By Peter Jaret, Natural Solutions
It wasn’t until my annual physical examination, and a simple question from the doctor about my family health history, that I found myself thinking, Uh-oh.
Fourteen years ago my mother died of lung cancer. Ten years later my aunt died of the same disease. Not long ago my brother was diagnosed with lymphoma. Of course I’d known all that. But somehow I hadn’t consciously admitted to myself how often cancer had struck. Brain tumors, skin cancer, prostate cancer–they all showed up somewhere in the family tree. Were we especially susceptible to this terrible disease? And was there anything to do to lower the risk?
Risk for some cancers, in fact, does run in families. Some inherited genes seem to make it easier for healthy cells to mutate into malignancy; others can impair the body’s built-in ability to disable cancer-causing substances before they cause trouble. Inherited risk helps explain why some smokers live until they’re 95 and others, like my mother and her sister, die of lung cancer in their sixties. Someday, genetic tests may be used routinely to assess a person’s risk of specific cancers. But I don’t want to wait for that. I want to do whatever I can to lower my risk. Now.
So I called Melanie Polk, a dietitian and director of nutrition education at the American Institute for Cancer Research, and she told me the same thing I would hear from almost every expert, alternative or mainstream, including the National Cancer Institute and the American Cancer Society. “Eat more fruits and vegetables. That’s the single most important step most people can take to lower their cancer risk.”
After decades of waging war against cancer, was that the best researchers could offer? Steer your cart to the produce aisle?
“Absolutely,” says John Weisburger, a physician and expert on diet and health at the American Health Foundation/Institute for Cancer Prevention. “It’s hardly news that fruits and vegetables–really, almost any foods that come from plants–are good for health. The real surprise has been discovering just how much protection they contain.” Indeed, foods from plants are turning out to be rich in hundreds, even thousands of newly identified substances that work in many different ways to lower cancer danger. Some boost levels of enzymes in the body that neutralize cancer-causing substances. Some protect cell walls, so carcinogens can’t get in and cause damage. Antioxidants in foods can prevent damage from free radicals that might otherwise disrupt DNA, setting in motion genetic changes that could lead to cancer. Researchers have even discovered substances in food that trigger damaged cells to self-destruct, preventing tumors from forming.
“Cancer-fighting agents in fruits and vegetables work in a variety of ways, and they work together synergistically in ways that we’re only beginning to understand,” says Arthur D. Heller, an internist, gastroenterologist, and clinical nutrition specialist at New York City’s Weill Cornell Medical Center.
Even when we can’t confirm exactly how some foods protect against cancer, hundreds of studies show that they do. Indeed, the data suggests that one-third of all cancers are related to diet, according to Heller. Some of those are cancers that could be prevented by avoiding highly salted foods or charbroiled meats, which have been linked to cancer risk. But we could ward off many more by simply eating more plant-based foods.
In a recent example, researchers at Simmons College in Boston pored over data from the Nurses Health Study, which collects information via questionnaires from nurses around the country. Women in the study who ate plenty of fruits, vegetables, and legumes were about half as likely to develop colon and rectal cancer as women who skimped on foods from the produce aisle in favor of meat, sweets, and refined carbohydrates. Nothing else researchers know about can cut the risk of colon cancer, one of the leading causes of cancer death, by that much. The danger of prostate cancer can also be slashed with a healthier diet, research shows. Eating foods high in the antioxidant lycopene–red tomatoes are the richest source–can cut prostate cancer risk by as much as 50 percent. And a study from Sweden published this past April showed a reduced risk of mutations that are linked to several types of cancers in people who frequently ate vegetables, citrus fruit, and berries.
The National Cancer Institute, which leads the nation’s research on cancer prevention and treatment, is so convinced of the power of fruits and vegetables that it recently changed its well-known 5-servings-a-day program, designed to encourage Americans to eat more fruits and vegetables, to the 5-to-9-servings-a-day program.
Everyone seems unanimous that the single best way to lower cancer risk is to load up on produce. But that still left me with questions.
What’s a “serving”? Does everything in the produce section count? And for people having a tough time hitting five, are there ways to get more cancer protection without making it feel like work? Here’s what the experts have to say:
If the goal is eating 5 to 9 fruits and vegetables a day, is it okay to just get 5?
