What Labs Can Detect Early Alzheimer’s Risk?
Last Updated: December 2025
Dr. Jessica Knape of HealthSpan Internal Medicine in Boulder, CO, explains how advances in blood biomarkers, imaging, and functional testing now allow Alzheimer’s risk to be detected years before symptoms appear. She highlights the importance of early testing to identify root causes and enable prevention or reversal of cognitive decline.
For decades, Alzheimer’s could only be diagnosed after memory loss had already begun.. Now, that’s changing. Advances in blood-based biomarkers, imaging, and functional testing allow us to detect risk years — even decades — before symptoms appear.
At HealthSpan Internal Medicine in Boulder, CO, we use a combination of conventional and functional lab tests to identify the root causes of cognitive decline early, when prevention and reversal are still possible.
Your BrainSpan Snapshot
Alzheimer’s disease begins silently, often 10–20 years before symptoms.
Blood tests can now detect amyloid, tau, and neurodegeneration markers.
Additional labs measure inflammation, metabolism, hormones, and vascular health — all major contributors to brain aging.
Early detection means more time to intervene with lifestyle, metabolic, and therapeutic support.
1. Core Alzheimer’s Biomarkers
These are the most specific indicators that Alzheimer’s-type changes are happening in the brain.
Aβ42 / Aβ40 Ratio (Amyloid Beta):
Low ratios suggest excess amyloid buildup, one of the earliest signs of Alzheimer’s pathology. Blood versions of this test now correlate strongly with amyloid PET scans.
pTau-181 or pTau-217 (Phosphorylated Tau):
Tau proteins inside neurons become abnormally phosphorylated as the disease progresses. Elevated levels signal early neurodegeneration even before memory loss.
Neurofilament Light Chain (NfL):
A marker of neuronal injury and axonal damage. It rises in Alzheimer’s, vascular dementia, and other neurodegenerative conditions.
GFAP (Glial Fibrillary Acidic Protein):
Reflects inflammation in glial cells — the brain’s support and immune network. Elevated GFAP often precedes both amyloid and tau changes.
Where to Get These Tests:
Available through major diagnostic labs (e.g., C2N Diagnostics, Quest, Labcorp) and often included in research-grade “plasma AD biomarker panels.”
2. Genetic and Epigenetic Risk Factors
Genetics set the stage, but environment and lifestyle determine expression.
APOE Genotype:
APOE ε4 increases Alzheimer’s risk, particularly in homozygous (ε4/4) individuals.
APOE ε2 may be protective.
This doesn’t guarantee disease but helps personalize prevention.
MTHFR and Detox Genes:
Affect methylation and homocysteine metabolism, both crucial for vascular and brain repair.
Epigenetic Age Tests:
DNA methylation-based “biological age” testing can identify accelerated aging linked to metabolic or inflammatory stress — a potential early cognitive risk signal.
3. Metabolic and Mitochondrial Health
The brain is an energy-intensive organ. Poor glucose control, insulin resistance, or mitochondrial dysfunction create the “metabolic storm” that accelerates aging.
Recommended Labs:
Fasting insulin and HOMA-IR (insulin sensitivity)
Fasting glucose and HbA1c
Lipid panel (HDL, LDL, triglycerides)
C-peptide (beta cell activity)
Lactate and pyruvate (mitochondrial efficiency)
Thyroid panel (TSH, Free T3, Free T4, Reverse T3)
Interpretation Tip:
Even “normal” fasting glucose can mask early insulin resistance. Fasting insulin under 8 µIU/mL is ideal for long-term brain protection.
4. Inflammatory and Immune Markers
Neuroinflammation is a key driver of dementia — often fueled by chronic systemic inflammation.
