Although the field of investigation in the role of nutrition in the cancer process is very broad, a clear and recurring conclusion is that nutrition plays a major role in cancer. A daily diet that incorporates a good quantity of fruits, vegetables, and whole grains has been shown time and time again to be protective against a wide range of cancer types. Based on research evidence that these foods could decrease cancer risk, the National Cancer Institute implemented its ‘Five A Day’ program more than a decade ago, encouraging Americans to eat at least five servings per day of fruits and vegetables. Other organizations, such as the American Institute for Cancer Research, devote the majority of their energy to educating the public on nutrition and cancer risks. The strongest evidence of a relationship between diet and cancer has been shown in cancers of the breast, prostate, and lung, and in cancers of the gastrointestinal tract, such as esophageal, stomach, pancreas, and colon cancers.
Fruits and vegetables are the greatest sources of vitamins, minerals, and nutrients such as flavonoids and carotenoids, which are types of antioxidants. To understand what an antioxidant is, you need to understand that the cells in our bodies are constantly being damaged by oxidative stress, which is when oxygen molecules “steal” tiny, electrically charged particles, called electrons, from the molecules that make up our cells. Without these electrons, our cells lose the ability to function normally and become more likely to give rise to cancer. The damaging oxygen molecules carrying these extra electrons are called free radicals. Antioxidants work by binding to free radicals and transforming them into non-damaging compounds. If present in sufficient quantities, antioxidants can make a big difference in keeping our own cells healthy and functioning properly, lessening the likelihood that they’ll become cancerous.
Why are plant-based foods so high in antioxidants? One main reason is that the antioxidants are necessary in order to protect the leaves, stems, shoots, and fruit of plants from cellular damage as a result of exposure to the sun’s ionizing ultraviolet radiation. Antioxidants can also protect plants from insects and toxic metals found in the soil. Antioxidants called anthocyanins give plants their bright pink, purple, and bluish colors and, together with the orange and yellow carotenes, provide the varied colors characteristic of autumn foliage. The names of some antioxidants, such as beta carotene, folate, and selenium, might be familiar to you. Others, such as ellagic acid, myricetin, and resveratrol, sound rather foreign. The most important thing to remember is that a diet that is rich in fruits, vegetables, legumes, whole grains, and healthy sources of proteins and fats is the best way to eat—and the best way to teach your children to eat—to live a long and healthy life.
When you think of a traditional American meal, you probably think of comfort foods like meatloaf and apple pie or ballpark fare such as hamburgers, French fries, and milkshakes. The “Western diet” that many Americans embrace typically contains a lot of refined sugar, white flour, and meats that are high in saturated fat. This type of diet has been linked to an increased risk of various cancers, as well as heart disease, obesity, diabetes, and arthritis. Refined sugar and white flour can be avoided by staying away from white bread and sugary baked goods and by paying greater attention to food labels. Fats are a little bit trickier. Unsaturated fats come in two main categories: monounsaturated and polyunsaturated—and both of these are much better for you than the saturated type. Trans fats are created when a fat that is in oil form at room temperature is pumped full of hydrogen atoms and made into a solid. Basically, trans fats are an unsaturated fat that has been turned into a saturated fat. Any food whose label includes the words ‘hydrogenated oils’ or ‘partially hydrogenated oils’ contains trans fats. They can contribute to cancer risk by promoting obesity, and they increase cholesterol levels and may lead to atherosclerosis—a main cause of heart disease. Here are some examples of foods high or low in saturated fats:
Foods high in saturated fat: Bacon, pork chops, pork loin, regular cuts of beef, marbled meats, sausage, spare ribs, butter, cream, cream cheese and hard cheeses like cheddar, egg yolks and whole eggs, whipping cream, whole milk, buttermilk, many brands of chocolate milk, chicken wing meat/dark meat/giblets, and oils such as corn oil and cottonseed oil
Foods low in saturated fat: Chicken white meat, most types of fish and seafood (salmon, tuna, shrimp, tilapia, crab), very lean pork and beef, low-fat and nonfat dairy products (such as nonfat or low-fat cottage cheese, feta cheese, mozzarella cheese, other reduced-fat cheeses, skim and low-fat milk, nonfat and low-fat yogurt), egg whites, oils (such as safflower oil, olive oil, canola oil, peanut oil), nuts and seeds (pecans, hazelnuts, almonds, cashews, Brazil nuts, pistachios, walnuts, sunflower kernels, and pine nuts. Macadamia nuts are particularly high in polyunsaturated fat). Avocados carry the stigma of being a fatty food, but they contain mainly monounsaturated fat—a good fat.
