Ergothioneine and Heart Disease: The Mushroom Antioxidant

Mushrooms & Atherosclerosis Prevention

21.4 Years

In a prospective Swedish cohort of 3,236 adults tracked for a median of 21.4 years, those with higher plasma ergothioneine had significantly lower rates of coronary disease and cardiovascular mortality.

Smith et al., Heart (British Cardiac Society), 2020

3,236

participants in the landmark Swedish cohort

OCTN1

the only dedicated human transporter protein for any dietary antioxidant

Fungi only

virtually the sole meaningful dietary source of ergothioneine

Smith et al., Heart (British Cardiac Society), 2020

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Researchers in Sweden drew blood from 3,236 middle-aged adults in the early 2000s, measured a compound almost no one had heard of, and then waited 21 years. What they found, published in 2020 in the British journal Heart, was that the adults with the highest blood levels of ergothioneine — a compound found at meaningful levels in virtually no food except mushrooms — were significantly less likely to develop coronary artery disease or die from a cardiovascular cause.^[1]

Ergothioneine is a sulfur-containing amino acid your body cannot make from scratch. Fungi produce it; nearly every other organism in the food chain can only pass it along or lose it. What makes it unusual — beyond its mushroom exclusivity — is that human cells have built a dedicated protein channel specifically to absorb and concentrate it. That channel, called OCTN1, accumulates ergothioneine preferentially in cardiac tissue, red blood cells, and the cells lining arterial walls.

This article covers the cardiovascular disease evidence for ergothioneine from mushrooms: the epidemiology, the cell-level plaque mechanisms, the post-heart-attack data, and where the evidence honestly runs out. For the broader picture of how mushrooms support cholesterol management and overall heart health, the pillar article in this cluster covers multiple species and compounds.

The Swedish Cohort: Following 3,236 People for 21 Years

Smith et al. recruited participants from the Malmö Diet and Cancer Study, measured their plasma ergothioneine at baseline, and then tracked cardiovascular outcomes over a median of 21.4 years.^[1] Participants in the highest ergothioneine quartile had significantly lower rates of coronary artery disease, cardiovascular mortality, and all-cause mortality compared to those in the lowest quartile.

The structure of this study matters. The researchers measured blood levels before participants developed disease, not after. People in the cohort did not know their ergothioneine status and were not making dietary choices based on it. The measurement came first; the cardiovascular outcomes came 21 years later. This design strips out the reverse-causation problem that undermines many nutritional studies — where sick people eat differently precisely because they are sick.

The 2021 review by Cheah and Halliwell in Redox Biology called the Smith finding one of the strongest epidemiological signals for any dietary antioxidant in cardiovascular protection, while noting that a cohort association cannot establish causation on its own.^[6] People with higher ergothioneine might differ in diet quality, exercise, or socioeconomic status in ways the analysis did not fully capture. The study identifies a compelling candidate; it does not close the case.

Why Ergothioneine Behaves Differently From Other Antioxidants

Most dietary antioxidants — vitamin C, vitamin E, polyphenols — are absorbed broadly, circulate briefly, and get metabolized or excreted within hours. Ergothioneine does something more unusual.

The transporter protein OCTN1 sits on cell membranes and actively pulls ergothioneine out of the bloodstream and concentrates it inside cells. It is present in particularly high densities in the heart, red blood cells, kidneys, and the endothelial cells lining arterial walls — the exact tissues most vulnerable to the oxidative damage that initiates cardiovascular disease. In tissues without OCTN1, ergothioneine barely accumulates. In cardiac cells, it reaches concentrations far above circulating plasma levels.

The 2017 review by Servillo et al. in the Journal of Cardiovascular Pharmacology mapped the chemistry: ergothioneine scavenges singlet oxygen and hydroxyl radicals more effectively than glutathione does, and it chelates metal ions — particularly iron and copper — that would otherwise catalyze the oxidative chain reactions that convert LDL cholesterol into its plaque-initiating oxidized form.^[4] The transporter biology is what elevates ergothioneine above a generic antioxidant: the body routes it specifically to the places it is most needed.

