Benefits of a High Fiber Diet

Diets low in saturated fat and cholesterol and high infiber binds to dietary cholesterol, helping the body to
fiber are associated with a reduced risk of certaineliminate it. This reduces blood cholesterol levels, which,
cancers, diabetes, digestive disorders, and heartin turn, reduces cholesterol deposits on arterial walls
disease.that eventually choke off the vessel. There also is
Diets low in fat and rich in fiber-containing grainsome evidence that soluble fiber can slow the liver's
products, fruits, and vegetables may reduce the risk ofmanufacture of cholesterol, as well as alter low-density
some types of cancer.lipoprotein (LDL) particles to make them larger and less
Diets low in saturated fat and cholesterol and rich indense. Researchers believe that small, dense LDL
fruits, vegetables, and grain products that contain fiber,particles pose a bigger health threat.
particularly soluble fiber, may reduce the risk ofRecent findings from two long-term large-scale studies
coronary heart disease.of men suggest that high fiber intake can significantly
Diets low in fat and rich in fruits and vegetables, whichlower the risk of heart attack. Men who ate the most
are low-fat foods and may contain fiber or vitamin Afiber-rich foods (35 grams a day, on average)
(as beta-carotene) and vitamin C, may reduce the risksuffered one-third fewer heart attacks than those
of some cancers.who had the lowest fiber intake (15 grams a day),
Found only in plant foods, such as whole grains, fruits,according to a Finnish study of 21,903 male smokers
vegetables, beans, nuts, and seeds, fiber is composedaged 50 to 69, published in the December 1996 issue
of complex carbohydrates. Some fibers are soluble inof Circulation. Earlier in the year, findings from an
water and others are insoluble. Most plant foodsongoing U.S. study of 43,757 male health professionals
contain some of each kind.(some of whom were sedentary, overweight or
Some foods containing high levels of soluble fiber aresmokers) suggest that those who ate more than 25
dried beans, oats, barley, and some fruits, notablygrams of fiber per day had a 36 percent lower risk of
apples and citrus, and vegetables, such as potatoes.developing heart disease than those who consumed
Foods high in insoluble fiber are wheat bran, wholeless than 15 grams daily. In the Finnish study, each 10
grains, cereals, seeds, and the skins of many fruits andgrams of fiber added to the diet decreased the risk of
vegetables.dying from heart disease by 17 percent; in the U.S.
Fiber's Health Benefitsstudy, risk was decreased by 29 percent.
What can fiber do for you? Numerous epidemiologicThese results indicate that high-fiber diets may help
(population-based) studies have found that diets low inblunt the effects of smoking and other risk factors for
saturated fat and cholesterol and high in fiber areheart disease.
associated with a reduced risk of certain cancers,Obesity: Because insoluble fiber is indigestible and
diabetes, digestive disorders, and heart disease.passes through the body virtually intact, it provides few
However, since high-fiber foods may also containcalories. And since the digestive tract can handle only
antioxidant vitamins, phytochemicals, and otherso much bulk at a time, fiber-rich foods are more filling
substances that may offer protection against thesethan other foods--so people tend to eat less. Insoluble
diseases, researchers can't say for certain that fiberfiber also may hamper the absorption of calorie-dense
alone is responsible for the reduced health risks theydietary fat. So, reaching for an apple instead of a bag
observe, notes Joyce Saltsman, a nutritionist withof chips is a smart choice for someone trying to lose
FDA's Office of Food Labeling. "Moreover, no oneweight.
knows whether one specific type of fiber is moreBut be leery of using fiber supplements for weight loss.
beneficial than another since fiber-rich foods tend toIn August 1991, FDA banned methylcellulose, along with
contain various types," she adds.110 other ingredients, in over-the-counter diet aids
Recent findings on the health effects of fiber show itbecause there was no evidence these ingredients
may play a role in:were safe and effective. The agency also recalled
Cancer: Epidemiologic studies have consistently notedone product that contained guar gum after receiving
an association between low total fat and high fiberreports of gastric or esophageal obstructions. The
intakes and reduced incidence of colon cancer. A 1992manufacturer had claimed the product promoted a
study by researchers at Harvard Medical School foundfeeling of fullness when it expanded in the stomach.
that men who consumed 12 grams of fiber a dayRecent research suggests that as much as 35 grams
were twice as likely to develop precancerous colonof fiber a day is needed to help reduce the risk of
changes as men whose daily fiber intake was aboutchronic disease, including heart disease. A fiber
30 grams. The exact mechanism for reducing the risksupplement can help make up the shortfall, but should
is not known, but scientists theorize that insoluble fibernot be a substitute for fiber-rich foods. "Foods that are
adds bulk to stool, which in turn dilutes carcinogens andhigh in fiber also contain nutrients that may help reduce
speeds their transit through the lower intestines andthe risk of chronic disease," Saltsman notes. In addition,
out of the body.eating a variety of such foods provides several types
The evidence that a high-fiber diet can protect againstof fiber, whereas some fiber supplements contain only
breast cancer is equivocal. Researchers analyzinga single type of fiber, such as methylcellulose or
data from the Nurses' Health Study, which trackedpsyllium.
