Information from the Physicians Committee for Responsible Medicine
Approximately 80 percent of cancers are due to factors that have been identified and can potentially be controlled, according to the National Cancer Institute. Not only do we have the potential to prevent most cancers, we can also improve the survival rates of people who have cancer.
At least one-third of annual cancer deaths in the United States are due to dietary factors. A recent review of diet and cancer shows that much of our risk for colon, breast, and prostate cancer, among other types, is due to dietary factors.
The link between diet and cancer is not new. In January 1892, Scientific American printed the observation that “cancer is most frequent among those branches of the human race where carnivorous habits prevail.” Numerous research studies have since shown that cancer is much more common in populations consuming diets rich in fatty foods, particularly meat and dairy products, and much less common in countries with diets rich in grains, vegetables, and fruits. One reason is that foods affect the action of hormones in the body. They also affect the strength of the immune system. While fruits and vegetables contain a variety of vitamins, minerals, antioxidants, and phytochemicals that protect the body, research shows that, by contrast, animal products contain potentially carcinogenic compounds that may contribute to increased cancer risk.
Building your strength against cancer
Some dietary changes have a preventive effect for many types of cancer. Boosting your intake of vitamin-rich vegetables and fruits strengthens your immune system. It is also smart to avoid meats, dairy products, and fried foods. Choosing fiber-rich legumes, grains, vegetables, and fruits helps keep many types of cancer at bay. Plant foods also contain a wide variety of cancer-fighting substances called phytochemicals.
These facts all point to choosing a vegetarian diet to help prevent cancer and improve cancer survival. Studies of vegetarians show that death rates from cancer are only about one-half to three-quarters of those of the general population. Breast cancer rates are dramatically lower in countries such as China and Japan, where diets are typically based on rice, vegetables, and bean products, with very little use of meat, dairy products, or oily foods. When people from those countries adopt a Western, meat-based diet, their breast cancer rates soar.
Foods and immunity
Even if we follow healthy lifestyles, cancer cells will arise in the body from time to time. Luckily, we have white blood cells that roam our bloodstreams. Some white blood cells, called natural killer cells, seek out and destroy cancer cells and bacteria. They engulf and destroy aberrant cells before they can cause damage. The function of natural killer cells and other white blood cells is improved by as little as 30 milligrams of beta-carotene per day — the amount in two large carrots.
The best way to get beta-carotene is not in pills, but in the packages in which nature supplies it. Beta-carotene is only one of two-dozen related substances called carotenoids that occur naturally in vegetables and fruits.
In a research review, cancer experts found significant evidence suggesting that carotenoids help protect against esophageal, lung, and mouth cancers.
In addition to their antioxidant effects, vitamins C and E and selenium bolster immune function, but the importance of these effects in protecting against cancer is not yet clear.
Too much fat in the diet can impair immunity, and cutting down on fat helps strengthen the immune defenses against cells that turn cancerous. Researchers in New York tested the effect of low-fat diets on immunity. They put healthy volunteers on a diet that limited fat content to 20 percent, reducing all fats and oils. Three months later, the researchers took blood samples from the volunteers and examined their natural killer cells. The natural killer cell activity was greatly improved.
Dietary fat intake can also contribute to weight gain, which can impair immune function. Studies show that individuals who are overweight are at increased susceptibility to various infections and to certain forms of cancer.
Studies of white blood cell samples from vegetarians have shown them to have more than double the cancer cell-destroying ability of their nonvegetarian counterparts. The immune-boosting power of vegetarian diets is partly due to their vitamin content, low fat content, and other contributors, such as reduced exposure to toxic chemicals and animal proteins.
Grains, vegetables, fruits, and legumes ensure plenty of fiber, but animal products contain no fiber at all.
Getting the fat off your plate is important — but that is just the first step. Other food choices play important roles in cancer prevention.
Vegetables, fruits, grains, and beans provide fiber, which helps the body dispose of excess estrogen.
