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. Here’s the nutritional content of 1 cup (86 grams) of raw P. ostreatus oyster mushrooms:

• Calories: 28
• Carbs: 5 grams
• Protein: 3 grams
• Fat: <1 gram
• Fiber: 2 grams
• Niacin: 27% of the Daily Value (DV)
• Pantothenic acid (vitamin B5): 22% of the DV
• Folate: 8% of the DV
• Choline: 8% of the DV
• Potassium: 8% of the DV
• Iron: 6% of the DV
• Zinc: 6% of the DV

The mushrooms also contain smaller amounts of other nutrients, including vitamin D and selenium. Oyster mushrooms are a good source of fiber, protein, and a variety of vitamins and minerals.

Antioxidants are molecules that lessen cellular damage in your body, and oyster mushrooms are a good source of them. Seven phenolic substances, such as gallic acid, chlorogenic acid, and naringenin, which all function as antioxidants in your body, have been found, for instance, in P. ostreatus extracts. The amino acid ergothioneine, which possesses potent antioxidant properties, is also present in these mushrooms. In an investigation conducted on rodents in 2007, oyster mushroom extract administration increased antioxidant levels and decreased several inflammatory indicators, such as malondialdehyde (MDA), in older rats.

The extract had antioxidant benefits and assisted in reducing liver damage brought on by harmful substances, according to a 2020 rat research. Additionally, a 2016 test-tube study discovered that the amino acid ergothioneine may have a role in the extract from gray oyster mushroom (Pleurotus pulmonarius) inhibiting oxidative damage to human artery cells and preventing oxidation of LDL (bad) cholesterol. Atherosclerosis, or the accumulation of plaque in the arteries that can cause heart disease, is a process in which LDL (bad) cholesterol gets oxidized. Oyster mushrooms may deliver antioxidants and may guard against cellular damage, according to animal and in vitro studies, but further human studies are required.

By lowering heart disease risk factors including high cholesterol and high blood pressure, oyster mushrooms may improve cardiovascular health. P. ostreatus is particularly rich in many substances, including the fibers known as beta-glucans, that are good for heart health. Short-chain fatty acids are created when gut bacteria digest beta-glucans, and they can aid in lowering your body's creation of cholesterol. Interestingly, compared to white button mushrooms, P. ostreatus offers double the amount of beta-glucans (A. bisporus). Compared to a placebo, 20 participants in a short 2011 randomized control study who had a soup containing 30 grams of dried P. ostreatus for 21 days saw lower levels of triglycerides, total cholesterol, and oxidized LDL (bad) cholesterol.

The consumption of P. ostreatus also assisted in lowering blood sugar, triglycerides, blood pressure, and insulin levels, all of which may reduce the risk of heart disease, according to a 2020 analysis of eight human research. To further understand how consuming P. ostreatus may benefit heart health, the authors noted that there is a substantial risk of bias in all already published research and that further, well-designed studies are required.

Oyster mushrooms not only support heart health but may also assist control blood sugar. Taking powdered P. ostreatus decreased post-meal blood sugar levels, according to research including 22 participants with and without type 2 diabetes. According to the authors, the mushrooms boosted the body's utilization of sugar while blocking several proteins that raise blood sugar levels. Eating 150 grams of cooked P. ostreatus every day for seven days lowered fasting blood sugar by 22% and post-meal blood sugar by an average of 23%, according to a 2007 research on 30 hospitalized type 2 diabetics.

Participants' fasting and post-meal blood sugar levels increased on average by 13 and 20 percent, respectively, after stopping the mushroom therapy for a week. Blood pressure, cholesterol, and triglyceride levels of individuals were all considerably lower after the therapy. In addition, therapy with 3 grams of powdered P. ostreatus powder per day for three months significantly decreased hemoglobin A1c (HbA1c), a measure for long-term blood sugar management, in a trial of 27 men with type 2 diabetes and high blood pressure. According to a review published in 2020, the mushroom's high content of beta-glucans, a kind of fiber that slows down carbohydrate digestion and absorption, may be responsible for these possible blood sugar-lowering benefits.

Your immune system may benefit from oyster mushrooms in a number of ways. For instance, it has been demonstrated that pleuran, a form of beta-glucan fiber produced from P. ostreatus, exhibits immune-modulating capabilities. The mushrooms may also have antibacterial and antiviral properties. Treatment with a pleuran, vitamin C, and zinc supplement relieved HSV-1 symptoms and decreased the length and severity of respiratory symptoms more than vitamin C alone in 130-day research including 90 persons with herpes simplex virus type 1 (HSV-1).

Additionally, it has been demonstrated that pleuran therapy considerably reduces the frequency of upper respiratory tract infections in athletes and significantly improves symptoms in kids with recurrent respiratory infections. In addition, an 8-week trial including 41 individuals discovered that taking an oyster mushroom extract supplement on a regular basis improved immune function by triggering interferon- (IFN-), a chemical essential for fighting illness.

Health specialists frequently suggest eating a diet high in fiber-rich vegetables as a way to achieve and maintain a healthy weight. Mushrooms, however, could also help you maintain improved metabolic health. In one published study, the impact of edible mushrooms on obesity was investigated. According to the researchers, "regular ingestion of mushrooms is useful in treating obesity and the metabolic syndrome". However, they cautioned that the practice must be accompanied by consistent exercise, dietary changes, and lifestyle adjustments.

According to some preliminary studies, oyster mushrooms may have cancer-preventing abilities. A 2012 research found that an oyster mushroom extract may inhibit the development and metastasis of breast and colon cancer in human cells. Scientists say that further research is necessary to properly grasp the link and that research is currently happening.