Metformin for Alzheimer's Disease
Also known as: Glucophage
Insulin resistance is increasingly recognized as an Alzheimer's risk factor. Metformin addresses metabolic dysfunction that may drive neurodegeneration.
Mechanism of Action
Metformin improves central insulin sensitivity, reduces tau hyperphosphorylation via AMPK-mediated GSK3β inhibition, promotes autophagic clearance of misfolded proteins, and reduces neuroinflammation through NF-κB suppression. The concept of Alzheimer's as 'type 3 diabetes' supports metabolic intervention.
General mechanism: AMPK activator via Complex I inhibition. Reduces mTOR signaling, glucose production, and inflammatory pathways.
Current Evidence
Epidemiological studies show mixed results — some suggest reduced AD risk with metformin use, others show no effect or increased risk (possibly due to B12 depletion). The TRIMAAD trial is investigating metformin in early AD. B12 co-supplementation may be important.
Clinical Status: Epidemiological data mixed. TRIMAAD trial ongoing. Not approved for AD.
Safety Profile
GI effects (diarrhea, nausea). Lactic acidosis risk (rare). B12 depletion with long-term use. Contraindicated in severe renal impairment.
Key Research Questions
- Does B12 co-supplementation resolve the conflicting epidemiological data?
- Can metformin slow Alzheimer's progression in patients with metabolic syndrome?
- What is the interaction between metformin and anti-amyloid antibodies?
Frequently Asked Questions
Can metformin prevent cancer?
Epidemiological studies show diabetic patients on metformin have 20-40% lower cancer incidence. Metformin activates AMPK, inhibits mTOR, and reduces insulin/IGF-1 signaling — all relevant to cancer prevention. The TAME trial is studying metformin for aging and age-related diseases including cancer.
What is the TAME metformin trial?
TAME (Targeting Aging with Metformin) is a landmark clinical trial testing whether metformin can delay age-related diseases including cancer, cardiovascular disease, and dementia in non-diabetic adults aged 65-79. It's the first FDA-approved trial targeting aging as a condition.
Metformin dosage for longevity
Longevity-focused protocols typically use 500-1500mg daily, lower than the diabetes dose of 2000mg. Extended-release formulations reduce GI side effects. Vitamin B12 monitoring is recommended with long-term use.