Ergothioneine: Dietary Sources and How to Get It

If ergothioneine turns out to matter for long-term health, the practical question becomes simple: how do you get it? The answer is refreshingly concrete. Mushrooms are by far the richest dietary source — not by a little, but by an order of magnitude or more over anything else on the plate. Among mushrooms, oyster and king oyster lead, with specialty species like porcini even higher; shiitake and maitake sit in the middle; and the familiar white button, cremini, and portobello (all the same species) are the lowest of the mushrooms but still far ahead of non-fungal foods. Smaller amounts appear in organ meats, some beans, and oat bran, all of which acquire it indirectly from fungi in the food chain. Best of all, ergothioneine is heat-stable, so ordinary cooking — unlike with many delicate antioxidants — does not destroy it. This page ranks the sources, explains why cooking is safe, and offers practical, honest guidance, including where the numbers are firm and where they vary widely.

Mushrooms Are By Far the Richest Source
Ranking the Mushrooms
Why Cooking Does Not Destroy It
Non-Mushroom Sources
Why Plants and Animals Contain Any at All
How Much Do People Actually Eat
Absorption and Bioavailability
Supplements
Practical Ways to Increase Intake
Honest Notes on Amounts and Variability
Key Research Papers
Connections
Featured Videos

Mushrooms Are By Far the Richest Source

Ergothioneine is synthesized by fungi, so it should be no surprise that fungi are where it is most concentrated. What is surprising is the size of the gap. Analyses such as the 2017 Food Chemistry study by Kalaras, Richie, Calcagnotto, and Beelman — aptly titled "Mushrooms: A rich source of the antioxidants ergothioneine and glutathione" — found that mushrooms contain vastly more ergothioneine than any other common food, often by one to two orders of magnitude. A single serving of a rich mushroom variety can deliver more ergothioneine than an entire day of a mushroom-free diet.

This is why every population-level analysis of ergothioneine intake tracks mushroom consumption so closely, and why the longevity-vitamin discussion is really, at the level of the plate, a discussion about eating mushrooms. For anyone wanting to raise their ergothioneine intake, the entire strategy can be summarized in one word: mushrooms.

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Ranking the Mushrooms

Ergothioneine content varies substantially by species. The broad, well-replicated ranking is as follows, from richest to least (though all are good sources relative to non-fungal foods):

Highest — specialty and oyster-type mushrooms. King oyster and oyster mushrooms (genus Pleurotus) are the richest widely available culinary mushrooms. Certain wild specialty species such as porcini (Boletus edulis) test even higher, among the highest of any food measured.
Moderate — shiitake and maitake. Shiitake and maitake carry solid mid-range amounts — less than oyster mushrooms but well above the button family.
Lower (but still far ahead of non-mushrooms) — the button family. White button, cremini, and portobello are all the same species, Agaricus bisporus, at different stages of maturity. They contain the least ergothioneine among common culinary mushrooms, yet a serving still provides more than most people get from the rest of their diet combined. See the white button mushroom page.

A useful rule of thumb: if you want to maximize ergothioneine, reach for oyster or king oyster mushrooms; if you are cooking with everyday white or cremini mushrooms, you are still doing well. Darker, more strongly flavored, and specialty mushrooms tend to be richer than pale, mild ones.

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Why Cooking Does Not Destroy It

Many prized food antioxidants are fragile — vitamin C leaches into cooking water and degrades with heat, for instance. Ergothioneine is the opposite: it is notably heat-stable. Studies measuring ergothioneine in mushrooms before and after cooking find that it survives boiling, sauteing, frying, and other ordinary preparation with little loss. The same thione chemistry that lets it resist auto-oxidation in the body (explained on the antioxidant page) also makes it robust in the pan.

This is genuinely good practical news, and it removes a common worry. You do not need to eat mushrooms raw — which is not advised anyway, since cooking improves the digestibility of mushrooms and breaks down certain undesirable raw-mushroom compounds. Cook mushrooms however you enjoy them; the ergothioneine comes along for the ride. If you cook them in a soup or stew, any small amount that leaches out stays in the broth, so you still consume it.

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Non-Mushroom Sources

Beyond mushrooms, ergothioneine appears in a scattering of other foods, in much smaller amounts. These matter mostly for people who eat few mushrooms, since together they can still contribute:

Organ meats — liver and kidney are the best animal sources, because animals accumulate ergothioneine from their own diets and concentrate it in these organs (which, like ours, express the OCTN1 transporter). See beef liver and chicken liver.
Beans — certain beans, particularly black and red/kidney beans, contain modest amounts taken up from soil fungi.
Oat bran — among grains, oats and especially oat bran carry measurable ergothioneine.
Fermented foods — foods fermented with fungi, such as tempeh, can contain ergothioneine contributed by the mold used in fermentation.

Ey, Schömig, and Taubert catalogued dietary sources in a 2007 Journal of Agricultural and Food Chemistry study, confirming this pattern: mushrooms far in the lead, with organ meats, some legumes, and certain grains providing lesser amounts, and most other foods containing little or none.

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Why Plants and Animals Contain Any at All

Since only fungi and some bacteria can synthesize ergothioneine, its presence in beans, oats, and liver requires an explanation — and the explanation is the food chain. Plants do not make ergothioneine, but their roots take it up from the soil, where it is produced by soil fungi and by the mycorrhizal fungi that live in partnership with plant roots. Legumes and grains grown in fungally active soils therefore accumulate small amounts.

Animals, in turn, obtain ergothioneine by eating plants and other organisms, and concentrate it in tissues rich in the OCTN1 transporter — liver, kidney, and blood. This is exactly parallel to how humans acquire it. In every case, the ultimate source is fungal; the ergothioneine simply travels up the food chain from the organisms that can make it to those, like us, that cannot. It is a small, elegant illustration of how dependent the rest of life is on fungi.

