Ergothioneine - the longevity vitamin from mushrooms? What the data shows
Ergotioneina: odpowiedzi oparte na badaniach naukowych. u Bucha.
Ergothioneine (EGT) has remained in the shadow of more well-known antioxidants for decades. This is changing. Recent epidemiological and mechanistic studies have sparked serious interest in this amino acid - particularly the discovery that the body has a dedicated cellular transporter, OCTN1, that actively accumulates EGT in tissues most exposed to oxidative stress (Grundemann et al., PNAS, 2005). The fact that evolution has 'designed' a special transporter for this substance suggests that it is biologically important - although clinical evidence is still building. This article gathers what is truly known.
KEY INFORMATION
• The body has a dedicated transporter OCTN1 for ergothioneine - an evolutionary signal of its biological significance (Grundemann et al., PNAS, 2005).
• Oyster mushrooms contain 2.5-5 mg of EGT per 100 g of fresh weight - among the richest food sources.
• A prospective study (Koh et al., 2023) suggests a 30% lower risk of cardiovascular events in the highest quartile of EGT in the blood.
• Phase I clinical studies confirm the safety of doses of 5-30 mg daily.
• There are still no completed RCTs confirming causal protective effects - correlations are strong, but they remain correlations.
What is ergothioneine and where does it come from?
Ergothioneine is a betaine derivative of histidine with a thiol group - an amino acid synthesized exclusively by fungi and certain soil bacteria (e.g., Actinomycetales). Humans, plants, and animals cannot synthesize it de novo - the only way to obtain it is through diet. EGT intake accumulates in tissues very slowly (the half-life in the blood is several weeks), but effectively - in erythrocytes, liver, kidneys, brain, and mitochondria.
A key discovery was in 2005 when Grundemann and colleagues identified the OCTN1 transporter (SLC22A4) as a specific 'pump' for ergothioneine into cells (Grundemann et al., PNAS, 2005). This transporter is highly expressed in tissues exposed to oxidative damage - mitochondria, red blood cells, bone marrow. If EGT were an ordinary dietary metabolite of no significance, evolution would not have preserved a highly specific transporter for millions of years. This is a biochemical argument - but a strong one.
Professor Bruce Ames from UC Berkeley and Irwin Rosenberg from Tufts University called EGT the 'longevity vitamin' in the context of a broader theory that deficiencies of certain micronutrients essential for protecting mitochondrial DNA may accelerate aging. Ergothioneine, along with selenium and coenzyme Q10, is on this list.
Where to get ergothioneine from the diet?
Mushrooms are an unparalleled source of EGT. The concentration depends on the species and growing conditions - mushrooms growing in soils richer in manganese (a cofactor for the enzyme synthesizing EGT in fungi) have higher concentrations. Oyster mushrooms (Pleurotus ostreatus) are among the richest sources - up to 5 mg of EGT per 100 g of fresh weight. Button mushrooms (Agaricus bisporus) contain about 0.4 mg/100 g, shiitake - 0.4-1.3 mg/100 g.
For comparison: meat contains trace amounts of EGT (mushrooms in the diets of animals accumulate it in muscle tissues, but at very low concentrations). Beef liver contains about 0.2 mg/100 g - significantly less than oyster mushrooms. The Western European diet provides an estimated 1-5 mg of EGT daily, while Asian societies that regularly consume shiitake and other mushrooms may intake 5-10 mg daily.
We have noticed that many epidemiological studies on EGT come from Singapore and Japan - countries with high mushroom consumption. This raises the question of confounding: does EGT provide protection, or is mushroom consumption a marker of an overall healthier diet rich in fiber, polyphenols, and other protective components? Well-conducted RCTs with isolated EGT are needed to answer this question.
What do the data say about the protective effects of ergothioneine?
Epidemiological data are consistent and include several independent cohorts. The study by Koh and colleagues from Singapore (2023, n=3159) showed an inverse correlation between EGT levels in plasma and the risk of cardiovascular events - individuals in the highest quartile had about a 30% lower risk over a 5-year observation (Koh et al., Eur Heart J, 2023). Earlier studies have shown correlations with a lower risk of dementia and a milder course of Parkinson's disease.
Mechanistic data are more homogeneous. EGT is unique among thiol antioxidants in that its sulfur radical is relatively stable and does not convert into reactive forms after neutralizing free radicals - meaning that 'used' EGT does not become a pro-oxidant. This property distinguishes it from N-acetylcysteine (NAC) and glutathione under certain oxidative conditions. In mitochondria - the site of the highest production of free radicals - EGT appears to act as an oxidative buffer.