The range is meant to reflect an acceptable spectrum of recommended amounts, and where you fall on it depends on your age, activity level, and body size. Basically, the more calories your body requires to supply daily needs, the more fruit and vegetable servings you should be eating. Young children should eat 5 servings a day; women and teenage girls should shoot for 7; men and teenage boys (yeah, right) should aim for 9. And vegetables carry slightly more weight–the official recommendations suggest 3 to 5 servings of vegetables and 2 to 4 servings of fruit.
The range is meant to reflect an acceptable spectrum of recommended amounts, and where you fall on it depends on your age, activity level, and body size. Basically, the more calories your body requires to supply daily needs, the more fruit and vegetable servings you should be eating. Young children should eat 5 servings a day; women and teenage girls should shoot for 7; men and teenage boys (yeah, right) should aim for 9. And vegetables carry slightly more weight–the official recommendations suggest 3 to 5 servings of vegetables and 2 to 4 servings of fruit.
But while the numbers give people a goal and a way to gauge their diets, there’s nothing magical about them. “The bottom line is that the more fruits and vegetables you eat, the more protection you get,” says Colleen Doyle, director of nutrition and physical activity at the American Cancer Society.
What’s a serving, anyway? And how is it possible to fit so many into one day?
Meeting your daily quota is far easier than you’d think because a recommended serving just isn’t all that much. According to the experts, a serving of fruit juice is only 3/4 of a cup. A serving of fruit slices is a scant 1/2 cup. And dried fruit? One-quarter cup.
Meeting your daily quota is far easier than you’d think because a recommended serving just isn’t all that much. According to the experts, a serving of fruit juice is only 3/4 of a cup. A serving of fruit slices is a scant 1/2 cup. And dried fruit? One-quarter cup.
Most of us aren’t about to carry cup measurers around. Nor do we need to. “The good news is that serving sizes are actually smaller than most people realize,” says Doyle. “Most people tend to overestimate how big a serving has to be.” One cup of salad greens, for instance, is the equivalent of a small side salad. One-quarter cup of raisins is the amount you might scatter on a bowl of cereal. A half cup of chopped vegetables constitutes a serving. “We’re not talking huge amounts here,” says Doyle. “Eat a generous salad of leafy greens with grated carrots, sliced red peppers, and black beans and you could be getting three servings.”
One easy way to get a feel for what constitutes a serving is to use visual equivalents. But don’t get hung up worrying about precise amounts, Doyle advises. Instead, think about helpings. Aim to get two helpings at breakfast (a small glass of orange juice and sliced fruit on your cereal, for instance). Two helpings at lunch (a sandwich with lettuce, tomatoes, and avocado and an apple for dessert). Three or four at dinner (spaghetti with tomato sauce, grilled asparagus on the side, a small salad, and berries for dessert). And voila, you’re at 7 to 8 servings. Throw in a glass of tomato juice, a snack of fruit or sliced carrots, and you’re over the bar.
Do all fruits and vegetables, from avocados to zucchini, contain cancer-fighters?
Almost everything in the produce section has a place in a cancer-prevention diet. Unfortunately, that doesn’t include two of America’s favorite vegetables: French-fried potatoes and iceberg lettuce. (White potatoes are mostly starch, and iceberg lettuce is mostly water.)
Almost everything in the produce section has a place in a cancer-prevention diet. Unfortunately, that doesn’t include two of America’s favorite vegetables: French-fried potatoes and iceberg lettuce. (White potatoes are mostly starch, and iceberg lettuce is mostly water.)
In contrast, cruciferous vegetables–including broccoli, cauliflower, kale, bok choy, cabbage, and brussels sprouts–are powerhouses of cancer protection. They’re loaded with substances called isothiocyanates and sulforaphane, which have been shown to boost the body’s own cancer-fighting enzymes. Also high on the list are allium vegetables, including onions and garlic. They contain organosulfates that are believed to block cancer in a variety of ways, including inhibiting the growth of cancer cells. And berries like strawberries, blackberries, blueberries, and raspberries get their color from anthocyanins, potent antioxidants that are believed to protect cells from damage that can lead to cancer. Then there’s the lycopene in tomatoes, the beta-carotene in leafy greens, and the flavonoids in citrus fruit. “The best rule of thumb is to go for color,” says the American Cancer Society’s Doyle. “In general, the deeper or brighter the color, the more antioxidants and cancer-fighting substances a fruit or vegetable contains.”
