Nutrition Diva listener Holly wants to know whether mushrooms are a vegetable. And the short answer is: No. But I think we should grant them honorary vegetable status.
Technically, mushrooms are not vegetables because mushrooms are not plants. They are a type of fungi–a biological kingdom that also includes molds and yeasts. In some ways, fungi are actually more similar to animals than plants. While plants are able to produce their own food through the process of photosynthesis–which, as you should remember from 6th grade science, involves converting sunlight, water, and carbon dioxide into carbohydrates, or energy. It’s really quite miraculous when you think about it. Fungi and animals, on the other hand, are both dependent on other organisms to provide their nutrition.
What we call mushrooms are actually only a part of the organism–the so-called “fruiting bodies” that appear above the ground. Underneath the ground is the mycelium, a vast network of fine thread-like filaments that secrete enzymes that help break down organic matter in the soil, and then absorb the nutrients.
There is much more to say about the ways that fungi interact with and influence our entire biosphere. It gets pretty freaky. But in the interests of time, let me pivot back to the part of this story that deals with human nutrition.
What are mushrooms if not vegetables?
Taxonomically speaking, mushrooms are not vegetables. But when talking about diet and nutrition, we play pretty loose with those botanical classifications. Zucchini, tomatoes, acorn squash, and bell peppers are all technically fruits, because they grow from the flower of a plant. But all are commonly referred to as vegetables. Corn is technically a seed, like wheat. But we consider it to be a vegetable, not a grain. Peanuts are technically legumes, but nutritionists generally group them with nuts.
Mushroom nutrition
When it comes to nutrition, we’re less concerned with the botanical classification and more concerned with the nutrient profile and how the food functions in the diet. And here’s where I think I can make a case for giving mushrooms honorary status as vegetables.
There are many different types of edible mushrooms, everything from Japanese shiitake and enoki to Italian porcini to the common white button mushroom and the ever-popular portabella, also known as crimini. The various kinds of mushrooms all have different flavors, shapes, and textures—which is fun for culinary types.
Like most other vegetables, mushrooms are nutrient dense–meaning they provide a lot of nutrition in very few calories, mostly in the form of carbohydrates, including fiber. They contain small amounts of protein and are virtually fat free. In terms of macronutrient profile, they are similar to spinach or cauliflower.
What vitamins are in mushrooms?
I know we often make a big deal about eating more colorful vegetables, because they are rich in antioxidants. Mushrooms are a bit of an exception here. Despite their earth-tone color palette, they are quite rich in antioxidants. Although the nutrient profiles vary from type to type, most mushrooms are also good sources of B vitamins, iron, and other minerals.
Mushrooms stand apart from vegetables, however, as a potential source of vitamin D. And here’s another way in which mushrooms seem a little closer to animals than plants. Like humans, mushrooms exposed to sunlight produce vitamin D!
Some commercial mushrooms are treated to boost vitamin D content. But you can also boost the vitamin D content of mushrooms by putting them on a sunny windowsill or—if sunlight is not plentiful—a UVB bulb works, too. You’ll find UVB bulbs at pet stores that carry supplies for reptiles. Just put your mushrooms under the bulb for a couple of hours and then cook and eat them as usual. This method is so effective that it can even reverse a vitamin D deficiency.
How can you eat mushrooms?
Given their nutrient profile, I think you can and should consider mushrooms as a valid option to help fulfill your vegetable quota. Almost all fresh mushrooms are delicious thinly sliced and sautéed over low heat in a bit of oil. You can cook them like that all by themselves or add in other vegetables too. They can also be enjoyed raw in salads. (Be sure to try the delicate and delicious enoki mushrooms as a salad topper if you’ve never tried them!)
Dried mushrooms can be reconstituted in warm water and then added to soups, casseroles, or stir-fries. Reserve the soaking water after removing the mushrooms. This mushroom “liquor” adds depth and richness to soups or stews—or use it as the liquid to cook rice or other grains.
Wild mushrooms are a delicacy but unless you really know what you’re doing, I’d advise against gathering your own. Some wild mushrooms are highly toxic and I, personally, wouldn’t trust myself to tell the difference. But you can order kits to grow your own mushrooms. I haven’t tried it yet but I understand that mushroom farming is fun and easy. I bet it would be fun to do with kids. Fungi Perfecti is a good online source for mushroom kits and all kinds of other information about the medicinal and culinary properties of mushrooms.
Do mushrooms help the brain or fight cancer?
Aside from the nutritional and culinary benefits of mushrooms, there are also lots of claims regarding specific types of mushrooms as a way to boost brain power, or even to fight cancer. Let’s take a closer look at some of those.
Certain mushrooms contain unique compounds that appear to boost your immune defense, and there has been a lot of interest in the cancer-fighting potential of mushrooms. Certain mushroom extracts have been demonstrated to have anti-tumor activity—at least in test tubes. In humans, mushroom extracts have been shown to increase immune system activity–but it’s not clear what impact, if any, that might have on someone fighting cancer. Other lines of research are looking at mushrooms as an adjuvant therapy to ameliorate some of the negative effects of traditional cancer therapy, and perhaps even boost its effectiveness.
Although we have yet to see a breakthrough cancer treatment derived from mushrooms, many people believe that including mushrooms in their diet can help reduce their risk of cancer. It certainly can’t hurt. In fact, a few studies have found that people who eat more mushrooms have lower incidence of certain types of cancer, including breast cancer and stomach cancer. But these are correlations, not proof of a protective effect.
The immune boosting compounds in mushrooms don’t appear to be affected by drying, by the way, so you can get the same benefit from dried and powdered mushrooms as you do from fresh.
Is mushroom coffee good for you?
And speaking of powdered mushrooms, perhaps you’ve also seen the mushroom coffee trend – blends that combine various medicinal mushrooms with coffee, cocoa, tea, and/or various herbs and are claimed to increase your productivity, energy, and immunity while relieving stress.
Some of these so-called medicinal mushrooms, such as cordyceps and chaga, are really only used in teas, tinctures, and supplements. Others, such as reishi and lion’s mane, are varieties that you might also use in cooking. But you generally wouldn’t be consuming them in sufficient quantities to be considered therapeutic.
The evidence to support the alleged benefits of mushroom coffee (or other functional mushroom beverages) is mostly anecdotal. People claim that after drinking them, they feel remarkably energized, focused, or calm. They sleep better, they work better, they feel better.
How much of that is due to the good old-fashioned placebo effect? It’s hard to say. Sleep, energy, well-being, and focus are aspects of human experience that are notoriously subjective and suggestible. Then again, what’s wrong with exploiting a placebo effect if it makes us feel and function better?
That said, the power of suggestion can be a double-edged sword. It’s possible to experience negative effects from a sham treatment, something we call the nocebo effect. A friend of mine, for example, tried some mushroom coffee and experienced a temporary but unpleasant state of agitation. Was it a reaction to the mushroom or power of suggestion? Who cares? It was enough for him to decide that this product was not for him.
So, are mushrooms a vegetable?
Whether or not you want to make room for mushrooms in your medicine cabinet, I hope I’ve convinced you that they deserve a place on your dinner plate–and that we can justifiably consider mushrooms “honorary vegetables.”