Coffee and Caffeine Ameliorate Hyperglycemia, Fatty Liver, and Inflammatory Adipocytokine Expression in Spontaneously Diabetic KK-A^y Mice

Abstract

Epidemiological surveys have demonstrated that habitual coffee consumption reduces the risk of type 2 diabetes. The aim of this work was to study the antidiabetic effect of coffee and caffeine in spontaneously diabetic KK-A(y) mice. KK-A(y) mice were given regular drinking water (controls) or 2-fold diluted coffee for 5 weeks. Coffee ingestion ameliorated the development of hyperglycemia and improved insulin sensitivity. White adipose tissue mRNA levels of inflammatory cytokines (MCP-1, IL-6, and TNFalpha), adipose tissue MCP-1 concentration, and serum IL-6 concentration in the coffee group were lower than the control group. Moreover, coffee ingestion improved the fatty liver. Caffeine ingestion as drinking water also caused an amelioration of hyperglycemia and an improvement of fatty liver. These results suggest that coffee exerts a suppressive effect on hyperglycemia by improving insulin sensitivity, partly due to reducing inflammatory cytokine expression and improving fatty liver. Moreover, caffeine may be one of the effective antidiabetic compounds in coffee.

Low-energy diets differing in fibre, red meat and coffee intake equally improve insulin sensitivity in type 2 diabetes: a randomised feasibility trial

“…Chronic coffee consumption has been reported to have similar effects [30]. On the other hand, coffee can impair insulin sensitivity, while liver steatosis and inflammation is reduced, despite identical and unchanged body weight in spontaneously diabetic mice [31]. Thus, L-RISK and H-RISK diets are likely to improve insulin sensitivity by different mechanisms, which may occur independently of the weight loss resulting from energy restriction.…”

Coffee Improves Insulin-Stimulated Akt Phosphorylation in Liver and Skeletal Muscle in Diabetic KK-Ay Mice

“…In another experiment, we showed that coffee or caffeine ingestion prevented the development of glucose intolerance and insulin resistance in C57BL/6J mice fed a high-fat diet for 17 wk (5). In KK-A y mice, the accumulation of triglycerides in liver was reduced by coffee ingestion (4). As fatty liver provokes insulin resistance in liver, coffee might decrease insulin resistance in liver by ameliorating fatty liver.…”

“…We recently examined the anti-diabetic effect of coffee using KK-A y mice, a type 2 diabetes animal model, and demonstrated that coffee or caffeine ingested as drinking water ameliorated hyperglycemia, insulin resistance, and fatty liver in those mice (4). In another experiment, we showed that coffee or caffeine ingestion prevented the development of glucose intolerance and insulin resistance in C57BL/6J mice fed a high-fat diet for 17 wk (5).…”

Coffee Consumption is Associated with a Lower Incidence of Fatty Liver in Middle-aged Men

“…It was reported that caffeine might also improve insulin sensitivity and fatty liver in mice. 28) In addition, coffee and caffeine can cause weight loss, 29,30) possibly reducing visceral fat and thereby reducing lipid accumulation in hepatocytes. Of all the types of fat tissue, visceral fat is the most metabolically active and which plays an important role in the development of fatty liver.…”