Which statement best describes insoluble fiber?

• A. Dissolves, lowers cholesterol.
• B. Doesn't dissolve, promotes regularity, decreases risk of diverticulitis.
• C. Does not dissolve, increases blood pressure.
• D. Doesn't dissolve, promotes regularity, decreases risk of diverticulitis.

Answer: (B)

Insoluble fiber resists dissolution in water and adds bulk to stool. This bulk speeds up intestinal transit and increases stool frequency, which promotes regularity. By reducing intracolonic pressure and helping stool move through the colon, higher intake of insoluble fiber is associated with a lower risk of diverticular disease and its complication, diverticulitis. That’s why the statement describing insoluble fiber as not dissolving, promoting regularity, and decreasing the risk of diverticulitis is the best description. Statements claiming it dissolves (which would describe soluble fiber) or claiming it increases blood pressure aren’t accurate descriptions of insoluble fiber’s effects.