We all know that having the correct amount of dietary
fibre in our diets is extremely important. There are countless articles
in
the media, and reports from the Department of Health urging us to increase
our fibre intake. From the moment we are born, we constantly flush our
digestive tract with food. At three meals per day a 20 years old will
have eaten 15,000 meals. It is important that the flow of foods be regular
and that debris not plug up our intestinal walls and interfere with the
nutrient transfer into our body.
But what is dietary fibre, what does it do and how do I get the
right amount in my diet? This resource aims to answer these questions.
What Exactly is Dietary Fibre?
Dietary fibre is the roughage found in cereals,
fruit and vegetables. It is basically the plant cell walls that give
shape
and rigidity to trees, shrubs, grasses
and herbs. When plants are eaten, we gain a number of health benefits
from the nutrients they provide, along with the positive effects of fibre
within the digestive tract.
The fibre composition of plants varies based on plant species but, generally,
all plants contain all kinds of fiber. The 2 main categories are:
Water-insoluble, including cellulose, hemicellulose, and lignin;
and
Water-soluble, including pectin, gums, and mucilage. Water-soluble
fiber is considered the most health-benefiting type of fiber, especially
mucilage fiber.
Insoluble Fibre
Wheat bran and whole grains, as well as the skins of many fruits and
vegetables, and seeds, are rich sources of insoluble fibre. The outer
fibre layer is often removed in food processing by milling, peeling,
boiling or extracting and so people are often not eating enough insoluble
fibre.
Insoluble fibre makes stools heavier and speeds their passage through
the gut. Like a sponge, it absorbs many times its weight in water,
swelling up and helping to eliminate feces and relieve constipation.
Soluble Fibre
Soluble fibre is found in oats, legumes (peas, kidney beans, lentils),
some seeds, brown rice, barley, oats, fruits (such as apples), some
green vegetables (such as broccoli) and potatoes.
Soluble fibre breaks down as it passes though the digestive tract,
resulting in a gel that traps some substances related to high cholesterol.
Evidence
exists that soluble fibre may reduce heart disease risks by reducing
the absorption of cholesterol into the bloodstream.
Recent studies have found that people consuming high-fibre diets have
lower total cholesterol levels and may be less likely to form harmful
blood clots than those who consume less soluble fibre. A recent USA
report found that, in sufficient amounts, fibre apparently reduced
heart disease
risks among men who ate more than 25 grams per day, compared to those
consuming less than 15 grams daily.