All of these cancer-fighting powerhouses also have something else going for them: fiber. “Fiber contains lignans, which bind to cancer-causing substances and help the body eliminate them,” says Glenn S. Rothfeld, clinical assistant professor of family medicine at Tufts University School of Medicine and medical director of WholeHealth New England. “It also promotes bacteria in the gut that may help lower cancer risk by breaking down carcinogens before they cause trouble.”
Is it better to cook vegetables or eat them raw?
Only one vegetable (and it’s technically a fruit) is a significantly stronger cancer-fighter when cooked: the tomato. Cooking makes the antioxidant lycopene more readily available, so everything from stewed tomatoes to tomato sauce is likely to offer more protection than raw tomatoes. For most vegetables, however, cooking can remove some important nutrients–unless you use the right method. Boiling leaches out most water-soluble nutrients, including the antioxidants beta-carotene and vitamin C, as well as folate. Steaming or baking are better choices because they preserve more disease-fighting substances. But if you use a recipe that calls for boiling vegetables, save the water for stock to use in a soup or sauce and you’ll take advantage of any nutrients removed from the vegetables.
Only one vegetable (and it’s technically a fruit) is a significantly stronger cancer-fighter when cooked: the tomato. Cooking makes the antioxidant lycopene more readily available, so everything from stewed tomatoes to tomato sauce is likely to offer more protection than raw tomatoes. For most vegetables, however, cooking can remove some important nutrients–unless you use the right method. Boiling leaches out most water-soluble nutrients, including the antioxidants beta-carotene and vitamin C, as well as folate. Steaming or baking are better choices because they preserve more disease-fighting substances. But if you use a recipe that calls for boiling vegetables, save the water for stock to use in a soup or sauce and you’ll take advantage of any nutrients removed from the vegetables.
What about organic versus conventional?
There are plenty of reasons to choose organic, from promoting a healthier environment to supporting local farmers. Now there’s evidence you may also get more cancer protection. In findings reported this year at the University of California at Davis, some organically grown produce was found to have higher levels of cancer-fighting antioxidants called flavonoids than the conventionally grown stuff. (Experts theorize that pesticide-free plants may produce more antioxidants to ward off pests.) The scientists looked at three foods: Organic corn had 59 percent higher levels of cancer-fighting flavonoids; marionberries were 50 percent higher; and strawberries, 19 percent. Also, organic produce has lower levels of pesticide residues. Conventional crops were six times more likely to contain residues in a recent study.
There are plenty of reasons to choose organic, from promoting a healthier environment to supporting local farmers. Now there’s evidence you may also get more cancer protection. In findings reported this year at the University of California at Davis, some organically grown produce was found to have higher levels of cancer-fighting antioxidants called flavonoids than the conventionally grown stuff. (Experts theorize that pesticide-free plants may produce more antioxidants to ward off pests.) The scientists looked at three foods: Organic corn had 59 percent higher levels of cancer-fighting flavonoids; marionberries were 50 percent higher; and strawberries, 19 percent. Also, organic produce has lower levels of pesticide residues. Conventional crops were six times more likely to contain residues in a recent study.
Is a glass of juice as rich in cancer-fighters as whole fruit or vegetables?
Juice that’s made of 100 percent fruit or vegetables is almost as good as the real thing, with one caveat: Most juice doesn’t have nearly as much fiber as whole produce. And experts think fiber is one of the reasons a diet loaded with plant foods protects against cancer. Many commercially available juices have another drawback: added sugar, which some experts are convinced may increase cancer risk.
Juice that’s made of 100 percent fruit or vegetables is almost as good as the real thing, with one caveat: Most juice doesn’t have nearly as much fiber as whole produce. And experts think fiber is one of the reasons a diet loaded with plant foods protects against cancer. Many commercially available juices have another drawback: added sugar, which some experts are convinced may increase cancer risk.
Still, juices have one important advantage: convenience. Drinking a glass of orange juice is a lot easier on a hectic morning than cutting up an orange or grapefruit. Even better is to blend fresh fruit or vegetables into a smoothie. A tall one can pack several servings of produce, fiber and all.
When you have neither a blender nor the time, pour yourself a prepackaged drink made only with fruit or vegetables. Pure juice and vegetable drinks are much easier to find these days–even mass market grocery chains stock them.
What about supplements?
