STEROIDS that help athletes to enhance their physique may also cause their brains to waste away, research suggests.

Large doses of steroids are known to boost levels of the male hormone testosterone and cause a condition known as hyperexcitability, characterised by heightened aggression and suicidal tendencies. Anger brought on by steroid use is well known in the bodybuilding world, where it is known as “roid rage”.

Professor Barbara Ehrlich, of the Yale School of Medicine, said that hyperexcitability could be evidence of impaired brain function. She said: “Next time a muscle-bound guy in a sports car cuts you off on the highway, don’t get mad, just take a deep breath and realise that it might not be his fault.”

To test the theory, Professor Ehrlich’s team exposed cultured nerve cells to testosterone. The scientists found that high levels of the hormone triggered programmed cell death, or apoptosis — a natural process that clears away damaged cells.

Apoptosis forces cells to “commit suicide” and plays a role in combating cancer.

“We have demonstrated for the first time that the treatment of [cancerous] neuroblastoma cells with elevated concentrations of testosterone for relatively short periods, six to twelve hours, induces a decrease in cell viability by activation of a cell death programme,” said Professor Ehrlich. “Low concentrations of testosterone had no effects on cell viability, whereas at high concentrations the cell viability decreased with incremental increases in hormone concentration.”

The findings appear in the Journal of Biological Chemistry.The researchers said that apoptosis is linked to neurologial illnesses including Alzheimer’s and Huntingdon’s diseases.

In a recent study in the journal Behavioural Neuroscience, hamsters given anabolic steroids became unusually aggressive. For two weeks after the drug was withdrawn, the animals attacked intruders on their territory before reverting to normal placid behaviour.

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