What Is Maitake Mushroom? Nutrition, D-Fraction and Immune Research Overview
Maitake mushroom (Grifola frondosa) is an edible mushroom also known as hen-of-the-woods, valued for its low calorie count, fiber, and vitamin D content. Its beta-glucans, including the studied D-fraction, are the focus of small human trials on immune activity and blood sugar, though current evidence stays limited and preliminary.
This guide covers maitake’s nutrition facts, what D-fraction and beta-glucans actually are, how maitake compares with shiitake and other studied species, and what the current blood sugar, immune, and safety research does and does not show.
What Are Maitake Mushroom’s Nutrition Facts Per 100g?
Maitake mushroom nutrition is defined by very low calories, a small amount of plant-based protein, and a notable vitamin D content compared with most fresh vegetables. According to USDA FoodData Central’s entry for raw maitake, 100 grams supplies about 31 calories, 1.9 grams of protein, and 2.7 grams of fiber.
The list below reflects USDA FoodData Central values for raw Grifola frondosa, per 100-gram serving:
- Calories: 31 kcal
- Protein: 1.9 g
- Total Fat: 0.2 g
- Carbohydrates: 7.0 g
- Dietary Fiber: 2.7 g
- Vitamin D: 28 mcg (about 140% of the Daily Value)
- Potassium: 204 mg
- Phosphorus: 74 mg
- Niacin (B3): 6.6 mg
- Riboflavin (B2): 0.24 mg
- Copper: 0.26 mg
Two things stand out here. Maitake’s vitamin D content is unusually high for a food that isn’t fortified or animal-derived, though this can vary depending on how the mushroom was grown and exposed to light. The calorie and fat content remain low across most preparations, which is why maitake often appears in general low-calorie nutrition guidance.
Part of maitake’s fiber content consists of polysaccharides, including beta-glucans, the same broad family of compounds studied in D-fraction research. Eating maitake as a whole food is a different exposure than taking a concentrated extract, so the nutrition numbers above describe the food, not a supplement dose.
What Is Maitake D-Fraction? Beta-Glucans Explained
Maitake D-fraction is a specific polysaccharide extract isolated from Grifola frondosa, identified as a beta-1,6-glucan, a complex carbohydrate found in the mushroom’s cell walls. It is one of several maitake compounds studied, not a single settled active ingredient with confirmed effects in people.
Beta-glucans as a group are typically structured as glucose chains with 1,3 linkages and 1,6 branch points, and they appear across many mushroom species, not only maitake. What differs between species is the exact glucan structure, the extraction method, and the extent of human research on that specific extract. Memorial Sloan Kettering Cancer Center’s clinical review identifies beta-1,6-glucan as maitake’s main studied constituent and notes that D-fraction is the extract most often used in laboratory and small clinical studies of immunomodulation.
D-fraction is a manufactured extract, not something present in the same concentrated form when maitake is eaten as food. Some wellness marketing describes maitake as an adaptogen, but clinical classification as an adaptogen requires evidence that has not been established for maitake. Laboratory results on D-fraction cannot be assumed to apply to eating whole mushrooms or taking a general powder. Our beta-glucans research and evidence page explains how these compounds are studied across species and why form matters for interpreting a study.
The extraction method also changes what ends up in the finished product. A hot-water extraction pulls out a different mix of polysaccharides than an alcohol-based extraction, and neither process is standardized consistently across all supplement brands. This is another reason a single study on a single named extract does not translate cleanly to every product labeled “maitake” on a store shelf.
Maitake vs Shiitake: How Do These Two Mushrooms Compare?
Maitake and shiitake are both edible, cultivated mushrooms studied for polysaccharide compounds, but each centers on a different extract with a separate research history. Maitake’s research focus is D-fraction and related beta-glucans, while shiitake’s most-studied compound is lentinan, with its own long, largely Japan-based research trail.
