FOODS AS THE ULTIMATE PROTECTOR
According to the American Cancer Society, cancer is the leading killer of Americans under age 85, causing about 25 percent of all deaths. Thankfully, when it comes to cancer prevention, food is powerful medicine. Study after study shows that a healthful diet—eating less fat and getting more fruits, vegetables, whole grains, and legumes—can vastly reduce the risk of cancer. In fact, research indicates that if we all ate more of the right foods and less of the wrong ones, the incidence of all cancers would be reduced by at least 30 percent.
“Food goes beyond being crude fuel, as we once believed,” says Keith Block, MD, medical director of the Block Center for Integrative Cancer Care in Evanston, Illinois. “Our experience over the past 2 decades indicates that diet plays an important role when dealing with cancer. We’re discovering that there are compounds in foods that can actually both prevent and help fight cancer at the cellular level.”
Researchers have known for a long time that people who eat the most fruits, vegetables, and other plant foods are less likely to get cancer than those who fill up on other, less wholesome foods. Recent research suggests that eating five servings of fruits and vegetables each day reduces cancer deaths by 35 percent. One study in particular found that a diet rich in fruits and vegetables slashes the risk of pancreatic cancer—a particularly deadly kind—in half.
But it’s only recently that researchers have discovered the reason why plant foods offer such powerful cancer protection. Certain substances found only in plant foods and known collectively as phytonutrients (phyto is a Greek word meaning “plant”) have the ability to stop cancer.
Research has shown, for example, that eating just one serving of watermelon or pink grapefruit a day can reduce a man’s risk of developing prostate cancer by 82 percent! Watermelon and pink grapefruit are high in a phytonutrient called lycopene. In fact, watermelon contains about 40 percent more lycopene than do fresh tomatoes— the produce most people probably think of when they think of lycopene.
When processed into sauce, juice, or ketchup, however, tomatoes do yield more usable lycopene. Interestingly, a recent study found that organic ketchup has up to three times more lycopene than ordinary kinds. Why? Perhaps because organic ketchups are made with riper tomatoes than other types of ketchup. The darker red a ketchup is, the greater its lycopene content.
Another common garden dweller, garlic, has a long tradition as a healing food, and it turns out it is also very rich in phytonutrients. Some of the most impressive are called allyl sulfides, which appear to help destroy cancer-causing substances in the body. In a study of nearly 42,000 women, researchers at the University of Minnesota School of Public Health in Minneapolis found that those who ate more than one serving of garlic—either one fresh clove or a shake of powder—a week were 35 percent less likely to get colon cancer than those who ate none.
Every day, your body is attacked, again and again, by a barrage of harmful molecules called free radicals. These are oxygen molecules that have lost an electron, and they careen around your body looking for replacements. In the process of pilfering electrons, they damage healthy cells, possibly kicking off the cancer process.
Nature anticipated this threat by packing fruits, vegetables, and other foods with antioxidants, protective compounds that either stop the formation of free radicals or disable them before they do harm.
There are many compounds in foods that act as antioxidants in the body, but two of the best studied and most powerful are beta-carotene and vitamin C.
Beta-carotene is the pigment that gives many fruits and vegetables their lush, deep orange to red hues. It’s more than nature’s palette, however. Beta-carotene has been shown to stimulate the release of natural killer cells, which hunt down and destroy cancer cells before they have a chance to cause damage.
Literally dozens of studies have shown that people who get a lot of beta-carotene in their diets can reduce their risks of certain cancers, especially those of the lungs, intestinal tract, mouth, and gums.
It doesn’t take a lot of beta-carotene to get the benefits. Evidence suggests that getting 15 to 30 milligrams a day—the amount provided by one or two large carrots— is probably all it takes. Cantaloupes, sweet potatoes, spinach, and bok choy all are excellent sources of beta-carotene.
Another antioxidant is vitamin C, which has been shown to help prevent cancercausing compounds from forming in the digestive tract. In one large study, Gladys Block, PhD, professor of epidemiology and public health nutrition at the University of California, Berkeley, analyzed dozens of smaller studies that looked at the relationship between vitamin C and cancer. Of the 46 studies she examined, 33 showed that people who consumed the most vitamin C had the lowest risk of cancer.
The DV for vitamin C is 60 milligrams, an amount that’s very easy to get in foods. One green bell pepper, for example, contains 66 milligrams of vitamin C, while a half-cup of broccoli has 41 milligrams.
