The Mighty Mushroom: Why it Should Be a Fall & Winter Staple

article by Shannon Dahlum

When you think of seasonal fall vegetables, winter squash and pumpkins probably come to mind, along with potatoes, sweet potatoes, beets, and other root veggies. Common fruits in season this time of year include apples, pomegranates, figs, cranberries, and persimmons. Another plant food that’s abundant this time of year that may not immediately come to mind is mushrooms. To be fair, wild mushrooms have both a spring and autumn harvesting season, and are neither fruit nor vegetable; they’re fungi.

Several mushroom varieties grow abundantly in Louisiana, including oyster, chantrelle, and morels. Oyster mushrooms are considered a delicacy and can be found in many wooded areas around the state. Chantrelles are also a delicacy, with their bright orange or yellow caps and a fruity aroma. These can’t be grown commercially so they must be wild harvested by hand, which makes them more expensive to purchase. Morels have a very distinctive appearance, with a spongy or honeycomb like texture on its caps, and are highly sought after by mushroom hunters.

I’ve never known anyone to be unbiased about mushrooms; most seem to either love them or hate them. Regardless of how you feel about the taste or texture, the one thing that can’t be denied is their nutritional content. Mushrooms are a good source of selenium, which is vital for healthy thyroid function, DNA production and healthy cell function.

They also contain vitamins B2, B3, B5 and B9 which are essential for energy production, cell growth and formation. Additionally, mushrooms are rich in beta glucans, which enhance immune function, ergothioneines for antioxidative potentiation, nerve growth stimulators for helping brain function, and antimicrobial compounds for limiting viruses.

What may be most impressive about the mighty mushroom is its vitamin D content. Few plant foods naturally contain vitamin D, and mushrooms are actually the only plant food you’ll find in the grocery store that can increase its vitamin D content through exposure to ultraviolet light, or sunlight. In the same way that sunlight hitting your skin triggers the production of vitamin D in your body, the mushroom produces vitamin D when exposed to sunlight.

The recommended daily allowance of vitamin D (which is the minimum required to prevent diseases of deficiency) is 20 micrograms. Raw white mushrooms that you find in the produce aisle contain about 0.18 mcg. However, when those mushrooms are exposed to UV light, their vitamin D content shoots up to a whopping 23.6 mcg! Brown, or cremini mushrooms go from 0.08 mcg to 25.52 mcg after proper light exposure. Raw Portabellas contain 0.25 mcg and increase to 23.9 mcg of vitamin D after sitting in the sun.

If you’re able to find and purchase locally grown, wild harvested mushrooms which naturally had sun exposure, they’re already rich in vitamin D content. If you’re purchasing mushrooms in the grocery store that were likely farmed indoors, you can pump up their D content by giving them sun exposure yourself. Interestingly, even sliced and previously dried mushrooms will still synthesize vitamin D with sun exposure.

To take advantage of the mushroom’s ability to generate vitamin D, it’s recommended to place your raw mushrooms in the midday sun for about an hour when you get them home from the store. Researchers have found that letting the mushrooms sit outside for even just 15 minutes on a cloudy day can significantly increase D levels. In studies, the largest increases in vitamin D production came from oyster and enoki mushrooms, followed by portobello and shiitake. Regardless of the mushroom variety, production of D can be enhanced even further by slicing them before placing them in the sunlight. This is because slicing them increases the surface area being exposed to the UV light.

Vitamin D is an essential nutrient needed for keeping our immune systems strong and for supporting our mental health. As our sun exposure and vitamin D production begins to diminish this time of year as the days get shorter, rates of depression and seasonal affective disorder increase. This makes it especially important for us to be intentional about consuming more vitamin D rich foods. Regularly eating mushrooms that have had some time in the sun is a simple way to do this!

Mushrooms have very tough cell walls that are essentially indigestible to us, which means that we may not absorb their nutrients efficiently when eating them raw. Thoroughly heating them releases the many nutrients they contain and makes them more available to our bodies. I prefer sautéing my sliced mushrooms in some organic, grass-fed butter which is also rich in vitamin D. Vitamin D is fat soluble, so the fat in the butter helps our bodies absorb that vitamin D, as well. A bit of Celtic sea salt, fresh cracked pepper and fresh thyme really makes them irresistible to me!

The growing and harvesting season for wild mushrooms is actually coming to a close this month. Of course, you can always find white, portobello and shiitake mushrooms year round in the produce aisle. Even better, try your hand at growing your own mushrooms! Milliman Mushroom Farm, located in West Monroe, sells mushroom growing kits that make it easy to grow your own at home. Check Fiesta on Eighteenth, for His Temple family foods, and Gibson’s Fresh Grocer for their products.

The outdoor veggie growing season may be coming to an end, but you can begin growing mushrooms inside and keep them going all winter long! Whatever mushrooms you’re going to cook, just don’t forget to give them time outside to soak up some sun before cooking them.