Predictions And Prevention: Research Moves Closer To Diagnosing Alzheimer’s In Advance of Symptoms

You may remember that, back in November, we reported on the emergence of additional blood biomarker tests for Alzheimer’s that, while not actually giving you an Alzheimer’s diagnosis, would be able to rule out one of the proteins highly predictive of Alzheimer’s in patients who are experiencing worrisome symptoms. In the past few years, there has been more and more research that supports the use of blood testing to determine if someone with cognitive impairment might actually be suffering from Alzheimer’s. These tests are not supposed to be used by the “worried well” (i.e., people with no symptoms) but can be used in conjunction with other cognitive testing and scans to confirm or rule out an Alzheimer’s diagnosis.

Now comes word, from a study published in Nature Medicine, of a blood test that can pick up rogue tau proteins in the blood, which are indicative of the formation of Alzheimer’s in the brain, and through this testing can predict the rise of tau accumulation to the point of being able to estimate when Alzheimer’s symptoms are likely to begin in an individual patient. This is a genuinely new capability that appears highly predictive, so that in a person with no known dementia symptoms, researchers may be able to predict when such symptoms may surface, with a current error rate of 3-4 years. We know that the formation of amyloid and tau in the brain can develop sometimes years, even decades, before Alzheimer’s symptoms may arise, so that this blood test may be able to identify those at risk before any brain damage has occurred. Identifying people who may develop Alzheimer’s, who have yet to show symptoms, could create a huge leap in our ability, through clinical trials, to establish treatments that not only slow the progression of the disease (as current treatments do) but even forestall or prevent the development of symptoms in the first place. This is an exciting potential for the study and treatment of Alzheimer’s. Someday, it may even be possible that, similar to a cholesterol test, mid-life and older adults will be routinely blood tested to assess whether treatment for Alzheimer’s should be started before symptoms surface. Exciting, for sure, but we are not quite there to make this a current reality.

This is an important point to emphasize. This new blood biomarker test is not yet ready to be used on currently healthy people with no symptoms of Alzheimer’s. Further research on this blood test needs to happen on a more diverse patient population, and researchers need to better assess the accuracy of the test as well as to reduce the projected timetable error window to lower than a 3-4 year margin of error. Nonetheless, the ability to forecast the development of Alzheimer’s before symptoms arise is a huge research milestone. Studies are already underway to develop treatments that could be used for individuals who have not yet experienced cognitive impairment, so being able to identify people who might benefit from such research offers an exciting possibility going forward. As one of the researchers stated, “If we could predict (Alzheimer’s disease onset) within a year or so, that would really be valuable. I think it’s closing in, but not there yet.”

In the meantime, we already know that many actionable lifestyle and behavioral steps can be taken to lower your risk of Alzheimer’s. New, recently published research provides even further actionable steps for you to take. First, underscoring the important role of proper sleep for brain health and clearing toxins from the brain, a new study published in The Journal of Gerontology: Series A projects that one in 8 cases of Alzheimer’s is tied to poor sleep. Given that the projections from this study are that 13% of dementia cases- almost half a million cases- are attributable to insomnia (on par with the risk of Alzheimer’s due to hearing loss or high blood pressure), this research emphasizes that addressing insomnia among adults could be a promising new target for dementia prevention efforts as we go forward. 

One additional new study also elucidates another potential lifestyle habit that may be connected to the risk of Alzheimer’s. According to this study, just published in the journal Neurology,  mentally stimulating activities, such as reading, playing board games, visiting libraries or museums, etc., over the course of your lifetime could be responsible for delaying the onset of Alzheimer’s significantly, in comparison to those who have lived less stimulated lives. For example, the research found that those in the top 10% of “cognitively enriched” lifestyles developed Alzheimer’s at the average age of 94 compared to those in the least enriched category, who developed Alzheimer’s at the average age of 88. This suggests that such an enriched lifestyle could extend your cognitive health by several years. The same differences in brain health also held for those who were eventually diagnosed with mild cognitive impairment.

What’s even more remarkable about this study is that brain autopsies were performed on deceased study participants, and many of those with delayed Alzheimer’s onset due to enriched lifestyles nonetheless had amyloid plaques and tau tangles in their brains. While this study demonstrates an association, not causation, what this means is that even in the presence of brain deterioration that is typically associated with Alzheimer’s, those who led more mentally enriched lives were able to remain cognitively resilient. As one expert was quoted as saying, “The more you challenge your brain, the stronger and more resilient it becomes.” In essence, those who engage in lifelong brain stimulation are helping to develop a more durable brain for themselves as they get older. So under the category of it’s never too late to build up your cognitive reserve and lower your risk of dementia, take out your library card and look here.