They may not be glamorous, but beans are showing their stuff as cancer fighters. A University of Minnesota study found that women who ate the most high-magnesium foods, such as beans, reduced their risk of developing colon cancer by 23 percent. Just a half-cup of beans provides 43 milligrams of magnesium, almost 11 percent of the 400-milligram DV. The optimum intake is 310 to 420 milligrams per day.
Another study, this one from the M. D. Anderson Cancer Center in Houston, found that people who ate the most foods containing phytoestrogens, such as beans, were the least likely to get lung cancer. Interestingly, men reduced their risk more than women—by 72 percent compared with 41 percent.
Beans also offer protection from breast cancer. A Harvard School of Public Health study found that women who ate beans twice a week had a 24 percent lower risk of developing breast cancer than women who rarely ate them.
Drinking a 4-ounce glass of red wine a day may cut a man’s prostate cancer risk in half, according to a study of more than 1,400 men by the Fred Hutchinson Cancer Research Center in Seattle. Which wine is best? Order a Pinot Noir from California. Researchers at the University of Mississippi tested 11 red wines and found that Pinot Noirs from California have the most resveratrol, an antioxidant that can help ward off cancer and even heart attacks.
Although the Fred Hutchinson researchers didn’t find an association between beer and prostate cancer in their study, researchers in Italy found that an antioxidant in hops called xanthohumol inhibits the growth of cancer cells. The results have been shown only in test tubes so far, but studies in humans are planned.
The world’s second most popular beverage (next to water) is tea, which has long had a reputation as a cancer fighter. It was known to defeat cancer cells in test tubes, but now it’s been shown to fight cancer in people, too. A Swedish study of 61,000 women found that those who drank 2 cups of tea a day decreased their risk of ovarian cancer by 46 percent.
Yet one more beverage, milk, really does do a body good. Researchers reviewed 63 studies and revealed that high levels of vitamin D cut the risk of colon, ovarian, and breast cancer by up to 50 percent. The researchers recommend getting 1,000 IU of vitamin D per day. One cup of milk contains 100 IU. However, the FDA recently changed its vitamin D fortification guidelines so that food manufacturers can now add nearly three times more vitamin D to dairy products.
Eating just one Brazil nut a day could help ward off colon cancer. Brazil nuts are high in the trace mineral selenium, and doctors at the University of Arizona found that men with high levels of selenium are six times less likely to develop colon cancer than men with low levels.
For a long time, no one took dietary fiber seriously. It’s not a nutrient. It isn’t absorbed by the body. In fact, it doesn’t seem to do much of anything.
As it turns out, fiber does more than anyone ever imagined. “Consuming a high-fiber diet is essential for reducing the risk of certain types of cancer, particularly colon cancer,” says Daniel W. Nixon, MD, a scientific counselor with the Cancer Treatment Research Foundation in Schaumburg, Illinois.
Fiber works against cancer in several ways, he explains. Since fiber is absorbent, it soaks up water as it moves through the digestive tract. This makes stools larger, which causes the intestine to move them along more quickly. And the more quickly stools move, the less time there is for any harmful substances they contain to damage the cells lining the intestine. In addition, fiber helps trap cancer-causing substances in the colon. And since the fiber itself isn’t absorbed, it exits the body in the stool, taking the harmful substances with it.
According to doctors at the National Cancer Institute, you need between 20 and 35 grams of fiber a day to keep your risk of cancer low. That may sound like a lot, and it would be if you ate it all at once. (And truth be told, most people get only 11 grams of fiber per day.) But since many foods contain at least some fiber, it’s fairly easy to get enough if you pick the right foods. Simply make it a point to eat more fruits and vegetables—raw, when possible, and with their skins rather than peeled— than you’re currently eating. If you do this regularly, you’ll soon find that you’re getting most of the fiber you need, says Dr. Keith Block.
Beans and certain vegetables are among the best sources of fiber you can find. Eating one of them a few times a day will automatically bring your fiber intake into the comfort zone. A half-cup of kidney beans, for example, contains 7 grams of fiber, while the same amount of chickpeas contains 5 grams. As for vegetables, a half-cup of cooked okra contains 3 grams of fiber, while the same amount of Brussels sprouts has 3 grams.
Whether you’re eating whole-wheat toast (2 grams of fiber per slice) for breakfast or a bowl of kasha (about 3 grams per half-cup, cooked), whole grains are also great sources of fiber. If you can, get 6 to 11 servings of whole grains a day.