FDA Clears First Alzheimer's Blood Tests for Primary
Get the Health newsletter
Daily health & science — research, biotech, public health, the studies worth knowing. Free.
- Elizabeth A. Bevins, a UC San Diego neurologist and Alzheimer's specialist, recounts missing the disease in her own father despite her expertise, realizing it only when he failed to recognize the family's longtime dog after a granddaughter was born.
- Alzheimer's biology begins 15 to 20 years before symptoms become visible, meaning by the time of clinical diagnosis the brain has already sustained substantial and often irreversible injury from amyloid accumulation and tau pathology.
- The clinical system is calibrated to disease endpoints — no specialty owns prevention, primary care physicians lack tools and guidelines, and neurologists see patients only after symptoms emerge, leaving at-risk midlife adults undetected.
- In 2025, the FDA cleared the first blood tests for Alzheimer's disease, including one designed specifically for use in primary care, though they are currently indicated only for patients already showing symptoms.
- The AHEAD 3-45 clinical trial, which completed recruitment in 2024, is testing anti-amyloid therapies in presymptomatic people with elevated amyloid burden, building on the expectation that earlier intervention yields greater benefit.
- Large population studies have identified modifiable risk factors — cardiovascular and metabolic health, sleep, physical activity, and social engagement — that together account for a substantial proportion of dementia risk, with multidomain trials showing preserved cognitive function in at-risk groups.
- Bevins is building a prevention program at UC San Diego called Brain Longevity that offers structured risk assessment and longitudinal brain health planning for healthy adults concerned about hereditary risk.
Why it matters: With the FDA clearing the first Alzheimer's blood tests in 2025 and the AHEAD 3-45 trial testing prevention in presymptomatic patients, the bottleneck is no longer scientific knowledge but clinical infrastructure. Primary care lacks the standardized frameworks and referral pathways needed to identify at-risk patients before irreversible brain injury occurs, leaving a generation of midlife adults with modifiable risk factors to move through the healthcare system undetected.
