You won’t find fiber in cheeseburgers, grilled chicken, cheese, or any other animal products. But a diet based on whole grains, beans, fruits, and vegetables can provide plenty of this essential nutrient.

Dietary fiber, or roughage, is a known cancer fighter found only in the cell walls of plant foods. Studies have shown that increased fiber intake decreases the risk of cancer, particularly colorectal cancer.

Fiber adds bulk to the digestive system, shortening the amount of time that waste travels through the colon. This waste often contains carcinogens and potential cancer-causing hormones that need to be removed from the body as quickly as possible. Fiber decreases the chances for intestinal cells to be affected by carcinogens. When bacteria in the lower intestine break down fiber, a substance called butyrate is produced. Butyrate may inhibit the growth of tumors of the colon and rectum.

Fiber may also help protect against breast cancer, especially when the fiber comes from grains and wheat bran. High-fiber diets are often lower in fat, and dietary fat is believed to increase the risk of breast cancer because fat can increase hormones in the body and speed tumor growth.

Increased fiber also expedites the removal of potentially harmful excess estrogen. The liver filters estrogens out of the blood by passing them into the digestive tract where fiber helps remove them from the body.

Fiber may also have a protective effect against mouth, throat, and esophageal cancers. And fiber may be part of the reason that vegetarian diets have been shown to result in low risk of prostate cancer. Of course, vegetarian diets are also rich in cancer-protective antioxidants.

Most Americans consume only 10 to 15 grams of fiber per day. But studies have shown that optimal intake for cancer prevention is at least 30 grams to 35 grams of fiber per day.

Studies suggest that small increases in fiber, such as adding vegetables to a chicken stir-fry or having a hamburger on a whole wheat bun, do not offer much protection. Replacing high-fat animal products such as chicken, fish, cheese, and eggs with plant foods helps boost fiber to levels where real protection is possible.

There are two types of dietary fiber—soluble and insoluble. Soluble fiber dissolves in water and is found in a variety of fruits, vegetables, legumes, and grains. It cuts cholesterol, adds to a feeling of fullness, and slows the release of sugars from food into the blood. These actions reduce your risk for health problems including heart disease, obesity, and diabetes. Good sources of soluble fiber are oats, oat bran, oatmeal, apples, citrus fruits, strawberries, dried beans, barley, rye flour, potatoes, raw cabbage, and pasta.

Insoluble fiber does not dissolve in water and is found in grain brans, fruit pulp, and vegetable peels and skins. It is the type of fiber most strongly linked to cancer protection and improved waste removal. Good sources of insoluble fiber are wheat bran, whole wheat products, cereals made from bran or shredded wheat, crunchy vegetables, barley, grains, whole wheat pasta, and rye flour.

It is best to choose fiber-rich foods over fiber supplements to get the full range of cancer-fighting phytochemicals that fruits, vegetables, legumes, and grains contain.

Adding more fiber to the diet is easy. Just follow these steps:

1. Choose products that are minimally processed, like whole wheat bread instead of white bread and brown rice instead of white rice.
   
2. Do not remove the fiber-rich peels and skins of fruits and vegetables. Just be sure to wash them thoroughly before eating.
   
3. Plan each of your meals to include whole grains, fruits, vegetables, and legumes.
   
4. To avoid intestinal discomfort when increasing fiber intake, it is best to increase gradually and drink plenty of water.
   
5. Snack on baby carrots, apples, strawberries, oranges, and other fiber-rich fruits and vegetables.
   
6. Top your breakfast cereals with dried fruits like raisins or dates, or fresh fruits like strawberries or peaches.
   
7. Sprinkle garbanzo beans or peas on your salad.
   
8. Add a handful of grated carrots to spaghetti sauce.
   

Beans present a bit of indigestion or gas for some people. Here are some ideas that will help solve this problem:

1. Start with modest servings.
   
2. Some people notice that smaller beans are easier to digest, so try black beans, black–eyed peas, and lentils, and work your way up to pinto, kidney, and fava beans.
   
3. After soaking dried beans, drain them, and then cook them in fresh water. It may also help to add a pinch of baking soda to the soaking water.
   
