Prickly Pear Cactus is said to be beneficial in diabetes control, because it contains a high percentage of carbohydrate fibers known as mucilage which does not dissolve in water, but it does absorb water, so it swells up to form a bulky paste when exposed to fluids.  The fiber component is thought to produce hypoglycemic activity by affecting the intestinal uptake of glucose. In double-blind tests, insulin concentrations were favorably affected with the administration of Prickly Pear, and the herb is thought to reach maximum effect about three to four hours after eating a meal.