A white mushroom is not a plant. It is a fungus, and a protein study found that animals and fungi are each other’s closest relatives, with plants on a separate branch. The white button, the brown cremini and the large portobello are one species, Agaricus bisporus: white and brown forms, picked young or left to grow. A raw white mushroom is about 92% water.
A fresh white mushroom holds almost no vitamin D, about 0.2 µg per 100 g. It does hold ergosterol, which turns into vitamin D2 under UV light, so some growers expose mushrooms to UV after harvest. In trials, UV-exposed mushrooms raised the D2 form of vitamin D in blood but lowered the D3 form, so total vitamin D did not always rise.
Mushrooms are also the highest dietary source of ergothioneine, a sulfur-containing antioxidant, and 100 g a day of white button mushrooms doubled blood levels in one study. Raw button mushrooms hold agaritine, a natural compound that may be a weak carcinogen in mice, and storage and cooking lower it. Many of the cohort studies below ask about mushrooms in general, so each card says when that is the case.
Health benefits of white mushrooms
The top findings from 33 studies, strongest evidence first
What the stars mean
- Strong. Several randomized trials, pooled in a meta-analysis, point the same way, or regulators (FDA or EFSA) have approved the claim.
- Moderate. Good randomized trials support it, but there are fewer of them, or their results vary.
- Limited. Small, short or single trials, or mixed results. Promising, but it needs confirmation.
Population and lab studies get no stars: they show a link or a mechanism, not proof.
How we rate evidence →- ★★Mixed effects on vitamin D levelsUV-exposed mushrooms raised blood vitamin D by 15.2 nmol/L in European trials, but not in US trials. A vitamin D2 mushroom product did not keep 436 older adults’ levels up through winter.
- ★★Slightly lower fasting blood sugarIn 60 adults, 84 g a day of mushrooms added to a Mediterranean-style diet for 8 weeks lowered fasting blood sugar by 2.9 mg/dL. The mushrooms were white button and oyster, and no other measure clearly changed.
- ★More weight lost when mushrooms replaced red meatIn 73 obese adults on a weight-loss plan, replacing red meat with mushrooms for a year helped them lose about 7 lb (3.6%) more. The trial cannot separate mushrooms from eating less meat.
- ★Less hungry and fuller after mushrooms than meatIn 32 healthy adults, a breakfast of 226 g of Agaricus bisporus mushrooms left people less hungry and more full than 28 g of meat. The differences were small, and they ate the same amount later.
- ★No clear change in flu vaccine responseIn 85 adults aged 60 and over, 8 weeks of Agaricus bisporus powder (5 g a day) did not significantly change the flu vaccine response. IgM antibodies rose 73% more with mushrooms, but not significantly.
All 33 studies, strongest evidence first
UV-exposed mushrooms raised blood vitamin D by 15.2 nmol/L in European trials but not in US trials
Meta-analysis of 6 randomized trials of UV-exposed edible mushrooms; the abstract does not say which kinds. All six together showed no significant rise, with large differences between trials. The 3 European trials, where people started low (38.6 nmol/L), found the rise; the 3 US trials, where they started at 81.5 nmol/L, did not. The D2 form of vitamin D rose and the D3 form fell.
Six months of a vitamin D2-enriched mushroom product did not keep older adults’ vitamin D levels up through winter, while vitamin D3 did
Double-blind placebo-controlled trial in 436 healthy adults aged 60 and over, comparing about 600 IU of vitamin D3, enriched vitamin D2 in a mushroom matrix, standard mushroom and placebo. Total vitamin D held steady only in the D3 group. No treatment changed thinking or mood. The abstract does not name the mushroom type.
Adding 84 g a day of white button and oyster mushrooms to a Mediterranean-style diet for 8 weeks lowered fasting blood sugar by 2.9 mg/dL, with no other clear effect
Randomized trial in 60 adults without heart or metabolic disease, with all food provided and breadcrumbs in the control diet (white button 4 days a week, oyster 3 days). Blood sugar rose 0.6 mg/dL in the control group. Total cholesterol fell on both diets, so that came from the diet and not the mushrooms. The other risk factors measured, including blood pressure, blood fats and insulin, did not differ.
