New Study: Testing for Alzheimer’s Using Saliva

It’s clear we’ve entered a new age of medical testing. Whereas in previous generations, testing for disease and genetic conditions seemed nearly impossible, we’ve managed to develop relatively easy, innovative,  and effective ways doing just that, with surprising accuracy. Case and point: scientists may be able to determine a person’s risk for Alzheimer’s by testing their saliva. According to a new study published by Dr. Shraddha Sapkota, a graduate of neuroscience from the University of Alberta, Canada, saliva has promising potential for both predicting and tracking cognitive decline in older adults.

Better Testing For Alzheimer’s Needed

Medical News Today reports that “Alzheimer’s disease affects around 5.3 million people in the US and is the sixth leading cause of death in the country. It is predicted that by 2050, around 13.5 million Americans will have the condition.” Currently, there is no single test one can take to determine whether or not they have Alzheimer’s or are at risk of developing the condition. An Alzheimer’s diagnosis requires extensive medical evaluation, including physical and neurological testing, all of which can be tedious, not to mention expensive.

Dr. Sapkota and his colleagues note that many of these diagnostic methods for Alzheimer’s can be invasive and costly, which has prompted them to search for a simpler, cheaper technique. While there is no way to halt the progression of Alzheimer’s, early detection can allow the individual to better benefit from medications which treat the symptoms of the condition. Moreover, early detection of Alzheimer’s can raise the likelihood of individuals participating in clinical trials aimed at finding a cure for the disease, therefore increasing the chances of treating Alzheimer’s once and for all.

New Research Aims at Prevention and Early Detection

The study analyzed the saliva samples of 22 participants who had Alzheimer’s, 25 who had mild cognitive impairment, or MCI, and 35 participants with normal cognitive functioning. These samples were analyzed using liquid chromatography-mass spectrometry, or LCMS, to examine certain compounds within the saliva. In doing so, “The researchers identified compounds that were more pronounced in the saliva of participants with Alzheimer’s and MCI, differentiating them from healthy participants. These findings were validated in a further sample including seven participants with Alzheimer’s, 10 with MCI and 10 cognitively normal participants.” Additionally, further analysis revealed that the presence of higher levels of certain substances in the participant’s saliva was linked with poor cognitive functioning. For example, “a higher level of a certain compound in the saliva of participants with Alzheimer’s was linked to slower information processing speed.”

Where Does This Type of Research Lead?

But what is the future of this research? The team believes that the results of this study can potentially lead to more inexpensive, noninvasive, diagnostic techniques for Alzheimer’s that can still produce reliable results, although more research is, of course, needed. However, Sapkota appears optimistic, saying: “Saliva is easily obtained, safe and affordable, and has promising potential for predicting and tracking cognitive decline, but we’re in the very early stages of this work and much more research is needed.” Moreover, he adds: “Equally important is the possibility of using saliva to find targets for treatment to address the metabolic component of Alzheimer’s, which is still not well understood. This study brings us closer to solving that mystery.”

Interestingly, this is not the only recent breakthrough in Alzheimer’s research. Another study reveals a possible correlation between a protein in one’s cerebrospinal fluid, or CSF, and it’s ability to predict the decline from MCI to Alzheimer’s. Conducted by Dr. Maartje Kester of the VU University Medical Center in Amsterdam and his colleagues, this study assessed samples of CSF taken over a 2 year period from 162 participants with either MCI, Alzheimer’s, or normal cognitive function. Their analysis revealed that participants with Alzheimer’s possessed higher baseline levels of neurogranin, a protein in the brain, in their CSF samples than did participants with MCI or normal cognitive functioning. In addition, “baseline neurogranin levels were higher among participants whose MCI had progressed to Alzheimer’s, indicating that the protein may be a predictor of cognitive decline among individuals with MCI.”

Researchers also found that neurogranin levels increased over time for participants with normal cognitive functioning, a result which was not mirrored in participants with either MCI or Alzheimer’s. Because of this, Dr. Kester believes that “This may indicate that neurogranin levels in CSF reflect very early synaptic loss in Alzheimer’s and may be useful for early detection.”

New Insight into a Silent Killer

The studies of both Dr. Kester and Dr. Sapkota have succeeded in providing new insight into how we identify and define Alzheimer’s, particularly in its earlier stages. This can potentially assist in diagnosing Alzheimer’s and even predicting its occurrence, which can allow for better and more effective treatment options for those diagnosed. With early enough diagnosis, there may even be hope for the discovery of a cure. In the meantime, further research is needed, but thankfully, the future looks promising.