Taking a multivitamin can help ensure that you get enough folate, vitamin E, and other nutrients to meet your daily requirements. But don’t expect a pill to provide the cancer-fighting benefits of a menu abundant in fruits and vegetables. “We’ve seen again and again that isolating substances we think protect against cancer and putting them in pills doesn’t seem to work,” says Rothfeld. Beta-carotene supplements, for instance, don’t protect against heart disease the way the nutrient in foods appears to; not only that, the pills increase the risk of lung cancer in some patients. Similarly, studies have found no evidence that fiber supplements lower risk of colon cancer–though a stack of research points to protection from diets rich in fiber from plant sources. “The simple fact is, we don’t have the technology to replace real foods with fake foods,” says Rothfeld. “We don’t know enough about the beneficial substances in plant-based foods to put them in a pill.”
Taking a multivitamin can help ensure that you get enough folate, vitamin E, and other nutrients to meet your daily requirements. But don’t expect a pill to provide the cancer-fighting benefits of a menu abundant in fruits and vegetables. “We’ve seen again and again that isolating substances we think protect against cancer and putting them in pills doesn’t seem to work,” says Rothfeld. Beta-carotene supplements, for instance, don’t protect against heart disease the way the nutrient in foods appears to; not only that, the pills increase the risk of lung cancer in some patients. Similarly, studies have found no evidence that fiber supplements lower risk of colon cancer–though a stack of research points to protection from diets rich in fiber from plant sources. “The simple fact is, we don’t have the technology to replace real foods with fake foods,” says Rothfeld. “We don’t know enough about the beneficial substances in plant-based foods to put them in a pill.”
Is there more to a cancer-fighting diet than fruits and vegetables?
Yes. Not just fruits and vegetables but almost all foods that begin life as plants seem to offer some benefit. Tea, for example, is rich in flavonoids. Drinking 4 to 6 cups a day has been linked to lower risk of several forms of cancer. Studies show that people who help themselves to nuts may also gain protection.
Yes. Not just fruits and vegetables but almost all foods that begin life as plants seem to offer some benefit. Tea, for example, is rich in flavonoids. Drinking 4 to 6 cups a day has been linked to lower risk of several forms of cancer. Studies show that people who help themselves to nuts may also gain protection.
And, of course, there’s olive oil, which appears to contain special cancer-fighting properties. A 2002 study by Italian researchers showed that women who consumed the most olive oil had the lowest risk of ovarian cancer. In another Italian study, published the same year, scientists discovered that hydroxytyrosol, a substance that abounds in olive oil, slows the proliferation of leukemia and colon cancer cells. It also causes damaged cells to self-destruct, which could prevent tumors from growing.
Eating fish is another good hedge against cancer. (But avoid the ones most likely to contain mercury, like swordfish, ahi tuna steaks, and sea bass.) Earlier this year, Harvard University scientists found that eating fish more than three times a week was associated with a significant reduction in prostate cancer risk. Although no one knows why, the high levels of omega-3 fatty acids found in most fish are important in maintaining healthy cell walls. “By keeping cells healthy,” says Susan Lord, who directs the nutrition program at the Center for Mind-Body Medicine in Washington, D.C., “omega-3s may make them more resistant to cancer-causing substances.”
What foods can increase our cancer risk?
Experts are becoming increasingly convinced that dietary sugars and refined carbohydrates, which are quickly converted to glucose in the bloodstream, can damage healthy cells, making them more susceptible to becoming malignant. What’s more, tumor cells metabolize sugar very quickly, getting the energy they need to grow. Cutting back on their fuel source, experts say, can help slow that growth. You can do so by replacing simple with complex carbohydrates: Choose whole-grain cereals and breads, go for brown rice over white rice, and add more vegetables and less pasta to Italian dishes. Complex carbohydrates are rich in many of the same disease-fighting substances found in fruits and vegetables.
Experts are becoming increasingly convinced that dietary sugars and refined carbohydrates, which are quickly converted to glucose in the bloodstream, can damage healthy cells, making them more susceptible to becoming malignant. What’s more, tumor cells metabolize sugar very quickly, getting the energy they need to grow. Cutting back on their fuel source, experts say, can help slow that growth. You can do so by replacing simple with complex carbohydrates: Choose whole-grain cereals and breads, go for brown rice over white rice, and add more vegetables and less pasta to Italian dishes. Complex carbohydrates are rich in many of the same disease-fighting substances found in fruits and vegetables.
How you prepare foods can make a difference, too: Charbroiled, highly salted, and fried foods have all been linked to cancer.
Fonte: http://www.care2.com/greenliving/the-anti-cancer-diet.html
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