Soup made with UV-irradiated button mushrooms raised blood vitamin D by about 3.9 nmol/L a week, much like a vitamin D2 supplement
Single-blind randomized placebo-controlled trial in 26 young adults with low vitamin D (25OHD at or below 50 nmol/L), over 5 weeks of winter. The mushrooms were irradiated to hold 491 µg of D2 per 100 g, and the soup gave 28,000 IU in all, the same as the supplement group, which rose 4.7 nmol/L a week. Only 26 people took part.
Eating UV-treated white button mushrooms for 6 weeks raised the D2 form of vitamin D in blood but did not change total vitamin D status
Randomized trial in 38 healthy adults, with mushrooms giving 8.8 or 17.1 µg of vitamin D2 a day, against untreated mushrooms (0.85 µg) or a supplement. The D2 marker rose 13.8 and 12.7 nmol/L, but the D3 marker fell 10.4 and 20.6 nmol/L, so the total did not improve.
In adults with prediabetes and low vitamin D, 100 g a day of UV-treated mushrooms for 16 weeks raised blood vitamin D only modestly or not at all
Randomized trial in 43 overweight or obese adults, using mushrooms made to hold 600 or 4000 IU of D2, against vitamin D3 supplements. Cooking cut the D2 in the mushrooms, and the supplements did better. Neither the mushrooms nor the supplements changed type 2 diabetes risk factors.
Eating 84 g of UV-exposed white button mushrooms twice a day raised vitamin D2 in blood but did not prevent the winter drop in total vitamin D
Randomized trial in 41 adults with overweight or obesity over 6 weeks in late fall and winter, against breadcrumbs. The mushrooms were grown to hold 400 IU of D2 per serving, yet only 67% of them contained any D2. The D3 form fell more in the mushroom group.
Replacing red meat with mushrooms for a year helped obese adults lose about 7 lb (3.6%) more weight
Randomized trial in 73 obese adults (64 women, 9 men) on a weight-loss and maintenance plan, with 36 on the mushroom diet. They also had lower blood pressure (by 7.9 and 2.5 mm Hg) and better blood fats and inflammation markers. Mushrooms replaced meat, so the trial cannot separate the mushrooms from eating less meat, and the abstract does not name the mushroom type.
A breakfast of 226 g of Agaricus bisporus mushrooms left people less hungry and more full than 28 g of meat, but they ate the same amount later
Randomized open-label crossover trial in 32 healthy adults, with protein matched between the two breakfasts. The differences in hunger and fullness were small (p = 0.045 and 0.05). Calories eaten at lunch and over 10 days did not differ.
Ten days of eating Agaricus bisporus mushrooms twice a day raised stool weight and shifted gut bacteria toward more Bacteroidetes
Randomized open-label crossover trial in 32 healthy adults, against protein-matched meat. Firmicutes fell. Stool frequency, consistency, pH and short-chain fatty acids did not change, and stomach and bowel symptoms were higher on days one and two. The authors say the health meaning of the bacteria shift is unclear.
Adding white button and oyster mushrooms to a Mediterranean-style diet did not add to the gains in vigor and memory that the diet itself gave
From the same 60-adult feeding trial as the blood sugar result above (84 g a day for 8 weeks). Both diets, with or without mushrooms, improved self-reported vigor and immediate memory. Other measures of mood, anxiety and thinking showed mixed effects or none.
5 g a day of Agaricus bisporus powder for 8 weeks did not significantly change the flu vaccine response in adults aged 60 and over
Double-blind placebo-controlled trial in 85 people taking capsules of one strain (MES01706), from about 4 weeks before the shot to 4 weeks after. Blood ergothioneine rose, so the capsules were taken. IgM antibodies rose 73% more in the mushroom group, but not significantly (p = 0.09), and IgG, blood counts and flu-like illness did not differ.
