Study Finds Risk Of Listeria In Unrefrigerated Caramel Apples

DETROIT (WWJ) - Before you bite into a popular fall treat — you'll want to read this.

According to new research, listeria bacteria can grow on unrefrigerated caramel apples.

The study, out of the University of Wisconsin-Madison, found a thousand-fold increase of the bacteria on caramel apples with sticks that were stored at room temperature for three days compared to caramel apples without sticks.

Researchers say neither caramel, because of its low amount of water, nor apples, because of their acidity, are normal breeding grounds for listeria.

However, St. Joseph Mercy Nutrition expert Lisa McDowell says, you run into trouble if there are any bacteria cells on the fruit.

"When you puncture the apple with the stick, some of the juice from the apple can cause an environment, when you cover it with caramel, where the bacteria can grow," McDowell said.

McDowell recalled a case last year when 35 people across multiple states contracted listeria from caramel apples, and seven people died.

To be safe, researchers recommend consumers buy only refrigerated caramel apples or eat them fresh.

McDowell said, if you're going to make your own, only insert the stick right before you plan to eat the apple. She said caramel apples can remain safely refrigerated for about a week.

"And of course," she added, "an apple a day keeps the doctor away! We know apples are great for you, and if you can enjoy them without the caramel you're less likely to ever get listeria."

Listeria monocytogenes is an organism which can cause serious and sometimes fatal infections in young children, frail or elderly people, and others with weakened immune systems and can cause miscarriages and stillbirths among pregnant women.

Symptoms of listeria-related illness include high fever, severe headache, stiffness, nausea, abdominal pain and diarrhea. . Consumers should seek immediate medical care if they develop these symptoms.