Resistant starch and the impact on the metabolic syndrome

Until the late 1980s, it was believed that starch was completely digested and absorbed in the human small intestine. Starch is the most abundant reserve polysaccharide in the plant kingdom that is formed in leaves by photosynthesis and is stored in tubers, seeds, fruits and woody parts of plants. In fact, starch is a homopolymer of D-glucose consisting of two polymers with different structures: amylose, mainly a linear molecule, and amylopectin, a branched molecule. In the case of common types of starch, amylose and amylopectin are found in proportions of 25-28% and 72-75%, respectively. The different types of starch in food can be classified according to how they are metabolized in the small intestine into: fast-digesting starch, slow-digesting starch, and resistant starch. Resistant starch is a type of carbohydrate that is not digested in the small intestine. Instead, it ferments in the large intestine and feeds the saprophytic intestinal bacteria, with beneficial effects on the health of the body. Thus, resistant starch behaves like a soluble fiber, without caloric or glycemic load, a very important aspect in the metabolic syndrome.