Heart Health, Diet & Nutrition | Health Blog

More Fiber Benefits


We have all heard the health benefits of fiber extolled for years now.  Aside from the well-known ways whole foods can help your body, such as lowering the risk of cardiovascular disease, promoting better digestion, and maintaining a fit weight, they have now been shown to reduce the likelihood of dying prematurely from a whole assortment of ailments.

A study that took place at the National Cancer Institute in Rockville, Maryland, found that eating a diet rich in fiber was not only linked to a lower risk of mortality from heart disease or a heart attack, but from respiratory and infectious diseases as well.1  Curiously, the researchers found a connection between higher fiber intake and a lower risk of death from cancer that only seemed to hold true for men, not women.

The participants were 388,000 AARP members who were between 50 and 71 years old in 1995 or 1996 when they filled out questionnaires about their typical eating habits.  Over the nine-year course of the research, 31,000 of the subjects passed away.  But the volunteers whose diets were highest in fiber were 22 percent less likely to die from any illness during the study than their counterparts who reported the lowest fiber intake.

The male participants consuming lots of fiber generally ate approximately 30 grams per day and the female participants ate approximately 25 grams per day.  On the other end of the spectrum were those in the lowest consumption group, in which the men typically ate approximately 13 grams of fiber daily and the women ate 11 grams.  According to the American Dietetic Association, the recommended intake of fiber should be between 20 and 35 grams daily.  The average American only eats about 14 or 15 grams a day — very close numbers to those eating the lowest amount of fiber, and paying the price for it with their health, according to the study.

Those subjects who ate the most fiber were approximately 24 percent less likely to die from heart disease, 31 percent less likely to die from respiratory diseases such as pneumonia or bronchitis, and 56 percent less likely to die from infectious diseases than the low-fiber eaters.  The men in the high-fiber group also had a 17 percent lower risk of dying from cancer.

The lack of a finding associating fiber with a lower risk for women of dying from cancer is very curious, as there has been much research that proves the contrary.  Numerous studies have shown fiber to be beneficial in cancer prevention for both genders and for several types of cancer.  In fact, a 2005 study that tracked more than 61,000 Swedish women for 15 years found that those who consumed more than 4.5 servings of whole grain foods daily had a 35 percent lower risk of colon cancer than those who consumed less than 1.5 servings of whole grains daily.

The fiber in whole grains has also been shown in previous studies to protect us from diabetes.  Research published back in 2002 that followed 43,000 male health professionals found that those who consumed the most whole grains were 42 percent less likely to develop diabetes.  And those results were repeated similarly in a number of studies that followed.

But be careful before you jump onto the “whole grain” bandwagon. Not all grains are created equal. They vary wildly in their composition and in their effects on the human body. These differences range from the very basic such as:

  • What type of fiber they contain: insoluble, or water-soluble?
  • How they affect body pH?
  • How are they cooked? Are they alive or dead?
  • Do they contain phytates that block the absorption of minerals?
  • How quickly are they broken down? Are they long chain, or ultra-long chain? Do they stimulate a high-glycemic response or not?
  • How allergenic are they?

To the more complex, such as:

  • What beneficial phytochemicals are present in the grains?
  • How are the grains grown (GMO VS non-GMO)?
  • Organic versus non-organic?

And yes, whole grains are a good source of fiber and provide essential vitamins and minerals.  They also contain antioxidants that inhibit oxidation of cells, cell walls, and even DNA.  And lignans, which are naturally occurring compounds in whole grains, may provide protection against several types of cancer including breast, uterine, and prostate cancer. But all that said, remember that grains are not the only source of fiber. Whole fruits and vegetables (not juices) contain fiber too — not to mention even more antioxidants than grains.

In the end, the trick is to think balance when it comes to diet. Make sure your diet contains 30-35 grams of fiber a day — and make sure that fiber comes from multiple sources, both grain and vegetable.


1 Park, Yikyung; Subar, Amy F.; Hollenbeck, Albert; Schatzkin, Arthur. “Dietary Fiber Intake and Mortality in the NIH-AARP Diet and Health Study.” Archives of Internal Medicine. 14 February 2011.  American Medical Association. 13 April 2011. <http://archinte.ama-assn.org/cgi/content/abstract/archinternmed.2011.18v1?maxtoshow=&hits=10&RESULTFORMAT=&fulltext=yikung+park&searchid=1&FIRSTINDEX=10&sortspec=date&resourcetype=HWCIT>.