White button mushroom powder lowered PSA in some men with recurrent prostate cancer, an overall response rate of 11%
Phase I trial with no control group in 36 men with rising PSA after treatment, using powder doses that included 8, 12 and 14 g a day. No dose-limiting side effects occurred. Two men had a complete response and two a partial one, and 13 (36%) had some PSA drop after 3 months. It was a safety study of a powder, so it cannot show benefit.
100 g a day of white button mushrooms for 16 weeks doubled blood ergothioneine in adults with metabolic syndrome
Retrospective analysis of 37 people from an earlier vitamin D study, with no control group. An antioxidant capacity marker and the hormone adiponectin rose, and two oxidative stress markers fell, but insulin resistance and glucose measures did not change.
25 mg ergothioneine capsules three times a week for a year improved a word-learning test in 19 people with mild cognitive impairment
Pilot double-blind placebo-controlled trial of the compound itself, not of mushrooms. A blood marker of nerve damage (neurofilament light chain) stayed steady on ergothioneine and rose on placebo, and blood counts, kidney tests and liver tests did not change. With 19 people, it needs a larger trial.
People who ate the most mushrooms had a 34% lower risk of cancer, mainly breast cancer
Meta-analysis of 17 observational studies of mushrooms in general. The pooled risk ratio was 0.66 for any cancer, 0.65 for breast cancer (10 studies) and 0.80 for other cancers, and only breast cancer showed a link on its own. Eleven of the 17 studies were case-control studies, which depend on recall.
Higher mushroom intake went with an 18% lower risk of stomach cancer
Pooled analysis of 11 studies (3,900 cases, 7,792 controls) on mushrooms in general; relative risk 0.82. Adding four earlier studies gave 0.77. The link was strongest in Western Pacific countries (0.59), which the authors suggest may reflect the mushroom species eaten in Asia.
Across five cohorts, people who ate mushrooms had a 6% lower risk of dying
Meta-analysis of prospective cohorts with 601,893 people on mushrooms in general, including the authors’ own analysis of US survey data (30,378 adults, 2003 to 2014). The pooled risk ratio was 0.94. The US survey part alone was not significant (0.84, range 0.67 to 1.06).
US adults who reported eating mushrooms had a 16% lower risk of dying over about 20 years than those who did not
Cohort of 15,546 adults from NHANES III with 5,826 deaths, using a single 24-hour diet recall, on mushrooms in general. Swapping one daily serving of processed or red meat for mushrooms went with a 35% lower risk (hazard ratio 0.65). Deaths from specific causes showed no significant link.
Korean adults who ate mushrooms less than once a week or 1 to 3 times a week had a 10 to 14% lower risk of dying than non-eaters
Cohort of 152,828 adults over 40, followed 11.6 years on average with 7,085 deaths, on mushrooms in general. Lower heart disease deaths showed only in men. The abstract reports the lower and middle intakes and gives no result for 3 or more servings a week.
Japanese women who ate over 15 g of mushrooms a day had a 44% lower risk of disabling dementia
Cohort of 3,739 people aged 40 to 64, followed 16 years with 670 cases, on mushrooms in general. The hazard ratio was 0.56 for over 15 g a day against none, and 0.81 (not significant) for smaller amounts. Men showed no link.
Older adults in Singapore who ate mushrooms more than 2 portions a week had 57% lower odds of mild cognitive impairment
Cross-sectional study of 663 people aged 60 and over, against those eating them less than once a week (odds ratio 0.43), after adjusting for age, education, smoking and health conditions. It covers mushrooms in general, and a snapshot cannot show which came first.
Adults in the UK EPIC-Norfolk cohort who ate mushrooms scored better on thinking tests, most clearly at a portion a week or more
Cohort followed for 18 years, with mushroom intake from food questionnaires at three checkups and a cognitive test battery at the last one. It covers mushrooms in general. The link grew with intake, and the authors call for randomized trials to confirm it.
US adults aged 60 and over in the top mushroom group scored 3.9 points higher on the digit symbol substitution test
NHANES 2011 to 2014 data on 2,840 people, top against bottom intake (median 13.4 g per 1,000 kcal a day), on mushrooms in general; the range was 0.30 to 7.45 points. Animal fluency and delayed recall showed no clear link.
