Meatless Monday: More on Mushrooms

Happy Monday everyone.

Yes, mushrooms are the topic once again. But please humor me while I tell you some things you may not know about fungi and why they make a perfect Meatless Monday post. 

First of all, mushrooms are not meat. But neither are they vegetables. In fact, fungi form their own kingdom. Members of the fungi kingdom (which includes edible mushrooms) and the animal kingdom (which includes us) are more closely related to each other than they are to plants! Since neither animals or fungi can make their own food as plants and algae can, they are known as heterotrophs. 

All heterotrophs are not the same. While we ingest (or sometimes “inhale”) our food, fungi absorb nutrients from outside their bodies. Since fungi can digest compounds from a wide range of sources — both living and dead — they play an important role in the ecosystem. Their ability to consume any carbon-containing substance has led mycologist Paul Stamets to experiment with cultivating oyster mushrooms as a means of remediating oil spills. In fact, Stamets has written a book, Mycelium Running, describing the many ways mushrooms can help save the world — from filtering pathogens to providing a source of nutrients and medicines.

A fungus discovered in Oregon is 1998 is the world’s largest living thing, many times larger than a blue whale and, except for small outcroppings of mushrooms at its surface, hidden from our view. [What we know as a “mushroom” is actually the fruiting body of the organism, which erupts from an underground system of branching, thread-like mycelia in response to an environmental stimulus like rain.] This pathogenic honey mushroom fungus, occupying nearly four square miles of soil, causes the conifer-killing Armillaria root disease. Its age is estimated to be 2,400 years, but it could be as ancient as 8,650. Reports are that the honey mushrooms are edible but not particularly tasty to everyone.

But I digress — back to edible mushrooms and their nutritional properties. Mushrooms are a low calorie, low sodium source of protein, dietary fiber, iron and other essential minerals, as well as a variety of other compounds purported to have medicinal properties — a wonder food, particularly for a vegan. A good source of some B vitamins, mushrooms do lack A, C, and D. While A and C are found in many fruits and vegetables, getting enough dietary D can pose a problem for vegans. 

Nutritional data for the oyster mushroom

But here’s one more interesting thing. Mushrooms are one of the few food sources in which ergosterol, the precursor to vitamin D, occurs naturally. Researchers have discovered that a small amount of vitamin D is synthesized in mushrooms by exposure to naturally occurring UV light, and that this conversion can be accelerated by exposing the mushrooms to 18-20 additional seconds of UV light during processing. In short, mushrooms are already a really good food, and some day may be an even better one. 

Not everyone can experience the thrill of harvesting mushrooms in the wild, as Michael Pollan described in The Omnivore’s Dilemma. Yet in 2011 there is no reason to be mushroom deprived. While it is true that in the past mushrooms were only sold canned, now both fresh and dried varieties are readily available in most supermarkets and green grocers. According to a 2007 article in Scientific American, a large button mushroom farm can produce as many as one million pounds of mushrooms in a year. 

Mushrooms are a rather pricey source of protein, particularly when compared to beans. But they are versatile and you can use them sparingly, fresh or dried, to enhance a number of dishes, making them a perfect choice for Monday and every day.

The idea of growing edible fungi at home, has recently well, you might say, “mushroomed.” The New York Times has described “inoculation parties” for would-be backyard mushroom farmers, and countless others are growing them on their windowsills. Next week I’ll let you know what’s up with the mushroom kit I started.

I try to blog on food or food issues each Monday in support of Meatless Monday, one of several programs developed in the Healthy Monday project, founded in 2003 in association with Columbia University’s Mailman School of Public Health, Johns Hopkins Bloomberg School of Public Health and Syracuse University’s Newhouse School of Communications. Meatless Monday’s goal is “to help reduce meat consumption 15% in order to improve personal health and the health of our planet.”