Americans typically consume about 15 grams of fiber, including soluble fiber, daily. Increasing the amount of fiber in your diet to 25 grams a day for women and 38 grams for men can help lower your blood cholesterol. Soluble fiber can also help lower -- not raise -- your blood sugar levels.
Types of Fiber
Fiber, found in all plant foods, includes two types: soluble and insoluble. Beans, peas and the soft part of fruit contain soluble fiber, which absorbs water and forms a gel in your digestive tract. It slows the digestion of starch and fiber. Insoluble fiber, found in fruit peels, provides bulk and helps stool pass quickly through your digestive tract. Both types of fiber improve your digestion. The viscosity of fiber might prove as important as solubility in protecting you against heart disease. In other words, some types of insoluble fiber might work as well as soluble fiber to lower your cholesterol.
Soluble Fiber and Cholesterol
Soluble fiber helps to reduce your low-density lipoprotein -- LDL or "bad" cholesterol -- protecting you against heart attacks and strokes. It slows your digestion of sugar and starch. Reduced levels of sugar and starch in your bloodstream helps lower your cholesterol. Soluble fiber also helps you lose weight; it helps fill you up and keeps you feeling full, reducing the temptation to snack on high-calorie items. If you lose just 5 lbs. to 10 lbs., you can lower your cholesterol. Fiber also helps lower your blood pressure which might, in turn, lower your cholesterol.
Soluble Fiber and Blood Sugar
Sugar and starch carbohydrates elevate your blood sugar levels. But fiber passes through your system undigested, so it doesn't raise your blood sugar. Instead, it slows your body's absorption of sugar and starch, helping to regulate your blood sugar. For this reason, fiber helps people with type 2 diabetes manage their blood sugar levels. If you eat a piece of candy, the sugar in the treat quickly gets absorbed into your bloodstream. Fruit also contains sugar, but because it also contains fiber, the sugar from fruit enters your bloodstream gradually.
Fiber Sources
To help lower your cholesterol and your blood sugar, include a wide variety of fruits, vegetables, beans, nuts and seeds in your diet. Good sources of soluble fiber include split peas, 6.3 grams per 1 cup cooked; black beans, 15 grams per 1 cup cooked; raspberries, 8 grams per 1 cup; whole wheat spaghetti, 6.2 grams per 1 cup cooked, and oatmeal, 4 grams per cup cooked.. Fruits with edible skins or seeds -- apples or pears, for example -- provide both soluble and insoluble fiber.
References
- American Dietetic Association: Health Implications of Dietary Fiber; 2008
- MayoClinic.com: Nutrition and Healthy Eating -- High-fiber Foods; November 19, 2009
- MayoClinic.com: Nutrition and Healthy Eating -- Dietary Fiber, Essential for a Healthy Diet; November 17, 2009
- MayoClinic.com: High Cholesterol -- Lifestyle and Home Remedies; June 1, 2011
- University of Maryland Medical Center: Fiber
