December 2018 Issue

Ask the Expert: Mushroom Extracts
By Toby Amidor, MS, RD, CDN
Today's Dietitian
Vol. 20, No. 12, P. 7

Q: Many of my clients have been asking about mushroom extracts for multiple health benefits. What are the different types and their purported benefits; is there any research to back them up, and are the extracts safe?

A: Mushroom extracts have gained popularity as remedies for a variety of ailments, including seasonal allergies, insomnia, cancer, the common cold, and inflammation. Tinctures, powders, and pills with single mushroom extract or as a combination of numerous mushroom extracts are on the market.

Research on health effects is rather limited, and the safety of using several types of mushroom extracts at once can come into question, especially in clients with certain medical conditions.

Mushroom Varieties and Claims
Five of the most common varieties are reishi (Ganoderma lucidum), chaga (Inonotus obliquus), cordyceps (Ophiocordyceps sinensis), lion's mane (Hericium erinaceus), and turkey tail (Coriolus versicolor or Trametes versicolor).

Touted benefits of each mushroom extract vary. For example, chaga extract is thought to ward off the common cold; promote shiny, thick hair and glowing skin; lower inflammation caused by stress; and help fight cancer, while reishi extract is touted for its benefit to aid with sleep, decrease stress, and cure seasonal allergies.

Studies on these two common extracts will be discussed.

Reishi Mushroom Extract
This fungus is described as tough and woody with a bitter taste. Both the fruiting body and mycelium (filaments connecting a group of mushrooms) are used for medicinal purposes. Research shows that beta-glucans in reishi stimulate the immune system in animals1 and have an antitumor effect.2

One study examined short-term biomarkers for antioxidant activity and coronary heart disease risk. The results showed a slight increase in antioxidant activity with reishi supplementation; however, these results weren't statistically significant.3

While more research is needed to determine proper dosing, it's known that reishi mushroom extract interacts with medications for high blood pressure and blood clotting.

Chaga Mushroom Extract
Chaga mushrooms grow in the forests of Canada, northern Japan, Siberia, and the northeastern United States. They're used in Russia and Eastern Europe in herbal practices. The mushroom must be picked in the wild—only those harvested from living birch trees will contain all of the active compounds.

Chaga contains beta-glucans believed to play a role in lowering cholesterol.4 It contains the phytonutrients betulinic acid and polyphenols, which act as antioxidants. It also may lower blood sugar levels in those with diabetes. Several studies have demonstrated the anticancer properties of chaga extract, including one that showed anticancer properties in human colon cancer cells.5 Another study also found anticancer properties on human hepatoma HepG2 cells.6

Correct dosage of chaga isn't well known or established at this time. There's also concern that chaga can increase bleeding. Therefore, it's contraindicated in those with bleeding disorders or individuals undergoing surgery.

Recommendations for RDs
Because some supplements isolate one mushroom while others combine a variety of mushroom extracts, research on the efficacy of specific compounds is unclear.

RDs should encourage clients to bring in the supplement or take a photo of the nutrition facts panel. Combination mushroom extracts will need extensive research, as each mushroom needs to be evaluated for its touted benefits, safety, and contraindications. Although recommended dosage is listed on the label of extract supplements, there's insufficient research to determine what the correct dosage should be for any mushroom extract.

— Toby Amidor, MS, RD, CDN, is the founder of Toby Amidor Nutrition (http://tobyamidornutrition.com) and a Wall Street Journal best-selling author. Her four cookbooks are Smart Meal Prep for Beginners, The Easy 5-Ingredient Healthy Cookbook, The Healthy Meal Prep Cookbook, and The Greek Yogurt Kitchen. She's a nutrition expert for FoodNetwork.com and a contributor to US News Eat + Run, Muscle&Fitness.com, and MensJournal.com.

References
1. Chen HS, Tsai YF, Lin S, et al. Studies on the immuno-modulating and anti-tumor activities of Ganoderma lucidum (reishi) polysaccharides. Bioorg Med Chem. 2004;12(21):5595-5601.

2. Wang SY, Hsu ML, Hsu HC, et al. The anti-tumor effect of Ganoderma lucidum is mediated by cytokines released from activated macrophages and T lymphocytes. Int J Cancer. 1997;70(6):699-705.

3. Wachtel-Galor S, Szeto YT, Tomlinson B, Benzie IF. Ganoderma lucidum ('Lingzhi'); acute and short-term biomarker response to supplementation. Int J Food Sci Nutr. 2004;55(1):75-83.

4. Sima P, Vannucci L, Vetvicka V. β-glucans and cholesterol. Int J Mol Med. 2018;41(4):1799-1808.

5. Lee HS, Kim EJ, Kim SH. Ethanol extract of Innotus obliquus (Chaga mushroom) induces G1 cell cycle arrest in HT-29 human colon cancer cells. Nutr Res Pract. 2015;9(2):111-116.

6. Youn MJ, Kim JK, Park SY, et al. Chaga mushroom (Inonotus obliquus) induces G0/G1 arrest and apoptosis in human hepatoma HepG2 cells. World J Gastroenterol. 2008;14(4):511-517.
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