Children with type 1 diabetes can have the severity of their disease reduced if they are infused with blood saved from their umbilical cords, a study has found. Scientists think the infusion resets the body's immune system, stopping it from destroying insulin-producing cells that are needed to control blood sugar levels.

"After only six months it is too early to tell how long the children will benefit from this therapy, but early signs indicate that it may have helped enhance blood glucose control and management, said Michael Haller of the University of Florida College of Medicine, who led the new research.

There are 350,000 people in the UK with type 1 diabetes, and 20,000 of them are children. The disease occurs when the body's immune system destroys insulin-producing cells in the pancreas. It can result in debilitating effects such as heart disease, blindness, kidney disease, and amputations. The only treatment is multiple daily injections of insulin.

Dr Haller studied 20 children aged between two and seven with type 1 diabetes. Seven were infused with their cord blood, while the remainder were treated as normal with insulin injections. Scientists followed the group for several months, measuring blood glucose levels and the amount of insulin used by each patient.

The results, presented yesterday at the annual meeting of the American Diabetes Association in Chicago, showed that children given the cord blood had lower blood glucose levels and needed less daily insulin therapy to control their diabetes than children who did not get the therapy.

Desmond Schatz of the University of Florida, who also took part in the research, said the success of the therapy could be down to a type of cell in the cord blood, regulatory T cells, that can stop the immune system attacking the pancreas, thereby holding the diabetes in check.

"While we have not followed the participants long enough to determine how long these benefits will last, the improvement in blood glucose control appears to be related to the infusion of these cord blood cells."

The seven children in the trial were chosen because their parents had their cord blood frozen after birth. Several companies offer this service for a few thousand pounds. The argument goes that, because it contains stem cells, the blood might prove useful for the child in the future when scientists know how to use stem cells to rebuild organs and other damaged tissue if the child needed treatment.