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How Much Do People Actually Eat

Dietary ergothioneine intake varies enormously between individuals and between countries, driven almost entirely by mushroom consumption. Robert Beelman's work estimated average intake in the United States at only around 1 to 1.5 milligrams per day — low, because Americans eat relatively few mushrooms. Populations with mushroom-rich cuisines, such as parts of Italy and France, are estimated to consume several times more.

Beelman used this contrast to frame his "limited in the American diet" argument, discussed in full on the longevity-vitamin page. The practical point here is narrower and firmer: most people could easily multiply their ergothioneine intake several-fold simply by adding a couple of servings of mushrooms per week, moving from the low end of the intake range toward the high end without any supplement at all.

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Absorption and Bioavailability

Getting ergothioneine into food is only useful if the body can absorb it — and it can. The OCTN1 transporter is expressed in the lining of the small intestine, where it actively pulls ergothioneine out of digested food and into the bloodstream. Weigand-Heller, Kris-Etherton, and Beelman demonstrated in a 2012 Preventive Medicine study that ergothioneine from mushrooms is bioavailable in humans and raises blood antioxidant capacity after consumption.

The controlled human study by Cheah and colleagues (2017), covered on the antioxidant page, went further, showing that orally administered ergothioneine is well absorbed and then retained in the body for weeks with minimal urinary loss. In other words, ergothioneine from a plate of mushrooms is efficiently captured and held, not passed through — which is precisely what you would want from a nutrient the body appears to value.

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Supplements

Purified ergothioneine supplements exist and have been used in the human studies described across these pages; they are well absorbed and, in trials to date, free of notable adverse effects. That said, a few honest caveats apply:

Food is the tested vehicle for most benefit data. The strongest positive associations come from people eating whole diets rich in mushrooms, which deliver ergothioneine alongside fiber, B vitamins, potassium, and other compounds.
Efficacy is still being established. Because outcome trials are only beginning, buying a supplement is a bet on a hypothesis, not on proven benefit.
Mushrooms are cheaper and more nutritious overall. For most people, a few servings of mushrooms a week is the more sensible way to raise intake.

If someone chooses to supplement — for instance, someone who genuinely cannot or will not eat mushrooms — the safety record so far is reassuring, but it is reasonable to treat it as an experiment rather than a therapy.

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Practical Ways to Increase Intake

Make mushrooms a default vegetable. Saute them into eggs, pasta, stir-fries, grain bowls, and pasta sauces. Even everyday white and cremini mushrooms add up.
Choose oyster or king oyster when you can. These deliver the most ergothioneine per serving and have a meaty texture that works well roasted or seared.
Blend mushrooms into ground-meat dishes. Finely chopped mushrooms mixed into burgers, meatballs, tacos, or chili add ergothioneine (and moisture and flavor) while stretching the meat.
Use dried mushrooms. Dried porcini and shiitake are concentrated, keep indefinitely, and rehydrate into soups, stocks, and sauces — the soaking liquid holds the ergothioneine too.
Do not rely on non-mushroom sources alone. Beans, oats, and liver help, but no realistic amount of them matches a serving of mushrooms.

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Honest Notes on Amounts and Variability

A word of caution about precise numbers. Published ergothioneine values for a given mushroom can differ severalfold between studies, because content depends on species, strain, growing substrate, maturity at harvest, and the analytical method used. For that reason this page gives a reliable ranking of sources rather than false-precision milligram figures for each food — the ranking is robust even where the exact numbers are not.

The bottom line is durable regardless of the uncertainty: mushrooms dominate as a source, oyster-type and specialty mushrooms lead the mushrooms, cooking does not hurt, and the whole thing is easy, safe, and inexpensive to act on. Whether or not the grander longevity-vitamin hypothesis is ultimately confirmed, eating more mushrooms is a low-risk, well-supported dietary habit on its own merits.

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Key Research Papers

Kalaras MD, Richie JP, Calcagnotto A, Beelman RB (2017). Mushrooms: A rich source of the antioxidants ergothioneine and glutathione. Food Chemistry 233:429–433. — PubMed 28530594
Ey J, Schömig E, Taubert D (2007). Dietary sources and antioxidant effects of ergothioneine. Journal of Agricultural and Food Chemistry 55(16):6466–6474. — PubMed 17616140
Weigand-Heller AJ, Kris-Etherton PM, Beelman RB (2012). The bioavailability of ergothioneine from mushrooms and the acute effects on antioxidant capacity and biomarkers of inflammation. Preventive Medicine 54 Suppl:S75–S78. — PubMed 22230474
Beelman RB, Kalaras MD, Phillips AT, Richie JP Jr (2020). Is ergothioneine a ‘longevity vitamin’ limited in the American diet? Journal of Nutritional Science 9:e52. — PubMed 33244403
Cheah IK et al. (2017). Administration of Pure Ergothioneine to Healthy Human Subjects: Uptake, Metabolism, and Effects on Biomarkers of Oxidative Damage and Inflammation. Antioxidants & Redox Signaling 26(5):193–206. — PubMed 27488221
Tang RMY, Cheah IK, Yew TSK, Halliwell B (2018). Distribution and accumulation of dietary ergothioneine and its metabolites in mouse tissues. Scientific Reports 8:1601. — PubMed 29371632
Gründemann D et al. (2005). Discovery of the ergothioneine transporter. PNAS 102(14):5256–5261. — PubMed 15795384
Borodina I et al. (2020). The biology of ergothioneine, an antioxidant nutraceutical. Nutrition Research Reviews 33(2):190–217. — PubMed 32051057