Key Labs:
High-sensitivity C-reactive protein (hs-CRP) – general inflammation marker
Interleukin-6 (IL-6) and TNF-alpha – cytokines linked to neuroinflammation
Homocysteine – vascular and mitochondrial stress marker
Galectin-3 – associated with microglial activation and amyloid buildup
Ferritin – excess iron promotes oxidative damage
Fibrinogen and ESR – markers of clotting and inflammatory burden
These markers help identify underlying drivers that are treatable with anti-inflammatory nutrition, detoxification, and targeted therapies like TB006 (galectin-3 inhibition).
5. Hormones and Neurotransmitter Support
Hormones act as “growth signals” for neurons. Deficiencies accelerate atrophy, fatigue, and cognitive decline.
Labs to Assess:
DHEA-S
Estradiol and progesterone (in women)
Testosterone (in men and women)
Cortisol (AM/PM or salivary pattern)
IGF-1 and growth hormone markers
Maintaining optimal—not just normal—levels helps protect synapses, mitochondria, and mood.
6. Nutrient and Detox Labs
Even subtle deficiencies can impair neurotransmitter production and detox pathways.
Recommended Labs:
Vitamin D (25-OH) – ideal 50–80 ng/mL
Vitamin B12 and methylmalonic acid (MMA)
Folate (RBC)
Magnesium (RBC or ionized)
Zinc and Copper balance
Omega-3 Index (EPA + DHA % in RBC membranes)
Heavy metal screen (mercury, lead, arsenic)
Mycotoxin testing (for suspected mold-related illness)
Correcting deficiencies can improve cognition, energy, and resilience even in midlife.
7. Functional Brain and Imaging Studies
While not “labs” in the traditional sense, these tools provide deeper insights:
MRI with Volumetrics:
Tracks hippocampal size, white matter health, and microvascular changes.
PET or Amyloid Imaging (if indicated):
Used primarily in research or advanced diagnostic settings to confirm Alzheimer’s pathology.
8. How We Use These Tests at HealthSpan Internal Medicine
Our Brainspan Evaluation combines standard and advanced labs to create a full picture of cognitive resilience:
Amyloid/Tau Panel: Blood biomarkers for early Alzheimer’s changes.
Metabolic Panel: Insulin, glucose, lipids, and thyroid.
Inflammation Panel: hs-CRP, IL-6, homocysteine, galectin-3.
Hormone and Nutrient Panel: DHEA, testosterone, B vitamins, omega-3s.
Mitochondrial & Oxygen Testing: Energy metabolism and tissue oxygenation.
Clinical Genomics: with IntellxxDNA to assess genomics risks including APOE 4, MTHFR, IL6, and TOMM40 variations
We then design a targeted plan to correct what’s measurable — long before cognitive decline becomes permanent.
Bottom Line
You can’t change your genetics, but you can change your biology and your brain health.
Modern Alzheimer’s prevention focuses on detecting risk early — identifying inflammation, insulin resistance, oxidative stress, and amyloid/tau activity before symptoms arise.
With the right testing and early action, cognitive decline is no longer inevitable.
Alzheimer’s may begin decades before memory loss.
Get ahead of dementia with a personalized plan: lab biomarkers (amyloid/tau, NfL, GFAP), vascular/metabolic labs, lifestyle risk assessment, and ongoing monitoring — all through Dr. Knape’s BrainSpan program.
👉 Reserve your meet and greet today!
Sources
First FDA-Cleared Blood Test for Alzheimer’s — Lumipulse G pTau217/β‑Amyloid 1‑42 Plasma Ratio
Advances in Blood-Based Biomarkers for Alzheimer’s (p-tau, Aβ etc.)
Plasma Neurofilament Light (NfL) & GFAP: Early Markers of Neurodegeneration
Longitudinal Evidence: Blood Biomarkers Predict Future Cognitive Decline
Consensus and Emerging Guidelines for Clinical Use of Blood Biomarkers
Medically reviewed by
Dr. Jessica Knape, MD, MA Board Certified in Internal Medicine and Integrative and Holistic Medicine
Healthspan Internal Medicine — serving patients in Boulder, CO
Book a Discovery Call | About Dr. Knape
This content is for educational purposes and does not replace personalized medical advice.
