The high blood glucose levels that characterize diabetes significantly injure the body's blood vessels and other tissues due to increased levels of oxidative stress and other factors. This damage underlies the increased risk of heart attack, stroke and kidney disease observed in diabetic patients. In an article published online on July 15, 2008 in the journal Diabetes, researchers from the University of Warwick in England report that a compound in broccoli could help undo some of this damage.

Previous studies have found associations between diets rich in vegetables, including broccoli and other members of the Brassica family, and a lower risk of cardiovascular disease. Professor Paul Thornalley of Warwick Medical School and his associates tested the effect of the compound sulforaphane, found in Brassica vegetables, on human microvascular endothelial cells incubated in low and high concentrations of glucose. They found that the compound reduced reactive oxygen species (a type of free radical whose levels can triple with elevated glucose) by 73 percent. It was also discovered that sulforaphane doubled the activation a protein known as nrf2, which protects tissues from oxidative stress by activating protective enzymes. Additionally, the compound prevented increased cellular accumulation and excretion of methylglyoxal, a substance that increases glycation. Glycation is the bonding of sugar and protein molecules which increases under conditions of elevated blood sugar, and which can also damage blood vessels.

“Our study suggests that compounds such as sulforaphane from broccoli may help counter processes linked to the development of vascular disease in diabetes," Dr Thornalley commented. "In future, it will be important to test if eating a diet rich in Brassica vegetables has health benefits for diabetic patients. We expect that it will.”