A rice cultivar called ‘wx/ae’, double mutant in waxy (wx) and amylose extender (ae) genes, is
rich in resistant starch. Type 2 diabetic NSY mice were fed a test diet containing 30% roasted
wx/ae brown rice (wx/ae group) or its parental rice cultivar Kinmaze brown rice (WT group)
for 16 weeks. The insulin sensitivity of the wx/ae group was significantly higher than that
of the WT group, and the concentrations of fasting plasma triacylglycerol and nonesterified
fatty acids were lower. Gene expression analysis of the liver revealed that expression
levels of insulin-dependent genes and bile acid-related genes in the two groups were significantly
different. Moreover, expression of the G protein-coupled receptor 43 gene in the
epididymal white adipose tissue was significantly higher in the wx/ae group. These results
indicate that wx/ae brown rice is a good candidate food for the prevention of type 2 diabetes
and hypertriglyceridaemia.