Wild Mushroom Safety : Part 2

by Food and Drug Administration (FDA)

(Page 2 of 2)

In 1987, a food poisoning investigation by FDA's Detroit district led to a shipment of dried "morels" packed by two firms in India. The mushrooms contained Gyromitra as well as another toxic species, Verpa bohemica.

In December 1990, the agency identified Verpa bohemica in samples of two lots of dried "morels" from a third French firm.

The agency's current import alert instructs the districts to sample morels shipped from all the firms implicated in previous poisoning outbreaks and send them to Gecan for identification. Also, morel shipments from other firms — particularly in France, Switzerland and India — must be examined for proper labeling and packaging and, if necessary, sampled. When toxic species are identified, the shipment is refused entry.

The Survey

To determine the extent of the problem of toxic wild mushrooms in the U.S. market, Gecan and his FDA colleague, biologist Stanley Cichowicz, directed a two-year survey of wild mushrooms in commercial distribution. They published their results in the August 1993 Journal of Food Protection.

For the survey, 10 FDA districts were directed to collect samples of specific species of canned, dried and fresh imported and domestic mushrooms. About two dozen species were collected at ports of entry and from gourmet shops, supermarkets, health food stores, and other commercial establishments. They included morels, false morels, shiitakes, straw mushrooms, chanterelles, hiratakes, and others, as well as mixed mushrooms.

Of the 344 samples collected, toxic mushrooms were found only in the morels and the mixed mushrooms. Of the 42 morel samples collected, nine contained toxic species. Seven of the nine were from France, the other two from India. Of 13 mixed mushroom samples collected, two — both from France — contained toxic species.

Although all the toxic mushrooms identified in the survey originated overseas, potential problems exist with wild mushrooms harvested here at home as well. Except for Michigan, where wild mushroom growers and harvesters must be licensed, and Illinois, which prohibits the sale of wild-picked mushrooms through wholesale, retail or food service establishments, the states do not regulate the sale of wild mushrooms. And FDA has no regulatory authority for products not sold in interstate commerce.

During the survey, Gecan received a quart canning jar of mushrooms an FDA investigator bought in a Chicago bar. The investigator learned from the bar owner that some local women who had immigrated from Poland had been hired to pick the mushrooms in a Wisconsin woods. The mushrooms were packed in brine in mason jars and sold at local bars.

The mushrooms turned out to be okay, Gecan says, but both the possibility of toxic mushrooms and the brine levels were cause for worry. Improper processing could have caused botulism toxicity.

New World, New Species

Gecan says that immigrants who commonly pick mushrooms in their native lands have particular problems when they continue that tradition here. The mushrooms in this country may look like the ones they or their parents and grandparents picked in the old country. But appearances can be deceiving.

Cichowicz explains that North America has perhaps four times as many mushroom species as Europe, so European immigrants think they're picking the same mushrooms as back home, when actually they're harvesting toxic look-alikes.

Immigrants from other parts of the world have similar problems. Gecan tells of a group of Koreans in the Pacific Northwest who, looking for straw mushrooms, picked death caps instead. "They cleaned them, cooked them, and ate them, and all needed liver transplants," he says.

It gets still more complex, Cichowicz says, because even within different parts of this country, a particular mushroom grown under certain conditions — a certain type of soil or nutrient source — will look one way, whereas the same species grown under different conditions will have a slightly different appearance. He says a species grown east of the Rockies might be edible, whereas west of the Rockies it might not.

The Clubs

Not all wild mushroom harvesters are unskilled or unscrupulous. There are mycology (mushroom) clubs in the United States with extremely knowledgeable members that organize forays and gain continuing experience from their field work. Gecan recommends that interested amateurs contact a club through the North American Mycological Association.

He says, "Experienced collectors should go out in the field, know every mushroom they pick, and if there's a question in their mind, should chuck it away."

The common button mushroom Agaricus bisporus sold in retail markets is commercially grown under controlled conditions and presents no hazard of contamination with toxic mushroom species. But because there are no absolute guarantees that toxic mushrooms won't reach the market, Gecan endorses the maxim "buyer beware." Because of increased demand, retail food stores are offering more and more varieties of wild mushrooms, while their harvesting remains largely unregulated.

That is not to say that Americans need forever forgo the taste delights of wild mushrooms. Gecan says that although toxic morel look-alikes are occasionally found in commercial mushrooms, they are rarely fatal. In addition, individuals have different thresholds for the toxins, so that some people might display only mild symptoms or none at all. Someone who gets sick from eating wild mushrooms should go to a hospital emergency room for treatment.

These considerations are reminiscent of Peter Mayle's mind-set as he pondered a gift from his friend:

"He had been in the forest since six o'clock, and he had a present for us. From behind his back he produced his old checked cap, bulging with wild mushrooms. He gave us his favorite recipe — oil, butter, garlic, and chopped parsley — and told us a dreadful story about three men who had died after an ill-chosen mushroom supper. A neighbor had found them still at the table with wide, staring eyes — Monsieur Sanchez gave us a demonstration, rolling his eyes back in his head — completely paralyzed by malignant fungus. But we were not to worry, he said. He would stake his life on the mushrooms in his cap."

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.