Blueberries, blackberries, red and black raspberries, cranberries, strawberries, and lingonberries (popular in Europe and the Pacific Northwest) are chock full of cancer-fighting phenols. In the 1990s, Dr. Gary Stoner, a cancer scientist at Ohio State University, showed that concentrated black raspberry extract could fight colon and esophageal cancer. Now we know that the phenols in berries, such as the anthocyanins that give berries their blue or red color, can slow the growth and metabolism of cancerous and pre-cancerous cells. They can also inhibit the tumor’s ability to form blood vessels, and, without a blood supply, tumors cannot survive. Ellagic acid, coumaric acid, resveratrol, folate, and myricetin are antioxidants found in berries that have demonstrated anti-cancer abilities in numerous lab-based studies. Ellagic acid extracts from raspberries have been shown to effectively inhibit cervical cancer growth; lab studies of ellagic acid show it may decrease pancreatic cancer risk and skin cancer cell division. Other studies have demonstrated that berries may inhibit or help to prevent oral and breast cancer, as well as leukemia and lymphoma. And one cup of raspberries has almost twice the fiber of a medium-sized baked potato—including the skin! Berries are also loaded with the antioxidant vitamin C, and they are very low in calories. Frozen berries have an equivalent amount of cancer-fighting compounds and can be eaten when fresh berries are out of season.
Oranges, lemons, limes, tangerines, clementines, and grapefruit are the citrus fruits most commonly eaten in this nation, and for good reason. You can get them from Florida or California, ripe and juicy, year-round. Citrus fruits are rich in vitamin C, a powerful antioxidant long known for its ability to keep sailors from getting scurvy during extended periods of time at sea, and recent lab studies have shown it may fight breast cancer. It is better to peel an orange or grapefruit and eat it in sections rather than cutting it in half and spooning it out, because the white membrane that surrounds the fruit is packed with flavonoids—three times as much as is in the rest of the fruit. Citrus-fruit peel and pulp is also antioxidant-rich, and is particularly high in the flavanol quercetin as well as limonoids, phytochemicals with anti-cancer properties that give the citrus-fruit peel its fresh scent. In a recently published case-control study conducted in Northern Italy, individuals who ate the most citrus fruit had a 62 percent reduction in their esophageal cancer risk when compared to those who consumed the least citrus. Additionally, the pectin in citrus fruits has been shown to be a cancer-fighter and may delay the growth of cancerous cells in men diagnosed with recurrent prostate cancer. White grapefruit contains the flavonoid naringenin. In a large case-control study, people who ate the greatest average amounts of white grapefruit decreased their lung cancer risk by 50 percent compared to those who ate the least. Another citrus flavonoid, luteolin (also found in basil, green peppers, celery, parsley, thyme, peppermint, pomegranates, and artichokes) was studied in the Harvard-based Nurse’s Health Study of more than 66,000 women. Results of this recent study showed that high luteolin intake was associated with a 34 percent reduction in ovarian cancer risk.
Red and pink grapefruit, pink guava, papaya, watermelon, and tomatoes all contain lycopene. Lycopene is one of the carotenoids whose intake has been correlated to a decreased risk of pancreatic and prostate cancers, among others. Botanically speaking, the tomato is actually a fruit, and it is the world’s most popular fruit, with more than 60 million tons being produced each year. Each of these pink and reddish fruits also contains tons of vitamin C and beta carotene, which boost immunity and help fight infection by promoting free-radical scavenging. The white and greenish parts of watermelon also contain citrulline, which may assist in wound healing. Heating tomatoes does not destroy lycopene—in fact, it enhances it—so ounce for ounce, tomato paste, spaghetti sauce, and ketchup have even higher lycopene content than a raw tomato. Studies have also demonstrated that processed tomato products that contain a little bit of oil or fat (such as spaghetti sauce) are better foods for your body to absorb lycopene from, compared to raw tomato juice, from which the lycopene is poorly absorbed.
Apples have a high polyphenol quantity and contain the flavonoid quercetin, which is also found in onions, grapes, broccoli, and citrus fruit. Quercetin is a powerful antioxidant, and high quercetin intake has been associated with anti-inflammatory and anti-tumor activities, particularly in skin, prostate, esophageal, and lung cancers. Apples also contain antioxidants called procyanidins, and have been shown to have strong effects on the vascular system, improving blood flow to healthy cells and thereby lowering blood pressure and protecting the heart from damage.
