High dietary fiber intake helps prevent constipation, diverticular disease, hemorrhoids, irritable bowel syndrome, and perhaps colon polyps.
Soluble fiber helps control blood sugar levels in people with diabetes, and it reduces LDL cholesterol levels, thereby reducing risks of coronary heart disease.
An article in the journal Nutrition suggests how fiber may have beneficial effects in atherosclerosis (the cause of heart attacks and strokes), type 2 diabetes, and some cancers. These conditions are felt to be related to underlying systemic inflammation.
Systemic inflammation can be judged by blood levels of inflammatory markers such as interleukin-6, tumor necrosis factor-alpha-receptor-2, and high-sensitivity C-reactive protein.
Researchers looked at 1,958 postmenopausal women in the Women’s Health Initiative Observational Study, comparing inflammatory marker levels with dietary fiber intake. They found that high fiber intake was associated with significantly lower levels of inflammatory markers interleukin-6 and tumor necrosis factor-alpha-receptor-2. This association was true individually for total fiber, insoluble fiber, and soluble fiber. The researchers found no association with C reactive protein.
High intake of dietary fiber seems to reduce chronic inflammation, which may, in part, explain the observed clinical benefits of fiber.
Average adult fiber intake in the U.S. is 12 to 15 grams daily. Expert nutrition panels and the American Heart Association recommend 25 to 30 grams daily from whole grains, fruits, and vegetables.
Nutritionist Monica Reinagel at NutritionData.com has reviewed soluble vs insoluble fiber and good sources of soluble fiber: oranges, apples, carrots, oats and oat bran, psyllium husk, nuts, legumes, and flaxseed. Click the link for good sources of insoluble fiber.
Rest assured that the Mediterranean diet is naturally high in fiber.
Reference: Ma, Yensheng, et al. Association between dietary fiber and markers of systemic inflammation in the Women’s Health Initiative Observational Study. Nutrition, 24 (2008): 941-949.