C₉H₁₅N₃O₂S (EGT)
The Longevity Vitamin
1909
Discovered
2005
Transporter ID'd
2018 (Ames)
Proposed Vitamin
200+
Published Studies
Ergothioneine (EGT) is a unique sulfur-containing amino acid that has been proposed as a new vitamin — the 'longevity vitamin.' First discovered in 1909 in ergot fungi, it is produced exclusively by fungi and certain bacteria; humans cannot synthesize it and must obtain it from the diet. What makes ergothioneine extraordinary is that the human body has evolved a dedicated transporter protein (OCTN1/SLC22A4) specifically to absorb and distribute it to tissues under high oxidative stress — the brain, liver, kidneys, bone marrow, and eyes. No other dietary antioxidant has its own genetically encoded transport system.
While ergothioneine wasn't identified until 1909 by Charles Tanret, its effects have been unknowingly consumed through mushrooms for millennia. Traditional food cultures with high mushroom consumption (Japan, China, Korea, parts of Europe) correlate with populations known for longevity. The dedicated transporter OCTN1 was identified in 2005, and its existence in human biology strongly suggests that ergothioneine has been an essential nutrient throughout human evolution. Some researchers have called for its reclassification as a vitamin.
Dedicated human transporter (OCTN1) — suggests evolutionary importance
Accumulates in tissues under highest oxidative stress
Protects mitochondria — the cell's energy generators
Supports cognitive health and brain longevity
May protect against age-related cellular decline
More stable than glutathione — doesn't auto-oxidize
Richest Dietary Sources of Ergothioneine
A unique betaine-form thiol that resists auto-oxidation, making it far more stable than glutathione. Scavenges hydroxyl radicals, singlet oxygen, and hypochlorous acid.
The SLC22A4 gene encodes a specific transporter that actively imports ergothioneine from the gut and distributes it to high-stress tissues. Conserved across mammals.
A biosynthetic precursor to ergothioneine. Found in mushroom mycelium and part of the EGT synthesis pathway.
A selenium-containing analog of ergothioneine found in some marine fungi. Even more potent antioxidant but less studied.
Research into ergothioneine has accelerated dramatically since 2010, with over 200 published studies. Dr. Bruce Ames (UC Berkeley) proposed in 2018 that ergothioneine should be classified as a new vitamin, based on the existence of its dedicated transporter and correlations between low EGT levels and increased disease risk. A 2020 study in the British Medical Journal (Roth et al.) demonstrated an inverse relationship between blood EGT levels and cognitive decline risk. Population studies in Singapore (DIET & Healthy Aging study) found that mushroom consumption (and by extension EGT intake) was significantly associated with reduced risk of mild cognitive impairment. Mushrooms — particularly Shiitake, King Trumpet, and Oyster — are the richest dietary source.
*These statements have not been evaluated by the Food and Drug Administration. This information is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare provider before starting any supplement regimen.