89,494 women for eight years, concluded in 1992 thatTo fit more fiber into your day:
fiber intake has no influence on breast cancer risk inRead food labels. The labels of almost all foods will tell
middle-aged women. Previously, a review and analysisyou the amount of dietary fiber in each serving, as well
of 12 studies found a link between high fiber intake andas the Percent Daily Value (DV) based on a
reduced risk.2,000-calorie diet. For instance, if a half cup serving of
In the early stages, some breast tumors are stimulateda food provides 10 grams of dietary fiber, one serving
by excess amounts of estrogen circulating in theprovides 40 percent of the recommended DV. The
bloodstream. Some scientists believe that fiber mayfood label can state that a product is "a good source"
hamper the growth of such tumors by binding withof fiber if it contributes 10 percent of the DV--2.5
estrogen in the intestine. This prevents the excessgrams of fiber per serving. The package can claim
estrogen from being reabsorbed into the bloodstream."high in," "rich in" or "excellent source of" fiber if the
Digestive disorders: Because insoluble fiber aidsproduct provides 20 percent of the DV--5 grams per
digestion and adds bulk to stool, it hastens passage ofserving.
fecal material through the gut, thus helping to preventUse the U.S. Department of Agriculture's food pyramid
or alleviate constipation. Fiber also may help reduce theas a guide. If you eat 2 to 4 servings of fruit, 3 to 5
risk of diverticulosis, a condition in which small pouchesservings of vegetables, and 6 to 11 servings of cereal
form in the colon wall (usually from the pressure ofand grain foods, as recommended by the pyramid, you
straining during bowel movements). People whoshould have no trouble getting 25 to 30 grams of fiber
already have diverticulosis often find that increaseda day.
fiber consumption can alleviate symptoms, whichStart the day with a whole-grain cereal that contains
include constipation and/or diarrhea, abdominal pain,at least 5 grams of fiber per serving. Top with wheat
flatulence, and mucus or blood in the stool.germ, raisins, bananas, or berries, all of which are good
Diabetes: As with cholesterol, soluble fiber trapssources of fiber.
carbohydrates to slow their digestion and absorption. InWhen appropriate, eat vegetables raw. Cooking
theory, this may help prevent wide swings in bloodvegetables may reduce fiber content by breaking
sugar level throughout the day. Additionally, a newdown some fiber into its carbohydrate components.
study from the Harvard School of Public Health,When you do cook vegetables, microwave or steam
published in the Feb. 12 issue of the Journal of theonly until they are al dente--tender, but still firm to the
American Medical Association, suggests that abite.
high-sugar, low-fiber diet more than doubles women'sAvoid peeling fruits and vegetables; eating the skin and
risk of Type II (non-insulin-dependent) diabetes. In themembranes ensures that you get every bit of fiber.
study, cereal fiber was associated with a 28 percentBut rinse with warm water to remove surface dirt and
decreased risk, with fiber from fruits and vegetablesbacteria before eating. Also, keep in mind that whole
having no effect. In comparison, cola beverages, whitefruits and vegetables contain more fiber than juice,
bread, white rice, and french fries increased the risk.which lacks the skin and membranes.
High-fiber diets may help blunt the effects of smokingEat liberal amounts of foods that contain unprocessed
and other risk factors for heart disease.grains in your diet: whole-wheat products such as
Heart Disease: Clinical studies show that abulgur, couscous or kasha and whole-grain breads,
heart-healthy diet (low in saturated fat and cholesterol,cereals and pasta.
and high in fruits, vegetables and grain products thatAdd beans to soups, stews and salads; a couple of
contain soluble fiber) can lower blood cholesterol. Intimes a week, substitute legume-based dishes (such
these studies, cholesterol levels dropped between 0.5as lentil soup, bean burritos, or rice and beans) for
percent and 2 percent for every gram of soluble fiberthose made with meat.
eaten per day.Keep fresh and dried fruit on hand for snacks.
As it passes through the gastrointestinal tract, soluble