Talking to Your Diabetes Patients About Fiber

Achieving an optimal diet in thepatient with diabetes is not aneasy task. Individual meal planningwith a nutritionist or diabeteseducator is often necessary. However,all pharmacists can make some generalrecommendations to their patientswith diabetes with regard to fiberintake. While most of us recognizethat fiber is an essential part of ahealthy diet, we may not understandexactly what role fiber plays in ourhealth. In diabetes, fiber has 2 keyroles: stabilization of blood glucoseand lowering of cholesterol.

There are 2 types of fiber, solubleand insoluble. Both types provide differentand important benefits for ourbodies. Soluble fiber, made of substancessuch as pectin, forms a thickgelatin-like compound when dissolvedin liquid. In the intestinaltract, this gel binds with bile acids andcholesterol and removes them fromthe body, which results in reducedcholesterol levels. Soluble fiber alsoslows down the absorption of carbohydratesand can result in a more stablerise in blood glucose after a meal.Soluble fiber is found in foods such asoats, oatmeal, broccoli, asparagus,dried beans, soybeans, and certainfruits including pears, apples, oranges,and berries.

Insoluble fiber absorbs water as itmoves through the intestines, whichresults in bulk stool formation andincreased transit time. By movingstool through the intestines morequickly, conditions such as constipationand diverticulosis can be prevented.It is also believed that the risk ofcolon cancer is decreased when intestinaltransit time is quicker since toxicsubstances are removed more quickly.Insoluble fiber is found in wheat products,beans, grains, and a lot of fruitsand vegetables.

Fiber is a type of carbohydrate, butsince it is not absorbed or brokendown by the body, it contributes nocaloric value. Some diabetic patientsuse carbohydrate counting as their primarymeans of postprandial bloodglucose control. In some cases, fibercan actually be subtracted from thetotal grams of carbohydrate when calculatingcarbohydrate total for a particularmeal. The current recommendationfor daily fiber intake for mostindividuals is 20 to 35 g. However,most studies indicate that Americanstypically receive only 10 to 12 g offiber per day. Some small-scale studiesindicate larger amounts of daily fibercan be beneficial for patients with diabetes.One study published in the NewEngland Journal of Medicine demonstratedthat patients with diabetes hadbetter blood glucose control with ahigh-fiber diet of 50 g per day, versusthose on a moderate-fiber diet of 24 gper day. At 6 weeks, the group ofpatients on the high-fiber diet demonstrateda mean reduction in dailypreprandial glucose of 13 mg/dL versusthe moderate-fiber group. Thepatients randomized to the high-fibergroup also demonstrated significantlipid profile improvements as well.Total cholesterol concentrations werelowered 6.7% and triglyceride concentrations10.2%.

Large-scale studies are lacking, butenough data are certainly present torealize the importance of workingwith our patients with diabetes onimproving fiber intake in their diets.Most patients, when asked, will statethat the importance of fiber is to "keepthem regular."As pharmacists, we canexplain that the benefits of fiberextend far beyond regular bowelmovements. In addition to promotinga feeling of fullness, remind them thatfiber has beneficial effects on bothblood glucose control as well as cholesterolprofiles.

Good counseling points for patientstrying to increase fiber in their dietsinclude:

• When eating starches, thinkbrown instead of white. Wholegrain and whole-wheat products(such as whole-grain bread andtortillas, whole-wheat pasta, andwhole-grain rice) contain morefiber than their refined counterparts.
• Choose whole fruits (ie, with theskin on) as snacks whenever possibleinstead of drinking fruit juice
• Choose fresh vegetables and findcreative ways to add them tosoups, pastas, or other entrees
• Add beans to your meal plan severaltimes per week. They can betossed onto a salad or made intochili.
• Add barley or unprocessed bran todifferent foods such as soups,stews, or oatmeal
• Choose high-fiber cereals or oatmeal(not instant) for breakfast
• Do not forget to increase fiberintake gradually to avoid gastrointestinalupset
• Increase fluids (noncaffeinated) asyou increase fiber to avoid constipation

Dr. Brian is a clinical specialist withCornerstone Health Care, High Point, NC.