Many people take psyllium (pronounced SILL-ee-um) as a fiber supplement for its laxative effect. Metamucil is the best-known brand, but there are many others, including less expensive store brands. Made from the husks of seeds from the Plantago ovata plant, psyllium is sold as a powder or pill and is also an ingredient in a few breakfast cereals. Besides being a laxative, psyllium has other benefits, notably its cholesterol-lowering effect.
Here’s the scoop:
■ Psyllium husks are rich in certain types of soluble fiber, which help prevent constipation. This fiber absorbs water in the colon, resulting in bulkier stool—thus it's called a "bulkforming" laxative—and forms emollient gels that facilitate the passage of stool. It's also a good source of insoluble fiber (like whole bran, for instance), which enhances its laxative effect. Psyllium is gentle and relatively slow-acting. It usually takes 12 to 24 hours to affect bowel movements. If you take it, you need to drink extra water.
■ The soluble fiber in psyllium can help improve blood cholesterol levels, especially by lowering LDL (“bad”) cholesterol. It may also help reduce levels of smaller, denser LDL particles, which are associated with a greater risk for arterial damage than large, fluffy LDL particles. The government’s cholesterol guidelines recommend psyllium for this purpose, as does the American Heart Association.
■ Like other sources of soluble fiber, psyllium may help control blood sugar in people with diabetes. But don’t expect a large effect and be sure to use the sugarless preparations of psyllium.
■ It may aid in weight control because it helps you feel full. However, the amount of psyllium normally consumed won’t, by itself, cause pounds to drop off. The claims made for fiber supplements as weight-loss aids are almost always overstated. Increasing your intake of any kind of fiber can help you lose weight, but only if it helps you reduce your calorie intake.
Our take on psyllium
✓ If you have high cholesterol or diabetes, psyllium can help if it’s part of broader dietary strategies. By itself it won’t be enough to treat the problem. It may help you stay on a lower dose of statins.
✓ If you have a healthy diet—rich in fruits, vegetables, beans, and whole grains—and your cholesterol numbers are okay, you don’t need psyllium unless you have a problem with constipation. Such a diet will do everything psyllium is supposed to do, and more. It’s best to consume a variety of fiber-rich foods, so that you get various types of soluble and insoluble fiber, since they have different kinds of benefits.
✓ If you are occasionally constipated, eat more produce and whole grains, exercise more, and drink plenty of fluids. A self-help technique called "perineal self-accupressure" may also bring relief. If those steps don't work, fiber supplements such as psyllium are safer than other (“stimulant”) laxatives such as Ex-Lax or Correctol.
✓ In some people psyllium causes bloating, gas, diarrhea, or (if they don’t drink enough fluid) constipation. And some are allergic to it. Psyllium can interfere with certain drugs, so if you’re on medication, ask your pharmacist. You may have to take the drug either one hour before or two hours after the psyllium.
Besides psyllium, many kinds of fiber supplements are sold as bulk laxatives and diet aids. Nearly all are high in soluble fiber. For instance, Benefiber contains wheat dextrin; Citrucel has methylcellulose; FiberChoice and Fibersure supply inulin; FiberCon contains calcium polycarbophil. But different types of soluble fibers vary chemically and can act somewhat differently in the body, so don’t expect the same effects as psyllium. For instance, not all of them may lower blood cholesterol significantly.