09/18/2006

Food Safety Researchers Focused on Prevention

Writer:

Martha Filipic
filipic.3@cfaes.osu.edu
614-292-9833

Source:

Ken Lee, Center for Food Safety
lee.133@osu.edu
(614) 292-7797

Jeff LeJeune, Food Animal Health Research Program
lejeune.3@osu.edu
(330) 263-3739

Lydia Medeiros, Human Nutrition
medeiros.1@osu.edu
(614) 292-2699

COLUMBUS, Ohio -- Food safety researchers with Ohio State University Extension say the latest E. coli outbreak shows that food safety concerns must be taken seriously, "from the farm to the plate."

"The Centers for Disease Control and Prevention estimate that 5,000 people per year die of foodborne illnesses in the United States alone. This is abhorrent for the world's most developed nation," said Ken Lee, professor of food science and technology in the College of Food, Agricultural, and Environmental Sciences and director of Ohio State's Center for Food Safety. "Nobody should die from eating; the body count should be zero. I think with our current science and technology, we have the ability to make a significant reduction in foodborne illness within our lifetimes."

Lee is collaborating on a new research study funded by the U.S. Department of Agriculture to investigate how foodborne pathogens such as E. coli survive in fresh produce, particularly leafy salad vegetables. The study is being led by Jeff LeJeune, assistant professor with the Food Animal Health Research Program at Ohio State's Ohio Agricultural Research and Development Center in Wooster, whose primary research focus is pre-harvest food safety. Also involved in the study is Sally Miller, professor of plant pathology also based in Wooster, and a researcher and OSU Extension specialist in vegetable crop diseases. Their research is expected to find new ways to prevent foodborne-pathogen outbreaks in produce by targeting factors, such as lesions caused by plant diseases, that may contribute to contamination of vegetables in the field and during transportation.

"Outbreaks like are a rare occurrence, given how many people consume these products on a daily basis," LeJeune said. "But when there is a problem, the consequences can be high, especially for children and the elderly. What we hope to do is find ways to prevent outbreaks like this from happening even less often than they do now." LeJeune says he knows of no other food safety study with this blend of combined expertise.

The research will likely be viewed with interest, considering the current outbreak of E. coli O157:H7. As of Sept. 17, 109 cases of illness linked to this outbreak have been reported to the CDC in 19 states, including at least one death, and 16 cases involving a type of kidney failure called hemolytic uremic syndrome (HUS). Since 1995, there have been 19 outbreaks of foodborne illness caused by E. coli O157:H7 for which lettuce or leafy greens were implicated as the outbreak vehicle.

Lydia Medeiros, food safety specialist with Ohio Sate University Extension, said consumers sometimes don't recognize the symptoms that indicate foodborne illness. With E. coli, the symptom to be on guard for is bloody diarrhea.

"If you have the symptom of bloody diarrhea, seek medical attention. Do not try to treat yourself," Medeiros said. "Research has shown that if you have E. coli, over-the-counter anti-diarrheal medications may lead to complications because the pathogens stay in your intestine longer. So if you have bloody diarrhea, that's serious. Get to the doctor. Don't try to treat it yourself.

Medeiros, who is also an associate professor of human nutrition in the College of Education and Human Ecology, said consumers need to be aware that washing leafy greens "is not a way to prevent illness, because we don't know where bacteria might be located -- on the surface or internally. Research is being done to determine that, but right now, we don't know."

However, it's also important to note that E. coli is destroyed by heat, "so thoroughly cooked spinach should be safe," Medeiros said. "But 'thoroughly cooked' means 160 degrees Fahrenheit. Lightly sautéing spinach, as you might do for pasta, is not enough. But using spinach in a casserole or quiche, or in a spinach-artichoke dip that's baked, that should be fine."

While fresh fruits and vegetables are increasingly linked to foodborne illness, bagged ready-to-eat leafy greens may pose a special risk simply because they are designed for lengthier storage. "If they are contaminated, there's more opportunity for bacteria to multiply and grow to infective doses than for fresh leafy greens," Medeiros said. "They are thoroughly washed before being packaged, but the fact is, we don't know where the bacteria are." Currently, the Food and Drug Administration is advising consumers not to eat any fresh spinach or fresh-spinach containing products unless they are thoroughly cooked.

Lee added that the body of knowledge about food safety has intensified in recent years.

"The academic community is learning, just like consumers are learning, that safety is a continuous chain from the farm to the plate," Lee said. "Two decades ago, hardly anyone thought of E. coli in fruits and vegetables. Somehow, we always thought a fresh fruit was tacitly wholesome -- we either were unaware or ignored the potential of these uncooked foods to harbor unsafe bacteria. Today we know better; fresh fruits and vegetables are very significant source of potential illness."

Although the American food supply is generally safe and wholesome, the fact is that foodborne pathogens can be anywhere, and processors and researchers must uncover new ways to battle them.

"The presence of human pathogens on the farm will ultimately result in pathogens on the plate," Lee said. "We need to interrupt that chain of events to achieve the next level of safety of our food supply."

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