Shiitake mushroom improves immunity by Dr. Joseph Mercola for Mercola
Mushroom lovers will be pleased to know that researchers studying the earthy fungi continue to find benefits for health in them. One of the most popular mushrooms is the shiitake (Lentinus edodes), which grows on decaying hardwood trees such as oaks, maples, chestnuts, hornbeams and ironwoods in their natural environment, but are commercially grown elsewhere.1
Recreating the same environmental conditions has allowed growers in the U.S., as well as Canada, Singapore and China, to proliferate the brown-capped delicacies. According to Market Research Future,2 the shiitake mushroom forecast through 2023 is projected to reach $35.4 billion, due in part to its robust use in the food industry, although nutritional and medicinal market shares are also thriving.
Shiitake mushrooms are very versatile for a variety of dishes. They’re great as a filling for sandwiches and diced to use in soups, casseroles and stir-fries. A favorite method of preparation is to sauté them in a skillet, which is easy and quick with coconut oil or avocado oil, adding a bit of Himalayan salt (depending on the amount you’re making) and a few pinches of select herbs and garlic.
Not only are they highly sought after for their buttery flavor, which becomes rich and smoky when dried, shiitakes are loaded with vitamins, minerals and compounds that are remarkably health beneficial, even though they are close to 90% water.3
One study notes that shiitake mushrooms have a long history of use in folk medicine for treating “tumors, flu, obesity, high blood pressure, sexual dysfunction, aging, heart disease, diabetes, liver ailments, respiratory diseases, weakness and fatigue.”4
Rather than killing cancer cells directly, a sugar molecule in shiitakes called lentinan instead enhances your immune system, which may help slow the growth of tumors.5 According to the International Journal of Microbiology:
“Shiitake mushroom has been used for many years to investigate functional properties and to isolate compounds for pharmaceutical use; this is because of its positive effects on human health. It has been utilized to alleviate the common cold for hundreds of years and some scientific evidence has supported this belief …
It has been reported that lentinan enhances host resistance against infections by bacteria, fungi, parasites, and virus; it also promotes nonspecific inflammatory responses, vascular dilation, hemorrhage-inducing factors activation, and generation of helper and cytotoxic T cells.”6
Studies on shiitake mushroom compounds lentinan and β-glucans
The nutrients multiply in shiitakes after about 80% of the water is extracted or they otherwise dry out. In fact, that’s the most popular form for their consumption to get the greatest nutritional value.7 A study in 20158 found that whole, dried Lentinula edodes (shiitake) mushrooms could improve human immune function. Participants included 52 healthy adults who ate 5 to 10 grams of the mushrooms daily for four weeks.