Research could lead to a simple saliva test capable of diagnosing – at an early stage – diabetes and cancer, and perhaps neurological disorders and autoimmune diseases.
The study, the most comprehensive analysis ever conducted of RNA molecules in human saliva, reveals that saliva contains many of the same disease-revealing molecules that are contained in blood. It was published online by the peer-reviewed journal Clinical Chemistry.
According to researchers, the test also holds promise for diagnosing type 2 diabetes, gastric cancer and other diseases.
RNA is a cellular messenger that makes proteins and carries out DNA’s instructions to other parts of the cell. Researchers discovered that some of the same RNA that is inside human cells are also present in saliva and can be used to detect diseases – a surprising finding because enzymes in saliva can degrade RNA, making the mouth ‘a hostile environment’.
Scientists compared microRNA levels in saliva to those in the blood and other body fluids, and found the levels of microRNA in blood and in saliva are very similar – indicating that a saliva sample would be a good measure of microRNAs in the body.
The overriding conclusion is that saliva has tremendous medical and scientific value. In the not-too-distant future, dentists might be able to take saliva samples to analyse for a variety of diseases. And the research could lead to a new category of self-diagnostic devices.