Page 14 - Today's Dietitian (March 2020)

Integrative Nutrition By Jamie Santa Cruz

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contain much less). Mushrooms of all types are low in calories,
very low in fat and sodium, and cholesterol-free.
What’s more, mushrooms are high in several key vitamins,
including the B vitamins riboflavin (B 2) and niacin (B 3). They
contain only low amounts of vitamin B 12, but the form of B 12
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found in mushrooms appears to be highly bioavailable. Unlike
plant foods, mushrooms can be a good source of vitamin D
if they’re exposed to ultraviolet light. Mushrooms also are
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important sources of various minerals, including potassium,
phosphorus, and selenium (the latter of which is an excellent
antioxidant).
Finally, mushrooms are important sources of two other bio-
active compounds, namely the antioxidants glutathione and
ergothioneine. Although glutathione can be found in signifi-
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cant amounts in other foods, mushrooms are one of the only
significant dietary sources of ergothioneine. According to
Beelman, ergothioneine has received significant attention in
recent research as a potential key to good health and longevity.
“All mammals, including humans, make a genetically coded,
highly specific transporter for this molecule,” suggesting an
Mushrooms as Medicine important role in the functioning of the human body, Beel-
man says. “Red blood cells distribute it around the body, and it
Do their potentially health-promoting compounds tends to accumulate in tissues that are under the most oxida-
have a place in disease treatment? tive stress, because it’s an antioxidant. This kind of indicates
that the body wants to use [ergothioneine] as a defense against
M ushrooms have been used as medicine for thou- 1 take, oyster, and shiitake are the mushroom varieties with
oxidative stress and inflammation.” Porcini, king oyster, mai-
sands of years, including in the early Greek, Egyp-
the highest amounts of ergothioneine; standard white button
tian, Roman, Chinese, and Mexican civilizations.
mushrooms contain much lower quantities.
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Although medicinal use of mushrooms has only
recently begun to take off in the United States, Medicinal Properties and Health Benefits
new research suggests that mushrooms indeed may be a potent According to Solomon P. Wasser, PhD, a professor emeritus in
remedy for a variety of health conditions. the department of evolutionary and environmental biology at
The term “medicinal mushroom” usually refers to more the University of Haifa in Israel, mushrooms and other fungi
exotic, specialty mushrooms, says Robert Beelman, PhD, a pro- are thought to possess more than 200 different medicinal
fessor emeritus of food science and director of the Center for functions. They have antitumor, immunomodulating,
Plant and Mushroom Foods for Health in the Pennsylvania antioxidant, radical scavenging, antiviral, antibacterial,
State University College of Agricultural Sciences. But even the antifungal, hepato-protective, and antidiabetic effects, among
common white button mushroom widely eaten in the United other qualities. In turn, mushroom consumption is thought to
States still has some medicinal value. A medicinal mushroom impact the risk of a range of conditions and diseases. “I have
“is any mushroom that has medicinal properties, and that changed the English proverb,” Wasser says. “Instead of apples,
would be true of all mushrooms,” Beelman says. ‘One mushroom per day keeps the doctor away.’”

Nutrition and Bioactive Components Cancer
Although mushrooms often are classified as vegetables for the According to Wasser, some of the best evidence for the ben-
purpose of dietary recommendations, they’re neither plants efit of medicinal mushrooms relates to cancer. “Medicinal
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nor vegetables, but rather fungi. They’re relatively high in pro- mushrooms are especially important for the prevention and
tein, with each 100-g serving of white button mushrooms treatment of oncological diseases,” Wasser says. “There are
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containing about 3 g protein. In addition, mushrooms are an real drugs from medicinal mushrooms—for example, kres-
important source of carbohydrates, which compose about one- tin, lentinan, schizophyllan—that are being used especially in
half of mushroom dry matter. Specifically, mushrooms con- Asia (Japan, Korea, China) for treatment in different kinds of
tain chitin, a form of dietary fiber found in the exoskeletons of cancer. Mushroom compounds are very important as immuno-
insects and crustaceans but not in plants. In addition, mush- modulators that enhance our immune system.”
rooms contain beta-glucans and other polysaccharides, which Much of the research on mushrooms and cancer has focused
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are bioactive compounds that stimulate the immune system ; on breast cancer. Test tube experiments have isolated spe-
beta-glucans traditionally have been the primary focus of cific compounds from different species of mushrooms and
medicinal interest in mushrooms. Some species of mushrooms have shown that they inhibit breast cancer growth. In addi-
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are much richer in beta-glucans than others (oyster and enoki tion, a meta-analysis of 10 different observational studies
contain relatively high amounts; white button and maitake found that increased mushroom intake was associated in a

14 TODAY’S DIETITIAN • MARCH 2020