Diastase (Amylase): The Starch-Splitting Enzyme

Diastase is a traditional term for amylase — the enzyme that breaks down starch (amylose and amylopectin) into simple sugars. Starch digestion begins in the mouth with salivary amylase and continues in the small intestine with pancreatic amylase. Supplemental diastase/amylase can help people who produce insufficient amounts.

How It Works

Amylase cleaves alpha-1,4-glycosidic bonds in starch molecules, producing maltose, maltotriose, and limit dextrins. These are then further broken down by brush border enzymes (maltase, isomaltase) into glucose for absorption. Without adequate amylase, undigested starch passes into the colon where it's fermented by bacteria, potentially causing gas and bloating.

Interestingly, the amount of salivary amylase a person produces is genetically variable — populations with historically high-starch diets tend to have more copies of the AMY1 gene and produce more salivary amylase. The connection between resistant starch and incomplete amylase digestion is relevant here too.

External resources: NCBI — Amylase