Diana Hsieh traces how fasting lowers leptin, triggering cortisol release that creates oxidative stress in hair follicles. This damages stem cells and slows growth. Animal studies show chronic fasting can kill follicles entirely.
Tell me about the new study on fasting and hair loss. Intermittent fasting actually does lead to hair loss. When you fast, leptin goes down. Leptin's release from fat tissue, and that activates the brain to activate the hypothalamic pituitary adrenal axis. The adrenals kick out cortisol and epinephrine. Now, what cortisol and epinephrine are good at doing is stimulating fat burning. What happens is it causes the stem cells to burn them. Fatty acid oxidation, and at such a high rate that actually there's an increase in oxidative stress that overwhelms the antioxidant capacity, leading to basically poisoning and apoptosis, programmed cell death of these stem cells. And so hair growth slows. You know, longer fasts had a more potent effect if it was applied chronically, at least in the animal models, led to basically death of the hair follicle.
