The TL;DR
Glucose is the primary fuel for your cells, but it is also a “sticky” molecule. When blood glucose levels are chronically high or highly variable (spiking and crashing), glucose binds to proteins in a process called glycation, forming “Advanced Glycation End-products” (AGEs). This literally “gums up” your biology, stiffening blood vessels and aging skin. The goal is not zero glucose, but stable glucose.
Accessibility Level
Level 1 (Foundation): Glucose control is the most actionable longevity intervention. With tools like CGMs (Level 2) or standard blood tests (Level 1), feedback is immediate.
The Science of Glucose
The Goldilocks Zone
The body fights desperately to keep blood glucose in a tight range (70–100 mg/dL).
- Too Low (Hypoglycemia): Brain fog, seizures, death.
- Too High (Hyperglycemia): Toxicity, vessel damage, nerve damage.
Glycemic Variability (GV)
Average glucose (HbA1c) tells only half the story. Two people can have an HbA1c of 5.0%, but one is stable while the other swings wildly from 50 to 200 mg/dL. Variability is damaging. Large spikes drive oxidative stress and endothelial dysfunction (damage to the artery lining) more than stable, slightly elevated levels.
AGEs (Advanced Glycation End-products)
When glucose binds to hemoglobin, it forms HbA1c. When it binds to collagen in your skin, you get wrinkles. When it binds to blood vessels, you get stiffness (hypertension). Controlling glucose is controlling the rate of this “internal cooking” process.
Evidence Matrix
| Source | Verdict | Notes |
|---|---|---|
| Clinical Research | Strong Consensus | High glucose variability predicts mortality in non-diabetics (Ceriello et al.). |
| David Sinclair | Critical | Describes glucose spikes as accelerating the “epigenetic clock.” |
| Peter Attia | Critical | Targets flat, stable glucose curves to prevent insulin resistance. |
Optimal Ranges
| Marker | Standard Range | Longevity Target |
|---|---|---|
| Fasting Glucose | < 100 mg/dL | 75–85 mg/dL |
| HbA1c | < 5.7% | 4.8% – 5.2% |
| Peak Glucose | < 140 mg/dL | < 120-130 mg/dL (post-meal) |
| Standard Deviation | n/a | < 15 mg/dL (measured via CGM) |
How to Optimize
- Food Order: Eat fiber (veggies) first, protein/fat second, and carbs last. This blunts the glucose spike significantly.
- The “Post-Meal Walk”: Walking for 10 minutes after a meal can reduce the glucose peak by 30-50%.
- Muscle Mass: Muscle is a glucose sink. The more you have, the more carb-tolerant you are.
- Avoid “Naked Carbs”: Never eat sugar or starch alone. Always pair with fat, fiber, or protein.
References
Ceriello, A., et al. (2008). Oscillating glucose is more deleterious to endothelial function and oxidative stress than mean glucose in normal and type 2 diabetic patients. Diabetes, 57(5), 1349-1354.
Barr, E. L., et al. (2007). Risk of cardiovascular and all-cause mortality in individuals with diabetes mellitus, impaired fasting glucose, and impaired glucose tolerance. Circulation, 116(2), 151-157.
Mogi, M., et al. (2019). Glucose variability and visceral fat in non-diabetic adults. Cardiovascular Diabetology.