Is Grocery Shopping Making You Sick?

Quick Quiz:

1. Do you use reusable grocery bags?
2. If so, do you wash them regularly?

I’m going to put on my psychic turban and predict your answers were “yes” and “no.” And you wouldn’t be alone. I ran my own unscientific survey and found 94% of my friends have reusable bags, and while 38% of my friends wash them occasionally, 57% have never washed them. Not once. Ever.

Worse yet, my friends are over-achievers. According to a 2011 study published in Food Protection Trends, 97% of the users they studied have never washed their bags.

That study goes on to say that 75% of their respondents don’t dedicate separate bags for vegetables and meat. In my informal poll, the number was higher with 94% of my friends using bags randomly. I admit, I’m one of them.

But why does that matter, you ask? Simple answer, our food isn’t always clean. And before we get it home and subject it to proper preparation, it is likely as unsafe as it will ever be. The idea that we aren’t cross-contaminating from one bag to another is fairly far fetched. Especially when you think about how often those bags get used for things other than groceries. But more on that in a moment.

In that 2011 study, “Assessment of the Potential for Cross-Contamination of Food Products by Reusable Shopping Bags,” the authors found that almost all the reusable bags tested had some amount of bacteria. In fact, all but one bag had some level of bacteria. Worse still, 51% of the tested bags were positive for coliform bacteria. If you aren’t familiar with the family, you will probably recognize the name of its most famous member: E. coli. And yes, they found that nasty fellow in multiple bags.

But as one of my friends asked, “Is anyone actually getting sick?” While it is hard to identify every, or even most, causes of food poisoning, estimates are that 76,000,000 cases occur every year in the United States. Many or most of those cases are believed to originate in the home. So yes, we are getting sick. But tracking exactly why and how may be difficult.

However, some cases and causes are known. Returning to the issue of reusable bags being used for purposes other than groceries, illnesses from such use may be easier to trace. Case in point, a 2012 study tracing the cause of an illness affecting nine members of a soccer team. The illness was traced back to one reusable shopping bag used to transport team snacks. While this specific study relates to norovirus, it is clear case of proven cross-contamination.

How many of us grab one of those handy bags to toss in school or team treats? I know I have. In fact, when I polled my friends, 88% of them use their bags for all sorts of non-grocery purposes.

Where you store them may impact the bags’ bacteria colonization as well. Warm, or moist climates like car trunks in summer are likely ideal breeding grounds for

bacteria. However, storing contaminated bags in the kitchen may provide more opportunity for cross-contamination with other foods. In my friend poll, 56% keep their bags in the car, while the rest are split between the garage or the kitchen.

But there is some good news! According to that 2011 Food Protection Trends study, washing on regular machine cycle without bleach reduced bacteria to levels below detection. Hand washing was equally as effective. While study author Charles P. Gerba of the University of Arizona told me that the bags they studied did not have plastic base inserts, he suggests “using a disinfecting wipe–as the quat disinfectant they contain is considered safe to use around foods.”

Shockingly, only one of the people I polled knew much about this aspect of food safety. And in all honesty, she should, as her husband is a former food safety inspector! But things may be changing. Dr. Gerba told me that since the 2011 publication of his study he’s seen some increase in public awareness campaigns on bag cleaning, especially in areas where ordinances have been passed limiting the use of other bag types.

And more changes may be on the horizon. Dr. Gerba’s group is currently testing reusable bags with silver fibers. He is optimistic telling me that “they seem to work in keeping bacteria numbers down.” However, they aren’t currently available to the public.

So what have we learned? I’ll be honest, up until I started this article, I’d never once thought of tossing my bags in the wash. I can now tell you they are fresh and clean. Dr. Gerba takes it a step further, telling me that since his study he only uses reusable bags “to carry can goods.”

While that may be the best option, if that doesn’t seem feasible due to local regulations or personal beliefs, consider dedicating a few bags for only meats and a few others for use only with vegetables. I have also dedicated a couple of bags for non-grocery use only. In fact, I’m keeping them in my office and away from all food items.

And of course, add bag washing to your weekly routine. Which I’m sure you will all thank me for! As one of my lovely friends commented, “I was just thinking ‘if only I had more laundry to do!'”

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