A simple saliva test could provide an early indication of how likely a person is to die prematurely, new research suggests.
Lower levels of certain antibodies found in saliva were linked with an elevated risk of mortality and the risk of early death from most cancers, according to a study by Birmingham University scientists.
Over a 20-year period, the study examined associations between secretory immunoglobulin A (IgA) – a common antibody found in saliva – and mortality rates in the general public. Antibodies are proteins secreted by white blood cells and are essential for protecting people from infectious diseases.
More than 600 Scottish adults took part in the research, whose findings were published in the scientific journal PLOS ONE. Participants, who were aged 63 when the study began, had their IgA secretion rate measured and their mortality tracked. The associations were adjusted for factors including gender, smoking, medication use and self-reported health conditions.
Those with the highest levels of antibodies were 19 per cent less likely to die prematurely, and 32 per cent less likely to die early from most cancers, the study found.
Dr Anna Phillips, of Birmingham University, said: “Quite how saliva samples could be used in check-ups remains to be seen, as we need to better understand what secretion rate would be considered cause for concern – what we call the protective level.
“We could certainly say that, if found to be extremely low, it would be a useful early indicator of risk.”
The team say the next step would be to conduct a larger study to investigate the link with infectious diseases and the progression of illnesses like cancer in order to gain a better understanding of the mechanisms behind the association found in the study.