Contradicting the old perception that a new blood is good for transfusion and an old blood could be harmful. McMaster University  researchers say that using the freshest blood does not improve patients outcome.  Their study rebuts the common understanding that storing blood might be harmful. The study shows about 31,500 patients at six hospitals in four countries having a blood transfusion with the freshest one did not decrease the amount of patients who died in hospitals.

Nancy Heddle, the lead author, and research director from McMasterUniversity stated that  their study puts an end to the question and contentious issue whether stored blood could be harmful and the fresher blood would be better. Their study provides resilient evidence that the transfusion of fresher blood does not improve the patient result, and this reassures clinicians that fresher is not better.

There are 31, 497 adult patients calculated were at hospitals  in US,Australia,  Canada, and Israel. The mortality rate of people who receives the freshest blood is 9.1 per cent while those who received old blood is 8.7 percent. There was no notable distinction upon looking at those patient's blood type, diagnosis, hospital or country, The Indian Express reports.

John Eikelboom from McMaster said that more than 40 studies published earlier, failed adequately to answer the question whether the freshest blood was best. According to Eikelboom, the blood transfusion is a common medical intervention. The advances in blood storage now allowed blood to be stored up to 42 days before the transfusion and the usual practice is to use up blood that has been in the storage the longest, via Daily News.

There are structural, functional, and biochemical changes in the blood during the storage, and there had been concerns about the 'older' blood use but the study reassures again that aging is not bad even for blood, John Eikelboom said.

The McMaster study has been published by  New England Journal of Medicine and was funded by the Canadian Institutes of Health Research, Canadian Blood Services and Health Canada.