Grapes have been receiving a lot of press lately because they contain high levels of the polyphenol resveratrol, which has been rumored to be the ingredient found in red wine as well as grape juice that just might help keep the French thin. Resveratrol can make muscle cells function at a higher rate and thus may accelerate the body’s metabolism and ability to burn calories. While all grapes are good for you, purple and red grapes have about three times more antioxidants than green or white ones, including antioxidant anthocyanins (just like in berries), as well as ellagic acid, myricetin, quercetin, and kaempferol. In laboratory studies, resveratrol has been shown to be able to decrease or stop the growth of breast, prostate, pancreatic, stomach, liver, and colorectal cancers. A study of diet in Mediterranean countries showed that the more resveratrol-rich foods a woman consumes, the lower her breast cancer risk. Berries such as cranberries and raspberries are also high in resveratrol.
Tart cherries contain anthocyanins, the same cancer-fighting ingredient in berries, grapes, and plums, which also protect artery walls from the damage that leads to plaque buildup and heart disease. Studies have shown that cherries may help to decrease the risk of cardiovascular disease and ‘metabolic syndrome’ by improving cholesterol levels and the activity of insulin. Cherries have a high content of perillyl alcohol—a natural chemical that depletes the body of cancer-causing substances and helps to slow the growth of cancerous cells. The anthocyanin, cyanidin, contained in tart cherries has been shown to inhibit colon and breast cancer cell growth in lab studies. Cherries also contain a healthy dose of melatonin, the same hormone produced by your body’s pineal gland that has been used to treat jet lag and insomnia and may play a role in cancer treatment. High levels of fiber, vitamin C, and beta carotene are also found in cherries.
Plums, peaches, pears, nectarines, apricots, kiwi fruit and melon are fruits known for their high antioxidant and fiber content and have been associated with a decreased risk of many types of cancers. As mentioned, plums contain resveratrol. Peaches and nectarines are high in vitamin C; apricots contain plenty of beta carotene; and ounce for ounce, kiwi fruit has more vitamin C than an orange and more potassium than a banana. Each of these fruits contains large amounts of polyphenols, which can scavenge free radicals and keep them from damaging healthy cells.
The botanical name for the pomegranate is Punicum granatum, though other names for it include Chinese apple, granada, and melo grano. Pomegranates are one of the oldest known fruits and are rich in folklore. Every pomegranate is composed of exactly 840 seeds, each surrounded by a sac of sweet-tart juice contained by a thin skin. Originally from India, they were introduced to the United States in the late 1700s and are now grown in California, Utah, Alabama, and Louisiana. Pomegranate juice has demonstrated potent antioxidant, anti-malarial, and anti-atherosclerotic properties. In laboratory studies, four important chemical components found in pomegranates, ellagic acid, caffeic acid, punicic acid, and luteolin, demonstrated the ability to inhibit prostate cancer cell growth and invasion. Pomegranates contain plenty of folate and vitamin C. There is also evidence that antioxidants found in pomegranate fruit and juice can help prevent breast and lung cancer cells from dividing and can even induce cancer cell death.
Vegetables known as leafy greens include kale, spinach, escarole, collard greens, Swiss chard, curly endive, watercress, mustard greens, and arugula. Just about any type of lettuce—such as bib, Boston, butter, leaf, and red or green romaine—also qualifies as a leafy green vegetable, even if the leaves have a lot of red or brownish color to them. Leafy greens are loaded with vitamins, such as vitamin C, and minerals, as well as two types of carotenoids called lutein and zeaxanthin. Studies have shown that consuming healthy quantities of leafy greens and other lutein-rich foods decreases the risk of breast, skin, lung, head and neck, and stomach cancer. Additionally, greens such as spinach, kale, and watercress contain the flavonoid kaempferol. The Iowa Women’s Health Study, a large prospective study of more than 40,000 women, found that women with the highest intake of leafy greens decreased their risk of ovarian cancer by 56 percent. Watercress intake, in particular, was associated with decreased ovarian cancer risk. Leafy greens are also rich in folate, and large epidemiological studies have found that, compared to people who report low folate intake, individuals with the highest intake of folate-rich foods have, on average, a 40 percent decreased risk of colon cancer. And a Harvard-based study of more than 88,000 women found that folate decreased the risk of breast cancer in those women who drank at least one alcoholic beverage per day.
