Fiber
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 our diets.
Fiber
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
Water-soluble fiber dissolves in water and is found in oat bran,
legumes, psyllium, 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
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
problems.
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
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
may reduce the risk of coronary heart disease. This is due to its
cholesterol-lowering effect.
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 seed husk 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 is
necessary.
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.
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