Fiber! That's another word you shouldn't shout in a crowded theater. Seriously, bran fans, this could be difficult for you to digest, but unlike men, all dietary fibers are not created equal.
Food fibers, the "walls of plant cells," are as different as scotch and water, Kool-Aid and Kentucky Fried and Brando and Bugs Bunny. And no fiber-not one damn one-is finger-licking good;
"tasteless" is about as good as any of them get. Besides sporting calorie values that waver from zero to 60 per ounce, particular fibers can assist or obstruct essential body functions.
Regardless of resentful carnivores, the six-member fiber family has recently inspired a media binge, receiving the kind of press coverage worthy of a Second Coming. What's so great about
some little husks that couldn't survive a sneeze storm? By now you've heard it all, but despite the "husky" hype and hoopla, no report has documented their often dramatic-differences, and no
single probe has amplified which fibers possess which virtues-or vices. So brace yourself.
Lab studies conclude that the fiber family should never be viewed as a group of eggs dropped by the same chicken; au contraire, they're more like an intergalactic garden of flowers: Some are
clear, others yellow, gray or brown, and every shape is as original as a snowflake.
Various fibers have different calorie values and different effects on our metabolism. They also respond to the elements (e.g., heat, water, oxygen and acids) in a variety of ways. Ever since
oat bran's ability to blot cholesterol and reduce risk of heart disease was documented, people have been giving other fibers a closer look. Now other less-famed fibers are proving capable of
reducing cholesterol while rendering additional services.
For example, a cluster bean (cyamopsis tetragonolobus) produces a clear gum that lowers cholesterol. Upon entering the stomach, it absorbs great amounts of water, swelling to about 100 hundred
times its original weight. Besides filling the empty space created by a delayed dinner, this gum also helps slow the release of fast-rushing sugars into the bloodstream, which can balance
blood sugar instabilities.
Fiber and Origin
There are six major categories of fiber: gum, mucilage, pectin, cellulose, hemicellulose and lignin. Fiber can only come from vegetables, grain, fruits, legumes and seeds like corn. Incredibly,
fiber is cholesterol-free, practically sodium-free and, depending on a few digestive factors, virtually calorie-free.
Unfortunately, fiber, both soluble and insoluble types, presents difficulty when you're determining excess caloric value. First, some are soluble in water or acid and completely digestible,
while others are insoluble. Second, because no two people have the same ratio of digestive enzymes, one type of fiber can provide two individuals with calorie totals as divergent as night and
The calories of the mother kernel will generally exceed the calories of its bran husk, often to a remarkable degree. Al-though no bran fiber exceeds 65 calories per ounce, most of those calories
cannot be digested, since a majority of fiber is insoluble and/or indigestible. The percentage one can digest rarely exceeds 30 calories in a two-hour period. Consequently, the amount absorbed is
proportionate to the amount of intestinal gas that develops.
When it comes to producing intestinal gas, cellulose, found in the strings of celery and stalks of vegetables, is the worst offender; it contains the most insoluble material. Yet fiber's "gassy"
side effects and shifting caloric conclusions are offset by its benefits.
A little of the right fiber can go a long way in helping correct disorders like obesity, hypercholesterolemia, diabetes and diverticulosis, a disease that afflicts one out of every three Americans
over the age of 40.
Mistakenly, fiber fetishists believe that because oat bran has the reputation of being "the saint of science," all fibers can lower cholesterol, and therefore the more fiber you eat, the lower your
cholesterol will drop. Consumers take note, however: Only oat bran has the effect on cholesterol that surpasses other brans, and wheat bran has no effect on blood lipids at all.
The Truth About Oat Bran
Oat bran contains twice the fiber (soluble and insoluble) of whole oats; but when whole oats-the kind Quaker sells-are incorporated into a low fat diet, the benefits are the same.
Again, the phrases you find bannering boxes of cereal and bread bags ("more fiber added" or "contains fiber") don't mean you'll get the benefits of oat bran unless, of course, the product contains
oats or oat bran. But although it might be the least expensive cholesterol-lowering fiber on the market shelves today, oat bran is not the most cholesterol-decreasing fiber-nor the mildest in terms
of gas production.