Broccoli, cauliflower, Brussels sprouts, cabbage, and bok choy are cruciferous vegetables, otherwise known as members of the Brassica family. The Brassica family of foods contains high levels of several chemical constituents called isothiocyanates, which stimulate detoxification enzymes in the liver. One example of a potent isothiocyanate is the antioxidant sulforaphane. Sulforaphane and other isothiocyanates are capable of revving up the cellular defense enzymes in your body and neutralizing free radicals. In basic terms, the broccoli and cabbage that you eat is digested and then goes on to protect your cells from DNA damage and inhibit carcinogenesis (the process by which normal cells transform into cancerous cells) and tumor formation. In laboratory studies, the compounds in cruciferous vegetables have been shown to keep cancers from forming, as well as to slow the growth of tumors that are already present. There is strong evidence that they can help ward off prostate, lung, breast, head and neck, and pancreatic cancer. A study of 300 Chinese women found that those with the highest isothiocyanate consumption had a 45 percent lower breast cancer risk compared to the women with the lowest. Certain isothiocyanates have also demonstrated the ability to induce tumor cell death in leukemia cells that are resistant to chemotherapy. Cruciferous vegetables are also rich in vitamin C, other polyphenol antioxidants and quercetin, as well as flavonoids. Cabbage, in particular, has very high levels of kaempferol—one of the most potent antioxidants known—and research has shown that eating cabbage just a few times a week may protect you from breast, lung, and colon cancer.
Orange and yellow vegetables such as carrots, yams, squash, and sweet potatoes are loaded with beta carotene, a well-known and studied antioxidant that is a precursor to vitamin A. They are also rich in vitamin C. High intake of carrots and yams has been associated with a lower risk of breast cancer as well as head and neck cancers (such as laryngeal). Cigarette smokers have been shown to have lower blood levels of beta-carotene as well as alpha-tocopherol (a form of vitamin E), but smokers with higher intake of beta-carotene rich foods have been shown to significantly decrease their risk of developing lung cancer compared to smokers who don’t eat these types of foods.
Onions, shallots, garlic, chives, scallions, and leeks are all members of the onion, or Allium, family. Garlic has been known for centuries for its anti-inflammatory and immune-regulating properties, and some studies have shown that garlic may reduce cholesterol levels. The Iowa Women’s Health study demonstrated that women who ate garlic regularly had a lower risk of colon cancer, and a Korean study showed that garlic consumption was linked to a lower risk of stomach cancer. Onions may be the greatest food source of the flavonol quercetin. A case-control study from the Journal of the National Cancer Institute of 582 patients with lung cancer and 582 age-, sex-, and ethnicity-matched healthy controls found that those with the highest onion intake had a 50 percent lower incidence of lung cancer. There is also evidence that onions may play a role in fighting colon, bladder, skin, prostate, stomach, and endometrial cancers as well as leukemia. Red and yellow onions have higher quercetin concentrations than white onion varieties. Other allium-based antioxidant compounds found in onions and garlic include allicin, allyl sulfides, organosulfur compounds, and ajoene. The potent antioxidant allicin in garlic, however, is destroyed by heating, while cooking garlic actually releases ajoene. To preserve some of the allicin, you can slice or mince garlic and let it sit at room temperature for about 10 minutes prior to cooking. Quercetin, on the other hand, is preserved when heated.
Lentils, peas, and beans of all varieties are known as legumes. Vegans, vegetarians, and people of various European, Mexican, and South American cultures consume legumes regularly. Legumes contain a great number of cancer-fighting compounds, including lignans, saponins, phytic acid, and protease inhibitors. A large study of Seventh Day Adventists whose diet included more fruits, vegetables, legumes, whole grains and fish than typical Americans consume, demonstrated that they had a 55 percent lower risk of pancreatic cancer compared to the general population, much of which was correlated to their high legume intake. Beans are one of the most nutritious foods known and are high in protein as well as minerals such as magnesium, copper, potassium, manganese and calcium. One serving of pistachios, for instance, has the same amount of dietary fiber as 1/2 cup of broccoli. They are also an excellent source of antioxidants such as vitamin C, vitamin A (from beta-carotene), and folate. Black beans, in particular, contain a quantity of anthocyanins equivalent to that of cranberries and grapes. A recent case-control study of over 3,000 ethnically diverse men found that men who ate the highest quantity of beans decreased their risk of prostate cancer by 38 percent. Other studies have shown that people who eat foods high in vitamin C, beta-carotene, and folate decrease their risk of lung, esophageal, and colon cancer.
