming this type of diet are protected against chronic diseases such as cancer and heart disease.

Protection Against Cancer

More than 130 dietary studies confirm that regularly consuming fruits and vegetables provides significant protection against cancer. The risk of cancer is typically reduced by about 50 percent in those eating many servings of fruit and vegetables every day, compared with those eating few servings. Fruits and vegetables are most effective against those cancers that involve epithelial cells, such as cancers of the lung, cervix, esophagus, stomach colon, and pancreas. Results from a recent Italian study revealed that the risk of these cancers was 50 to 80 percent less in people who eat lots of vegetables, compared to those who eat just a few. High intake of fruits also provided a substantially reduced risk of many cancers, although the protection was generally less than that seen with vegetable consumption

A recent study of Greek women noted that vegetable and fruit consumption were associated with significant reductions in the incidence of breast cancer, a cancer claiming the lives of 44,000 women in the U.S. every year. Women who consumed the highest intake of vegetables had a 46 percent lower risk of breast cancer, and women who consumed the highest intake of fruits had a 35 percent lower risk, compared with women who consumed the lowest vegetable and fruit intakes, respectively.

Data collected from China indicates that death rates from colon cancer in that country are 40 percent less and from breast cancer 80 percent less than in the United States. On average, the Chinese consume 60 percent less fat and three times more fiber from fruits, vegetables, and grains than North Americans.

Different fruits and vegetables appear to provide protection against cancer at certain locations. For example, carrots and green, leafy vegetables provide substantial protection against lung cancer. Broccoli, cabbage, and cauliflower provide useful protection against colon cancer. In fact, regular consumption of cabbage has been shown to decrease the risk of colon cancer by 60 to 70 percent, while the regular use of onions or garlic can decrease the risk of stomach and colon cancer by 50 to 60 percent. Recently, regular consumption of tomatoes and strawberries was found to substantially protect against prostate cancer.

Fruits and Vegetables Needed Daily

The Five-a-Day for Better Health program is a nationwide campaign designed to encourage People to cat at least five servings a day of fruit and vegetables. The average American eats only about one and a half servings of vegetables Per day and less than one serving of fruit per day. A recent survey of American eating habits showed that only one in 11 Americans met the guidelines for eating, at least three servings a day of vegetables and at least two servings a day of fruit. In fact, one in every nine Americans surveyed ate no fruit and no vegetable on the day of the survey. When asked how many servings of fruit and vegetables someone should eat every day for good health, people gave amazing answers. Two out of every three Americans surveyed said they thought that only one or two servings were sufficient for good health.

Phytochemical Feast

The National Cancer Institute has identified about three dozen plant foods that possess cancer-protective properties. The foods and herbs with the highest anticancer activity-include garlic, soybeans, cabbage, ginger, licorice root, and the umbelliferous vegetables (including carrots, celery, coriander, Parsley, and parsnips). Foods with a modest level of cancer-protective activity include onions, flax, citrus, turmeric, cruciferous vegetables (broccoli, brussels sprouts, cabbage, and cauliflower), tomatoes and sweet peppers, brown rice, whole wheat, oats, barley, mints, rosemary, thyme, oregano, sage, basil, cucumber, cantaloupe, and berries.

Scientists have identified a host of cancer-protective phytochemicals in these foods. And because many of the compounds are fairly heat stable and since most are not water soluble, they are not appreciably lost in the cooking process. In fact, the effectiveness of some phytochemicals may be increased during cooking.

Soy: A Miracle Bean

Regular soybean consumption is a contributing factor in the low incidence of breast and prostate cancer in Japanese women and men, respectively. Chinese regularly consuming soybeans and/or tofu have only one half as much cancer of the stomach, colon, rectum, breast, and lung when compared with those Chinese who rarely consume soy or soy products. Soybeans contain fairly high levels of several compounds with demonstrated anti-cancer activity. For example, soybeans are a very rich and unique source of isoflavonoids, such as genistein. These isoflavonoids have been shown to inhibit the growth of both human breast and prostate cancer cells.

In addition, regular use of soy protein can lower blood cholesterol and triglyceride levels by 10 to 15 percent, especially in persons with elevated levels of these blood lipids. As little as one to two ounces of soy protein incorporated into muffins, breads, cookies, and other commonly eaten bakery items effectively lower the cholesterol levels. The soy isoflavonoids lower blood cholesterol levels, inhibit LDL cholesterol oxidation, and inhibit blood clots from forming. One can obtain substantial levels of dietary isoflavones by a daily consumption of an ounce or two of soy protein. One-half cup of soybeans, one cup of soy beverage, or four ounces of tofu can provide about 30 to 40 milligrams of genistein.

