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Cinco de Mayo: Before making guac for a party, the FDA has some advice for you

Zlati Meyer
The concern is that when you cut into an avocado, the knife could bring pathogens on the peel to the edible fleshy part.

Eat avocados without washing them? That's an avoca-don't.

The Food and Drug Administration is shocking guac lovers by recommending you thoroughly wash the peel, even though no one's going to eat it. Otherwise, you could be toast.

It's a way to prevent bacteria and dirt from hitching a ride on your knife from the dark green avocado skin to the light green fleshy part that you eat. To reduce the risk even more, scrub the peel with a produce brush and dry it with a clean or paper towel.

In December, the FDA announced that federal investigators’ sampling found Listeria monocytogenes on the peels of about one in every five avocados. The new data is part of a 2014-16 study, in which investigators tested 361 domestic and imported avocado skins; 64, or 17.73 percent, tested positive.

This January 22, 2015 file photo shows Hass avocados in Los Angeles, California. President Barack Obama dipped into what has become a raging national debate pitting traditionalists against innovators when making guacamole, the mashed avocado treat that has become a favorite American indulgence. The New York Times published a recipe in its weekly "Food" section July 1, 2015 in which it recommends adding a healthy portion of peas to the avocados -- a move the author freely acknowledged was "radical." The peas add intense sweetness and a chunky texture to the dip, making it more substantial on the chip," food writer Melissa Clark wrote in her column. Guacamole lovers across the United States -- including Obama -- turned up their noses at the thought.

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The research also tested for listeria and salmonella inside 1,615 avocados, but less than 1 percent tested positive for either.

According to the FDA, the very way people eat avocados — scooping out the inside part out of the soon-to-tossed peel before eating it as well as consuming the avocado very soon after cutting it open — helps reduces the risk of getting a foodborne illness.

Listeriosis symptoms include high fever, severe headache, stiffness, nausea, abdominal pain and diarrhea, and in pregnant women, the infection can cause miscarriages and stillbirths, the FDA said.

About 1,600 people get listeriosis each year and approximately 260 die, according to the Centers for Disease Control and Prevention. Pregnant women, newborns, adults ages 65 or older and people with weak immune systems are most likely to be affected.

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 William Hallman, a human ecology professor at Rutgers University, pointed out that likely very little listeria would even be transferred from the skin to the flesh of the avocado but called the FDA suggestion "good advice."

"Even though the risk is relatively small, you can reduce it to virtually nonexistent," he said. "There are many more dangerous things you can do than not wash an avocado, but having said that, the rate at which the FDA found listeria on avocados was a fair amount."

Angela Doporto Brown eats at least four avocados a week, but she doesn't wash them before putting them on her salads, mashing them into guacamole or spreading them on saltines.

"I don’t use the outside," said the 52-year-old Lovington, N.M., resident.

But when informed of the FDA suggestion, Brown, a former medical assistant, likened it to surgery, when the incision site on the skin is carefully washed.

"It makes sense," she said, adding that she might change her behavior. "I can see myself just for good measure washing the avocados."

Follow USA TODAY reporter Zlati Meyer on Twitter: @ZlatiMeyer

This article originally appeared on USA TODAY: Cinco de Mayo: Before making guac for a party, the FDA has some advice for you