Oyster Mushroom Facts
Ivan Herenchak-JonesOyster mushrooms, also referred to as Pleurotus species, belong to the category of gilled fungi. Although mushrooms are categorized as fungi, which is distinct from the plant kingdom, they make a valuable addition to any plant-based diet.
The oyster mushroom family encompasses approximately 40 distinct varieties, with one of the most recognized being Pleurotus ostreatus, commonly referred to as the American oyster mushroom. All these varieties are suitable for consumption and are frequently incorporated into dishes such as pasta and stir-fries (1).
These mushrooms are renowned for their notable health-enhancing qualities and are rich in various potent compounds. For their vital qualities, they have been employed in traditional medicinal practices for centuries (1, 2).
Nutrient Dense
Oyster mushrooms are rich in fiber, vitamins, minerals, and essential nutrients, all while being low in carbohydrates, making them an excellent choice for individuals adhering to low-carb diets.
Here is the nutritional profile of 1 cup (86 grams) of uncooked P. ostreatus oyster mushrooms (3):
- Calories: 28
- Carbohydrates: 5 grams
- Protein: 3 grams
- Fat: Less than 1 gram
- Dietary Fiber: 2 grams
- Niacin (Vitamin B3): Provides 27% of the Daily Value (DV)
- Pantothenic Acid (Vitamin B5): Supplies 22% of the DV
- Folate: Offers 8% of the DV
- Choline: Contains 8% of the DV
- Potassium: Provides 8% of the DV
- Iron: Offers 6% of the DV
- Phosphorus: Contains 8% of the DV
- Zinc: Provides 6% of the DV
Additionally, these mushrooms contain smaller quantities of other nutrients, including vitamin D and selenium.
Antioxidant Rich
Oyster mushrooms offer a valuable source of antioxidants, which are compounds that help mitigate cellular harm within the body (4).
For instance, extracts from P. ostreatus have been identified to contain seven phenolic compounds, including gallic acid, chlorogenic acid, and naringenin, all of which exert antioxidant properties within the body (5, 6, 7, 8).
Moreover, these mushrooms contain the amino acid ergothioneine, known for its potent antioxidant effects (9).
An investigation conducted in 2007 with rodents discovered that the administration of oyster mushroom extract boosted antioxidant levels and reduced certain inflammatory markers, such as malondialdehyde (MDA), in older rats (10).
Similarly, a study in rats from 2020 observed that the extract exhibited antioxidant properties and assisted in mitigating liver damage caused by harmful chemicals (11).
Furthermore, a 2016 laboratory study revealed that an extract derived from the gray oyster mushroom (Pleurotus pulmonarius) prevented oxidative damage to human artery cells and hindered the oxidation of LDL (low-density lipoprotein) cholesterol, potentially attributable to the presence of the amino acid ergothioneine (12).
The oxidation of LDL cholesterol is implicated in the development of atherosclerosis, a process involving the accumulation of plaque in arteries that can lead to heart disease (12).
While animal and laboratory investigations suggest that oyster mushrooms supply antioxidants and may offer protection against cellular damage, further research involving human subjects is necessary to confirm these effects.
Heart Positive
Oyster mushrooms have the potential to promote heart health by reducing risk factors associated with heart disease, such as elevated cholesterol levels and high blood pressure.
P. ostreatus, in particular, contains a variety of heart-healthy compounds, including beta-glucans, which are types of dietary fiber (13).
These beta-glucans undergo fermentation by beneficial gut bacteria, resulting in the production of short-chain fatty acids that can help lower cholesterol production in the body. Interestingly, P. ostreatus contains twice as many beta-glucans as white button mushrooms (A. bisporus) (14).
In a small randomized controlled trial conducted in 2011 with 20 participants, consuming a soup containing 30 grams of dried P. ostreatus over a 21-day period led to reductions in triglyceride levels, total cholesterol, and levels of oxidized LDL (low-density lipoprotein) cholesterol when compared to a placebo treatment (15).