4. Always make sure beans are thoroughly cooked. Even some brands of canned beans need more cooking before they are thoroughly cooked.
   

By Jennifer K. Reilly, R.D.

The Cancer Project

A recent study in the Journal of Clinical Oncology reinforced existing evidence that women with breast cancer can greatly reduce their risk of recurrence by eating a healthy plant-based diet rich in fruits and vegetables and making other healthy lifestyle choices.

The study, conducted by researchers with the University of California, San Diego, tracked dietary patterns and exercise habits among about 1,500 women who were diagnosed with early-stage breast cancer between 1991 and 2000. It found that the death rate for women who consumed a high-fiber diet rich in fruits and vegetables and practiced good exercise habits was 44 percent lower than the rate for women who exercised little and ate few plant-based foods.

The Women’s Healthy Eating and Living (WHEL) study showed that women previously treated for breast cancer who consume at least five fruit and vegetable servings per day and are physically active have a nearly 50 percent reduction in mortality risk.

The WHEL study included more than 3,000 pre- and postmenopausal women. Half the participants (the intervention group) were asked to have five vegetable servings, 16 ounces of vegetable juice, and three fruit servings daily, as part of a low-fat, high-fiber diet. A comparison group was asked to consume at least five fruit and vegetable servings per day.

After seven years, those women in the comparison group who followed the guideline of eating at least five fruit and vegetable servings daily and who were physically active turned out to have nearly a 50 percent lower rate of mortality, compared with women who did not meet these healthful guidelines.

A 2005 National Cancer Institute study found that breast cancer patients in the study who reduced their fat consumption lowered their risk of tumor recurrence by as much as 42 percent. High-fat foods, including beef, vegetable oils, and chicken, can boost the hormones that promote cancer cell growth. But most plant-based foods are naturally low in fat and offer people a healthy way to stay slim.

Researchers followed 2,437 postmenopausal breast cancer patients for five years after standard surgery and cancer treatments. They instructed 1,462 of the patients to continue their regular diets, while 975 patients were given intensive counseling with a dietitian to reduce their fat intake. The control group consumed an average of 51.3 grams of fat per day, which is still lower than the average American’s fat intake. The low-fat group averaged 33.3 grams per day—slightly more than in a typical vegetarian diet. After five years, 12.4 percent of the women eating their usual diet had cancer recurrences, compared with only 9.8 percent of the low-fat diet group: that’s a 24 percent reduction in recurrence. Low-fat dieters with estrogen-negative tumors experienced a 42 percent reduction in recurrence.

In 1982, the National Research Council linked eating habits—particularly high-fat, meat-heavy diets—to cancer of the breast and other organs. The Journal of the National Cancer Institute recently reported that the rate of breast cancer among premenopausal women who ate the most animal fat was one-third higher than that of women who ate the least animal fat.

Consuming meat only increases a woman’s risk of developing breast cancer. A study of postmenopausal Danish women looked at 378 women who developed breast cancer and matched them to control subjects who did not develop breast cancer. A higher intake of meat—including poultry and fish, as well as red meat and processed meat—was associated with a significantly higher breast cancer incidence rate.

Every 25 gram increase (about one ounce) in consumption of total meat, red meat, and processed meat led to a 9, 15, and 23 percent increase in risk of breast cancer, respectively. However, the degree of risk may depend on genetics. Certain genes activate the carcinogens (heterocyclic amines) found in cooked meat. The study showed that women with genes that rapidly activate these carcinogens are at particular risk of breast cancer if they eat meat.

There are more than 2 million breast cancer survivors in the United States, but many of these women eat fewer than five servings of fruits and vegetables a day, consume too much fat, and lead sedentary lifestyles.

Simply adding healthy foods to an otherwise poor diet, rather than getting rid of the troublemakers—meat, dairy products, and fried foods—may not offer the same benefits of adopting a fully plant-based diet. But science has repeatedly shown that a plant-based diet composed of legumes, whole grains, fruits, and vegetables can help prevent cancer and cancer recurrence.

While scientists are hard at work searching for specific breast cancer-fighting compounds, the best approach is to apply what we already know: Diets that are highest in a variety of plant foods and stay away from heavy oils, meat, and dairy products help prevent many diseases. The earlier in life we start, the better.

