Mushrooms are fungi, which is a separate kingdom of life from plants and animals. Technically, they are not a vegetable, but they are often used and served as a vegetable in recipes. They are a low-calorie, high-fibre food choice that can be used diversely in cooking. Mushrooms add a savoury flavour to recipes but are very low in sodium making them a healthy choice.

Mushroom Nutrition Facts

The following nutrition information is provided by the USDA for 1 cup (70g) raw mushroom pieces or slices.

Calories: 15

Fat: 0.2g

Sodium: 4mg

Carbohydrates: 2.3g

Fibre: 0.7g

Sugars: 1.4g

Protein: 2.2g

Carbs

One cup of raw mushrooms contains only 15 calories and 2.3 grams of carbohydrate. Mushrooms are also a good source of fibre, particularly the soluble fibre beta-glucan.

Mushrooms have a naturally low glycemic index, and studies have even been done on the effects of medicinal mushrooms for diabetes control. The glycemic load of a food item takes into account serving size, and, for mushrooms, it is estimated to be low at a value of 2. Mushrooms are assumed to have little negative effect on blood glucose or insulin response.

Fats

Mushrooms have only a minuscule amount of fat, most of which is polyunsaturated fat. As a result, mushrooms are considered a heart-healthy food choice.

Protein

Mushrooms provide a small amount of protein: 2.2 grams per cup. This is only 4% of your daily needs, so you should be sure to eat protein-rich foods, such as legumes, nuts, dairy, meat, or fish, as part of a balanced diet.

Vitamins and Minerals

Mushrooms are full of micronutrients. They are a good source of copper, niacin (vitamin B3), pantothenic acid (vitamin B5), potassium, phosphorus, and iron. B vitamins assist in the release of energy from carbohydrate, protein, and fat.

Copper assists in energy production and iron utilisation. It also maintains the integrity of connective tissues and assists antioxidant enzymes. Potassium is important for maintaining fluid and electrolyte balance. It is also required for proper nerve and muscle conduction and may help to lower blood pressure. Iron is a mineral that is needed for the synthesis of hemoglobin, DNA, amino acids, neurotransmitters, and certain hormones.

Health Benefits

A total of 126 health-related functions are thought to be produced by medicinal mushrooms and fungi. Research is ongoing about the potential for using mushrooms to improve health, prevent, or manage health conditions.

In addition to the many vitamins and minerals mushrooms contain, they have also been found to have high levels of some antioxidant compounds. All of these compounds can be beneficial to health.

Fights Cell Damage

Antioxidants have been shown to fight oxidative stress and inflammation, which contribute to signs of aging and to the development of chronic diseases. Several varieties of mushrooms, such as porcini and white button mushrooms, are high in the antioxidants glutathione and ergothioneine, which are not found in many other plant foods.

Improves Brain Function

Consuming mushrooms may also help slow the cognitive decline that comes with aging, according to both the antioxidant research above and a study of over 600 people aged 60 and over.

Supports Bone Health

Some mushrooms sold in stores have been treated with UV light to increase their vitamin D stores. These treated mushrooms are one of the best sources of vitamin D. Vitamin D is important for healthy bones. Eating these mushrooms has the same benefit as getting vitamin D from supplements or from sun exposure. Even untreated mushrooms are a good source of vitamin D.

Lowers Risk of Diabetes

Mushrooms are a good source of fibre. Consuming dietary fibre has many health benefits, including a lower risk of type 2 diabetes, lowered cholesterol levels, improved weight control.

Allergies

Food allergies to mushrooms are rare but have been reported. You may have a cross-reaction if you are allergic to moulds.

Adverse Effects

Some species of mushrooms can interact with alcohol in unpleasant ways. The inky cap mushroom contains coprine, which acts as the drug Antabuse, causing a racing heart, flushing, tingling, and other symptoms when you ingest alcohol as long as five days after eating the mushroom. Some other mushrooms cause digestive distress in susceptible people who consume alcohol alongside the mushroom dish.

The biggest concerns with adverse effects, however, are with wild mushrooms and the wide variety of poisonous substances they can contain. Effects of ingesting a toxic wild mushroom variety may include gastrointestinal irritation with nausea, cramps, vomiting, and diarrhea and may either pass on their own or be severe enough to require hospitalisation. Other mushroom toxins can affect the involuntary nervous system, kidneys, and liver, or are carcinogenic. Some of these toxins have no antidote and can be fatal within hours. Hallucinogenic mushrooms contain psilocybin and related compounds that produce psychological and perceptual effects.

Varieties

There are many types of culinary mushrooms, ranging from white button, crimini, shiitake, portabella, enoki, cloud ear, and more. The largest cultivated mushroom is the portabella, which can grow up to 6 inches in diameter.

Micro- and macro-nutrient levels can vary among different types of mushrooms. For example, white mushrooms have more potassium, while shiitake mushrooms have more fibre. But in general, all varieties have generous amounts of vitamins and minerals.

Dried and canned mushrooms can also be found all year long. Dried mushrooms tend to have more calories and other nutrients than raw varieties because they are more concentrated. When they are rehydrated before cooking or eating, their nutrition will be comparable to raw versions. Canned mushrooms are often a little higher in calories, and significantly higher in sodium, than raw mushrooms due to additives.

When They're Best

Fresh mushrooms are available all year long, with the peak season in the United States being April through June. Wild mushrooms are available seasonally, usually in the summer and fall.

Storage and Food Safety

Many wild mushrooms are deadly and can look like the safe varieties, so it is risky to gather wild mushrooms on your own for eating. Wild mushrooms that are sold by reputable purveyors should be safe to eat.

Many people use mushrooms, such as white button, to chop up and put in salads raw. Some experts suggest that you're better off cooking mushrooms because cooking helps to release the vitamins and minerals. Certain varieties of raw mushrooms contain small amounts of toxins, including a compound that is considered carcinogenic, which is destroyed through cooking. However, cooking will not render highly toxic mushrooms safe to eat.

When shopping for mushrooms, look for fresh mushrooms that are clean and free of blemishes, such as soft, moist spots and discolouration. Fresh mushrooms can be stored in the refrigerator in an open container for about five days. Do not wash them until just before use.

How to Prepare

Mushrooms can be cooked in a variety of ways, including grilling, baking, broiling, sauteing, and roasting. They are a hearty, vegetarian ingredient that can add texture, flavour, and substance to meals. Use mushrooms when making sauces, stews, and soups, or simply chop them up, saute them, and add them to grains, potatoes, or egg dishes.

Mushroom caps serve as a good vehicle for stuffing. Raw mushrooms can hold spreads and dips, or they can be baked with other kinds of stuffing, such as seafood or cheeses mixed with herbs, spices, and vegetables.

Start your day off with a protein and fibre-rich egg and mushroom dish or pair your main course with a side of simple grilled mushrooms. Top healthy pizzas with mushrooms or add them to your sides. Use them as a substitute for meat if you are looking to follow a vegetarian or vegan meal plan.