Putting ice on injuries 'could slow down healing'

London: Contrary to conventional wisdom, putting ice on injuries could slow down healing as it prevents the release of a key repair hormone, says a new study.

For years, people have been told to freeze bruised or sprained muscles to reduce the swelling. Now, an international team claims that slapping a packet of frozen peas on a black eye or a sprained ankle may prevent it getting better.

The study, published in the 'Federation of American Societies for Experimental Biology' journal, suggests muscle inflammation after acute injury is essential to repair. It can also lead to new therapies for acute muscle injuries that lead to inflammation.

In the study, Prof Lan Zhou and colleagues at the Cleveland Clinic in Ohio discovered inflamed cells produce a high level of a hormone called insulin-like growth factor-1 (IGF-1) which significantly increases the rate of muscle regeneration.

During the study, the scientists studied two groups of mice. The first group was genetically altered so they could not form an inflammatory response to injury. The second group was normal.

All mice were then injected with barium chloride to cause muscle injury. The first group of mice did not heal, but the bodies of the second group repaired the injury. When they studied the muscle tissue they saw the healthy mice produced a high level of IGF-1 in their inflamed tissue.

"We hope that our findings stimulate further research to dissect different roles played by tissue inflammation in clinical settings, so we can utilise the positive effects and control the negative effects of tissue inflammation," 'The Daily Telegraph' quoted Prof Zhou as saying.

Added Gerald Weissmann, editor of the journal: "For wounds to heal we need controlled inflammation, not too much, and not too little. This study goes a long way to telling us why insulin-like growth factor and other materials released by inflammatory cells helps wound to heal."