For optimal liver health, most of us know that we should watch our weight, drink alcohol in moderation, and limit the fatty foods that we eat. But did you know that a diet rich in fiber can also promote a healthy liver? That’s right. Fiber, beneficial in helping keep bowel movements regular, lower cholesterol levels, and control blood sugar levels, can also help keep our liver healthy.
Here’s a primer about fiber.
Dietary and functional fibers
Fiber is technically considered a carbohydrate, and it can be broken down into two categories: dietary fiber and functional fiber.
Dietary fiber is the kind that you eat. It’s naturally present in foods like fruits and vegetables, nuts and seeds, and whole grains.
Functional fiber consists of isolated carbohydrates that are nondigestible and absorbed in the small intestine. It can help to normalize bowl function and prevent constipation. It’s taken as a supplement and added to foods like cereals, baked goods, dairy products, and reduced-calorie, low-fat, and low-sugar foods.
Our bodies — including our liver — benefit from both forms, but fiber supplements alone can’t make up for a poor diet. In studies that link lower cancer risk to higher dietary fiber intake, researchers think the benefits may be coming from the other nutrients in the food. In other words, it’s better to get your fiber from the foods that you eat.
Soluble and insoluble fibers
Dietary and functional fibers can be categorized into soluble and insoluble, and they both have different benefits.
Soluble fiber dissolves in water to form a gel-like material. It can help to lower blood cholesterol and glucose levels (processes that the liver plays a role in) and is found in food like oats, peas, beans, apples, citrus fruits, carrots, barley, and psyllium.
Insoluble fiber promotes the movement of material through the digestive system and increases stool bulk, so it can be of benefit to those who struggle with constipation or irregular stools. It’s found in whole-wheat flour, wheat bran, nuts, beans, and vegetables like cauliflower, green beans, and potatoes.
Viscous, fermentable, resistant fibers
All fibers are viscous, fermentable, or resistant, a way to classify how they function in our bodies. While we may think of fiber as something that is crunchy, viscous fiber is the type that forms a gel-like paste when combined with water in the digestive system. Healthy bacteria in the gut feeds on fermentable fiber and increases the number and balance of friendly gut bacteria. Resistant starch — starch that passes through the digestive tract unchanged — functions like soluble, fermented fiber.
The same food, whether apples, dried beans, or oatmeal, may contain several types of fiber. The take-home message: Consume fiber from a wide variety of foods to gain the full range of potential health benefits for the body — including your hard-working liver.
How much fiber should you eat?
The recommended dietary fiber intake is 14 grams per 1,000 calories. For the average person, this means 25 to 35 grams of fiber per day. Most Americans only consume 13.5 to 18 grams a day!
Check the food label and serving size. A good source of fiber is 10 percent of the daily value or 2.5 grams per serving. High fiber is considered 20 percent of the daily value or 5 grams per serving.
See how easy it is to consume over 35 grams of fiber in one day:
Oatmeal, 1 cup, 4 grams
Raspberries, 1/2 cup, 4 grams
Nut butter sandwich on whole wheat bread, 3.8 grams
Carrots, 5 baby, 1.7 grams
Apple, medium, 4.4 grams
Almonds, 1 ounce (about 23), 3.5 grams
Popcorn, 3 cups air popped, 3.6 grams
Spaghetti with whole-wheat pasta, 1 cup, 6.3 grams
Broccoli, 1 cup, 5.1 grams
Mixed green salad, 1 cup, 1 gram
Caroline manages the internal wellness program to improve the health of Methodist Health System’s employee and dependent population. A University of Oklahoma graduate, Caroline has 10 years experience as a registered and licensed dietitian.