Prostate Cancer Patients Benefit from Adding Fiber to their Diet
As with many types of cancer, the risk of developing prostate cancer in men has a dietary component. A low-fat, vegetarian diet has been described as one of the ways to lower the risk. New research adds that a high-fiber diet may stop cancer from progressing in men who already are diagnosed with early stages of the disease.
Prostate cancer is the most common cancer among men after skin cancer. About 241,740 new cases are diagnosed each year. A new report on the status of cancer indicates that prostate cancer is one of those that are currently on the decline in the US, likely due to successful early treatment and improved awareness of prevention habits. More than 2 million men in the US are prostate cancer survivors.
Kormal Raina, a research instructor at the Skaggs School of Pharmaceutical Sciences, conducted the study on a set of mice that were fed with inositol hexaphosphate (IP6) which is part of a high fiber diet, especially in foods such as beans, brown rice, corn, sesame seeds, and wheat bran. Past animal research has found that IP6 may be effective in lowering tumor incidence and slowing tumor growth.
Researchers used MRI to check the progress of cancer in the mice. Per Raina, “We saw dramatically reduced tumor volumes, primarily due to the anti-angiogenic effects of IP6.” It is suggested that the nutrient prevents cancer cells from making new blood vessels that they require to stay alive. IP6 may also work by reducing the rate which glucose is metabolized in the cancer cells, possibly due to a reduction in the protein called GLUT-4 which is vital for transporting glucose.
"Researchers have long been looking for genetic variations between Asian and Western peoples that could explain the difference in prostate cancer progression rates, but now it seems as if the difference may not be genetic but dietary. Asian cultures get IP6 whereas Western cultures generally do not," Raina says.
Inositol hexaphosphate is sold as a dietary supplement in the US, but experts warn against using these instead of making dietary changes using real food. The American Cancer Society also warns men with prostate cancer not to use a dietary supplement in place of proven medical care.
The Institute of Medicine recommends that children and adults consume 14 grams of fiber for every 1,000 calories of food they eat each day. For men up to age 50, this equals about 38 grams per day. After 50, the recommendation drops to 30 grams per day (due to fewer calories consumed).
However, the average American only eats between 10 and 15 grams per day. The University of California San Francisco offers these easy tips for increasing the amount of fiber you eat each day:
Grains and Cereals
• As a general rule, include at least one serving of whole grain in every meal.
• Keep a jar of oat bran or wheat germ handy. Sprinkle over salad, soup, breakfast cereals and yogurt.
• Use whole-wheat flour when possible in your cooking and baking.
• Choose whole grain bread. Look on the label for breads with the highest amount of fiber per slice.
• Choose cereals with at least 5 grams of fiber per serving.
• Keep whole-wheat crackers on hand for an easy snack.
• Cook with brown rice instead of white rice. If the switch is hard to make, start by mixing them together.
Legumes and Beans
• Add kidney beans, garbanzos or other bean varieties to your salads. Each 1/2 cup serving is approximately 7 to 8 grams of fiber.
• Substitute legumes for meat two to three times per week in chili and soups
• Experiment with international dishes (such as Indian or Middle Eastern) that use whole grains and legumes as part of the main meal or in salads.
Fruits and Vegetables
• Eat at least five servings of fruits and vegetables each day. Fresh fruit is higher in fiber than canned. Fruits and vegetables with the highest fiber content include apples (when eating the peels), orange, tangerine, pear, blueberries, strawberries, peas, cauliflower, carrots, sweet potato, squash.
• Have fresh fruit for dessert.
• Eat whole fruits instead of drinking juices. Juices don't have fiber.
• Add chopped dried fruits to your cookies, muffins, pancakes or breads before baking. Dried fruits have a higher amount of fiber than the fresh versions. For example, 1 cup of grapes has 1 gram of fiber, but 1 cup of raisins has 7 grams. However, 1 cup of raisins or any other dried fruit has more calories than the fresh fruit variety.
• Add sliced banana, peach or other fruit to your cereal.
• Grate carrots on salads.
Cancer Prevention Research January 2013
The Annual Report to the Nation on the Status of Cancer, 1975–2009 - American Cancer Society (ACS), the Centers for Disease Control and Prevention (CDC), the National Cancer Institute (NCI), and the North American Association of Central Cancer Registries (NAACCR). Journal of the National Cancer Institute issue 3, volume 105.
University of California San Francisco – Increasing Fiber Intake