In temperate ecosystems across the northern hemisphere, mushroom season is setting in. Already, I am finding an incredible diversity of fungi within the mixed deciduous in my own figurative backyard. The middle and end of August here in Western NY has been soaking wet, and I wouldn’t be surprised if this season turned out to be one of the most fruitful seasons we’ve had in 5 years. As summer turns to fall, temperatures drop and detritus builds atop the forest floor. These factors bring forth assemblages of fungi that mycophiles like you and I alike just wish occurred year-round. One of my favorite species that fruits early in the fall is Grifola frondosa, also known as hen of the woods or maitake.
Grifola frondosa, also known as hen of the woods or maitake. Photo by I. G. Safonov.
This species isn’t the least bit discrete when it fruits either. In early fall around the base of oak trees, Grifola frondosa emerges. Although their cap surfaces might blend in with their surroundings, this sizable fungus is hard to miss. Some clusters of Grifola frondosa are outright massive, growing two feet wide and nearly one foot tall. It is an easy favorite amongst foragers because of its delicious flavor and staggering yields when conditions are optimal. Besides being delicious, nutritious and bountiful, for decades, Grifola frondosa has been analyzed for health benefits.
Grifola frondosa fruiting gregariously around the stump of this mature oak. Photo by Charles Seltenright Sr.
In 1994 Japanese scientists Keiko Kubo, Hisao Aoki and Hiroaki Nanb a tested the anti-diabetic activity of this fungus. Using genetically diabetic mice, these researchers set up an experiment with two groups. One group of mice had Grifola frondosaadded to their diet while the control group of mice were not fed the fungal tissue. The group that was fed just one gram of dried Grifola frondosa a day had a significant reduction in their blood sugar, while the blood sugar of the mice in the control group just increased with their age. Along with reduced blood glucose, insulin levels, body weight, and triglycerides also had lower values in mice fed Grifola frondosa.
Filled in circles depict the group of mice fed Grifola frondosa. From Kubo et. al 1994.
There are skeptics out there that don’t see the medicinal value in fungi. I don’t blame them, especially in this modern era with just about everything being sensationalized. The number of “miracle” pill pyramid schemes alone is enough to make one’s head spin. But the diversity of secondary metabolites produced by fungi is even more staggering. These compounds can be extremely beneficial to human health, we just have to find them! Clearly, not every compound will be useful to humans, but surely, a small subset of these secondary metabolites can benefit our health. So, will Grifola frondosacure diabetes? No. But it may help stabilize a diabetic’s blood sugar.
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