In multiple animal studies, fisetin restored blood sugar levels of diabetic rats and mice to those of healthy animals.

It improved their ability to control blood sugar levels by:

l Increasing insulin levels

l Increasing enzymes that turn sugar into energy

l Removing sugar from the blood to store as glycogen in the liver

l Reducing the liver’s ability to make sugar from lactate and amino acids

Fisetin slowed the progression of cataracts and protected the kidneys of diabetic mice by blocking inflammation and oxidative stress. It also protected the liver of diabetic rats from high blood sugar levels by increasing antioxidant levels.

Another complication of diabetes is the hardening of the arteries and heart disease. In a cell study, fisetin prevented high sugar levels from causing inflammation in blood vessels.