The soybean is another type of legume that contains all of the same antioxidant compounds as described above, but also has some unique anti-cancer properties. Soy products contain phytoestrogens, which are plant-based weak estrogens similar to those that your body makes (men actually make a small amount of estrogen, too), but that can compete for the same estrogen receptor on tissues such as breast tissue. The most significant phytoestrogen is isoflavone, which contains two important compounds — genistein and daidzein. Higher intake of soy-based foods has been shown to protect against pre-menopausal breast cancer as well as endometrial and prostate cancer, and it is likely to play a protective role for other cancer types. In a 20-year study of more than 12,000 American men, men who drank one or more servings of soymilk per day reduced their prostate cancer risk by 70 percent! Soybeans contain all the essential and non-essential amino acids, making them a complete protein equivalent to animal proteins. And soy products are low in saturated fat. Examples of soy-based foods include soybeans, tofu, edamame, tempeh, miso, soy nut butter, soy-based veggie burgers, textured vegetable protein, and soymilk. Tofu is an incredibly versatile food for cooking and baking, and provides protein and texture while taking on the flavor of other ingredients in the recipe.
Nuts are one of nature’s most perfect foods. Nuts and seeds such as sunflower kernels and sesame seeds contain the healthy type of fat—monounsaturated fat—that has been shown to protect against breast cancer. Two of the phytosterols found in nuts, beta-sitosterol and campesterol—may suppress prostate and breast tumors. Nuts also have lots of fiber, are a good source of protein and B vitamins, and contain breast and colon cancer-fighting lignans, similar to flaxseeds and beans. Many types of nuts contain amino acids such as arginine that can give your immune system a boost. Pecans, pistachios, and Brazil nuts, among others, contain minerals such as zinc, magnesium, and selenium. Lab studies have found that selenium may inhibit the development or growth of prostate, lung, and bladder cancer cells, and both lab and human studies have shown that selenium may protect against colon cancer. Walnuts and walnut oil contain high levels of ellagic acid, the same potent antioxidant that is found in raspberries and pomegranates. Both nuts and seeds are also high in vitamin E content, an antioxidant that protects cell membranes, and nut oils contain omega-6 fatty acids.
Only one in 10 Americans eats the daily requirement of complex carbohydrates provided by whole-grain foods. Many of the carbohydrates that Americans consume are refined carbohydrates, such as bagels and pretzels. Whole grains include wheat and rye, couscous, millet, bulgur, oats, popcorn, kasha, quinoa, tabouleh, barley, and buckwheat. Whole-grain foods can be made into breads, cereals, muffins, pancakes, and other breakfast types of foods. Whole-grain brown rice, couscous, and whole-grain pastas should be a dinner staple on every American table. Whole grains are a great source of both soluble and insoluble fiber that helps you to feel full, improves regularity, and protects against pre-cancerous and cancerous disease of the small bowel and colon. Whole-grain foods contain the germ and bran parts of grain kernels, which have been removed from refined grains. Unlike simple sugars, such as glucose and fructose, the complex carbohydrates found in whole-grain foods are absorbed slowly and thus do not rapidly raise blood sugar levels and promote type II diabetes like simple sugars do. Type II diabetes increases the risk of developing some types of cancer, most notably the highly lethal pancreatic cancer. Whole grains are rich in B vitamins and folate, minerals such as iron and magnesium, and antioxidant phenols, saponins, lignans, and phytoestrogens. Many studies of whole grains have found high intake levels to correlate with reduced cancer risks. A recent case-control study of more than 2,000 individuals living in the San Francisco bay area, for instance, noted that adults who ate two or more servings per day of whole-grain foods decreased their risk of pancreatic cancer by 40 percent compared to individuals who ate less than one serving of whole grains per day. They also documented about a 35 percent reduction in pancreatic cancer risk among individuals who ate the highest amount of fiber (26.5 grams per day or more) compared with those who ate the least (15.6 grams per day or fewer). A separate study of more than 61,000 women showed that those with the highest whole-grain intake cut their colon-cancer risk by a third, while the prospective Iowa Women’s Health Study found that increased whole-grain consumption decreased endometrial and ovarian cancer risk.
Flaxseeds themselves are not digestible. Thus, if they are eaten whole, you will get plenty of fiber but you will not attain the benefits of the lignan portion of them, which is the cancer-fighting isoflavone phytoestrogen. Flaxseed flour and flaxseed meal are the greatest lignan sources, and some flaxseed oils are supplemented with lignans. Flaxseeds are one of the greatest plant sources of alpha-linolenic acid, one of the heart-protective omega-3 fatty acids that demonstrate anti-inflammatory action. Consumption of flaxseed meal has been shown to protect against prostate cancer. A study of men diagnosed with prostate cancer who consumed 30 grams per day of ground flaxseed (about 3 tablespoons) had a 30 to 40 percent reduction in the rate of cancer-cell division—which was a greater reduction than in the sub-set of those who ate a reduced-fat diet but didn’t eat the flaxseed meal. Lab-based studies have found that flaxseed consumption can decrease the growth rate of established breast-cancer tumors. Flaxseed meal and flour have a light, nutty flavor, and they can be used to make delicious baked goods.
