Eating fiber may be one of the easiest and least expensive ways to
practice preventive health care.
These days, people seem to be concerned with what kind of and how
many carbohydrates, proteins, and fats they ingest. The reason is simple—carbohydrates,
proteins, and fats attribute to how we look on the outside.
But as most health-conscious people know, what’s going on in the
inside matters more.
And what’s going on in the inside—from our digestive health to measures
of whole body health—can often be equated to the amount of fiber in
Fiber is the elongated, threadlike structures in fruits, vegetables,
and grains that cannot be digested. It has long been recognized as one
of the best food ingredients for maintaining bowel regularity and preventing
constipation. And because it acts to normalize bowel movements, it can
also be used to treat and manage chronic diarrhea (Murray 1996). Consuming
fiber reduces transit time and results in a more thorough evacuation
of waste materials. It is thought to improve all aspects of colon function.
There are two types of fiber: water-soluble and insoluble.
Water-soluble fiber dissolves in water and is found in oat bran,
, nuts, beans, pectins, and various fruits and
vegetables. It forms a bulky gel in the intestine that regulates the
flow of waste materials through the digestive tract.
Water-soluble fiber may lower cholesterol by preventing the reabsorption
of bile acids. Bile acids are made from cholesterol, and after they
aid fat digestion, fiber binds with them and escorts them out of the
body. The liver then has to pull more cholesterol from the blood. In
a meta-analysis of 67 controlled trials, it was found that some water-soluble
fibers lower the total cholesterol and the bad cholesterol (LDL) without
affecting the good cholesterol (HDL) (Brown 1999). A similar double-blind
study found that Psyllium
lowered LDL cholesterol without affecting
HDL cholesterol (Anderson 1999).
Water-soluble fiber may also stabilize blood sugar by slowing down
the absorption of carbohydrates into the blood. Plus, it can lower blood
sugar levels. Researchers have found that increasing fiber intake results
in a decrease in the body’s need for insulin (Nuttall 1993). Psyllium
supplementation, in particular, has been shown to improve blood sugar
levels in diabetics (Anderson 2000).
Insoluble fiber cannot be dissolved in water, meaning that our bodies
cannot digest it. This type of fiber includes the undissolvable parts
of plant walls and is found in greatest amounts in cereals, brans, and
vegetables. The primary function of insoluble fiber is to collect water
that increases stool bulk in the large intestine. This promotes bowel
movement, and as the bulk works through the intestine, it scours the
intestinal walls of waste matter, reducing the risk of colon-related
Fiber in the diet
Most nutritionists recommend consuming 25 to 40 grams of fiber per
day. The average American consumes 10 to 15 grams. The average Canadian
consumes 4.5 to 11 grams.
A variety of epidemiological (disease and population) studies have
found that in populations with high-fiber diets, the incidences of colon
cancer, appendicitis, and diverticulosis are very low. Industrialized
countries, which largely have diets high in fat and low in fiber, have
high incidences of these diseases.
Because fiber is low in calories, it can be added to your diet, providing
a greater feeling of satiety without significantly increasing your caloric
intake. In addition, fiber’s ability to stabilize blood sugar may also
curb the desire to snack. In other words, you may find yourself eating
less. This is beneficial in weight-loss programs.
Psyllium, a soluble fiber grown in India, has more than eight times
the bulking power of oat bran. In 1998, the U.S. Food and Drug Administration
approved the health claim that foods containing Psyllium
the risk of coronary heart disease. This is due to its cholesterol-lowering
Manufacturers of foods containing Psyllium
may use the claim with
certain restrictions. When making the claim, they must state that it
is in conjunction with a diet low in saturated fat and cholesterol,
that adequate amounts of fluids must be consumed with the food, that
there is a potential for choking if fluids are not consumed with the
food, and that people with difficulty swallowing should avoid consumption
of the food. As well, the food must provide at least seven grams of
soluble fiber per day.
A model claim would be: The soluble fiber from Psyllium
in this product, as part of a diet low in saturated fat and cholesterol,
may reduce the risk of heart disease. A serving of this product supplies
X grams of the 7 grams of soluble fiber necessary to have this effect.
Adding fiber to your diet
Once you understand what fiber is and what it does, the next step
is changing your diet to make sure you increase your fiber intake.
- Eat at least five servings of fruits and vegetables per day.
Fruits and vegetables that are high in fiber include apples, oranges,
broccoli, cauliflower, berries, pears, Brussels sprouts, lettuce,
figs, prunes, carrots, and potatoes.
- Switch from white bread to whole-grain breads and cereals. Switch
from white rice to brown rice.
- Eat dry bran cereals for breakfast. Be sure to check the label
to see how much fiber the cereals contain. Some have less fiber
than you would think.
- Add one-fourth cup of wheat bran to foods, such as cooked cereals,
applesauce, and meat loaf.
- Eat beans each week.
- Add a fiber supplement to your diet.
Remember, as you increase your fiber intake, increase the amount
of water you drink. To experience the benefits of fiber, adequate water
Experience and research indicate that fiber is an indispensable part
of your diet. Including adequate fiber in your diet can help prevent
many of today’s prevalent health care concerns.