US adults in the middle mushroom group had 69% lower odds of depression, but the highest group did not
Cross-sectional NHANES data on 24,699 people, of whom 5.2% ate mushrooms. The middle group (median 4.9 g a day) had an odds ratio of 0.31 and the highest (19.6 g a day) 0.91, so there was no dose-response. The data do not say which mushrooms were eaten.
Korean men in the top mushroom group had a 35% lower rate of type 2 diabetes
Cohort of 16,666 adults aged 40 and over without diabetes at the start, with an incidence rate ratio of 0.65 (range 0.47 to 0.90) in men; the abstract reports an inverse link in women too. Intake came from food questionnaires and covers mushrooms in general.
A review of nine studies found no link between mushrooms and cardiovascular disease, stroke or type 2 diabetes
Systematic review of 5 prospective cohorts and 4 clinical trials published through July 2023. It saw hints of benefit for blood sugar, HDL cholesterol, CRP, body weight and all-cause mortality. The authors say there are too few studies for firm conclusions.
People with higher blood ergothioneine, a compound mushrooms are rich in, had a 14% lower risk of dying for each standard-deviation rise
Malmö Diet and Cancer cohort of 3,236 people followed a median 21.4 years, with 843 deaths. Hazard ratios per standard deviation were 0.86 for death, 0.79 for cardiovascular death and 0.85 for coronary disease. Ergothioneine tracked a healthy food pattern in general, not only mushrooms, so it may mark healthy eaters.
Ergothioneine in mushroom species ranged from 0.15 to 7.27 mg per gram of dry weight
Lab analysis of many mushroom species. Glutathione varied more than 20-fold, and the two antioxidants rose together. Caps held more than stems, and Agaricus bisporus from the third crop flush held more than from the first. These are food measurements, not a study in people.
Frying cultivated Agaricus mushrooms cut their agaritine by 35 to 70%
Lab study of agaritine, a natural compound in two cultivated Agaricus species. Supermarket samples averaged 272 mg/kg, less than freshly picked ones, with most in the cap skin and gills. Storage cut it by 20 to 75%, dry baking by about 25% and microwaving to a third, while boiling drew about half into the broth. What agaritine turns into when cooked is not yet known.
After UV-B or sunlight exposure, agaritine in sliced button mushrooms dropped sharply while vitamin D2 rose
Lab test with artificial UV-B (0.53 J/cm²) and natural sunlight. UV-B lifted vitamin D2 to 67.1 µg per gram of dry weight and sunlight to 3.9, and vitamin D4 formed too. Agaritine stayed within normal ranges and fell at every dose, probably because it is unstable.
Agaritine is a potential weak carcinogen in mice, and a review put the added lifetime cancer risk in people at about 1 in 100,000
Review of hydrazine toxins in false morels and Agaricus mushrooms. No human data exist, so the figure is an estimate. The authors advise avoiding button mushrooms when they are raw or poorly cooked.
White button mushroom powder helped mice recover from induced colitis
Mouse study. Pretreatment did not significantly lower disease scores, but in a recovery model the mice gained weight better and had less inflammation in the colon. Digested powder also made gut cell layers less leaky. Some authors work for a mushroom company that supplied the powder.
Who should be careful with white mushrooms
Most people can eat white mushrooms freely. Take a little care if one of these applies:
- Eating them raw. Raw button mushrooms contain agaritine, a potential weak carcinogen in mice. A review estimated the added lifetime cancer risk in people at about 1 in 100,000 and advised avoiding them raw or poorly cooked. The risk looks small, and in lab tests cooking and storage cut agaritine.
- Irritable bowel syndrome. Monash University lists mushrooms among foods with polyols such as mannitol, which can trigger symptoms in some people with IBS. Check your serving in the Monash FODMAP app.
- Wild mushrooms. The deadly death cap has been mistaken for this species. Buy mushrooms from a shop unless an expert has identified them.
