Why We Should Know More About Psyllium
~ April 2000 No.99 ~
Psyllium is a rather new additive that has found its way into several of our regular foods, particularly breakfast cereals. So what is psyllium and how is it good for health?
Plantago psyllium is a plant native to Iran and India. Psyllium stalks contain tiny seeds, also called psyllium. The seeds are covered by husks, which is the part of the plant used in foods. The seed husk contains glycosides and mucilages which are used in the food industry to form gels that give thickening and textural changes to foods. The psyllium husk is a source of water soluble fiber, similar to fiber found in grains such as oats and barley. But the amount of soluble fiber in psyllium is much higher than oat bran. Every 100 grams of psyllium provides 71 grams of soluble fiber; a similar amount of oat bran would contain only 5 grams of soluble fiber. Only recently have scientists learned that soluble fiber has unique effects on metabolism.
Psyllium fiber is not broken down as it passes down the gastrointestinal tract and so psyllium has no nutritive value other than as a source of fiber. Adding water to dry psyllium causes it to swell to up to ten times its original volume. For many years products containing psyllium have been used to increase fecal bulk and loosen stools, as ways of treating constipation. Other uses of psyllium related to digestive problems are less well documented.
Recently the United States Food and Drug Administration acknowledged psyllium´s role in lowering blood cholesterol levels by allowing health claims to be made for products containing psyllium fiber. However it was recognized that psyllium is only one factor that can influence cholesterol levels and so the claim for psyllium is combined with a low fat diet that is also low in saturated fat and cholesterol. The combination of low fat diet, low in saturated fats and cholesterol plus psyllium, can reduce total cholesterol levels by 4% and low density lipoprotein (LDL) cholesterol by 7%. The soluble fiber in psyllium reduces absorption of blood cholesterol and bile acids from the intestine and that in turn lowers blood cholesterol levels.
It is sound advice to include as many sources of fiber in your diet as possible. Many fruits and vegetables are good sources of fiber, but it would appear that there are particular advantages to increasing the amount of soluble fiber in your diet - soluble fiber like the kind found in pysllium.
American Journal of Clinical Nutrition 2000;71-2, 472-479