With
changing dietary fashions, the current emphasis on low-fat
items - witness the vast array of 'light' and fat-reduced
products lining supermarket shelves - has given dietary fibre
a back seat. Although people may pay less attention to fibre,
its health benefits have not vanished. Fibre remains an essential
nutrient and a vital part of healthy eating for everyone,
including those with diabetes. In fact, soluble forms of plant
fibre may help to mute blood sugar swings.
Under the less trendy term 'roughage,' fibre
enjoyed great respect among our grandparents, and during the
1970s its image was resurrected by British physician Dennis
Burkett, who practised for many years in rural Africa. He
attributed the rarity of ailments such as hernias, hemorrhoids,
diabetes, diverticulitis (small outpunchings of the large
intestine), heart disease and bowel disease in that area to
native diets rich in whole grains, seeds, roots, vegetables
and nuts.
He blamed the high incidence of these disorders
in Western countries on a lack of dietary fibre. Burkett's
theories were enthusiastically adopted in the 1970s as the
'Bran Hypothesis'.
Many of us may remember the heyday of bran
during the late 1970s and early 1980s with massive promotion
of bran cereals and granola. Next came the oat bran craze,
with oat products in all shapes and sizes flooding the market
claiming to lower blood cholesterol and fight heart disease.
A 1990's review of many studies examining the link between
oats and health concluded that at best, oat cereals may modestly
reduce blood cholesterol.
However, after a lull, oat cereals are again
making headlines as the American Food and Drug Administration
has permitted product labels to carry health claims that oatmeal
and oat cereals may reduce the risk of heart disease - as
part of a diet low in fat and cholesterol. Although oat bran
may be back, most dietary experts caution that no one fibre
is better than others.
Neither oats nor wheat bran are the whole
story. 'A spoonful of oats (or bran) a day' is no cure for
many disorders. Most scientists agree that different types
of fibre confer different health benefits for everyone, including
seniors.
Traditionally, fibre was considered to be
an inert part of food, passing undigested from mouth to anus
and expelled intact in the stool. This view has been revised
and the term 'fibre' now encompasses complex carbohydrates
and natural polymers such as cellulose and woody plant lignin,
as well as pectin and various gums (guar, arabic, agar, carageen)
and psyllium, and many others not yet identified.
Far from being inert, different fibres exert
different bodily effects. Fibre is often divided into two
broad classes: insoluble and soluble forms. Wheat bran, for
instance, is an insoluble form that is a good stool-softener
but a poor absorber of cholesterol, a function that the soluble
form, oat bran, does better.
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. Wheat bran and whole
grains, as well as the skins of many fruits and vegetables,
and seeds, are rich sources of insoluble fibre.
High-fibre diets have replaced bland, low-residue
treatments for bowel problems such as diverticular disease.
Also note that as the outer fibre layer is
often removed in food processing by milling, peeling, boiling
or extracting, it's wise to eat more unrefined foods to obtain
insoluble fibre.
Soluble fibre includes pectin, gums (such
as guar), betaglucans, some hemicellulose and other compounds
and 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,
forming a gel that traps some substances related to high cholesterol.
There is some evidence that soluble fibre may lessen heart
disease risks by reducing the absorption of cholesterol into
the bloodstream.
Studies find that people on 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
under 15 grams daily.
Soluble fibre in oat bran, legumes (dried
beans of all kinds, peas and lentils), and pectin (from fruit,
such as apples) and forms in root vegetables (such as carrots)
is considered especially helpful for people with either form
of diabetes. Soluble fibre may help control blood sugar by
delaying gastric (stomach) emptying, retarding the entry of
glucose into the bloodstream and lessening the postprandial
(post-meal) rise in blood sugar. It may lessen insulin requirements
in those with type 1 diabetes.
Because fibre slows the digestion of foods,
it can help blunt the sudden spikes in blood glucose that
may occur after a low-fibre meal. Such blood sugar peaks stimulate
the pancreas to pump out more insulin. Some researchers believe
that a lifetime of blood glucose spikes could contribute to
type 2 diabetes, which typically strikes after the age of
40, and more than doubles the risk of stroke and heart disease.
The cholesterol-lowering effect of soluble fibres may also
help those with diabetes by reducing heart disease risks.
According to current guidelines, healthy
adults should consume at least 26 grams of fibre - ideally
26 to 35 grams daily. The present Canadian fibre intake only
averages 4.5 to 11 grams a day. Health Canada suggests increasing
this amount by eating more grains and unpeeled (but well-washed)
fruit and vegetables. Be sure to include both insoluble fibre
and soluble types.
Another plus of a fibre-rich diet is that
it provides plenty of vitamins and minerals, but it may be
wise to consult a physician before greatly increasing dietary
fibre intake and to ensure good nutritional status before
making drastic alterations. Initially, eating large quantities
of fibre may cause bloating, but this should subside in a
few weeks. It is best to increase amounts gradually.
Eating 26 grams of fibre daily may seem like
a lot but can be obtained by having two fruits at breakfast-time
(say a banana and raisins) with whole grain cereal, fruit
as between-meal snacks, three to five servings of vegetables
daily, and several bread and grain servings.
Enjoy
quality food| Overcoming
barriers to changing eating behavior| How to
Follow a Diabetic Diet| Veggie
diet|
Advantages
and Disadvantages of diabetic food| The
Benefits of Eating Fibre|
Major
Food Components in a diabetic meal
|
