Cracking the Code: How Epigenetics and Blood Tests Are Changing the Alzheimer's Landscape

Alzheimer’s disease, a condition that slowly erodes memory and cognitive function, has long been one of the most formidable challenges in medicine. With a rapidly growing patient population in the U.S., the impact of Alzheimer’s disease is profound and far reaching. In 2020, approximately 6.2 million Americans aged 65 or older were living with Alzheimer's disease, a number projected to more than double to 12.7 million by 2050. 

First identified by Dr. Alois Alzheimer in 1906, Alzheimer’s disease has been a complex target for research, effective treatment, and diagnosis. But recent breakthroughs in two distinct areas—epigenetics and diagnostic testing—are offering new hope for earlier detection and more personalized care.

What Is Epigenetics—and Why Does It Matter?

While most people understand that genes influence health, fewer realize that environment and lifestyle can affect how genes function. This is the focus of epigenetics, a field that explores how factors like stress, diet, and aging can switch genes on or off without changing the DNA sequence itself. 

In Alzheimer’s disease, researchers have discovered that epigenetic changes may significantly influence how the disease develops and progresses. For example, chemical modification through DNA methylation can be used to silence genes that protect brain cells, while other changes may activate genes that promote inflammation or the buildup of harmful proteins that are key markers of the disease. 

What makes this discovery so promising is that epigenetic changes are potentially reversible. Scientists are now exploring drugs that could “reset” these gene switches, opening the door to new treatments – or even prevention strategies – for Alzheimer’s in the future. 

A Simpler Way to Detect Alzheimer’s: The FDA-Approved Blood Test

While epigenetics helps to explain the “why” behind Alzheimer’s, a new diagnostic tool is helping to answer the “if.” In May 2025, the U.S. Food and Drug Administration approved the first blood test to help diagnose Alzheimer’s in people showing signs of cognitive decline. 

Developed by Fujirebio Diagnostics, the test measures two proteins in the blood—pTau217 and beta-amyloid 1-42—that are strongly linked to Alzheimer’s. Until now, confirming a diagnosis often required expensive brain scans or invasive spinal taps. This new test offers a simpler and more accessible alternative.

In addition to being less invasive, simpler, and more accessible, the newly approved blood tests have the potential to reshape Alzheimer’s care in several important ways:

• Improved Clinical Decision-Making – In clinical trials, the test accurately identified Alzheimer’s-related brain changes in 91.7% of cases compared to traditional methods like PET scans and spinal fluid analysis. This level of accuracy enhances diagnostic confidence, reduces risk of misdiagnosis, and helps ensure patients receive appropriate care.
• Faster Access to Treatment – Early diagnosis is critical, especially as new treatments—such as monoclonal antibodies targeting amyloid plaques, are most effective in the early stages. This test allows patients to begin treatment sooner, potentially slowing disease progression and preserving quality of life.
• Expanded Access in Underserved Areas – Because the test only requires a blood draw, it can be administered in rural or underserved communities, bringing high-quality diagnostics to populations that previously lacked access.
• Advancements in Research and Personalized Medicine – Widespread use of the test can accelerate clinical trials by identifying eligible participants earlier. Over time, it may also support more personalized treatment plans based on an individual’s biomarker profile. 

The Bigger Picture: Personalized and Preventive Care

Together, these advances point to a future where Alzheimer’s care is more personalized and proactive. Epigenetic research could lead to therapies tailored to an individual’s unique biological profile, while blood-based diagnostics make early detection more feasible—perhaps even before symptoms emerge.

As our understanding deepens, Alzheimer’s may shift from a devastating diagnosis to a manageable condition. And that is a future worth working toward.

Authored by Lisa Krist, Berkley Life Sciences, VP, Chief Customer Focus Officer