Citrus Beyond Vitamin C

Citrus, in addition to its ample supply of vitamin C, folic acid, potassium, and pectin, contains more than 150 phytochemicals that also protect our health. The flavonoids in citrus possess a wide range of properties, including anti-inflammatory and antitumor activity, inhibition of blood clot formation, and strong antioxidant activity. The flavonoids (tangeretin and nobiletin) and the limonoids (which provide the bitter taste) stimulate an enzyme that inhibits tumor formation. Citrus pulp and the white of the orange are rich in glucarates, substances being studied for their potential to prevent breast cancer. Tangerines, pink grapefruit, and oranges all contain significant levels of carotenoid pigments that protect us against cancer.

Protection From Whole Grains and Nuts

Many of the cancer-preventive phytochemicals found in fruit and vegetables are similar to those found in whole grains and nuts. Because phytochemicals are concentrated in the bran and the germ of the kernel, the health benefits of grains are maximized when the whole-grain product is consumed. Refining wheat, for example, causes about a 200- to 300-fold loss in Phytochemical content.

Cereal grains and nuts contain substantial levels of tocotrienols (a natural form of vitamin E), which strongly inhibit tumor growth and significantly reduce blood cholesterol levels.

Benefits of Flax

Flour derived from flaxseed is increasingly being used in bread and bakery products to add a nutty flavor and to increase the nutritional and health benefits of the finished product. Flaxseed in the diet can lower blood cholesterol levels because of its very low saturated-fat content.

Flaxseed oil is also a very rich source of the omega-3 type of fat. This provides flax with its anti-inflammatory action, making flax potentially useful to treat lupus, arthritis, and different allergies. Flaxseed is also known to enhance immune function.

Oil weds such as sesame seed and especially flaxseed are very rich sources of lignans. The colon converts plant lignans to substances that are similar to estrogens and can bind to estrogen receptors and inhibit the growth of estrogen-stimulated breast cancer.

Grapes Are Good for You

Red grape juice and red wine contain a significant level of flavonoids and red anthocyanin pigments that act as antioxidants. These substances protect cholesterol from oxidation, reduce blood lipid levels, and inhibit blood clot formation, thereby providing protection against heart disease. It is the transresveratrol (a flavonoid) content of red wine, rather than the alcohol content, that has been shown to reduce the tendency of blood clots to form. Substantial levels of transresveratrol and other antioxidant compounds are found in the grapes and unfermented grape juice, clearly safer sources than the red wine.

Eating three to four ounces of raisins (from Thompson seedless grapes) daily for two months lowers blood cholesterol and LDL cholesterol levels, improves bowel function, and possibly lowers the risk of colon cancer. A serving of sun-dried raisins contains about 10 grams of dietary fiber and four grams of tartaric acid, an active phytochemical commonly found in grapes.

Color Your Life

The various pigments provide color to our food and enhance the enjoyment of the eating experience. Presently, there are about 4,000 known plant pigments in our food, including thousands of flavonoids and hundreds of carotenoids and anthocyanins. These pigments do more than just appeal to our senses; they also protect us from disease.

Anthocyanins are the water-soluble, reddish pigments found in many fruits, such as strawberries, cherries, cranberries, raspberries, blueberries, grapes, and black currants. These anthocyanins inhibit cholesterol synthesis, providing protection against heart disease.

Carotenoids are the pigments found in yellow-orange vegetables (carrots, pumpkins, and sweet potatoes), leafy green vegetables (kale, broccoli, and collard greens), and red and yellow-orange fruits (mangoes, pineapples, tomatoes, peaches, strawberries, watermelons, cantaloupes). Carotenoids possess significant antitumor activity and enhance immune function. Persons with high blood levels of carotenoids have a reduced risk of heart disease and cancer.

Herbs for Flavor Also Protect Us

Garlic, onions, and other members of the allium family are rich in sulfides and other protective substances. Garlic is known to decrease the tendency of blood clots to form, significantly lower blood cholesterol levels, and decrease the risk of cancer at many sites. Terpenoids are responsible for the flavors of many common herbs and seasonings. Many terpenoids are reported to be useful cancer chemopreventive agents (see chart below). A diet in which herbs are used generously to flavor the food will provide a variety of substances that promote health and protect against chronic diseases.

Winston J. Craig, M.D., R.D., is chair of the Department of Nutrition at Andrews University, Berrien Springs, Michigan.