Why the romaine lettuce E. coli outbreak affects mostly women
A new outbreak of E. coli in 11 states has been linked by government investigators to bagged, chopped romaine lettuce grown in Yuma, Ariz. Consumer Reports is recommending—for the second time since January—that consumers avoid all romaine lettuce for Time
There's a striking aspect of the recent E. coli outbreak tied to Arizona romaine lettuce: 70% of those who've gotten sick are female.
Similarly, when leafy greens were the culprit of an E. coli outbreak last year, 67% of those infected were women or girls. In 2016, females were 73% of those ill from an outbreak in alfalfa sprouts, notes the U.S. Centers for Disease Control and Prevention.
Medical experts have wondered why women and girls seem to be the victims of E. coli more often than men and boys. Dr. Bruce Lee, an associate professor of international health at Johns Hopkins University, says there's three potential reasons for the trend.
The most likely contributing factor involves women's diets, which tend to include more vegetables. A 2012 study of nearly 15,000 men and women published in the medical journal Clinical Infectious Diseases found a higher rate of men ate meat and some poultry than women, who ate fruits and vegetables in higher proportions.
That might explain why a 2016 E. coli outbreak stemming from beef products affected more men than women, CDC statistics show. Yet women made up the majority of those affected by a 2015 outbreak tied to Costco rotisserie chicken salad.
British officials also suggested women's diets could be the reason behind the slanted number of E. coli infections. More women than men fell ill during a 2011 E. coli outbreak involving cucumbers, lettuce and tomatoes, The Guardian reported.
"We can't say with complete certainty why women have been disproportionately affected," Bob Adak, chief of the U.K. Health Protection Agency, told the newspaper in 2011, "but in previous outbreaks around the world associated with salad vegetables we have seen women and adults more severely affected than men and children, so it's possible that this could be an indicator of food preference."
Another factor, Lee said, could be the difference between how men and women report their symptoms to their doctors. The high numbers for women could be a result of more of them relaying information to medical professionals. Lee said studies show men are less likely to report symptoms of any type of disease.
Finally, it's been proposed women react more to E. coli because of differences in their gastrointestinal tracts. Although, Lee said there is no strong evidence to support this. Different outcomes between sexes and races, he added, often are driven by social and behavioral differences, not biological characteristics.
The E. coli outbreak related to romaine lettuce from the Yuma, Ariz., area has resulted in at least 53 illnesses and 31 hospitalizations. The CDC calls on everyone to throw away any romaine lettuce from that region.
And Lee, also executive director of Johns Hopkins' Global Obesity Prevention Center, stresses that's not an excuse to not eat vegetables.
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