When shopping for groceries for your household, you try to bag the best deals for healthy food. What you may not know is that in the process, you’re putting yourself and your household in danger.

You prepare for your shopping trip by making a list, scouring for deals and coupons, and packing reusable bags. But once you get to the store, do you use the cart wipes?

Grocery carts are ridden with germs. When shopping for food, you may be making yourself sick by carting around millions of bacteria. To understand the “gross” in grocery store, we swabbed shopping carts from four different stores: traditional, budget, superstore, and upscale. The results are shocking, and it might make you rethink your next shopping trip. Keep reading to see what we discovered.

Carting Around Germs


Traditional grocery stores, by far, had the highest bacteria count. Grocery carts at regular and budget stores carry hundreds of times more colony-forming units per square inch (or CFU/sq. in.) than surfaces in your bathroom.

Results show that a cart at a traditional grocery store has over 73,000 CFU/sq. in. – 361 times more CFU/sq. in. than a bathroom doorknob. More so, a shopping cart at a budget store has 270 times more CFU/sq. in. than your average toilet handle.

Superstores follow with over 1,000 CFU/sq. in., which is nearly triple the bacteria on an average kitchen countertop. However, carts at upscale markets had impressive results, with just 28 CFU/sq. in. – about the same as a computer keyboard.

Germ Breakdown


Of all the bacteria present on shopping cart handles, nearly 75 percent were identified as gram-negative rods. Over 90 percent of gram-negative rods can be harmful to humans, and to make it worse, most types are resistant to antibiotics.

Another 24 percent of surface bacteria were identified as gram-positive rods. Although most forms of these bacteria are harmless, they can lead to other illnesses.

Fewer than 1 percent of the samples’ surface germs showed signs of yeast and bacillus. Despite the trace amount, bacillus is commonly linked to food poisoning, while yeast can lead to a skin infection. Another percentage of the test sample included gram-positive cocci. Much like yeast, gram-positive cocci are associated with skin infections, in addition to pneumonia and blood poisoning.

Check-Out Germs


Shopping around? We broke down germ samples by grocery store type, and here’s the deal.

Over 88 percent of surface bacteria at superstores contained gram-negative rods – far more than any other grocery store. Both superstores and traditional grocery store samples contained more than 80 percent of gram-negative rods (keep in mind that over 90 percent of gram-negative rods are harmful to humans). To compare, budget stores had fewer than 20 percent, while upscale store samples contained no traces of gram-negative rods. In addition to the most gram-negative rods, superstores had the most gram-positive cocci at almost 5 percent.

According to the Food Marketing Institute, 85 percent of consumers routinely visit traditional grocery stores. In comparison, only 11 percent of consumers visit upscale stores to complete their shopping list.

Despite the low numbers of CFU/sq. in. on shopping carts in upscale grocery stores, samples from upscale stores contained somewhat comparatively high volumes of yeast and bacillus. Contact with yeast may cause fungus to grow on the skin, subsequently leading to skin infections. In addition to yeast, the samples included bacillus, which is most commonly related to food poisoning.

The Dirty Truth


So just how dirty are grocery stores compared to everyday items? Perhaps more than you think.

Refrigerator doors at a traditional grocery store had nearly 327,000 CFU/sq. in. Imagine all the people reaching for these door handles, passing the germs that might already be on their hands over to the door and onto the next person. For comparison, the average pet toy had 18,940 CFU/sq. in. Even the bottom of a handbag had less than 10 CFU/sq. in. of dirty microbes.

Produce sold in upscale grocery stores had more than 1,500 times as many germs than produce found at traditional grocery stores. Produce at upscale supermarkets may be more likely to carry traces of bacteria than conventional foods because of the lack of chemicals and other less effective natural methods farmers take to keep these foods clean.

A Closer Look at Germs


According to our research, over 58 percent of the germs covering grocery store refrigerator doors were identified as gram-positive rods. While some research has linked gram-positive bacteria to health treatments, they can sometimes be pathogenic, leading to negative side effects and harmful diseases.

More than a third of the bacteria on grocery store refrigerator doors were identified as gram-positive cocci – which can lead to negative effects in humans – while nearly 4 percent was yeast, and almost 2 percent was infectious gram-negative rods.


Produce tested at various grocery stores were more likely to be covered in harmful bacteria than the refrigerator doors in their vicinity. Less than half of produce bacteria were identified as gram-positive rods, while nearly 19 percent were gram-negative rods.

Microbes at the Market


Of the four stores examined, budget grocery stores had the highest amounts of the least harmful bacteria. More than 96 percent of the germs assessed on these refrigerator doors were identified as gram-positive rods. However, traditional, upscale, and superstores weren’t nearly so clean. Of the bacteria on the refrigerator doors at traditional grocery stores, less than two-thirds were also gram-positive rods. Upscale markets and superstores were where things got officially dirty, however. All germs identified on the refrigerator doors at these two markets were gram-positive cocci. Like gram-negative rods, gram-positive cocci can carry parasites and pathogens harmful to humans. In fact, gram-positive cocci are responsible for a third of all bacterial infections that impact humans.


Produce sold in upscale grocery stores had more than 1,500 times as many germs than produce found at traditional grocery stores. Produce at upscale supermarkets may be more likely to carry traces of bacteria than conventional foods because of the lack of chemicals and other less effective natural methods farmers take to keep these foods clean.

Conclusion

Grocery stores are where we find the fruits, vegetables, meats, and grains we use to feed our families. In 2016, the average American visited the grocery store more than once a week. Unfortunately, the surfaces we touch (and even the food we pick up) can be covered in millions of harmful bacteria.

Store Breakdowns

In the embeddable flipbook above, you’ll be able to see how each store's items fared in our tests.  

Methodology

We commissioned EMLab P&K to test swabs from various grocery stores. We based all values on an average of five carts from each store type, as well as three produce items and three refrigerator door handles from each store.

Spread Knowledge, Not Germs

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