Could Blood Test Detect Alzheimer’s 16 Years Before Symptoms?

An Arivale Hot Topic

Jennifer Lovejoy, Arivale Chief Science Officer, PhD
Jennifer Lovejoy
Arivale Chief Science Officer, PhD

The changes in the brain associated with Alzheimer’s disease actually occur decades before the onset of the disease’s clinical symptoms of memory loss and cognitive decline.

For example, accumulation of the protein amyloid-β in the brain occurs 15 to 20 years before the onset of Alzheimer’s, while decreases in metabolism in the brain’s cortex occur 10 to 15 years before, and brain atrophy occurs 5 to 10 years before.

Given this, it’s important to begin therapeutic interventions – either lifestyle changes or potentially drug treatments – as early in the disease process as possible. And, while it’s possible to get information on early signs of Alzheimer’s through brain imaging or sampling spinal fluid, those processes can be either very expensive or very invasive.

That’s why identifying biomarkers that would allow for early detection of Alzheimer’s progression through a simple blood draw would be a major advancement in the field.

The Study

recent study published in Nature Medicine identified just such a blood test.

A protein called “neurofilament light chain,” abbreviated NfL, was found to be elevated in people with a genetic mutation that causes an early onset form of Alzheimer’s disease (when compared to family members without the mutation). In a CNN story related to the new finding, the study’s author describes NfL as a blood marker that “gives an indication of nerve cell loss in the brain  …  The more neurofilament you have in the blood, the more brain damage you have.”

In a cross-sectional comparison of family members with and without the mutation, NfL levels in blood predicted the disease roughly seven years in advance of symptoms. But, the real power of the prediction came in following NfL in multiple measures over time – in this analysis the annual rate of change in NfL (i.e. a slow but steady increase over time) could predict who would develop Alzheimer’s more than 16 years in advance of symptoms.

The importance of tracking blood markers over time and looking for changes in trend, rather than simply looking at a single point in time, is a key component of personalized medicine and Scientific Wellness® – as well as the backbone of the Arivale program – and this study clearly shows how powerful this approach can be.

Arivale’s Take

Researchers somewhat aptly describe finding a blood biomarker that is predictive of Alzheimer’s as the “holy grail.” Given the number of people impacted by this terrible disease, and the poor outcomes to date of drug trials to treat it, it would indeed be revolutionary if we found a way to predict who was going to develop Alzheimer’s before the brain damage advances.

Current research is still preliminary. For example, in the study released last week the population used was a group at risk for a unique form of early onset inherited Alzheimer’s disease – which is not the form of the disease that impacts most people. It’s not known whether NfL would be as predictive in people who develop the more common form of Alzheimer’s. Furthermore, as noted by the study author, NfL levels simply reflect damage to the brain – thus it may not be a specific marker for Alzheimer’s.

But, there is good news. Even without a predictive blood test, there’s solid evidence that a “multi-domain” lifestyle program, such as that offered by Arivale, can delay or prevent cognitive decline associated with aging.

The components of a brain-healthy lifestyle program include: adequate sleep, an optimized diet, regular aerobic activity, brain training, stress management, and regular social interaction.  Adopting these lifestyle components in middle age can go a long way toward ensuring healthy older years. In addition, making sure that you are working with your doctor to effectively manage conditions like high blood pressure, high cholesterol, and depression is also important for optimizing brain health as you get older.

Further Reading



[Arivale Hot Topics address health stories currently in the news. The Arivale Clinical Team’s commentary on these news articles is not a review of the scientific evidence, nor an endorsement of a specific study, and is not meant as official medical opinion.]