Furthermore, a 2020 review of eight human studies found that the consumption of P. ostreatus contributed to lower blood sugar levels, reduced triglycerides, decreased blood pressure, and lower insulin levels, all of which are factors that could potentially reduce the risk of heart disease.
Nevertheless, the authors of this review noted that all the available studies had a high risk of bias, emphasizing the need for future well-designed studies to provide a more comprehensive understanding of how P. ostreatus consumption may enhance heart health (16).
Blood Sugar Regulating
Oyster mushrooms may not only support heart health but also assist in regulating blood sugar levels.
A study involving 22 individuals, both with and without type 2 diabetes, revealed that the consumption of powdered P. ostreatus led to a reduction in post-meal blood sugar levels. The researchers hypothesized that these mushrooms enhanced sugar utilization in body tissues while inhibiting specific proteins that increase blood sugar levels (16, 17).
Similarly, a 2007 study involving 30 hospitalized individuals with type 2 diabetes found that consuming 150 grams of cooked P. ostreatus daily for 7 days resulted in a 22% decrease in fasting blood sugar and an average reduction of 23% in post-meal blood sugar levels (16, 18). Following a one-week cessation of the mushroom treatment, fasting and post-meal blood sugar levels increased by an average of 13% and 20%, respectively. Furthermore, the treatment significantly lowered participants' blood pressure, cholesterol, and triglyceride levels (16, 18).
Additionally, a study involving 27 men with type 2 diabetes and high blood pressure found that daily treatment with 3 grams of powdered P. ostreatus for 3 months resulted in a significant reduction in hemoglobin A1c (HbA1c), a marker of long-term blood sugar control (16, 19).
A review conducted in 2020 suggested that these potential blood sugar-lowering effects might be attributed to the high concentration of beta-glucans in these mushrooms. This type of fiber slows down the digestion and absorption of carbohydrates (16).
Immune Boosting
Oyster mushrooms have the potential to bolster your immune system through various mechanisms.
One such mechanism involves pleuran, a specific type of beta-glucan fiber derived from P. ostreatus, which has demonstrated immune-modulating properties. Additionally, these mushrooms may possess antiviral and antibacterial properties.
In a 130-day study involving 90 individuals with herpes simplex virus type 1 (HSV-1), a treatment regimen consisting of a combination of pleuran, vitamin C, and zinc supplements proved more effective than vitamin C alone. This combined treatment not only improved HSV-1 symptoms but also reduced the duration and severity of respiratory symptoms (20).
Pleuran treatment has also exhibited significant symptom improvement in children with recurrent respiratory tract infections and has been shown to notably reduce the occurrence of upper respiratory tract infections in athletes (21, 22).
Furthermore, an 8-week study involving 41 participants found that daily consumption of an oyster mushroom extract supplement led to an enhanced immune response by activating interferon-γ (IFN-γ), a molecule crucial for protecting against infections (23).
These mushrooms have also demonstrated antiviral and antibacterial effects (24, 25).
Nevertheless, it's important to note that while these studies highlight the potential immune-boosting properties of oyster mushrooms, further research is needed to explore the immune health benefits of consuming whole oyster mushrooms, rather than just their extracts and supplements.
Anti-Inflammatory
Oyster mushrooms contain compounds with anti-inflammatory properties. A 2020 study involving rats found that oral treatment with P. ostreatus extract significantly reduced inflammation induced in the paw (30).
Conclusion
Oyster mushrooms are a well-regarded variety of mushroom associated with numerous health advantages.
Beyond their exceptional nutritional profile, they have the potential to enhance heart and immune system function, support blood sugar management, and offer antioxidant and anti-inflammatory properties.
Incorporating these versatile mushrooms into your diet can be achieved by using them in a variety of dishes, such as pasta, stews, and omelets. Try some of our recipes here.