A 2023 paper by Tian et al. in the British Journal of Nutrition argued that this dedicated transporter, combined with tissue-specific accumulation patterns and the epidemiological mortality associations, meets the biological criteria for reclassifying ergothioneine as a required dietary micronutrient rather than an optional antioxidant.^[8] For a deeper look at the OCTN1 biology and what makes this compound structurally unique, What Is Ergothioneine? The Only Amino Acid With a Dedicated Human Transporter covers the foundational biochemistry.

Inside Arterial Walls: How Ergothioneine Interrupts Plaque Formation

Atherosclerosis does not start as a blocked artery. It starts as an injury to the thin layer of cells lining artery walls — the endothelium — usually caused by oxidative stress from circulating oxidized lipids. Once those endothelial cells are damaged, they begin displaying surface molecules called VCAM-1 and ICAM-1. These molecules act as docking stations for monocytes, the immune cells that circulate in blood and attach to sites of vascular inflammation. Monocytes that dock to damaged endothelial cells are the biological first step of plaque development.

Zhu et al. tested ergothioneine directly against this mechanism in human aortic endothelial cells.^[2] Under inflammatory conditions, ergothioneine reduced monocyte adhesion to those cells. The immune cell docking — the trigger event for plaque — happened less readily when ergothioneine was present.

The 2021 review by Lam-Sidun et al. in the International Journal of Molecular Sciences synthesized these findings with additional preclinical evidence on endothelial protection and cardioprotection after ischemia, describing ergothioneine as one of the few dietary compounds with documented activity at multiple specific steps of the cardiovascular disease mechanism.^[3]

The mushroom antioxidant picture is broader than ergothioneine alone. For coverage of how VCAM-1 and ICAM-1 inhibition works across multiple mushroom species and what role species like antrodia and chaga play, Mushroom Antioxidants and Endothelial Damage: Stopping Atherosclerosis at the Source maps those parallel mechanisms.

Foam Cells: The Cholesterol Trap That Builds Real Plaque

After monocytes dock to damaged endothelial cells, they migrate into the arterial wall and transform into macrophages. Those macrophages begin absorbing oxidized LDL cholesterol particles. As they fill with lipid, they become foam cells — cholesterol-stuffed cells that cannot clean themselves out and that accumulate into the fatty streaks that eventually harden into atherosclerotic plaque.

Zhu et al. tested whether ergothioneine blocked this second step, too, and found that it did.^[2] In cell culture models, ergothioneine reduced the conversion of macrophages into foam cells. The likely mechanism is upstream: by protecting LDL from oxidative modification in the first place, ergothioneine reduces the substrate that macrophages accumulate.

Lam-Sidun et al. summarized this as ergothioneine operating at two early bottlenecks in the atherosclerosis cascade — monocyte adhesion and foam cell formation — rather than acting as a nonspecific free radical sponge.^[3] That specificity, combined with the transporter biology that routes ergothioneine to the arterial wall, is the mechanistic case for why mushroom consumption might translate to lower plaque burden over a lifetime.

After a Heart Attack: Evidence on Cardiac Recovery

A 2023 study by Duan et al. in the European Journal of Pharmacology asked what happens when ergothioneine is given to mice after a heart attack has already occurred.^[5] After a myocardial infarction, the heart undergoes remodeling: scar tissue forms, the ventricular wall reshapes, and cardiac function often permanently declines. The question was whether ergothioneine could influence that process.

The answer in the mouse model was yes. Ergothioneine-treated animals showed improved cardiac ejection fraction, less fibrosis, and reduced pathological remodeling compared to controls. The mechanism was suppression of the NF-κB/Wnt5a/sFlt-1 pathway — a molecular inflammation switch that, when active, drives the post-infarction remodeling response. Ergothioneine appeared to turn down this pathway through a chemical modification called S-glutathionylation.

This is a single animal study, and cardiac remodeling in mice does not translate directly to humans without dedicated clinical trials. What it adds to the picture is a plausible reason why cardiac tissue specifically builds the high-density OCTN1 transport machinery to concentrate ergothioneine: the tissue may be protecting itself against exactly this kind of stress.

