Leafy greens and poultry are normally associated with healthful eating, but they are two of the top culprits for foodborne illness and related deaths, a journal published by the Centers for Disease Control and Prevention reported Tuesday.
An expert on foodborne bacteria said, however, that safe preparation can reduce the risk and the number of cases because even those suspect categories are small compared with the amount consumed.
In the study, published in Emerging Infectious Diseases, researchers looked at foodborne illness outbreak data from 1998 to 2008 to determine the most common sources of disease
Looking at 4,589 outbreaks in which a cause and an infectious agent could be identified, the study estimated there are actually about 9.6 million such illnesses a year and 1,451 deaths. Produce was implicated the most, in 46 percent of illnesses, and leafy greens were the biggest culprit among the vegetables, causing 23 percent of the illnesses.
Meat accounted for more deaths, 43 percent, and poultry accounted for the largest share of those deaths.
Of the estimated 277 annual poultry deaths, 63 percent can be attributed to outbreaks of the bacteria Listeria monocytogenes, the study found.
That was no surprise to Dr. Stuart Thompson, a microbiologist who studies foodborne bacteria at Georgia Regents University.
“Listeria has a pretty high fatality rate,” he said – 20 percent or higher in some cases. It also defies refrigeration, he said.
“The growth of most bacteria is inhibited by refrigeration, but Listeria grows fine at refrigerator temperatures,” Thompson said. “So, for things that aren’t cooked subsequently, like ready-to-eat meats that have poultry in them, if they get Listeria contamination, it is really easy to transmit that to a person.”
One thing to keep in mind is that many of the infections show up in people with compromised immune systems or those who are at higher risk for infection, he said. Simply taking precautions, such as cooking meat to the proper temperature, can greatly reduce the risk, he said.
“Transmission of bacteria from uncooked items is much, much easier because most of the bacteria that cause these kinds of diseases are easily killed by cooking,” Thompson said.
The authors of the study point out that many of the products implicated in outbreaks are consumed in great quantities in the United States so that even low-risk foods would be likely to show up.
“If you look at the big picture, it is actually a relatively small number of deaths per year (87) compared to the number of people who eat leafy vegetables,” Thompson said.
Moreover, “the health benefits of consuming a diet high in fruits and vegetables must also be considered,” the authors wrote.
The relative risk is an important factor, particularly for American consumers, Thompson said.
“It’s certainly worth paying attention to, but I would say it is not something to be paranoid about,” he said. “I think the U.S. has the safest food supply in the world.”