How to choose, store and eat white mushrooms
- Cooked: in lab tests frying cut agaritine by 35 to 70% and microwaving left about a third, though cooking also lost some vitamin D2 from UV-treated mushrooms in one trial.
- UV-exposed: in one trial only 67% of mushrooms grown to hold vitamin D2 actually did, so look for a label that states the vitamin D amount.
- Amounts in trials: 84 g a day (a little over a cup) for 8 weeks lowered fasting blood sugar, and 100 g a day for 16 weeks doubled blood ergothioneine.
Pick mushrooms with caps closed around the stem or only partly open, with pink or light tan gills, and keep them in the fridge in a paper bag for up to about 3 days, because plastic traps moisture that spoils them. Residues are no reason to skip them: in USDA tests of 707 mushroom samples for its 2022 report, none had a residue above the legal limit.
Sources
- Lagrange E, Vernoux JP. Warning on false or true morels and button mushrooms with potential toxicity linked to hydrazinic toxins: an update. Toxins (Basel). 2020.
- Schulzová V, Hajslová J, Peroutka R, Gry J, Andersson HC. Influence of storage and household processing on the agaritine content of the cultivated Agaricus mushroom. Food Addit Contam. 2002.
- What are the polyols?. Monash FODMAP blog. 2016.
- Can microwaving fruits and vegetables reduce their FODMAP content? A laboratory study. Monash FODMAP blog. 2026.
- Mehrotra A, Calvo MS, Beelman RB, et al. Bioavailability of vitamin D2 from enriched mushrooms in prediabetic adults: a randomized controlled trial. Eur J Clin Nutr. 2014.
- Comboni LM, Glover ES, Napolitano SC, et al. Does consuming fresh ultraviolet light-exposed mushrooms offset the seasonal decline in serum total 25OHD in adults classified as overweight and class I obese? Results from a randomized controlled trial. Foods. 2026.
- Uffelman CN, Schmok JN, Campbell RE, et al. Consuming mushrooms when adopting a healthy Mediterranean-style dietary pattern does not influence short-term changes of most cardiometabolic disease risk factors in healthy middle-aged and older adults. J Nutr. 2024.
- Calvo MS, Mehrotra A, Beelman RB, et al. A retrospective study in adults with metabolic syndrome: diabetic risk factor response to daily consumption of Agaricus bisporus (white button mushrooms). Plant Foods Hum Nutr. 2016.
- Preparing and preserving mushrooms. Penn State Extension. 2024.
- Pesticide Data Program annual summary, calendar year 2022. USDA Agricultural Marketing Service.
History of white mushrooms
In the wild, Agaricus bisporus grows in grasslands and leaf litter across Eurasia and North America. Its genome holds a large set of enzymes that break down plant matter, including lignin, which helps it live on decaying material. Genetic studies trace the species back millions of years: one puts its origin in Europe about 4.6 million years ago, and another dates a split into varieties to about 2 million years ago.
People have grown it for only a few centuries. A genome study calls its cultivation history around 300 years, and Wikipedia credits Joseph Pitton de Tournefort with the earliest scientific description of commercial growing, in 1707. The white form is still called champignon de Paris in French.
Paris growers moved into the limestone quarries beneath the city. AFP reports about 250 growers there by the late 19th century, drawn to a “royal” variety that Louis XIV had made popular by having it grown at Versailles. City growth and the building of the Metro pushed them out from the early 1900s. Around 50 were left in the 1970s, and five traditional producers remain after cheaper imports took over.
Growing got more reliable in 1893, when the Pasteur Institute in Paris produced sterilized pure-culture spawn, the mushroom’s “seed,” to grow on composted horse manure.
The white color began as a lucky mutation. A white variety turned up in 1925 at the Keystone Mushroom Farm in Coatesville, Pennsylvania, owned by the mycologist Louis Ferdinand Lambert, and most cream-colored store mushrooms descend from it. A 2026 genome study of 482 strains found that the white cap was the key trait people selected as they domesticated the species.
