Rich Fiber Diets
More evidence suggests a diet rich in fiber sources reduces risk of colorectal cancer, the third most common cancer worldwide with 1.2 million new cases diagnosed each year. It has been well established that a higher intake of fiber-rich foods like fruits, vegetables, and whole grains is associated with a reduced risk of cardiovascular disease but the relationship with cancer was not clearly supported. It has been presumed for nearly four decades that dietary fiber played a role in reducing the risk of colorectal cancer but studies attempting to demonstrate the relationship have not been consistent.
UK and Dutch researchers investigated the association between intake of dietary fiber and whole grains and risk of colorectal cancer as part of the World Cancer Research Fund/American Institute for Cancer Research’s Continuous Update Project (CUP).The recent findings were published in the British Journal of Medicine (2011). Based on the findings, researchers suggest that fiber is an essential component to human health and believe the new evidence provides further support for public health recommendations to increase fiber intake. Although the overall reductions in risk of colorectal cancer were small, researchers suggest that fiber from cereal and whole grains are relevant in the prevention of colorectal cancer. According to the study, there was a clear gradient in risk associated with the amount of dietary fiber consumed; compared with the lowest levels of total dietary fiber intake, each 10 g/day increase in intake was associated with a 10% reduction in risk of colorectal cancer. Adding three servings (90 g/day) of whole grains was associated with about a 20% reduction in risk. Common whole-grain foods include high-fiber breads and cereals, oatmeal, and brown rice. Most agree that the fiber should come from its natural-occurring source instead of fortified products which have gained recent popularity.
According to investigators, increasing intake of dietary fiber and whole grains is also linked with a reduction in the risk of cardiovascular disease, type 2 diabetes, overweight and obesity, and possibly overall mortality suggesting there are several health benefits by increasing fiber intake and replacing refined grains with whole grains. However, the authors still believe that further research is needed to explain the biological mechanisms responsible for the beneficial effects of these foods in detail and to study barriers to increasing the intake of whole grain products in World diets.
Good sources of fiber include:
Fruits | Serving size | Total fiber (grams)* |
Raspberries | 1 cup | 8.0 |
Pear, with skin | 1 medium | 5.5 |
Apple, with skin | 1 medium | 4.4 |
Strawberries (halves) | 1 1/4 cup | 3.8 |
Banana | 1 medium | 3.1 |
Orange | 1 medium | 3.1 |
Figs, dried | 2 medium | 1.6 |
Raisins | 2 tablespoons | 1.0 |
Grains, cereal & pasta | Serving size | Total fiber (grams)* |
Spaghetti, whole-wheat, cooked | 1 cup | 6.2 |
Barley, pearled, cooked | 1 cup | 6.0 |
Bran flakes | 3/4 cup | 5.3 |
Oat bran muffin | 1 medium | 5.2 |
Oatmeal, quick, regular or instant, cooked | 1 cup | 4.0 |
Popcorn, air-popped | 3 cups | 3.5 |
Brown rice, cooked | 1 cup | 3.5 |
Bread, rye | 1 slice | 1.9 |
Bread, whole-wheat or multigrain | 1 slice | 1.9 |
Legumes, nuts & seeds | Serving size | Total fiber (grams)* |
Split peas, cooked | 1 cup | 16.3 |
Lentils, cooked | 1 cup | 15.6 |
Black beans, cooked | 1 cup | 15.0 |
Lima beans, cooked | 1 cup | 13.2 |
Baked beans, vegetarian, canned, cooked | 1 cup | 10.4 |
Sunflower seed kernels | 1/4 cup | 3.9 |
Almonds | 1 ounce (23 nuts) | 3.5 |
Pistachio nuts | 1 ounce (49 nuts) | 2.9 |
Pecans | 1 ounce (19 halves) | 2.7 |
Vegetables | Serving size | Total fiber (grams)* |
Artichoke, cooked | 1 medium | 10.3 |
Peas, cooked | 1 cup | 8.8 |
Broccoli, boiled | 1 cup | 5.1 |
Turnip greens, boiled | 1 cup | 5.0 |
Sweet corn, cooked | 1 cup | 4.2 |
Brussels sprouts, cooked | 1 cup | 4.1 |
Potato, with skin, baked | 1 medium | 2.9 |
Tomato paste | 1/4 cup | 2.7 |
Carrot, raw | 1 medium | 1.7 |
Source MayoClinic
*Fiber content can vary between brands.