Do Blackberries Have Soluble Fiber Or Insoluble Fiber?

A 1 c servings of blackberries contains 7.6 g of total fiber, or 30 percent of the recommended daily allowance, or RDA. Fiber is the part of plants that you cannot digest or absorb in the stomach or small intestine. Soluble fiber is found inside plant cells and includes pectin and gum. Insoluble fiber is found in cell walls; examples include cellulose, hemicelluloses and lignin. Blackberries have a mixture of soluble and insoluble fiber.

Fiber Recommendations

The RDA for fiber is based on your calorie intake: Aim for 14 g fiber for every 1,000 calories you eat. This is about 25 g daily for women and 38 g for men. The Daily Value used on food labels is 25 g total fiber, based on a 2,000-calorie diet. A 1 c serving of fresh or frozen blackberries is an excellent source of fiber, providing 30 percent of the RDA in a mixture of soluble and insoluble fiber.

Soluble Fiber

There is 1.6 g of soluble fiber in 1 c of blackberries. Soluble fiber attracts and dissolves in water, becoming soft and gel-like in the small intestine. It slows digestion and the rate of absorption of nutrients, especially carbohydrates. Soluble fiber has cardiovascular benefits. It lowers total and "bad" LDL cholesterol, lowers blood pressure and reduces levels of C-reactive protein, a marker that indicates inflammation. Soluble fiber also helps with weight control by slowing digestion and increasing satiety. It also promotes bowel movements by softening the stool.

Insoluble Fiber

Most of the fiber in blackberries is insoluble--6.0 g in 1 c. Insoluble fiber does not dissolve in water. Instead, it passes through the digestive tract essentially unchanged, adding bulk and form to the stool. Insoluble fiber improves digestive tract health by improving regularity, decreasing constipation and improving diarrhea. It can reduce symptoms of irritable bowel syndrome and diverticulosis. Insoluble fiber aids in weight control by increasing satiety and fullness. Researchers are still studying its role in preventing cancer, especially colorectal cancer.

Other Nutrients

A 1 c serving of fresh or frozen blackberries contains only 62 calories, 14 g of carbohydrate and less than 1 g of fat. Blackberries are naturally cholesterol-free and low in sodium. Blackberries are an excellent source of vitamins C and K and the mineral manganese. They rank the highest in antioxidant value among fruits commonly tested.