Resveratrol is a naturally occurring chemical found in grapes that has been reported to have cardioprotective, anti-inflammatory, anti-viral, and glucose-lowering properties. The effect of resveratrol on lowering blood glucose in diabetic rats has been reported by several investigators in the past.

Their results have shown that resveratrol improves glycemia by stimulating glucose transport in certain tissues including the skeletal muscle that expresses the insulin-sensitive Glut4 isoform of glucose transporters. However, the research by Drs. Martin and Ismail-Beigi shows that in cells expressing the Glut1 isoform, resveratrol blocks glucose transport by binding and inhibiting the Glut1 transporter. This may be of importance because certain cells and tissues, including brain, retina, placenta, and red blood cells express large amounts of this transporter. Hence, the presumed inhibition of the Glut1 transporter in these tissues in-vivo may have undesired and negative effects on their normal function.