Studies on mouse models of neurodegeneration show protection of dopaminergic neurons from oxidative stress with EGT supplementation. Target tissues are those that contain the most OCTN1 transporter: brain, erythrocytes, bone marrow. But - and this is an important caveat - mice are not humans, and pharmacological efficacy in vivo does not always translate to clinical effects in humans.
Table of EGT sources and estimated intake
| Product | EGT (mg/100 g) | A 100 g serving provides |
|---|---|---|
| Oyster mushrooms (Pleurotus ostreatus) | 2,5-5,0 | 2,5-5,0 mg EGT |
| Shiitake (Lentinula edodes) | 0,4-1,3 | 0,4-1,3 mg EGT |
| White button mushroom (Agaricus bisporus) | 0,3-0,6 | 0,3-0,6 mg EGT |
| Beef liver | ~0,2 | ~0.2 mg EGT |
| Chicken (breast) | <0,05 | <0,05 mg EGT |
| EGT supplements (typical) | 5-25 mg/kaps. | 5-25 mg EGT (1 kaps.) |
Ergothioneine and cognition and brain aging - what do the data suggest?
The brain is among the tissues most exposed to oxidative stress - it consumes about 20% of the total oxygen while constituting only 2% of body mass, generating huge amounts of reactive oxygen species. Dopaminergic neurons of the striatum and prefrontal cortex are particularly susceptible to oxidative damage. These are the areas that degenerate in Parkinson's disease and early cognitive aging.
Epidemiological studies from Singapore have shown that individuals consuming mushrooms more than twice a week had a 57% lower risk of mild cognitive impairment (MCI) compared to those eating mushrooms less than once a week (Feng et al., J Alzheimers Dis, 2019). The authors identified ergothioneine as one of the potential protective mechanisms, although the study was observational and did not establish causality.
Animal studies have shown that EGT supplementation protects dopaminergic neurons from neurotoxins used to induce Parkinson's models. In mice supplemented with EGT for 4 weeks before exposure to MPTP (a selective neurotoxin), significantly less loss of dopaminergic neurons in the substantia nigra was observed compared to the control group. These are mechanistic data - not clinical - but they indicate the direction researchers are heading.
How does this translate into practical recommendations? So far, there is no basis to recommend EGT supplementation for the prevention of dementia or Parkinson's - lack of RCTs. However, increasing the intake of edible mushrooms (oyster mushrooms, shiitake, button mushrooms) to 100-200 g several times a week is a reasonable strategy based on a healthy diet that simultaneously provides EGT, fiber, beta-glucans, and other protective components. This approach has solid epidemiological justification without the need to wait for RCTs with the supplement.
Ergothioneine is an amino acid synthesized by fungi and bacteria - humans cannot produce it. The body has a dedicated transporter, OCTN1, that actively accumulates it in tissues exposed to oxidative stress. The name 'longevity vitamin' comes from researchers (Ames, Rosenberg) who classified it among micronutrients that may slow biological aging, although it is not formally a vitamin (Grundemann et al., 2005).
Which mushrooms contain the most ergothioneine?
Oyster mushrooms (Pleurotus ostreatus) - about 2.5-5 mg/100 g of fresh weight - are one of the richest available sources. Shiitake provides 0.4-1.3 mg/100 g, button mushrooms about 0.3-0.6 mg/100 g. Regular consumption of 100-150 g of oyster mushrooms several times a week can provide doses similar to those studied in supplements.
Does ergothioneine protect the heart according to research?
Epidemiological studies suggest a strong inverse correlation between EGT levels and CV risk. A prospective study by Koh et al. (2023, n=3159) showed about a 30% lower risk of CV events in the highest quartile of EGT (Eur Heart J, 2023). The lack of completed RCTs does not yet allow for conclusions about causality.
How to dose ergothioneine as a supplement?
Phase I clinical trials used 5-30 mg daily for 7 days - without serious adverse effects. Available supplements contain 5-25 mg per capsule. There is no official daily intake recommendation from EFSA or NIH ODS. The manufacturer of synthetic EGT (Teeroze) uses 5 mg as a reference dose.
Is ergothioneine safe as a supplement?
Available data suggest a good safety profile at doses of 5-30 mg. EGT has been present in the human diet for millennia, and the body has a dedicated transporter suggesting an 'expected' biologically active substance. Long-term RCTs on safety at higher doses are still ongoing - caution is warranted at supplemental doses significantly exceeding dietary intake.
This article is for informational and educational purposes and does not replace consultation with a doctor. If you are pregnant, breastfeeding, taking medications, or have chronic conditions, consult the use of supplements or herbs with a specialist.
Author: Michał Waluk · Published: 2026-05-04 · Updated: 2026-05-04