The Longevity Vitamin Argument

In 2018, Bruce Ames published a paper in the Proceedings of the National Academy of Sciences proposing a category he called "longevity vitamins."^[7] The concept: some micronutrients are not essential for short-term survival but are critical for preventing the slow cumulative oxidative damage that drives chronic disease over decades. Ergothioneine was on the list. Deficiency in these compounds does not produce acute symptoms — which is why they were never classified as vitamins — but creates a background increase in cellular damage that shows up as earlier cardiovascular disease, neurodegeneration, and reduced lifespan.

Tian et al. extended this argument in their 2023 British Journal of Nutrition review, noting that ergothioneine's tissue accumulation in mitochondria is particularly significant.^[8] Mitochondria are the energy-generating structures inside cells. They produce oxidative byproducts as a side effect of metabolism, and they are among the most vulnerable cellular structures to oxidative damage. An antioxidant that specifically concentrates in mitochondria via a dedicated transporter is doing something different from one that simply circulates in plasma.

The most recent interventional evidence comes from Katsube et al. in GeroScience in 2024, who fed ergothioneine to male mice over their lifespan and measured outcomes.^[9] The supplemented mice had a longer median lifespan and improved physical and cognitive function markers compared to controls. This study does not directly measure cardiovascular mechanisms, but it provides the only published mammalian evidence that ergothioneine supplementation extends healthy aging — giving the longevity vitamin hypothesis its first direct interventional support.

Mushrooms, Cardiovascular Disease, and the Mortality Signal

The Smith 2020 cohort measured plasma ergothioneine directly. Two 2021 papers by Ba et al. asked a related question without blood tests: do people who regularly eat mushrooms live longer?

The first Ba analysis used NHANES III data, a US prospective cohort, and found that regular mushroom consumers had significantly lower all-cause mortality and lower CVD mortality compared to non-consumers.^[10] The second Ba paper expanded the dataset to NHANES 2003-2014 and added a meta-analysis, finding consistent associations between mushroom intake and reduced mortality risk across the larger and more recent cohort.^[11]

These dietary studies cannot attribute the effect to ergothioneine specifically. Mushrooms contain beta-glucans, polysaccharides, B vitamins, and other bioactives. But the convergence across three types of evidence — direct plasma ergothioneine measurement over 21 years, cell-level mechanism data on the specific steps that cause plaque, and population-level mortality associations from NHANES — points consistently in the same direction.

What No Clinical Trial Has Tested Yet

The honest summary of where this evidence sits: the biology is specific, the epidemiology is compelling, and the preclinical mechanisms are well-characterized. What does not exist is a randomized human trial testing ergothioneine supplementation against cardiovascular outcomes.

The cell studies establishing monocyte adhesion inhibition and foam cell reduction were done in cultured human cells — which is more translatable than animal cells, but still not a human trial. The post-AMI cardiac remodeling data is from mice. The lifespan extension data is from mice. The NHANES mortality associations are observational.

Cheah and Halliwell named this gap explicitly in their 2021 review, and it remains open.^[6] The mechanistic picture is unusually coherent for a dietary compound: a dedicated transporter system, tissue-specific accumulation precisely where oxidative damage drives cardiovascular disease, and documented activity at two specific bottlenecks in plaque formation. The missing piece is a clinical trial that closes the loop in humans.

The Bottom Line

Ergothioneine is a mushroom-exclusive antioxidant with a dedicated human transport system that concentrates it in cardiac tissue and arterial walls. A 21-year Swedish cohort found higher plasma levels predict lower coronary disease and cardiovascular mortality, and cell studies show it blocks two early steps in plaque formation. Direct human intervention evidence for CVD prevention does not yet exist.

Frequently Asked Questions

What is ergothioneine and why does it matter for heart health?

Ergothioneine is a sulfur-containing amino acid found at meaningful levels almost exclusively in mushrooms. It matters for heart health because human cells have a dedicated protein — OCTN1 — that specifically absorbs and concentrates it in cardiac tissue and arterial walls, and because a 21-year cohort study of 3,236 adults found that higher plasma ergothioneine predicted significantly lower coronary disease and cardiovascular mortality (Smith et al., 2020).

Does ergothioneine prevent cardiovascular disease?

