Can a saliva test advance Alzheimer's disease diagnosis?

Scientists have identified biomarkers that can help in early detection of mild cognitive impairment and Alzheimer's disease in saliva samples.

A saliva test would prove useful in clinical settings for its ease and non-invasive nature. It also has the potential to detect neurodegenerative diseases earlier on, allowing for early intervention, said a team from the University of Alberta in Canada.

Liang Li, Professor in the Department of Chemistry, and Roger Dixon, Professor in the Department of Psychology examined saliva samples from three sets of patients -- those with Alzheimer's disease, those with mild cognitive impairment and those with normal cognition.

Using a powerful mass spectrometer, the team examined more than 6,000 metabolites -- compounds that are part of our body's metabolic processes -- to identify any changes or signatures between groups.

"In this analysis, we found three metabolites that can be used to differentiate between these three groups," said Li.

"This is preliminary work because we've used a very small sample size. But the results are very promising. If we can use a larger set of samples, we can validate our findings and develop a saliva test of Alzheimer's disease," Li noted.

In addition, identifying these biomarkers is the ability to conduct efficacy testing for treatments.

"Using the biomarkers we can also do testing to see what types of treatments are most effective in treating Alzheimer's disease, from diet to physical activity to pharmaceuticals," added Li.

"So far, no disease-altering interventions for Alzheimer's disease have been successful," said Dixon. "For this reason, researchers are aiming to discover the earliest signals of the disease so that prevention protocols can be implemented."