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Saliva holds the key to reducing upper respiratory illness in athletes

Posted on 28/12/2008

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Saliva holds the key to reducing upper respiratory illness in athletes

A Loughborough University study has identified a protein in saliva that could be key to ensuring the health and well-being of Britain’s elite athletes.

Vernon Neville, Professor Michael Gleeson and Dr Jonathan Folland from the University’s School of Sport and Exercise Sciences have discovered that levels of the immunoglobulin A protein (IgA), which is found in human saliva, can provide advance warning of upper respiratory infections (URIs) a common cold, which are the most common medical complaint of athletes.

The study involved 38 athletes from the prestigious America’s Cup yacht race and is the most comprehensive of its kind. It is the first to show that URIs can be predicted by monitoring saliva protein levels in groups of elite competitors. The results have huge potential for athletes as well as other groups such as the armed forces, where good health is paramount for performance and infections are easily spread.

The study was carried out over 50 weeks and subjects were from a top yacht crew preparing for the 32nd America’s Cup (2007). Athletes provided weekly saliva samples and rated their level of fatigue, while their sailing and training load and any respiratory illnesses and infections were also recorded.

Results showed that levels of the saliva protein declined in the weeks prior to infection, and as a group the lower the level of IgA the greater the risk of illness. When IgA levels dropped below 40% of the normal value, athletes had a one in two chance of infection. Low levels of IgA also corresponded with high levels of fatigue, identified by the athletes.

Upper respiratory infections have a huge impact on athlete health. In a two-year training period before the 31st America’s Cup, 40% of all illnesses were URI, which accounted for 60% of days absent from sailing due to illness.

Dr Folland believes regular monitoring of saliva holds the key to reducing occurrences of URI.

“This is the first real evidence of an immune system marker that can help to predict upper respiratory illness,” he said. “URIs may be avoided by regularly monitoring saliva levels of a group and using illness prevention strategies such as reduced training, improved nutrition and limiting exposure to infections when low values occur.

“Not only is this information invaluable for those managing groups of elite athletes, but it has much wider implications in many environments where good health is vital to performance.”