By David Grotto, RD, LDN
Early in my career, I often considered mushrooms as a “non-player” in the produce arena. I never really considered them to be a major contributor of nutrients, but after much research, I’m convinced there should be much more fungus among us!
And for clarity, what we eat is actually not a fungus. Mushrooms are technically the fruits of fungus called mycelium that you can find growing in the forest, lawns, and moist and decaying areas. Mushrooms come in over 1000 varieties ranging in all kinds of shapes, sizes, colors, and flavor. Some of the more popular culinary mushrooms include: Black Trumpet, Chanterelles, Cloud Ears, Lobster, Morel, Oyster, Porcini, Portobello, Shiitake, Truffles, White Button, and Wood Ear.
Mushrooms are an excellent source of the mineral selenium and provide more of this nutrient than any other produce item. A cup of mushrooms is also an excellent source of riboflavin, biotin, niacin, copper, chromium, and a good source of pantothenic acid. Mushrooms are the only vegetarian source of vitamin D, but typically are not considered a good source of the nutrient. However, researchers have found that exposing mushrooms to just five minutes of UV light can boost vitamin D content up to nearly 900% of the daily value for vitamin D. Just like people, UV exposure can cause mushrooms to darken a bit, but other than that, there aren’t any drawbacks. Maitake mushrooms are the highest source of vitamin D in the mushroom kingdom, supplying an amazing 943 i.u. per 84-gram serving. Mushrooms may also be an under-recognized source of potassium. White, Crimini, and Portobello mushrooms provide about 300 mg potassium per three-ounce serving and over 550 mg per 1 cup cooked serving. Lastly, mushrooms contain many plant nutrients such as polyphenols and an a nutrient called ergothionene, which has powerful antioxidant properties that can help control oxidative damage and inflammation.
Eastern cultures have cherished mushrooms for millennia as both food and medicine. There may be more than 50 species that have healing properties, but the maitake, shiitake, and reishi varieties are prominent among those being researched for their potential anti-cancer, anti-viral, and/or immunity-enhancement properties. Mushrooms are loaded with a substance called beta glucan, which can help lower cholesterol and boost the immune system. Mushrooms and mushroom extracts have been the source of much research and may hold promise in treating and preventing both breast and prostate cancer by affecting aromatase, an enzyme that helps convert androgen into estrogen.
With fewer than 50 calories a cup cooked, substituting mushrooms for more calorie-dense proteins may save pounds on the scale. Lawrence Cherskin, MD found that when mushrooms were substituted for meat, study subjects found dishes prepared with mushrooms to be as satisfying and tasty, and they also saved an average of 450 calories per day by making the substitution. Their satisfaction with the taste of mushrooms may have to do with the meaty fifth taste that mushrooms possess called umami.
Now that you are inspired to add more mushrooms into your diet, here’re a few pointers for maximum ‘shroom enjoyment.
- If the gills are showing, it’s an indication of age, and they are probably past their prime.
- Choose mushrooms with a firm texture and even color with tightly closed caps.
- Wash your mushrooms, don’t brush the dirt off. Mushrooms are a bit porous but if you wash them off quickly under cold water you are sure to remove more dirt than brushing will. Pat them dry when done.
- Store unwashed mushrooms in your refrigerator crisper.
- Keep partially covered to prevent them from drying out, but never store packaged fresh mushrooms without venting. Paper bags are a good storage alternative.
- Use fresh mushrooms within three days.
- Store dried mushrooms in an airtight container.
- Dried mushrooms should be soaked in hot water or part of the recipe cooking liquid for about an hour before using. The liquid may be used for added flavor.
How do you like to prepare mushooms? Have you ever swapped out a burger for a Portobello mushoom before? Let’s hear about it!