Science:
Fasting insulin rises 10-15 years before glucose becomes abnormal — making it the earliest detectable marker of metabolic dysfunction. The optimal range is 2-6 uIU/mL. Most people told their glucose is “normal” have fasting insulin above 10.
Action:
Request fasting insulin specifically — it is not in standard metabolic panels and must be explicitly requested.
Calculate HOMA-IR: (fasting glucose x fasting insulin) / 405. Below 1.0 is optimal; above 2.0 indicates insulin resistance. This is a blood test calculation that estimates how well your body handles insulin and glucose.
If fasting insulin above 10 uIU/mL: prioritize time-restricted eating, reduce refined carbohydrates, add Zone 2 cardio 3/wk (at a pace where you can comfortably converse ie. a brisk walk or easy jogging).
Walk 10 minutes after every meal — reduces postprandial glucose by up to 30% and lowers insulin demand.
Retest after 12 weeks of dietary and exercise modifications — fasting insulin responds faster than any other metabolic biomarker.
Dose and Frequency:
Test fasting insulin annually. Intervene immediately if above 10 uIU/mL — the sooner addressed, the more reversible it is.
From the Neurologist:
Insulin resistance in the brain - “type 3 diabetes” in research literature - is among the most studied mechanisms of Alzheimer’s pathology. Insulin receptors are densely expressed in the hippocampus, where insulin signaling promotes neurogenesis, synaptic plasticity, and amyloid clearance. When neurons become insulin resistant, these processes fail.
Call to Action:
Request fasting insulin at your next doctor’s visit. Optimal is 2-6 uIU/mL. Post on social media where your level lies. Tag us!
References:
Disclaimer: The content published in The Brain Capsule is for informational and educational purposes only. It is not intended to substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider before making any changes to your health, diet, or wellness routine. The views expressed are based on current research and are subject to change as new evidence emerges.