Your spit may hold clues to future brain health, say scientists who have found that small molecules in saliva can help identify those at risk of developing Alzheimer's disease.
Alzheimer's disease, a degenerative brain disorder with no cure and few reliable diagnostic tests, is predicted to reach epidemic proportions worldwide by 2050.
Scientists at the Beaumont Research Institute in the US wanted to identify valid and reliable biomarkers to diagnose the disease in its earliest stages before brain damage occurs and dementia begins.
They found salivary molecules hold promise as reliable diagnostic biomarkers.
"We used metabolomics, a newer technique to study molecules involved in metabolism," said Stewart Graham, from Beaumont Research Institute.
"Our goal was to find unique patterns of molecules in the saliva of our study participants that could be used to diagnose Alzheimer's disease in the earliest stages, when treatment is considered most effective," said Graham.
"Presently, therapies for Alzheimer's are initiated only after a patient is diagnosed and treatments offer modest benefits," he said.
Metabolomics is used in medicine and biology for the study of living organisms.
It measures large numbers of naturally occurring small molecules, called metabolites, present in the blood, saliva and tissues.
The pattern or fingerprint of metabolites in the biological sample can be used to learn about the health of the organism.
"Our team's study demonstrates the potential for using metabolomics and saliva for the early diagnosis of Alzheimer's disease," said Graham.
"Given the ease and convenience of collecting saliva, the development of accurate and sensitive biomarkers would be ideal for screening those at greatest risk of developing Alzheimer's," he said.
"In fact, unlike blood or cerebrospinal fluid, saliva is one of the most noninvasive means of getting cellular samples and it's also inexpensive," he added.
The study participants included 29 adults in three groups - mild cognitive impairment, Alzheimer's disease and a control group.
After specimens were collected, researchers positively identified and accurately quantified 57 metabolites. Some of the observed variances in the biomarkers were significant.
From their data, they were able to make predictions as to those at most risk of developing Alzheimer's.
"Worldwide, the development of valid and reliable biomarkers for Alzheimer's disease is considered the number one priority for most national dementia strategies," said Graham.
"It's a necessary first step to design prevention and early-intervention research studies," he said.