When carbohydrates are ingested, digestive enzymes break them down to simple sugars or monosaccharides known as glucose, fructose and galactose. Digestive enzymes are cellular proteins that break bonds between atoms in a carbohydrate molecule and add water. They are produced primarily in salivary glands and pancreas. The amount and types of carbohydrates you consume dictate how they are digested, absorbed and stored in the body and what levels circulate in the blood.
Digestive Enzymes and Carbohydrates
Digestion begins in the mouth with an enzyme secreted from salivary glands called alpha-amylase. Alpha-amylase is responsible for only a small percentage of the breakdown of carbohydrates because it is destroyed when the food reaches the high-acidic environment of the stomach. In the small intestines, glucosidase enzymes such as lactase, maltase and sucrase, breakdown the remaining carbohydrates to glucose and other monosaccharides. The monosaccharides are absorbed through the intestinal wall and transported via blood to the liver.
Glycemic Index
The most calorie-rich foods are carbohydrates composed of mostly simple sugars or monosaccharides. These sugars are easily absorbed into the blood. These foods have a high glycemic index. The glycemic index is a ranking system that measures the effects of carbohydrates on blood sugar levels. A food is measured against a reference food, such as white bread, by how high blood sugar levels are for two hours following ingestion. High glycemic index foods have a glycemic index greater than 70 percent.
Blood Sugar and Insulin
When a diet consists mainly of high glycemic index foods, blood sugar levels rapidly rise. When blood sugar levels rise, a hormone called insulin is released from the pancreas. It plays a role in grabbing the sugar from the blood and transporting it to the cells for energy production. But when there is too much sugar in the blood, insulin cannot keep up with removal and the liver cannot keep up with insulin production. Continual and long-term bombardment of sugar eventually wears down the production of insulin to create conditions called insulin resistance and hyperglycemia. These conditions play roles in diabetes and cardiovascular disease.
Digestive Enzyme Deficiencies
Digestive enzyme deficiencies are rare and are typically caused by inherited genetic disorders that disrupt glucose metabolism. Chronic pancreatitis and other diseases associated with poor pancreatic function, cause a decrease in digestive enzymes. A decrease in digestive enzymes can lead to low blood sugar levels. Certain digestive enzyme supplements prescribed by a physician can help individuals with such conditions properly digest foods.
Enzyme Inhibitors
A possible way to reduce the amount of sugar in the blood is to consume a diet rich in low glycemic index foods. A medically prescribed alternative is enzyme inhibitors that stop the breakdown of complex sugars to easily absorbed simple sugars. A clinical review in a 2011 edition of "Nutrition Journal" found that people had improvement in cardiovascular disease and hyperglycemia when taking prescribed digestive enzyme inhibitors. The review concluded that alpha-amylase inhibitors showed improvement in weight loss because it slows the absorption of carbohydrates.
References
- "Advanced Nutrition and Human Metabolism, Fifth Edition"; Sareen Gropper et al; 2009
- "Nutrition Journal"; A Proprietary Alpha-Amylase Inhibitor From White Bean: A Review of Clinical Studies on Weight Loss and Glycemic Control; Marilyn Barrett and Jay Udani; 2011
- Merck Manuals Online Medical Library; Carbohydrate Metabolism Disorders; February 2010
- Merck Manuals Online Medical Library; Chronic Pancreatitis; August 2007
