Maitake mushrooms are praised for their immune-boosting effects. Some people believe they may offer protection against the new coronavirus, but what does the science say? Read on to discover their potential pros and cons when it comes to COVID-19.
This article is for informational purposes only. The current coronavirus outbreak is an ongoing event, and details may change as new information comes to light. No adequate or FDA-approved products are yet available to treat or prevent COVID-19 infection.
Immune-Stimulating Effects of Maitake
In 18 patients with suppressed bone marrow, maitake extract enhanced the production and activity of neutrophils and monocytes, thus improving their immune response [1].
In 34 older breast cancer patients, post-treatment supplementation with a maitake extract boosted some immunity parameters but suppressed others. The authors called for further research on maitake’s immune-modulating effects [2].
Studies in animals and test tubes indicate the potential of maitake polysaccharides to stimulate the bone marrow and increase the activity of white blood cells. A combination with another medicinal mushroom, shiitake, may be even more potent [3, 4, 5].
The D-fraction (beta-glucan) is primarily responsible for the observed immune-boosting activities [6].
However, it’s untested whether maitake would be able to support the response against respiratory infections, such as the one caused by COVID-19.
Maitake mushroom extract stimulated macrophages to produce antiviral cytokines such as TNF-α, which inhibited the growth of the influenza virus in infected kidney cells [7].
A maitake polysaccharide inhibited the replication of enterovirus 71 in a cell-based study [8].
In another study in cells, a maitake extract (D-fraction) inhibited hepatitis B virus replication and enhanced the antiviral effect of interferon-alpha2b [6].
A protein isolated from maitake mushroom inhibited the replication of herpes simplex virus 1 in cells and improved the symptoms in mice [9].
Maitake & COVID-19 Risk Factors
According to preliminary data, patients with hypertension (high blood pressure) and diabetes may be at risk of more severe COVID-19 infections [10].
Maitake extracts (SX- and D-fraction) reduced hypertension and inflammation and improved metabolic health in multiple animal studies [11, 12, 13, 14].
They likely work by inhibiting the renin-angiotensin system (RAS). In theory, this may increase the expression of ACE2 receptors and worsen COVID-19 infection, but it’s too early for conclusions [12, 13].
A group of doctors reported a series of cases in which they successfully treated type 2 diabetes with maitake polysaccharides. They observed significantly lower blood glucose and HbA1c levels, even in the absence of standard treatment [15].
Maitake extract was able to improve glucose control in multiple studies on diabetic animals. Most of them tested the SX-fraction and discovered its potential to enhance insulin sensitivity [16, 17, 18].
Maitake Dosage & Safety Precautions
Side Effects
Most patients tolerated maitake mushrooms and extracts well. Mild digestive issues were the most common side effect. In rare cases, they may provoke an allergic reaction with rash, swelling, and breathing difficulties [19, 20, 1].
Maitake may interact with blood thinners and drugs for diabetes and high blood pressure. Consult with your doctor before supplementing [21, 15, 13, 14].
Exposure to maitake mushroom spores can cause lung inflammation. People prone to respiratory conditions should pay special attention while handling large amounts of maitake or any other mushroom [22].
Dosage & Supplements
This mushroom is available in various supplement forms. Dry extracts (caps, bulk powders) and liquid extracts (tinctures) are the most common, and some of them are standardized to 30% of D-fraction.
For boosting the immune response, the effective dosage in one clinical trial was 3 mg/kg, twice daily. That would be 420 mg of maitake extract daily for a 70-kg adult [1].
However, the mentioned dosage may not apply to you, so make sure to speak with a healthcare professional before supplementing.
Takeaway
Maitake mushrooms are praised for their immune-boosting properties. They can support bone marrow function and increase the activity of protective white blood cells.
Maitake was able to suppress different viruses in preclinical research, including the influenza virus, which can have similar respiratory complications as the new coronavirus. It also improved the two main risk factors for severe COVID-19 infections: high blood pressure and diabetes.
However, none of the above implies the protective effects of maitake against coronavirus. There’s not enough evidence to suggest it for COVID-19 prevention or treatment.
While researchers work to identify potential treatments, the best protective measures you can take are social distancing, hand washing, and not touching your face.
