What is Starch?
By definition starch is a polysaccharide composed of a chain of glucose molecules held together by glycosidic bonds. Starch is common in nearly all green plants and is used for short term energy storage.
Different Types of Starches
Starch can come in two distinct forms: amylopectin a compound with a complex system of branching glucoses, and amylose a simple straight chain of glucose molecules. Because of amylopectin’s larger and more complicated nature it has a much larger surface area than amylose making it significantly easier to digest. The amylose cannot effectively be broken down by the enzymes of the digestive system. Instead it is left to be dealt with by the human gut microbiome. For this reason it is commonly referred to as a resistant starch.
How are Resistant Starches Beneficial?
An international research article including authors from Harvard Medical School suggests that resistant starches have a myriad of benefits. Some resistant starches which thwart digestion in the stomach and small intestine, make their way all the way down to the large intestine where they are subject to fermentation by the microscopic bacteria of the human gut. The fermentation process can metabolize a multitude of different useful products. For example some significant and common place output of gut fermentation are simple fatty acids. One key short chain fatty acid created during this process is Butyrate, the preferred fuel oof the cells lining the colon. In addition to Butyrate there exist many other short chain fatty acids that help maintain and fuel the body. These fatty acids can be used for many different purposes, all beneficial to both the gut microbiome and the host. The benefits may range from weight loss to curbing the progression of chronic kidney disease.
In addition to their ability to be changed into more useful forms, resistant starches also serve to enhance the effectiveness of the gut microbiome. Constant ingestion of resistant starches can stimulate an increase in the size and health of gut microbiomes in addition to raising host metabolism.
Common Uses For Resistant Starches
Resistant starches are often used in weight reducing diets in order to encourage an increase in metabolic rates. Although results of these diets are often compelling, a diet must consist of all types of food groups and should contain a variety of vitamins and minerals. Eating only amylose and other resistant polysaccharides will not on its own help you achieve weight loss. It should be paired with exercise and an otherwise healthy diet.
Should resistant starches be used in dieting or do they promote malnutrition? There are many benefits to a diet high in resistant starches, including building up a healthy gut microbiome. However you cannot survive solely on carbohydrates. This is a complex question, and I would be interested in hearing your opinions in the comments.