Need help making dietary changes? Visit http://www.CancerProject.org for delicious vegetarian recipes, information on nutrition and cooking classes, fact sheets on nutrition and cancer, DVDs, videos, books, and a free copy of The Cancer Project’s booklet Healthy Eating for Life: Food Choices for Cancer Prevention and Survival.

By Jennifer K. Reilly, R.D.
The Cancer Project

Prostate cancer is the most common cancer, other than skin cancers, in American men, according to the American Cancer Society (ACS). ACS estimates that 192,280 new cases of prostate cancer will be diagnosed in the United States in 2009.

What men eat strongly influences prostate cancer risk, and consuming dairy products can contribute to an increased risk of this disease.

Men who consume low-fat and nonfat milk face an increased risk of prostate cancer, according to two studies in the American Journal of Epidemiology. One study included 82,483 men in the Multiethnic Cohort Study, 4,404 of whom developed prostate cancer over an average follow-up of eight years. Researchers found no association between prostate cancer risk and calcium and vitamin D intake, whether in the form of food or supplements. But the study did find a positive association between consuming 1 cup or more per day of low-fat or nonfat milk and developing prostate cancer.

The other study included 293,888 participants in the National Institutes of Health (NIH)-AARP Diet and Health Study. Consuming two or more daily servings of skim milk was associated with an increased risk of advanced prostate cancer.

Several previous studies—including two large Harvard studies—have shown that milk-drinking men have a significantly higher risk of prostate cancer. Researchers offer two possible reasons for the association: Milk drinking increases blood levels of insulin-like growth factor, which is associated with cancer risk. It also decreases activation of vitamin D precursors. Vitamin D helps protect the prostate against cancer.

Men who have prostate cancer can increase their chances of survival by following a low-fat vegan diet. By increasing consumption of cancer-fighting vegetarian foods and avoiding foods that feed tumor growth, such as dairy products and meat, men may significantly increase chances of living longer after prostate cancer diagnosis, according to a review in Nutrition Reviews in 2007.

Researchers found that low-fiber diets raise circulating testosterone, estradiol, and insulin levels, which in turn may fuel prostate cancer cell growth. Among men with the highest intake of saturated fat, the risk of dying from prostate cancer is three times higher than among men with the lowest intake.

Men with prostate cancer who follow a low-fat vegetarian diet benefit from increased quality of life and slowed PSA doubling time, according to a study in Urology. PSA doubling time is the amount of time it takes for levels of prostate-specific antigen, a biological marker for prostate cancer, to increase by 100 percent.

The study, led by Dean Ornish, M.D., focused on 36 men who had been diagnosed with prostate cancer, had undergone primary treatment for more than six months, and had continuous increases in PSA levels. The men were assigned to attend vegetarian nutrition and cooking classes or to a control group. Those in the vegetarian intervention group consumed significantly less saturated fat, more vegetable protein, and less animal protein, including fewer dairy products. The mean PSA doubling time at the three-month follow-up was substantially longer for the intervention group compared with that of the control group, meaning that the diet slowed cancer growth.

Men who want to avoid prostate cancer should follow a low-fat vegetarian diet. Which foods should men focus on? Building a balanced diet from whole grains, beans, fruits, and vegetables is the best way to go. But a few foods stand out as powerful fighters in the battle against prostate cancer.

Black, pinto, small red, and kidney beans are high in fiber, which helps the body rid itself of excess testosterone, and are among the 20 most antioxidant-rich foods. Beans are also rich in inositol pentakisphosphate, a known cancer-fighter.

Tomatoes and other lycopene-rich foods, such as watermelon and pink grapefruit, are associated with a reduced risk of prostate and other cancers. Studies from the Harvard School of Public Health have shown that men who frequently consume lycopene-rich foods cut their prostate cancer risk by one-third.

Broccoli and other cruciferous vegetables, including kale and cauliflower, are rich in sulforaphane, a cancer-fighting phytochemical that helps rid the body of excess testosterone and reduces the risk of prostate and other cancers.