In the kitchen, the two behave differently too. Maitake grows in overlapping, feathery clusters with a delicate texture, while shiitake has a firmer cap and a stronger umami flavor. Nutritionally, both are low-calorie and low-fat, but maitake’s vitamin D content tends to run higher in USDA data, while shiitake is often noted for selenium and copper. Neither mushroom’s research supports treating it as a substitute for the other, since each extract has been tested separately.
Our shiitake research and safety profile covers lentinan and the shiitake evidence base in greater depth, including the same kind of form-and-dose caveats that apply to maitake.
How Does Maitake Compare to Other Medicinal Mushrooms?
Several mushroom species have been studied for immune-related polysaccharides, but each has a distinct compound, research focus, and stage of evidence. The comparison below is a general orientation, not a ranking, since no species listed currently has strong, replicated human evidence for a specific health claim.
- Maitake (Grifola frondosa): Key compound beta-1,6-glucan (D-fraction). Primary research area: immunomodulation, glycemic control. Study stage: small human trials, mostly preclinical otherwise.
- Shiitake (Lentinula edodes): Key compound: lentinan. Primary research area: immune-related research, largely in Japan. Study stage: human trials with specific extract forms.
- Turkey tail (Trametes versicolor): Key compounds PSK / PSP. Primary research area: immune support alongside cancer treatment. Study stage: human trials with specific extract forms.
- Reishi (Ganoderma lingzhi): Key compounds: triterpenes, ganoderic acids. Primary research area: general wellness, immune signaling. Study stage: preliminary to mixed human evidence.
- Lion’s mane (Hericium erinaceus): Key compounds: hericenones and erinacines. Primary research area: cognitive and nerve-related research. Study stage: small human trials.
Every item above represents an early or narrow evidence base, not a settled conclusion. Our evidence grading and source policy explains how grades like these are assigned and why a small human trial is treated differently from a cell culture or animal study.
What Does Maitake Blood Sugar Research Show?
Maitake blood sugar research is limited to small human and animal studies, and it points to a possible effect on insulin sensitivity rather than to proven glycemic control. Memorial Sloan Kettering’s clinical summary notes preclinical work on alpha-glucan compounds and insulin receptor sensitivity, as well as a published case involving hypoglycemic medication.
This is also where caution matters most. Because maitake may lower blood sugar and may add to the effect of medications that already do so, MSKCC specifically flags a possible interaction with hypoglycemic drugs. If you manage blood sugar with medication, then treat maitake as a reason to check with your clinician first, not as a supplement to add on your own. This is a safety consideration, not evidence that maitake treats diabetes.
What Does Maitake Immune Research Show?
Maitake immune research centers on small clinical studies of the D-fraction and related beta-glucan extracts, most of which are conducted in specific patient groups rather than the general population. These studies measure immune markers, not disease outcomes, and they do not establish that maitake products boost immunity in healthy adults.
Human work referenced in Memorial Sloan Kettering’s clinical summary includes a phase I/II trial evaluating immune measures in breast cancer patients, a study of neutrophil and monocyte function in people with myelodysplastic syndrome, and a trial examining maitake alongside chemoradiotherapy in laryngeal and pharyngeal cancers. Each study examined a specific extract in a specific population for a specific outcome, so none supports a general immunomodulation claim for maitake products sold to the public. See our full maitake human evidence and safety review for a closer look at these trials and their limits.
What Are Maitake Mushroom’s Side Effects and Who Should Use Caution?
Seek medical care right away if you notice unusual bruising or bleeding, or signs of a possible allergic reaction such as hives, swelling, or trouble breathing, after eating maitake or taking a maitake supplement. These are the warning signs to act on first, before considering the more general safety notes below.
Maitake mushroom side effects reported in clinical literature are limited but specific. Memorial Sloan Kettering’s review lists asymptomatic eosinophilia, an increase in a type of white blood cell on lab work, as a documented adverse reaction, along with a published case report of an increased INR, a measure of blood-clotting time, in a person taking warfarin alongside maitake extract. Neither finding proves maitake is unsafe for most people, but both are reasons to disclose supplement use to a healthcare provider.