The evidence is suggestive but not yet definitive. A Swedish cohort tracked for 21.4 years found a significant association between higher plasma ergothioneine and lower CVD mortality. Cell studies confirm it inhibits monocyte adhesion to endothelial cells and reduces foam cell formation — the two earliest steps in plaque development. No randomized human trial has tested ergothioneine supplementation specifically for CVD prevention, so a causal claim remains premature.

Is ergothioneine a longevity vitamin?

Bruce Ames proposed this classification in a 2018 PNAS paper, arguing ergothioneine is not essential for short-term survival but prevents the cumulative oxidative damage that drives chronic disease over decades. A 2024 GeroScience study found ergothioneine extended median lifespan in male mice. Whether that finding translates to humans requires clinical trials that do not yet exist.

Which mushrooms have the most ergothioneine?

Oyster mushrooms, king oyster mushrooms, and porcini (Boletus edulis) tend to have the highest ergothioneine concentrations among commonly available species. Shiitake, maitake, and white button mushrooms also contain meaningful amounts. Concentrations vary by species, cultivation method, and growing conditions. Cooking appears to preserve most of the ergothioneine content.

How much ergothioneine do you get from eating mushrooms?

Estimates vary widely by species and growing conditions. A 100g serving of oyster mushrooms provides roughly 5 to 13 mg of ergothioneine; white button mushrooms provide approximately 1 to 5 mg per 100g. The Smith 2020 cohort measured plasma levels rather than dietary intake, so no precise milligram threshold has been established for cardiovascular protection. Regular mushroom consumption several times per week appears sufficient to maintain detectable plasma ergothioneine levels in population studies.

Sources & References

1. 1RTHM-00655·Smith, Einar et al. (2020). “Ergothioneine is associated with reduced mortality and decreased risk of cardiovascular disease..” Heart (British Cardiac Society).Study breakdown →PubMed →↩
2. 2. Source details for this reference are not yet available.
3. 3RTHM-00696·Lam-Sidun, Daniel et al. (2021). “Mushroom-Derived Medicine? Preclinical Studies Suggest Potential Benefits of Ergothioneine for Cardiometabolic Health..” International journal of molecular sciences.Study breakdown →PubMed →↩
4. 4RTHM-00490·Servillo, Luigi et al. (2017). “Ergothioneine Antioxidant Function: From Chemistry to Cardiovascular Therapeutic Potential..” Journal of cardiovascular pharmacology.Study breakdown →PubMed →↩
5. 5RTHM-00822·Duan, Rui et al. (2023). “Ergothioneine improves myocardial remodeling and heart function after acute myocardial infarction via S-glutathionylation through the NF-ĸB dependent Wnt5a-sFlt-1 pathway..” European journal of pharmacology.Study breakdown →PubMed →↩
6. 6RTHM-00678·Cheah, Irwin K et al. (2021). “Ergothioneine, recent developments..” Redox biology.Study breakdown →PubMed →↩
7. 7RTHM-00936·Ames, Bruce N (2018). “Prolonging healthy aging: Longevity vitamins and proteins..” Proceedings of the National Academy of Sciences of the United States of America.Study breakdown →PubMed →↩
8. 8RTHM-01805·Tian, Xiaoying et al. (2023). “Ergothioneine: an underrecognised dietary micronutrient required for healthy ageing?.” The British journal of nutrition.Study breakdown →PubMed →↩
9. 9RTHM-00884·Katsube, Makoto et al. (2024). “Ergothioneine promotes longevity and healthy aging in male mice..” GeroScience.Study breakdown →PubMed →↩
10. 10RTHM-00673·Ba, Djibril M et al. (2021). “Association of mushroom consumption with all-cause and cause-specific mortality among American adults: prospective cohort study findings from NHANES III..” Nutrition journal.Study breakdown →PubMed →↩
11. 11RTHM-00674·Ba, Djibril M et al. (2021). “Prospective study of dietary mushroom intake and risk of mortality: results from continuous National Health and Nutrition Examination Survey (NHANES) 2003-2014 and a meta-analysis..” Nutrition journal.Study breakdown →PubMed →↩