Soy, nut, and rice milks are a healthy alternative to cow’s milk, which is known to increase the risk of prostate cancer. According to two major Harvard studies, men who avoided dairy products cut their prostate cancer risk by as much as 25 to 40 percent. Soy foods are also associated with a lower risk of cancer. Excellent plant sources of calcium are broccoli, brussels sprouts, kale, mustard greens, and fortified products such as orange juice and soymilk, and these foods will also provide your body with important cancer-fighting nutrients.

Need more information on prostate cancer and or making the transition to a vegetarian diet? Visit http://www.CancerProject.org for delicious recipes, information on nutrition and cooking classes, fact sheets on nutrition and cancer, DVDs, videos, books, and a free copy of The Cancer Project’s booklet Healthy Eating for Life: Food Choices for Cancer Prevention and Survival.

By Jennifer K. Reilly, R.D.
The Cancer Project

Researchers have known for years that meat-eaters have higher cancer rates, compared with people who avoid meat. But now we also know that grilled meats pose a unique threat. Cancer-causing chemicals called heterocyclic amines (HCAs) have been found in chicken and other meats, and the very highest concentrations occur when these products are grilled.

Grilling meat, especially chicken, produces carcinogenic HCAs, which are formed from the creatinine, amino acids, and sugar found in muscle tissue. More HCAs are produced by long cooking times and hot temperatures, which make grilling, pan frying, and oven broiling particularly dangerous cooking methods.

The federal government added HCAs to its list of carcinogens in January 2005. But most Americans remain unaware that these compounds lurk in cooked meat. As known mutagens, HCAs can bind directly to DNA and cause mutations, the first step in the development of cancer.

Grilling is also problematic because when fat from meat drips onto an open flame, carcinogens called polycyclic aromatic hydrocarbons (PAHs) form and are deposited back onto the meat through smoke.

Scientists have discovered more than 16 different HCAs. One type commonly found in grilled meats is PhIP, which has been on Californiaâ€s list of cancer-causing chemicals for more than a decade. Scientists have not determined a safe consumption level of PhIP, meaning that any amount is believed to potentially increase cancer risk.

Recent studies have shown that the consumption of well-done meat, which contains PhIP and other HCAs, is associated with an increased risk for colon, rectal, esophageal, lung, larynx, pancreatic, prostate, stomach, and breast cancer, and non-Hodgkinâ€s lymphoma.

In a recent review of 30 epidemiologic studies on the link between eating well-done meat and cancer at various sites, 80 percent of the studies showed a positive correlation. HCAs have also been specifically linked to colorectal cancer: One review found that high cooking temperature increased colon cancer risk almost twofold and increased risk for rectal cancer by 60 percent.

Meat cooked at high temperatures may also increase the risk of pancreatic cancer, according to a study presented at the American Association for Cancer Research annual meeting. In this nine-year study, researchers analyzed information on meat consumption and preferred cooking methods for 62,581 participants. Participants who cooked meat at high temperatures and consumed more well-done meat had about a 60 percent higher risk of pancreatic cancer, compared with other people.

Many people switch to chicken and fish, believing these to be healthier alternatives to beef. But that is not the case. Grilled chicken produces more than 10 times the amount of the carcinogenic HCAs found in grilled beef. Furthermore, nearly all the HCAs detected are in the form of PhIP, which has specifically been implicated in breast cancer risk. Fish also contains significant amounts of creatine, one of the other main ingredients for the formation of the carcinogens.

HCAs are not the only cancer risk that comes from eating meat. Countries with a higher fat intake, especially fat from animal products, have a higher incidence of breast cancer. One hypothesized reason is that low-fiber, high-fat foods increase the amount of estrogen in the bloodstream, which encourages breast cancer cell growth. A similar phenomenon can occur when men eat high-fat fare, leading to a higher risk of prostate cancer.

The consumption of meat and other fatty foods is strongly linked to colon cancer. Recent studies have shown that red meat—even red meat cooked at a low temperature—can increase colon cancer risk by as much as 300 percent.

These facts seem to pose a dilemma for meat-eating consumers. Cook chicken or beef too little, and you could easily end up with a bacterial infection. Turn up the heat enough to kill the bacteria, and you may create cancer-causing compounds.

There is a healthy—and delicious—alternative. Instead of meat products, try grilling up a homemade veggie burger or vegetable-and-tofu kebobs.

