The secret to developing stem cell therapies for diseases such as diabetes, Parkinson's and heart disease is to use cells taken from women, scientists claimed yesterday.

Female stem cells are better at healing disease than those from males, according to a study by researchers at the University of Pittsburgh.

Using research into animals with muscular dystrophy, the team found female stem cells regenerated muscle tissue more effectively than male cells. If replicated in humans, their discovery could enhance the success of therapies in which stem cells are used to repair damaged organs and replace lost tissue.

Scientists believe stem cells, which have the ability to grow into different kinds of tissue, have the potential to help sufferers of cancer, motor neurone disease, and many others.

The study is the first to report a difference between the sexes on the regenerative capabilities of muscle stem cells. The authors believe their findings will also yield clues to the differences between men and women with regards to ageing and disease.

Dr Johnny Huard, senior author of the report, said: "The implantation of female stem cells led to significantly better skeletal muscle regeneration.

"Based on these results, future studies investigating regenerative medicine should consider the sex of the stem cells to be an important factor.

"Furthermore, investigations such as ours could lead to a better understanding of sex-related differences in ageing and disease and could explain, at least partially, the high variability and conflicting results reported in the literature on stem cell biology."

Dr Bridget Deasy, made the discovery at the university, while searching for a cure for Duchenne muscular dystrophy (DMD).

DMD is a genetic disease estimated to affect one in every 3500 boys. Sufferers lack dystrophin, a protein that gives muscle cells structure.

Dr Deasy took animals with DMD and injected their muscles with stem cells which could deliver the missing dystrophin. When she measured the ability of these stem cells to regenerate muscle fibres, she found the female cells performed significantly better, on average, than the male cells.

Dr Deasy said the difference may be because of the different ways male and female cells respond to "oxidative stress" - caused by damaging highly-reactive molecules. "The major difference was what we observed after exposing the cells to stress or after cell transplantation in the animals that suffer from muscular dystrophy.

"Transplantation of female cells leads to a much more significant level of skeletal muscle regeneration."

The study was published yesterday in the Journal of Cell Biology.