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# Shiitake mushroom high in toxic arsenic
- URL: https://www.foodconsumer.org/shiitake_mushroom_high_in_toxic_arsenic_0603141124/
- Published: 2014-06-03T12:24:00.000Z
- Updated: 2026-09-22T16:18:54.000Z
- Description: A Food Chemistry study found shiitake products carry mostly toxic inorganic arsenic, at up to 1.38 mg per kg, across fresh, canned, dried and supplement forms. The authors say shiitake should not be ignored where intake is high; an editor's note suggests occasional use is likely fine.
- Author: Food Consumer
- Tags: Chemical, Food Safety, #vivvo-import

Tuesday June 3, 2014 (foodconsumer.org) -- Shiitake mushroom is delicious! But a study in Food Chemistry suggests that eating too much shiitake mushroom (Lentinula edodes) may get arsenic poisoning.

The study shows that arsenic present in shiitake mushroom is mainly the toxic inorgnic arsenic and it can be present in shiitake mushroom at a concentration of 1.38 mg per kg or 1.38 ppm.

Researchers tested a wide variety of edube shiitake products including fresh mushroom, food supplements, canned and dehydrated shiitake mushroom.

The study concluded "Shiitake products had high proportions of iAs and therefore should not be ignored as potential contributors to dietary iAs exposure in populations with a high intake of Shiitake products."

Shiitake mushroom preparations may help prevent cancer. Studies have shown that shiitake mushroom extract protected against breast cancer. In a word, shiitake mushroom is a delicious and healthful food.

Anyhow, shiitake mushroom is not the one and only food that is found high in inorganic arsenic. Rice produced in the U.S. is also found high in arsenic. (David Liu, PHD)

(Editor's comment: Should we be concerned? Probably not. Most food consumers use shiitake mushroom moderately and very occasionally. But if you use shiitake mushroom daily, you may want to cut back a bit.)

Reference

Llorente-Mirandes T, Barbero M, Rubio R, López-Sánchez JF. Occurrence of inorganic arsenic in edible Shiitake (Lentinula edodes) products. Food Chem. 2014 Sep 1;158:207-15.