A recent study hints that Vitamin C may be the key to stopping the blood vessel damage commonly caused by diabetes. When Type 1 diabetics were given high dose injections of Vitamin C along with insulin, damage to their blood vessels ceased. The results suggest that this treatment may also be able to stop or reduce the long-term complications of diabetes such as increased risk of heart attack, blindness and limb amputation.

Once endothelial dysfunction begins, it continues to worsen even when diabetics get their blood sugar under control ...

This is the first time this treatment has been shown to be effective in humans.

Researchers at the Harold Hamm Oklahoma Diabetes Center, in collaboration with researchers at the University of Warwick in the UK, are currently testing the therapy on patients with the more common, Type 2 diabetes.

Type 1 diabetes is caused by a lack of insulin production; Type 2 diabetes is typically due to a decrease in the effectiveness of insulin.

The high blood sugar resulting from diabetes eventually causes damage to blood vessels (endothelial dysfunction). This damage is thought to be the primary cause of the most serious symptoms of long term diabetics: increased cardiovascular problems, kidney disease, poor circulation that may lead to limb amputation and diabetic retinopathy, which can lead to blindness. Once endothelial dysfunction begins, it continues to worsen even when diabetics get their blood sugar under control (though controlling blood sugar does help). In the study, Vitamin C halted this damage, presumably through its strong antioxidant activity. Neither insulin nor Vitamin C was able to do this alone; they were only effective when combined.

While researchers do suggest that diabetics eat foods and take multivitamins rich in antioxidants such as Vitamin C, they caution that it is unlikely that oral Vitamin C intake will give the same results as seen in the study. The researchers were introducing Vitamin C directly into the bloodstream, while oral doses must first pass through the digestive system.

The researchers are seeking more details about how Vitamin C manages to halt blood vessel damage, eventually hoping to discover the molecular mechanism involved. They're also testing a number of other antioxidants to see if any of them can be used as an effective, simple and inexpensive treatment for diabetes.

The research was published online June 2, 2009 in the Journal of Clinical Endocrinology & Metabolism.