Alzheimer's Disease
The brain's metabolic crisis. Alzheimer's is the most common cause of dementia, characterized by memory loss, cognitive decline, and behavioral changes. Beyond plaques and tangles, it's increasingly understood as a metabolic disease—"type 3 diabetes" reflects brain insulin resistance.
Key Mechanisms
Amyloid Plaques
Beta-amyloid protein accumulates outside neurons. Toxic oligomers most harmful. Not the whole story.
Tau Tangles
Tau protein forms tangles inside neurons. Disrupts cell transport. Correlates with symptoms.
Neuroinflammation
Microglia chronically activated. Inflammatory cytokines. May drive progression.
Brain Insulin Resistance
"Type 3 diabetes." Neurons can't use glucose. Energy crisis. Metabolic dysfunction.
Mitochondrial Dysfunction
Brain is energy-hungry. Damaged mitochondria. Oxidative stress increases.
Synaptic Loss
Connections between neurons die. Correlates best with cognitive decline.
Risk Factors
Non-Modifiable
- Age: Biggest risk factor
- Genetics: APOE4 allele major risk
- Family history: Increases risk
- Sex: Women at higher risk
Modifiable
- Cardiovascular: What's bad for heart is bad for brain
- Diabetes: Major risk factor
- Sedentary: Exercise is protective
- Sleep: Poor sleep increases amyloid
The "Type 3 Diabetes" Concept
Brain Insulin Resistance
Neurons become resistant to insulin. Can't take up glucose properly. Energy starvation.
Glucose Hypometabolism
PET scans show reduced glucose use. Especially in hippocampus. Precedes symptoms.
Ketones as Alternative
Brain can use ketones for fuel. Bypass insulin resistance. Ketogenic approaches studied.
Diabetes Connection
Type 2 diabetes doubles AD risk. Shared pathways. Blood sugar control matters.
Metabolic Syndrome
Obesity, high BP, high triglycerides. All increase AD risk. Inflammation link.
Intranasal Insulin
Delivers insulin to brain. Being studied in clinical trials. Some positive signals.
Prevention Strategies
Exercise
Most powerful intervention. Increases BDNF, blood flow. Both cardio and strength.
Blood Sugar Control
Avoid spikes and chronic elevation. Low glycemic diet. Consider intermittent fasting.
Quality Sleep
Glymphatic system clears amyloid during sleep. Treat sleep apnea. 7-8 hours goal.
Mediterranean Diet
Strong evidence for brain health. MIND diet variant. Anti-inflammatory foods.
Cognitive Engagement
Use it or lose it. Learning, social connection. Build cognitive reserve.
Manage Cardiovascular
Blood pressure, cholesterol. What's good for heart is good for brain.
Supportive Nutrients
Omega-3 (DHA)
Brain is 60% fat. DHA critical. Low levels associated with AD. 1-2g EPA+DHA.
Vitamin D
Low levels increase risk. Neuroprotective. VDR in brain. Optimize levels.
B Vitamins
B12, folate, B6. Lower homocysteine. May slow atrophy. MTHFR considerations.
Lion's Mane
Mushroom that promotes NGF. Early research promising. Worth considering.
Curcumin
Anti-inflammatory, may reduce amyloid. Absorption challenge. Needs enhancement.
MCT Oil/Ketones
Alternative brain fuel. C8 MCT best. Some cognitive benefits shown.