Alzheimer’s disease is the most prevalent cause of dementia, a progressive neurological condition that significantly impairs memory, thinking, and behavior. It is characterized by the gradual accumulation of abnormal proteins—amyloid plaques and neurofibrillary tangles—in the brain. These biological changes lead to the death of brain cells and progressive brain shrinkage.

In a significant advancement for early detection, the U.S. Food and Drug Administration (FDA) has granted marketing authorization to a new blood test designed to aid in the diagnosis of Alzheimer’s disease. This marks the first blood-based diagnostic tool to receive FDA clearance for Alzheimer’s in the United States.

A Breakthrough Diagnostic Tool

The newly approved test, known as the Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio, is intended for adults aged 55 and older who are exhibiting symptoms of Alzheimer’s. The test detects two blood proteins—pTau217 and beta-amyloid 1-42—whose ratio reflects the presence of amyloid plaques, a hallmark of Alzheimer’s disease. Although the test does not directly detect plaques, it serves as a reliable indicator of their presence.

The FDA emphasized that the results of the blood test should be interpreted alongside other clinical data, as there remains no singular definitive test for Alzheimer’s. Physicians continue to rely on a comprehensive diagnostic approach, including medical history assessments, neurological and cognitive evaluations, brain imaging, spinal fluid analysis, and now, increasingly, blood-based biomarkers.

Clinical Trial Findings and Impact

Developed by Pennsylvania-based Fujirebio Diagnostics Inc., the test aims to reduce reliance on more invasive and costly procedures such as Positron Emission Tomography (PET) scans, which can cost thousands of dollars and are not always covered by insurance.

In FDA-reviewed clinical trials, blood samples from 499 cognitively impaired individuals were analyzed using the new test and compared against PET scan and Cerebrospinal Fluid (CSF) results. The findings were promising:

• 91.7% of participants who tested positive with the blood test were confirmed to have amyloid plaques through PET or CSF testing.

• 97.3% of those with negative blood test results had no plaques confirmed by follow-up testing.

The primary risks associated with the test are related to potential false positives or false negatives. Nonetheless, the test represents a significant stride toward broader, less invasive screening capabilities.⁽¹⁾

Can Alzheimer’s Be Prevented? What We Know So Far

While there is currently no cure or definitive method to prevent Alzheimer’s disease, research suggests that certain lifestyle choices can reduce risk.

Many of the same behaviors that promote heart health also appear to protect the brain. These include:

• Regular physical activity

• Managing high blood pressure, diabetes, and high LDL cholesterol

• Quitting smoking and alcohol

Diet also plays a crucial role. Numerous studies indicate that adherence to a Mediterranean diet—rich in fruits, vegetables, whole grains, fish, nuts, and olive oil—can support cognitive health and slow decline. This diet limits foods high in saturated and trans fats, such as red meat, fried items, and pastries.⁽²⁾

Keeping the Mind Active

Engaging in lifelong mental and social activity has been associated with lower rates of cognitive decline. Activities that may help reduce the risk of Alzheimer’s include:

• Reading regularly

• Learning new languages

• Playing musical instruments

• Participating in group sports or social clubs

• Pursuing hobbies and new experiences

• Maintaining strong social connections

• Solving puzzles

References:

1. "US Approves First Blood Test For Alzheimer's,” The Hindu, May 18, 2025. https://www.thehindu.com/sci-tech/health/us-approves-first-blood-test-for-alzheimers/article69590170.ece

2. “Alzheimer's Disease,” NHS, Last modified on July 4, 2024. https://www.nhs.uk/conditions/alzheimers-disease/

(Input from various sources)

(Rehash/Dr. Hansini Bhaskaran/MSM)