Pleurotus ostreatus, the oyster mushroom, oyster fungus, hiratake, or pearl oyster mushroom is a common edible mushroom. It is one of the more commonly sought wild mushrooms, though it can also be cultivated on straw and other media.
Oyster mushrooms are beloved the world over for their delicate texture and mild, savory flavor. The mushrooms typically have broad, thin, oyster- or fan-shaped caps and are white, gray, or tan, with gills lining the underside. The caps are sometimes frilly-edged and can be found in clusters of small mushrooms or individually as larger mushrooms. Oyster mushrooms are more expensive than white button mushrooms but less so than rarer mushrooms like morels, and take little prep since they can be used whole or chopped. They are even used to make mycelium furniture and many other products.
6 Impressive Benefits of Oyster Mushrooms
- 1.Rich in nutrients
Oyster mushrooms are loaded with fiber, vitamins, minerals, and other important nutrients. They’re also low in carbohydrates, so they’re a good choice for people following low carb dietary patterns.
The mushrooms also contain smaller amounts of other nutrients, including vitamin D and selenium.
- 2.Source of antioxidants
Oyster mushrooms provide antioxidants, which are substances that help reduce cellular damage in your body.
For example, seven phenolic compounds have been detected in P. ostreatus extracts, including gallic acid, chlorogenic acid, and naringenin — all of which act as antioxidants in your body .
These mushrooms also contain the amino acid ergothioneine, which has powerful antioxidant effects .
A 2007 study in rodents found that treatment with oyster mushroom extract improved antioxidant levels and lowered certain inflammatory markers, including malondialdehyde (MDA), in older rats .
Similarly, a 2020 rat study observed that the extract showed antioxidant effects and helped reduce liver damage caused by toxic chemicals .
What’s more, a 2016 test-tube study found that extract from gray oyster mushroom (Pleurotus pulmonarius) inhibited oxidative damage to human artery cells and prevented oxidation of LDL (bad) cholesterol, possibly thanks to the amino acid ergothioneine.
Oxidation of LDL (bad) cholesterol is involved in the process of atherosclerosis, which is the buildup of plaque in the arteries that can lead to heart disease .
Although animal and test-tube studies suggest that oyster mushrooms provide antioxidants and may protect against cellular damage, more research in humans is needed.
- 3.May benefit heart health
Oyster mushrooms may promote heart health by reducing heart disease risk factors like high cholesterol and high blood pressure.
P. ostreatus is especially high in several compounds that benefit heart health, including fibers called beta-glucans .
Beta-glucans are fermented by gut bacteria to produce short-chain fatty acids that can help reduce cholesterol production in your body. Interestingly, P. ostreatus provides twice as many beta-glucans as white button mushrooms .
A small 2011 randomized control trial in 20 people found that eating a soup containing 30 grams of dried P. ostreatus for 21 days decreased triglycerides, total cholesterol, and oxidized LDL (bad) cholesterol levels compared with placebo treatment.
Plus, a 2020 review of eight human studies found that P. ostreatus intake helped lower blood sugar, triglycerides, blood pressure, and insulin levels, all of which could decrease heart disease risk.
However, the authors acknowledged that all available studies have a high risk of bias and that future well-designed studies are needed to better understand how P. ostreatus intake may improve heart health.
- 4. May promote blood sugar regulation
In addition to promoting heart health, oyster mushrooms may help regulate blood sugar levels.
A study in 22 people with and without type 2 diabetes found that taking powdered P. ostreatus reduced post-meal blood sugar levels. The authors speculated that the mushrooms increased sugar use in body tissues while inhibiting certain blood sugar-increasing proteins .
Similarly, a 2007 study in 30 hospitalized people with type 2 diabetes found that eating 150 grams of cooked P. ostreatus daily for 7 days reduced fasting blood sugar by 22% and post-meal blood sugar by an average of 23% .
After participants had stopped the mushroom treatment for 1 week, fasting and post-meal blood sugar increased by an average of 13% and 20%, respectively. The treatment also significantly reduced participants’ blood pressure, cholesterol, and triglyceride levels .
What’s more, a study in 27 men with type 2 diabetes and high blood pressure found that treatment with 3 grams of powdered P. ostreatus powder per day for 3 months significantly reduced hemoglobin A1c (HbA1c), a marker for long-term blood sugar control .
A 2020 review suggested that these potential blood sugar-lowering effects may be attributed to the mushroom’s high concentration of beta-glucans, as this type of fiber slows down carbohydrate digestion and absorption.
- 5. Immune-supportive benefits
Oyster mushrooms may support your immune system in several ways.
For example, pleuran — a type of beta-glucan fiber derived from P. ostreatus — has been shown to have immune-modulating properties. Plus, the mushrooms may boast antiviral and antibacterial effects.
In a 130-day study in 90 people with herpes simplex virus type 1 (HSV-1), treatment with a combined pleuran, vitamin C, and zinc supplement improved HSV-1 symptoms and reduced the duration and severity of respiratory symptoms more than vitamin C alone.
Pleuran treatment has also been shown to significantly improve symptoms in children with recurrent respiratory tract infections and significantly reduce the incidence of upper respiratory tract infections in athletes.
Additionally, an 8-week study in 41 people found that compared with placebo, taking a daily oyster mushroom extract supplement heightened the immune system by activating interferon-γ (IFN-γ), a molecule that plays a critical role in protecting against infection.
These mushrooms have also been shown to have antiviral and antibacterial effects.
However, studies focusing on the potential immune health-promoting properties of whole oyster mushrooms — and not just extracts and supplements — are needed.
- 6. Other potential benefits
In addition to the possible benefits listed above, research suggests oyster mushrooms may promote health in other ways:
Potential anti-tumor properties. Research in test tubes and animals suggests that these mushrooms may provide anti-tumor effects. However, human research is lacking .
Gut health benefits. A 2021 rodent study found that supplementing the diet of obese rats with oyster mushrooms decreased the growth of pathogenic bacteria and increased the production of beneficial short-chain fatty acids in their guts.
Anti-inflammatory effects. These mushrooms contain anti-inflammatory compounds. A 2020 rat study found that oral treatment with P. ostreatus extract significantly reduced induced paw inflammation.