ABSTRACT
This chapter discusses the effects of fructose consumption on other hormones involved in carbohydrate metabolism. Hormones which will be discussed include gastric inhibitory polypeptide (GIP), glucagon, growth hormone, cortisol, and thyroid hormones. GIP, which is primarily secreted in the proximal small intestine, inhibits gastric acid secretion, thus its name. Glucagon, an important regulator of hepatic glucose production, has been measured in response to various carbohydrates. Growth hormone was measured in response to oral doses of sucrose, glucose, and fructose. Fructose ingestion before and during exercise did not result in cortisol levels different from those due to glucose ingestion or a sweet placebo. Thyroxine levels have been reported to be normal in both type I and type II diabetics, but triiodothyroxine levels are reduced. Interrelationships among the glucoregulatory hormones are very complicated and not fully understood. Little research has been reported describing the effects upon these hormones of either oral fructose doses or adaptation to chronic fructose ingestion in man.
