Americans forgo fiber at their own risk

Trendy diets skip the carbs, a big source of fiber we need

Health & Fitness

December 28, 2003|By Mary Beth Regan | Mary Beth Regan,Special to the Sun

As you enjoy these last days of splurging on sugar cookies and eggnog, perhaps you've given a passing thought to improving your eating habits in the new year.

If so, consider advice from the nation's nutrition experts to put more bulk into your body. Fiber, it seems, is one of the most lacking ingredients in the typical American diet. As a result, popular low-fiber diets are contributing to health ailments including obesity, intestinal disorders, heart disease and diabetes.

"The bottom line is, Americans aren't eating nearly enough fiber," says Jon A. Story, a Purdue University nutrition professor who worked on the first dietary guidelines for fiber intake, released last year.

Counter to trendy advice based on low-carbohydrate diets such as the Atkins and South Beach diets, fiber, which is found in carbohydrates, can improve chances of losing weight as well as help prevent serious health problems such as heart disease, diabetes and possibly colorectal cancer.

A study reported in the November American Journal of Clinical Nutrition found that middle-aged women who ate a high-fiber diet cut nearly in half chances of gaining weight over a 12-year period. A second study -- both were conducted at Harvard School of Public Health -- confirmed earlier research that high-fiber diets also help to lower risks of serious ailments including coronary heart disease and Type 2 diabetes.

These studies come on the heels of the National Academies' Institute of Medicine decision in September 2002 to issue the first-ever daily intake requirements for fiber and other nutrients.

Earlier this month, the organization, which makes dietary recommendations to the government, called on federal policymakers to use these daily requirements to update food and supplement labels nationwide. Today's food labels are based on 1968 guidelines, considered by many to be woefully out of date.

Scientists know much more today about how diet affects health. Since the early 1900s, Americans have been eating more and more processed foods. As a result, they are eating less fiber. Many people, for example, eat breads, muffins and baked goods made from refined, low-fiber flour, losing the benefit of bulk such as wheat bran.

On average, Americans today eat between 13 grams and 15 grams of fiber daily from fruits, vegetables, whole grains and other sources. According to the new dietary guidelines, women and men under the age of 50 should have a daily intake of 25 grams and 38 grams of fiber, respectively. For women and men older than 50, the numbers fall to 21 grams and 30 grams, respectively. Children between age 4 and 13 should eat 25 grams daily, with boys ramping up to 31 grams by adolescence.

"That's a lot more fiber than most people are eating," says Cynthia Finley, dietician at the Johns Hopkins Weight Management Center in Greenspring Station. "I rarely have anyone come in here who is eating the recommended nine fruits and vegetables daily."

There is a wealth of research that points to the dangers of this low-fiber trend:

* Colon health: For women and men, colon and rectal cancers are leading cancer killers, behind lung, prostate and breast cancer. Research has not yet conclusively linked a lack of fiber to greater incidence of colon cancer, but scientists know high-fiber foods help fight cancer.

Fiber also keeps your intestines and colon healthy. Cereal grains, for example, act as laxatives to help move potentially dangerous cancer-causing substances through the colon quickly, reducing the time that potential carcinogens remain in the body.

High-fiber diets also aid people suffering from colon disorders and irritable bowel syndrome. Health care experts estimate that half of Americans between age 60 and 80 will develop diverticulosis, which are small pouches in the colon. When food collects in them, the pouches can become infected, leading to diverticulitis, a serious condition that can require surgery. A high-fiber diet can help these conditions.

* Heart health: Scientists say fibers found in cereals, oats and beans, as well as pectin in citrus peels, jellies and jams, help lower cholesterol levels in the blood. While the precise mechanism is not understood, it is suspected that these fibers disrupt the circulation of bile acids, which lowers cholesterol.

* Blood health: Fiber also plays a significant role in regulating the amount of glucose absorbed by the body. That's why high-fiber diets are important for people suffering from Type 2 diabetes, a less severe form of the disease than Type 1 diabetes because the body still is able to produce insulin.

Research shows that fiber slows the rate of absorption of glucose into the bloodstream, helping to keep blood-sugar levels steady. It's those high-blood-sugar levels that lead to health problems such as kidney damage, nerve damage and other ailments.

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