Long ago relegated to horsefeed and rejected by the palates of America, oat bran has become perhaps the best example, if not the boldest, of advertising overkill. Oat bran was embraced by cereal
conglomerates when a daring advertising mind retrieved this "new nutritional necessity" from storage sacks in stable yards.
Alas, certain plant gums, when mixed with pectin (found in apples and citrus fruits), are at least as effective in lowering cholesterol and are more gastronomically mild. Whereas oat bran can taste
like cardboard, neither plant gums nor pectin have any color or taste. This is the reason why manufacturers use them to emulsify and thicken packaged food. (Gums are also used to solidify pith
particles in paper-making.) So why aren't they sold like their sibling brans? Both pectin and plant gums cost more to process.
Cholesterol (CHOL) and Diabetes
Studies show that three out of four diabetics already adjusted to a high-carb-and-fiber diet (75 percent carb) can decrease plasma CHOL by 30 percent and safely discontinue using antidiabetes drugs
by adding 14 grams of plant gum and pectin to their diets. Furthermore, without any al-teration of dietary fat, CHOL levels of normal-CHOL people fall an average of 13 percent after several weeks of
ingesting a similar amount of these fibers.
Presumably, a fiber that contains greater amounts of solubles (gum or pectin) will have a higher hypo-cholesterolemic effect. Hence, the almost totally insoluble wheat bran does not alter CHOL.
(Note: The recommended limit for serum CHOL is between 225 and 240 milligrams per deciliter of blood.)
Transit Time: Faster Than a Speeding Carrot
A small portion of a high-fiber cereal can markedly reduce transit time of food. Absorption tests reveal that the faster food travels through your intestines, the fewer calories your body can absorb
and the "cleaner" your colon will be.
Claiming a high-fiber diet can decrease risk of colon cancer, scientists use the low incidence of colon cancer in tribal Africans to argue that fiber minimizes intestinal contact time with cancer-causing
elements such as rancid fats.
In critical candor, skeptics report that this is a flimsy theory, as Eskimos, who often eat only animal flesh and presumably have prolonged transit times, also have a low incidence of colon cancer.
Regardless, most experts support improved transit times, if only to reduce food purification and the rancidification of fats that ultimately produces free radicals. Thus, if the average transit time
of America is 60 to 90 hours, certainly the average African's 30-hour transit time is preferable.
Meanwhile, wheat bran has a tremendous stool-bulking capacity of about 127 percent, a rating superior to the effect of many laxatives. Psyllium seed husk, which hides in Metamucil-brand products, is
another nonlaxative fiber whose stool-bulking effect is better than the result of most laxatives.
The Bad News
Apart from the grain gossip, all the husk-hype, fiber-fanaticism and cultlike devotion to a substance that's about as pleasurable to eat as sawdust, some aspects regarding fiber de-serve more scrutiny.
1 Gastrointestinal responses to various fibers are individual. Reactions following the consumption of fibrous foods can range from "Please, sir, may I have more?" to "I'm out of toilet paper."
2 Fibers have specific and possibly divergent effects on the intestines. One fiber can scratch; another can scour or just plain irritate. Often, bodybuilders complain about distended abdominals or a
sense of "bloating." ("From my pecs to my hips, I feel like the Pillsbury Doughboy," a normally narrow-waisted champ complained over salad.)
3 Insoluble fibers-particularly cellulose and the lignin of legumes- produce varying and often uncomfortable amounts of gas.
4 Although a hastened transit time of food through the gastrointestinal tract does decrease calorie absorption, it also decreases the absorption of vital nutrients. For example, grain hulls contain
nutrient-obstructing phytic acid, and spinach releases oxalic acid, which neutralize the body's access to iron.
As with any foodstuff, there's more to know about fiber than what meets the eye or hits the tongue. Chances are, however, the next time someone shouts the word "Fiber!" you won't leave your seat until
you see the whole picture.