Emil Imbach gave the species its current name, Agaricus bisporus, in 1946. Wikipedia lists it as cultivated in at least seventy countries, and in 2022 China produced about 94% of the world’s mushrooms and truffles.
Sources
- Agaricus bisporus. Wikipedia.
- Baldauf SL, Palmer JD. Animals and fungi are each other’s closest relatives: congruent evidence from multiple proteins. Proc Natl Acad Sci U S A. 1993.
- Morin E, Kohler A, Baker AR, et al. Genome sequence of the button mushroom Agaricus bisporus reveals mechanisms governing adaptation to a humic-rich ecological niche. Proc Natl Acad Sci U S A. 2012.
- Zhang MZ, Xu JP, Callac P, et al. Insight into the evolutionary and domesticated history of the most widely cultivated mushroom Agaricus bisporus via mitogenome sequences of 361 global strains. BMC Genomics. 2023.
- Ling ZL, Chen GT, Zhang MZ, et al. Genomic signatures of evolution and domestication in the button mushroom Agaricus bisporus. Curr Biol. 2026.
- Inside Paris’ underground mushroom farms. AFP, published by The Local France. 2021.
Frequently asked questions about white mushrooms
Are white mushrooms good for you?
For most people, yes, though the evidence is modest. Raw white mushrooms have 22 calories per 100 g and are a very good source of copper (35% of the daily value per 100 g), riboflavin (31%), pantothenic acid (30%) and biotin (33%). Across five cohorts, people who ate mushrooms in general had a 6% lower risk of dying. That is a link, not proof, and no study here reaches strong evidence.
Is a mushroom a vegetable or a plant?
A white mushroom is a fungus, not a plant. A protein study placed animals and fungi as each other’s closest relatives, with plants on a separate branch. Cooks and nutrition tables treat it as a vegetable, and so does this site.
Do white mushrooms have vitamin D?
Only a little, unless they were exposed to UV light. Raw white mushrooms have 0.2 µg of vitamin D per 100 g, 1% of the daily value. UV light turns their ergosterol into vitamin D2, but in one trial only 67% of mushrooms grown to give 400 IU per serving held any, and trials found UV mushrooms raised the D2 form in blood while the D3 form fell. A label that states the vitamin D amount is the best guide.
Can you eat white mushrooms raw?
You can, but cooking is the more careful choice. Raw button mushrooms contain agaritine, a potential weak carcinogen in mice, and a review estimated the added lifetime cancer risk at about 1 in 100,000 and advised against eating them raw or poorly cooked. In lab tests, frying cut agaritine by 35 to 70% and storage cut it by 20 to 75%.
Do white mushrooms have protein?
A little. Raw white mushrooms have 3.09 g of protein per 100 g, or 2.2 g in a cup (70 g). The protein is not complete: its completeness score is 56 out of 100, limited by methionine and cysteine. They add to a meal without being its main protein.
Are white mushrooms low FODMAP?
Not reliably. Monash University lists mushrooms among foods with polyols such as mannitol, which can trigger symptoms in some people with IBS. A Monash lab test found that heating diced mushrooms in water and rinsing them cut total FODMAPs by 58%, but it did not name the variety. If you have IBS, check your serving in the Monash FODMAP app.
How many mushrooms should you eat a day?
No study here sets an ideal amount. Trials used 84 g a day for 8 weeks and 100 g a day for 16 weeks. In cohorts, Korean adults who ate mushrooms less than once a week or 1 to 3 times a week had a 10 to 14% lower risk of dying than non-eaters, and Japanese women who ate over 15 g a day had a 44% lower risk of disabling dementia.
Are white mushrooms good for diabetes or cholesterol?
They can fit, but the evidence is thin. Raw white mushrooms have 22 calories and 2.3 g of net carbs per 100 g. In a 60-adult trial, 84 g a day lowered fasting blood sugar by 2.9 mg/dL but did not change cholesterol beyond what the diet did, and in prediabetes, 100 g a day of UV mushrooms for 16 weeks did not change diabetes risk factors. Check portions with your care team.