Since creatine, one of the ingredients for the formation of HCAs, is mostly found in muscle tissue, it is not surprising that grilled veggie burgers and other vegetarian foods contain either no HCAs or negligible levels.

Choosing plant-based foods instead of meat also lowers cancer risk in other ways. Not only are vegetables low in fat and high in fiber, they also contain many cancer-fighting substances. Carotenoids, the pigment that gives fruits and vegetables their dark colors, have been shown to help prevent cancer. Beta-carotene, present in dark green and yellow vegetables, helps protect against lung cancer and may help prevent cancers of the bladder, mouth, larynx, esophagus, breast, and other sites. Many studies have found that diets rich in fruits and vegetables and low in animal fat cut cancer risks.

Want to grill up something healthy? Visit www.CancerProject.org for delicious vegetarian recipes, information on nutrition and cooking classes, fact sheets on nutrition and cancer, DVDs, videos, books, and a free copy of The Cancer Projectâ€s booklet Healthy Eating for Life: Food Choices for Cancer Prevention and Survival.

By Jennifer K. Reilly, R.D.

The Cancer Project

Fruits and vegetables contain a variety of vitamins, minerals, antioxidants, and phytochemicals that protect the body. Building a plant-based (or vegan) diet from fruits, vegetables, beans, and whole grains can help prevent some cancers and improve the survival rates of people who have cancer.

Eighty percent of cancers are due to factors that have been identified and can potentially be controlled, according to the National Cancer Institute, and at least one-third of annual cancer deaths in the United States are due to dietary factors, according to the American Cancer Society. Much of our risk for colon, breast, and prostate cancer, among other types, is nutrition-related.

While vegan diets can help fight cancer and other diseases, consuming animal products—meat, eggs, dairy products—and other fatty foods can contribute to cancer risk.

Numerous research studies have since shown that cancer is much more common in populations consuming diets rich in fatty foods, particularly meat, and much less common in countries with diets rich in grains, vegetables, and fruits. The reason? Food affects the action of hormones in the body and the strength of the immune system.

Plant-based diets can be helpful in preventing cancer and cancer recurrence because they are generally low in fat and high in fiber. Fat has many effects within the body. It increases hormone production (and may raise breast cancer risks) and it stimulates the production of bile acids which have been linked to colon cancer.

The average diet in the United States is about 37 percent fat from calories. The National Cancer Institute suggests that people lower that number to 30 percent; however, studies have shown that fat intake should be well below 30 percent to have an anti-cancer affect. Ten percent or less is the most effective.

Fiber is essential for preventing disease and staying healthy. Animal products contain no fiber, but diets based on fiber-rich, plant-based foods provide plenty of this important nutrient. Fiber helps move food more quickly through the intestines, helping to eliminate carcinogens and potentially harmful hormones.

In the United States, the average daily fiber intake is 10 to 20 grams per day. Experts recommend 30 to 40 grams per day for cancer prevention and survival. The best sources of fiber are whole grains, beans, peas, lentils, vegetables, and fruits. Foods that are closest to their natural state, unrefined and unpeeled, are highest in fiber.

The United States and other Western nations whose diets are based upon animal products have the highest rates of colon cancer.

Eating a variety of vegetables is important because vegetables contain so many cancer-fighting substances. Carotenoids, the pigment that gives fruits and vegetables their dark colors, have been shown to help prevent cancer. Beta-carotene, present in dark green and yellow vegetables, helps protect against lung cancer and may help prevent cancers of the bladder, mouth, larynx, esophagus, breast, and other sites.

Vegetables such as cabbage, broccoli, kale, turnips, cauliflower, and Brussels sprouts contain flavones and indoles, which are thought to have anti-cancer effects. Vitamin C, found in citrus fruits and many vegetables, may lower risks for cancers of the esophagus and stomach.

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.

By Jennifer K. Reilly, R.D.
The Cancer Project

Need help getting started? Visit www.CancerProject.org for delicious vegetarian recipes, information on nutrition and cooking classes, fact sheets on nutrition and cancer, DVDs, videos, books, and a free copy of The Cancer Project’s booklet Healthy Eating for Life: Food Choices for Cancer Prevention and Survival.