Based on this sourced information, a few decision points are worth knowing. If you take warfarin or another blood thinner, ask your prescriber before trying maitake, since a documented interaction can affect clotting measures. If you take blood-sugar-lowering medication, then treat maitake supplements the same way, given the possible additive effect described above.
- Anyone with a known mushroom allergy or history of allergic reactions to fungi should avoid self-testing maitake products.
- Anyone pregnant, breastfeeding, or managing a diagnosed health condition should ask a clinician first, since these groups are typically excluded from the small studies available.
These cautions apply mainly to concentrated supplements and extracts, more than to maitake eaten as a cooked food in ordinary amounts. Our mushroom safety and interactions guide covers these distinctions across species in more detail.
How Do You Cook Maitake Mushroom?
Maitake mushroom is typically cooked before eating, most often sautéed, roasted, or pan-fried, which softens its texture and brings out its earthy flavor. Because its clusters have a lot of surface area, maitake tends to crisp well at the edges when cooked with direct, dry heat rather than steamed or boiled.
- Tear the cluster into smaller pieces by hand along its natural ruffles, rather than cutting straight through, to keep more surface area for browning.
- Heat a small amount of oil in a pan until hot, then add the torn pieces in a single layer.
- Saute without stirring too often, letting the edges turn golden and slightly crisp before flipping.
- For larger batches, roast on a sheet pan at high heat instead of crowding a pan on the stovetop.
- Add cooked maitake to soups, stir-fries, or grain dishes toward the end of cooking so the texture doesn’t turn mushy.
Maitake should always be cooked, never eaten raw, and should come from a reliable grocer, farmers market vendor, or trusted cultivator rather than foraged unless you can positively identify it, since some similar-looking mushrooms are not safe to eat.
What Are the Research Limitations for Maitake?
The overall research limitation for maitake is straightforward: most of what looks promising is early-stage. Laboratory and animal studies of maitake compounds outnumber published human trials, and the human trials that exist are typically small, involve specific patient populations, and test a particular extract rather than the mushroom as food.
A few gaps are worth remembering. Studies on D-fraction or other extracts do not automatically apply to whole mushrooms, powders, or teas sold under the same maitake name. Small trials in patients with cancer or diabetes do not establish benefits for healthy adults. None of the research reviewed here supports the use of maitake to diagnose, treat, support, or prevent any disease.
Long-term human trials, the kind that track outcomes over months or years in large, diverse groups, are largely absent from maitake’s published research so far. Most available studies are short, involve a few dozen participants at most, and focus on lab measurements rather than lasting health outcomes. That gap is exactly why maitake’s evidence grade stays limited rather than established.
Frequently Asked Questions
Is maitake D-fraction the same as eating maitake mushrooms?
No. D-fraction is a manufactured polysaccharide extract used in laboratory and clinical studies, not something present in the same concentrated form when you eat whole maitake as food. Research on the extract cannot be assumed to apply to eating the mushroom itself.
Is maitake the same as hen-of-the-woods?
Yes. Hen-of-the-woods is a common English name for Grifola frondosa, the same species known as maitake, a Japanese name.
Can maitake mushroom supplements lower blood sugar?
Small studies and a published case report suggest that maitake compounds may affect blood sugar and insulin sensitivity, and clinical sources note a possible interaction with blood sugar-lowering medication. This is not established evidence that maitake treats diabetes.
What side effects have been reported with maitake?
Documented reactions include a rise in a type of white blood cell called eosinophilia and a case report of increased bleeding-time measures in someone taking warfarin alongside a maitake extract. Mushroom allergy is also a consideration for some people.
What’s the best way to prepare maitake mushroom at home?
Tear the cluster by hand along its natural ruffles, then sauté or roast it over a small amount of oil and direct, high heat until the edges are crisp. Maitake should always be cooked, never eaten raw.
This article provides general educational information about maitake mushroom nutrition and research. It does not diagnose, treat, support, or prevent any disease, and it is not a substitute for personalized medical advice. Ask a qualified clinician before starting, stopping, or combining any supplement with medication, especially blood thinners or diabetes medication. Read our medical disclaimer for more information.