Low-fat and nonfat dairy products, to a great degree, are synonymous with calcium. Although there are many other sources of calcium, dairy products provide one of the simplest and most readily available means of getting your calcium. For instance, spinach also contains calcium, but you would have to eat an awful lot of spinach to get the same amount of calcium as in a large glass of milk. Calcium intake was studied prospectively in 45,354 women by the National Cancer Institute and was shown to protect against colon cancer. Compared to those with a calcium intake of less than 400 milligrams a day, women who consumed more than 800 milligrams per day had a 25 percent reduction in colorectal cancer risk. Calcium and vitamin D have also been linked to lower rates of pre-menopausal breast cancer. On-going research will help to determine if vitamin D might decrease the risk of other types of cancer.
Fatty fish, such as salmon, tuna, bluefish, mackerel, sardines, and raw herring contain high levels of omega-3 fatty acids, selenium, lignans, calcium, and vitamins A and D. Omega-3 fatty acids are known for their ability to protect the heart from damage and maintain lower blood pressure. The nutrients in fatty fish may also help decrease cancer risk. The role of vitamin D and calcium has already been described as helping to lower colon and pre-menopausal breast cancer risk, and there is some evidence that it may be protective against lung cancer. Additionally, a study of more than 90,000 Swedish women conducted between 1987 and 2004 found that those women who ate at least one portion of fatty fish per week decreased their risk of kidney (renal) cancer by 74 percent, compared with those who did not regularly eat fatty fish. And a recent Swedish case-control study of more than 2,000 men demonstrated that men who ate fatty fish at least once a week had a 43 percent decreased risk of prostate cancer compared to those who never ate fatty fish.
Green tea has received a lot of press lately for its ability to lower the risk of many cancers, including breast, esophageal, and stomach cancer. People who live in Asian countries have been reaping the health benefits of green tea for more than 5,000 years. Green tea contains a multitude of cancer-fighting compounds, including polyphenols and flavonoids, catechins such as tannins, a variety of minerals and alkaloids, such as caffeine and theobromine. Tea is also the best source of anti-cancer compounds called catechins, and green tea contains about three times as much as black tea. Laboratory studies have demonstrated that green tea can slow or prevent colon-, prostate-, lung-, liver-, and breast-cancer development. One early study showed that drinking three or more cups of green tea per day reduced the recurrence rate of Stage I (early) breast cancer.
Red wine and red or purple grape juices contain polyphenol compounds such as anthocyanosides, catechins, procyanidins, stilbenes, and other phenolics. The stilbene called resveratrol was described in the section on grapes, but these other antioxidants have immune-modulating and anti-tumor effects and help to relax blood vessels—which is why drinking a little red wine may help to prevent heart disease and decrease the risk of stroke. Recent studies have shown that moderate red wine or grape juice intake may decrease the risk of kidney cancer as well as Hodgkin’s and non-Hodgkin’s lymphomas. Note: drinking moderate to large amounts of alcohol has been shown to increase the risk of cancers of the upper airway and digestive tract (mouth, pharynx, larynx, and esophagus), as well as breast and colorectal cancer. Even one glass of alcohol a day may increase a woman’s risk or developing breast cancer. Very heavy alcohol intake is associated with liver cancer. Current recommendations are that women drink no more than one alcoholic beverage per day and men no more than two beverages per day. A 12-ounce beer, 5-ounce glass of wine, or 1 ?-ounce shot of hard liquor qualifies as one alcoholic beverage.
I was at the checkout counter of a store last week and saw a display of dark chocolate bars whose label read ‘The Healthy Snack.’ That was something that I would never have thought I would see, but it’s true—dark chocolate has some proven health benefits. Cocoa products have been consumed since at least 460 A.D. and have been used to treat lung and liver diseases as well as indigestion, fever, and premenstrual syndrome. Cocoa and dark chocolate contain procyanidins, catechins, and epicatechins. Unsweetened cocoa powder appears to have the most, followed by dark chocolate. Milk chocolate contains fewer of these antioxidants because the milk binds to them and decreases the antioxidant activity (so don’t wash down that piece of dark chocolate with a glass of milk!). Laboratory studies have shown that cocoa and extracts of dark chocolate can inhibit the formation of breast, colon, and prostate cancers and can decrease the division rate of liver cancer cells. Studies of dark chocolate consumption in humans have shown that it can lower your blood pressure. In 2003, scientists at Cornell University compared the chemical anti-cancer activity in certain beverages, and found that unprocessed cocoa has nearly twice the amount of antioxidants in red wine and up to three times of those found in green tea.