One way the body rids itself of sex hormones is through the digestive tract. The liver pulls sex hormones from the blood, chemically alters them, and sends them down the bile ducts into the intestinal tract. There, fiber ushers sex hormones through the intestine as waste. As animal products have taken up more and more space on the American plate, they have displaced grains, vegetables, beans, and fruits. Without adequate fiber to hold them in the digestive tract, sex hormones are reabsorbed into the bloodstream, where they once again become biologically active. Building your diet from plants ensures plenty of fiber for the body’s needs.
Until major public education programs spread the word about the role of dietary factors and help people to change, cancer will remain an epidemic.
Always discuss any diet change with your personal physician. In some cases, diet changes may alter your need for medication. Persons who follow a vegetarian diet should be sure to include a source of vitamin B12 in their daily routine, such as fortified cereals, fortified soymilk, or any common multiple vitamin. For more information, visit www.pcrm.org.
Try the new four food groups and discover a healthier way to live!
Vegetables (4 or more servings a day)
Vegetables are packed with nutrients, including vitamin C, beta-carotene, riboflavin, iron, calcium, fiber, and other nutrients. Dark-green leafy vegetables, such as broccoli, collards, kale, mustard and turnip greens, chicory, and bok choy, are especially good sources of these important nutrients. Dark-yellow and orange vegetables such as carrots, winter squash, sweet potatoes, and pumpkin provide extra beta-carotene.
Serving size: 1 cup raw vegetables • 1/2 cup cooked vegetables
Whole Grains (5 or more servings a day)
This group includes bread, rice, pasta, hot or cold cereal, corn, millet, barley, bulgur, buckwheat groats, and tortillas. Build each of your meals around a hearty grain dish. Grains are rich in fiber and other complex carbohydrates, as well as protein, B vitamins, and zinc.
Serving size: 1/2 cup hot cereal • 1 ounce dry cereal • 1 slice bread
Fruit (3 or more servings a day)
Fruits are rich in fiber, vitamin C, and beta-carotene. Be sure to include at least one serving each day of fruits high in vitamin C — citrus fruits, melons, and strawberries are all good choices. Choose whole fruit over fruit juices, which do not contain very much fiber.
Serving size: 1 medium piece of fruit • 1/2 cup cooked fruit
• 4 ounces juice
Legumes (2 or more servings a day)
Legumes, including beans, peas, and lentils, are all good sources of fiber, protein, iron, calcium, zinc, and B vitamins. This group also includes, soymilk, tempeh, and texturized vegetable protein.
Serving size: 1/2 cup cooked beans • 4 ounces tofu or tempeh
• 8 ounces soymilk
Easy Bean Salad
Makes about 10 1-cup servings
This salad has tons of fiber to help move carcinogens, and excess cholesterol and hormones out of your body to improve overall health.
1/2 c low-fat Italian salad dressing
1 15-oz can kidney beans, drained and rinsed, or 1½ c cooked kidney beans
1 15-oz can pinto beans, drained and rinsed, or 1½ c cooked pinto beans
1 15-oz Can black-eyed peas, drained and rinsed, or 1½ c cooked peas
1 10-oz package frozen lima beans (preferably Fordhook lima beans), thawed completely,
1½ c cooked lima beans, or 1½ c cooked green soybeans (shelled edamame)
1 c frozen corn, thawed completely, or cooked fresh corn, chilled
1 large red bell pepper, seeded and chopped
½ medium purple onion, chopped
1 tsp salt, or to taste
1 tsp black pepper, or to taste
Toss all ingredients together. Serve cold or at room temperature. May be covered and stored in refrigerator for several days.
Per serving (1/10 of recipe): 183 calories; 3 g fat; 0.5 g saturated fat; 14.6% calories from fat; 0 mg cholesterol; 9.9 g protein; 31 g carbohydrate; 2.9 g sugar; 8 g fiber; 539 mg sodium; 43 mg calcium; 2.7 mg iron; 36.7 mg vitamin C; 311mcg beta-carotene;
0.8 mg vitamin E
Recipe by Jennifer Reilly, R.D.
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