Alpha-Lipoic Acid (ALA)
Universal antioxidant and mitochondrial cofactor
What It Is
Alpha-lipoic acid is both water- and fat-soluble, giving it access to every compartment of the cell. It's a cofactor for mitochondrial enzymes (pyruvate dehydrogenase, alpha-ketoglutarate dehydrogenase) and regenerates other antioxidants including vitamins C and E, and glutathione.
How It Works
ALA serves as a cofactor in the mitochondrial pyruvate dehydrogenase complex, directly supporting energy metabolism. It also chelates heavy metals, activates AMPK (an energy-sensing enzyme), and upregulates endogenous antioxidant defenses via Nrf2.
The Science
Alpha-lipoic acid as a dietary supplement: molecular mechanisms and therapeutic potential
Biochimica et Biophysica Acta (2009) · PubMed
Comprehensive review of ALA's mechanisms including mitochondrial cofactor role, antioxidant recycling, and AMPK activation.
Treatment of diabetic polyneuropathy with alpha-lipoic acid (NATHAN 1 trial)
Diabetes Care (2011) · PubMed
4-year RCT showing ALA improved neuropathic symptoms in diabetic patients, though the primary composite endpoint was not met.
Dosage
300–600mg/day of R-alpha-lipoic acid (the bioactive form). The R-form is preferred over racemic ALA. Take on an empty stomach for best absorption.
Safety
Generally safe. May lower blood sugar — monitor if diabetic or on glucose-lowering medications. High doses (>1200mg) can cause nausea and GI discomfort. May interfere with thyroid hormone levels.
Skeptic's Corner
ALA has solid biochemistry and moderate human data for diabetic neuropathy and blood sugar management. However, anti-aging-specific evidence is limited. Most longevity claims extrapolate from its role as an antioxidant, and the 'antioxidant supplementation extends lifespan' hypothesis has been largely debunked by clinical trials. Its value may be most clear for people with metabolic dysfunction.
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