There has also been a lot of debate about meat, particularly red meat, and whether regular consumption increases cancer risk. Red meat means beef, lamb, veal, and pork. Although pork looks more white than red, its chemical properties place it in the category of a red meat. Some studies have found a link between high intake of red meat and gastrointestinal cancers—particularly stomach, colon, and pancreatic cancer. A 2006 study from the United Kingdom found that people who consumed red meat on a daily basis had a significantly higher risk of colon cancer than those who ate it only once a week. Another recent study from the United States demonstrated that survivors of colon cancer who continued to eat lots of red meat each week greatly increased their risk of having a recurrence of colon cancer. Legumes, soy protein, low- or non-fat dairy products, and lean chicken and poultry should be your main protein sources, with an occasional three-ounce (cooked) serving of red meat being an acceptable part of a healthy diet.
If you have been reading the newspaper lately, you may have learned that grilling meat, fish, and poultry can create carcinogens in your food. The results of a case-control study published in the journal Epidemiology in May 2007 demonstrated that postmenopausal women who consumed large amounts of grilled, barbecued, or smoked meats each week had a 47 percent increased risk of breast cancer compared with women who ate small quantities of these types of meats. Additionally, their breast-cancer risk was increased by 74 percent if they also reported low fruit and vegetable intake. The carcinogenic substances created by cooking at high temperatures are produced when the amino acids in the protein are heated, and they have names like polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs). However, if you want to grill food more safely, here are a few things that you can do:
• Trim any excess fat from meat prior to grilling and remove the skin from chicken or other poultry.
• Grilling fruits and vegetables doesn’t create these same cancer-associated compounds, so combine a small amount of grilled meat, poultry, or fish with a larger portion of grilled fruits and veggies to get the same flavor.
• Marinate meat, poultry, or fish for 30 minutes prior to cooking. This will help form a barrier between the meat and the heat. (Never reuse marinade as a sauce because the raw meat contaminates it!)
• Pre-cook meat, either in an oven or microwave, and then grill just briefly to get the flavor.
• Turn food often to avoid charring it. Any charred or black bits should be removed prior to eating.
• Cook meats only to a rare or medium-rare degree.
Based on the fact that foods containing antioxidants may decrease the risk of some cancers and the discovery that people diagnosed with cancer often have low levels of antioxidants in their bloodstream, the idea was born that, perhaps, taking a nutrient-containing supplement might decrease cancer risk. To date, there has not been enough conclusive evidence that supplements can decrease cancer risk. Research has shown that vitamin D may lower pancreatic and invasive breast-cancer risk and calcium may decrease colon and breast cancer risk, but these findings need to be confirmed in large-scale prospective studies.
A few studies have even found that supplements may INCREASE cancer risk. The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Trial was a cancer-prevention trial conducted from 1985 to 1993 to determine whether certain vitamin supplements would prevent lung cancer in a group of almost 30,000 male smokers. What the researchers found, in fact, was that men who took a beta-carotene supplement for five to eight years had an 18 percent increased incidence of lung cancers and an 8 percent increased overall mortality (death rate)! Furthermore, a study in 2007 by researchers at the National Cancer Institute followed 295,344 men over five years and found that men who exceeded the recommended dose of multivitamins—taking more than seven a week—increased their risk of advanced prostate cancer by about 30 percent.
It is almost impossible to get too much of any given vitamin through food alone, but loading up on some vitamins in pill form can cause significant problems. The fat-soluble vitamins—A, D, E, and K—are called fat-soluble because they are absorbed best in the digestive tract when fat is present. They also tend to accumulate in the fat in your body, particularly in your liver, where they can build up to dangerous levels. If a certain amount of a nutrient is good for you, two or three times as much is not necessarily better.
People wonder whether buying organic foods makes sense in a disease-fighting context. Unfortunately, there isn’t an easy answer to this question because there have been few, if any, scientific studies that compared health outcomes of people who eat only organic foods and those who eat nothing that is organic. The term ‘organic’ means that food is grown or animals are raised without the use of synthetic pesticides or herbicides (weed-killers), fertilizers, antibiotics, growth hormones, genetically modified organisms, or the use of irradiation. Organic farmers use manure or compost as fertilizer, and they kill weeds with plant-based weed killers. Some past studies have demonstrated that organically grown foods have higher levels of vitamins, minerals, and other antioxidants than conventionally grown or raised foods. A recent study showed that eating organic foods could help patients with Crohn’s disease suffer fewer intestinal problems. Here is a breakdown of the foods that the Environmental Working Group and other experts recommend to purchase organically and those that are acceptable in non-organic versions:
Organic is best: apples, peaches, bell peppers, celery, nectarines, cherries, strawberries, imported grapes, pears, spinach, lettuce, potatoes, carrots, and baby food because conventional versions have higher pesticide levels; milk, dairy products, meat, and poultry because of growth hormones and antibiotics.
