A Pharmacist's Guide to OTC Therapy: Fiber

Although fiber is most widely recognized for the prevention or relief of constipation and for maintaining normal bowel function, research has shown that an increased intake of fiber can promote additional health benefits and possibly prevent or reduce various chronic health problems. The American Dietetic Association (ADA) recommends a daily intake of 25 to 30 g of fiber for healthy adults. Children over the age of 2 years should consume an amount of fiber equal to their age plus 5 g per day. Unfortunately, many individuals do not meet the ADA's recommended goal of daily fiber intake. The average daily intake of fiber for most people is 10 to 15 g.

Some Benefits of Increased Fiber Intake

• Promotes and maintains bowel regularity
• May lower risk of developing hemorrhoids or diverticulosis
• May aid in the management of irritable bowel syndrome
• May aid in lowering cholesterol and blood pressure?which may reduce cardiovascular risks
• May promote management of glucose and diabetes
• Can restore regularity for low-carbohydrate dieters
• May play a role in reducing the risk of colon cancer, because fiber can absorb and remove toxic substances in contact with the colon
• May promote weight loss

Types of Dietary Fiber

Dietary fiber can be divided into 2 basic categories: soluble and insoluble. Soluble fiber dissolves in the water found in the large intestine and forms a gel. Soluble fiber can aid in lowering total cholesterol levels and low-density lipoprotein cholesterol levels, as well as regulating blood glucose in patients with diabetes. Common food sources include oats, oat bran, barley, peas, beans, apples, citrus fruits, carrots, and psyllium husk.

Insoluble fiber does not dissolve in water, but it increases the movement of waste through the intestinal tract. In addition to preventing constipation, this type of fiber can aid in removing toxic waste in the colon. Common food sources include wheat bran, whole grains, flax seed, nuts, and vegetables.

Fiber Supplements

Because many individuals may find it difficult to consume the ADA-recommended amount of fiber on a daily basis through diet alone, the use of any of a variety of fiber supplements currently on the market may be a more convenient means of increasing one's fiber intake (Table). These products are available in various formulations, which include powder, chewable tablets, caplets, wafers, and shakes. Since many people are becoming increasingly proactive about their health?especially through implementing preventive measures such as lifestyle modifications into their daily routines?more patients may benefit from the use of fiber supplements in conjunction with eating more high-fiber foods.

Role of the Pharmacist

Pharmacists can provide essential guidance to patients regarding the proper selection of fiber supplements, as well as ensuring that patients utilize them correctly according to manufacturers' recommendations. Patients should be reminded that adding too much fiber too rapidly can cause various adverse events, such as intestinal flatulence, bloating, and cramping. The increase should be gradual over a few weeks, and, if possible, patients should increase water intake at the same time.

Prior to recommending the use of any fiber supplements, pharmacists should advise patients to seek the advice of their health care provider regarding these products. Furthermore, because fiber supplements can decrease the absorption of many medications, patients always should be advised to take supplements 2 to 3 hours before or after other medications, as well as to report any concerns to their physicians.

Patients should be reminded that the use of fiber supplements never should be a substitute for a fiber-rich diet that contains other essential vitamins and minerals necessary for health. For more information on the importance of fiber, visit the following Web sites: American Dietetic Association at www.eatright.org and American Heart Association at www.americanheart.org.

Ms. Terrie is a clinical pharmacy writer based in Haymarket, Va.

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