Want that fiber regular or decaf?

Researchers in Spain report that a cup of coffee can deliver a significant portion of daily dietary fiber. The drink hadn’t been known to contain any fiber.

Like the cholesterol-lowering substances found in oat bran, fiber in coffee consists of carbohydrates that the body can’t digest, but which dissolve in digestive fluids. However, unlike oat bran’s soluble fiber, the fibrous constituents of coffee haven’t been proven to benefit health, notes food scientist Fulgencio Saura-Calixto. His team at the Spanish National Research Council in Madrid recently developed a technique to isolate fiber from various drinks, including those assumed to have none.

Coffee’s fiber molecules are small enough to easily pass through most coffee filters, Saura-Calixto and team member M. Elena Díaz-Rubio report in an upcoming Journal of Agricultural and Food Chemistry. Per unit volume, liquid coffee made using freeze-dried crystals contained 60 percent more fiber than conventionally filtered coffee did. Saura-Calixto says that he suspects that more fiber is extracted from coffee beans by the 200°C process used to make freeze-dried coffee crystals than by the cooler steps used in making ground coffee.

The recommended amount of dietary fiber the United States is about 28 grams per day, but most people don’t come near that target. The new data indicate that 2 cups of instant coffee per day might contribute up to 3.6 g of fiber.

Janet Raloff is the Editor, Digital of Science News Explores, a daily online magazine for middle school students. She started at Science News in 1977 as the environment and policy writer, specializing in toxicology. To her never-ending surprise, her daughter became a toxicologist.

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