Non-organic is okay: onions, broccoli, bananas, frozen sweet peas, frozen sweet corn, asparagus, avocados, pineapples, cabbage, papaya, mangoes, and kiwifruit because conventional versions have low pesticide-residue levels; seafood because no USDA organic certification yet exists and any seafood contains mercury, PCBs and other contaminants; processed foods such as bread, chips, pasta, and oils because, while they do often contain whole grains or other healthy ingredients, processed foods sometimes still include non-organic ingredients, and the processing itself can remove some of the vital nutrients.
Organic food manufacturing is now on an industrial scale. In fact, General Mills owns one of the largest organic food companies in the nation, Cascadian Farms. I opt for many organic foods in the grocery store, but I am even more likely to visit the local farmers market in the summer seasons and support the small, regional organic farmer.
Eating out can be a touchy issue for Americans. While most of us strive to be health-conscious, we often view an evening of dining at a nice restaurant as a treat or reward and thus tend to over-indulge. The National Restaurant Association estimates that on a typical day, more than four out of 10 adults patronize restaurants. When people eat out at restaurants, they consume a greater quantity of saturated fat and calories, fewer nutrients, and less fiber than when they eat at home. Children eat almost twice as many calories in the average restaurant meal compared to a home-cooked meal (770 versus 420 calories). There are some easy ways to stay on track when dining out:
• Try to avoid large chain restaurants that typically have many higher-fat entrees and avoid buffet-style dining. Enormous salad bars often have unhealthy choices—like mayonnaise-loaded macaroni or potato salad—that can easily corrupt a healthy plate of greens, vegetables, and fruits.
• Limit portion sizes, share a large main course, or get an appetizer size of a desired dish and a big salad.
• Choose whole-grain bread in the bread basket, order sandwiches with whole-grain or -wheat bread, and choose a wheat or whole-grain tortilla or wrap over one made of white flour.
• Try to incorporate leafy greens and vegetables into your meal as much as possible. If you can have a main course of salmon, or salmon served on a bed of greens, go for the greens. Instead of fries or chips on the side, opt for steamed vegetables or a mixed green salad.
• If ordering a dinner salad, go for a harvest-type salad that contains berries, fruit and nuts, rather than a Caesar or other lettuce and dressing-only salad.
• Anything can be served on the side and, for the sake of flavor, should be: dressings, sauces, even cheese on a salad can be put on the side—that way, you control how much you get.
• Use balsamic vinegar on salads and add a little bit of dressing. Balsamic doesn’t have that acidic taste of other vinegars and will enhance the flavor.
• Ask for the skin to be removed from chicken or other poultry before serving. Ask for minimal oil or butter to be used. Opt for lemon juice if you are having broiled, baked, or steamed fish.
• Anything in a Chinese restaurant can be steamed. Beware especially of sweet-and-sour sauces, as they are often loaded with sugar, fat, and calories.
• Try to have berries or other fruit if you choose to have dessert. Instead of cake or pie or other caloric desserts, have a scoop of sorbet or frozen yogurt with berries, if it is available.
• If having an alcoholic beverage, choose red wine if available. Many restaurants now have iced green tea or citrus-based cold beverages. Hot green tea is a great way to end a meal.
• Healthy condiments: mustard, lemon juice, chutney, salsa, soy sauce (though it is high in sodium), cocktail sauce, ketchup (in moderation), vinegar, horseradish
• Less healthy condiments: butter or clarified butter, cheese, margarine, bacon or bacon bits, regular or creamy salad dressings, cream, sour cream, whipped cream, hollandaise sauce, cream cheese (unless it is low-fat)
Foods cooked by healthy cooking methods include those described as:
Baked
Broiled
Steamed
Lightly sautéed (make sure it is a healthy oil)
Garden fresh
Au jus
Roasted
Poached
Pan-seared
Aglio-Olio (if light on the oil)
Less healthy cooking methods will appear on the menu as:
In cheese sauce or au gratin
Buttered, in butter, au beurre
Alfredo
In cream sauce, in vodka cream sauce, in tomato cream sauce
Fried, chicken-fried (as in ‘chicken-fried steak’)
Candied, glazed, maple-glazed
Béarnaise sauce
Stuffed
Pesto