Blood Tests for Alzheimer’s: What They Can and Can’t Tell Us
New research has brought renewed attention to blood tests that may help detect biological markers associated with Alzheimer’s disease. These tests, which identify proteins such as amyloid and tau, have generated headlines for their potential to identify brain changes long before symptoms appear. But as promising as the science may be, they come with important limitations—and even more important context for patients and families.
To help clarify the role these tests currently play in neurological care, insight was provided by Reeva Salkin, MSN, APN-BC, ANP-BC of Shore Physicians Group’s Neurology Division in Somers Point, NJ. Salkin evaluates patients who worry their memory lapses may signal something serious and understands both the appeal and the risk of relying too heavily on these newly publicized tests.
“These blood tests can’t be done at your local lab,” she explained. “They have to be sent to a private specialty company and are used only in very specific cases. Even if the result is positive, it doesn’t necessarily predict what a person’s future will look like.”
Salkin notes that test results—positive or negative—can easily lead to misunderstandings. “If the test shows certain biomarkers, someone may interpret that as an inevitable sign of Alzheimer’s, and that isn’t the case. But if it’s negative, a person might feel they don’t need to make healthy changes. Neither reaction is helpful.”
Right now, these emerging tests support—but do not replace—a full evaluation. Alzheimer’s is diagnosed through careful history-taking, cognitive assessments, medical review, and imaging when appropriate.
Salkin emphasizes starting with the basics because many common medical issues can mimic dementia and are far more easily treated. Vitamin B12 deficiency, thyroid disorders, vitamin D deficiency, and even infections can produce symptoms that look like early cognitive decline. “B12 deficiency is extremely common,” she said. “Addressing it can dramatically improve mental clarity.”
Brain imaging, while useful, is also only one piece of the picture. Some individuals show age-related changes on MRI and function perfectly well, while others with normal scans experience real symptoms. This is why clinical context remains critical.
When discussing what constitutes concerning symptoms, Salkin draws an important line. Occasional misplaced keys or a forgotten phone are not the red flags. “What concerns us are changes truly out of character—getting lost on the way to a familiar place, difficulty managing bills, or confusion that persists. Those are the cues to look deeper.”
Yet despite the anxiety many patients feel, Salkin stresses that there is meaningful room for optimism. “Lifestyle plays a significant role,” she said. “Keeping the brain active, learning new things, staying socially connected—these can all influence cognitive health. If something feels mentally challenging, that’s good. It means the brain is engaged.”
While Alzheimer’s blood tests may someday offer earlier insights, they are not intended as first-line screening tools, nor should they be interpreted without a larger medical context. As Salkin explains, “People are understandably worried when memory changes begin. The best approach is a thoughtful, step-by-step evaluation that looks at the whole person.”
For now, the most effective path forward remains careful clinical assessment, attention to overall health, and habits that keep the mind active—long before turning to a specialized blood test for answers.
Reeva Salkin, MSN, APN-BC, ANP-BC, treats patients at Shore Physicians Group’s Neurology Division offices located at 700 Shore Road in Somers Point, NJ. To schedule an appointment with Reeva Salkin, call 609-365-6202.
