Nothing really beats the convenience of prepackaged, prewashed greens -- especially is you're cooking for a big family or don't have a whole lot of time on your hands.

In fact, more than 70% of U.S. households consume packaged or bagged salads -- which make up part of a nearly $7 billion industry.

But considering all the recent reports (which continue to surface more often) of diseases and other potentially harmful and unhealthy things that may be lurking in those prepackaged bags -- on top of the fact that you're supposed to wash the contents anyway -- they may not be the best choice.

The potential health risks

An outbreak of Listeria recently infected 15 people across eight states -- with an increase of three cases since the last update on January 22. According to the CDC, Listeria causes 1,600 illnesses and 260 deaths every year.

An investigation into the latest outbreak traced the source to a Dole processing facility in Springfield, Ohio, which packages salad greens under the labels Dole, Fresh Selections, Simple Truth, Marketside, The Little Salad Bar, and President’s Choice Organics.

The problem is while many packages contain "prewashed" greens, sometimes even "triple washed," they can still contain harmful disease-causing bacteria, like Listeria, salmonella or E. coli, which can't always be rinsed off.

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After the most recent outbreak, the CDC issued a warning that “consumers do not eat, restaurants do not serve, and retailers do not sell packaged salads produced at the Dole processing facility in Springfield, Ohio.” 


Prepackaged vs. non-packaged greens

So why is bagged lettuce more at risk of containing bacteria than a regular old head of lettuce you buy at the store?

Bagged greens typically contain younger leaves, which have a higher risk of contamination. According to Jeri Barak, associate professor of plant pathology and executive member of the Food Research Institute at the University of Wisconsin-Madison, “Data suggests that bacteria (Salmonella and E. coli) can enter wounds, such as the harvesting cut, and travel some distance into a leaf. But fresh produce that’s harvested as a head has longer leaves and is more mature. A consumer has the opportunity to remove part of the head away from the harvest cut and eat leaves in which a pathogen did not reside in the harvest wound.”

On top of that, a lot more steps are required to get bagged lettuce from the harvesting stage to your local grocery store -- which means more opportunities for contamination. Plus, many prepackaged greens contain more than one type -- so spinach carrying bacteria could not only contaminate bags of spinach, but it could also contaminate bags of mixed greens as well.

Some research suggests that the inside of the bags can even foster the growth of bacteria.

And don't assume organic greens are exempt -- they are no more or less likely to carry harmful bacteria.

So when it comes to bagged greens, the health risks are still low, but if you have the option of choosing prepackaged or non-packaged, the latter is the safer choice -- and you should still rinse and clean the produce as thoroughly as possible.

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