By: Keeba Smith

As of late yesterday, the Public Health Agency of Canada announced that they believe their country’s outbreak of E. coli O157 illnesses linked to romaine lettuce appears to be over. The United States is still investigating its mystery outbreak, and believes “leafy greens” may be the culprit.

On December 28, 2017, the Centers for Disease Control and Prevention (CDC) issued a health advisory for Romaine Lettuce.  Approximately 66 people in the U.S. and Canada were infected with a serious strain of E. coli. Nine people in the U.S. were hospitalized, and one died.  In Canada, 41 cases were reported with one death.  The reported infections occurred in 15 states and 5 Canadian provinces (California, Connecticut, Illinois, Indiana, Maryland, Michigan, Nebraska, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Virginia, Vermont, and Washington state). Illnesses started on dates from November 15 through December 12, 2017. Canadian health authorities identified Romaine lettuce as the source of the outbreak and advised everyone to consider eating other types of salad greens until further notice.  The strain of E. coli (0157:H7) found in the lettuce can lead to serious illness, kidney failure, and even death.

With the health warning against Romaine lettuce, many people are wandering if what they think they know about lettuce food safety is true.

MYTH 1:  E. COLI CAN ONLY CONTAMINATE DAIRY AND MEATS

Most people associate foodborne illnesses with meat, chicken, seafood and eggs but not with salad, spinach and vegetables.  In fact, E. coli 0157:H7, the strain of bacteria that likely contaminated the Romaine lettuce, is most commonly found in ground beef.  E. coli infects meat more often than vegetables because it lives in the intestines of mammals, including cows.  It is relatively easy for E. coli to infect beef during processing if the contents of the cow’s intestines come into contact with meat, cutting utensils or surfaces.

FACT:

E. coli can infect fruits and vegetables as well as meats and dairy. Bacteria on vegetables can be spread through cross-contamination. Possible sources for E. coli contamination include:

  • People: A person infected with coli can transfer it to food by not washing their hands.
  • Animals: Animals can defecate or track waste from other areas into the vegetable fields.
  • Runoff: Heavy rains can sweep fecal matter from farms where animals live to vegetable fields.
  • Food-processing equipment: Contaminated equipment in a food-processing plant can spread bacteria to lots of food very quickly.

MYTH 2:  WASHING ONLY THE LETTUCE WILL PREVENT CONTAMINATION

Ok, so you’ve bought a head of lettuce from the supermarket.  Before you chop it up to use in your salad, sandwich or juice, you wash it in the sink.  After you have washed and dried it, you feel that you have removed all risk of foodborne illness.  WRONG!

FACT:

The produce is not the only thing you need to wash.  Your hands should be thoroughly washed, using warm water and soap, for at least 20 seconds before and after handling food.  Lettuce should be washed under a stream of cool water or using the spray nozzle from the faucet.  Rub the produce with your hands or scrub with a vegetable brush to remove potential bacteria in all the grooves and crevices.

Even then, there is not a 100% guarantee all of the bacteria is gone. Washing, however, will greatly reduce the risk.

MYTH 3:  WHOLE LETTUCE HAS LESS BACTERIA THAN BAGGED

With the recent outbreak, many wonder if bagged lettuce is better than just buying a whole lettuce and cutting it themselves.  Buying a whole lettuce is better for your health.  Many people feel the nutrients and health benefits get washed away in the bagging process.  It is suggested that buying a whole lettuce, rinsing it and drying it before adding it to your salad will increase the antioxidant activity.  While whole lettuce may be healthier, it is not necessarily safer.

FACT:

Bagged lettuce goes through a triple-washed cycle before it is packaged.  This process drastically reduces the risk of foodborne illness versus hand-washed lettuce.  Triple-washed process doesn’t just use water.  It also uses sanitizers to kill bacteria and other pathogens.  Despite the recent lettuce scare, foodborne illnesses are actually on the decline overall due to food safety procedures at packaging plants.

MYTH 4:  LETTUCE CAN LAST LONGER IF STORED IN THE FREEZER

Most foods can be preserved and kept longer if they are frozen.  Many people believe that it is cheaper to buy bagged lettuce in the family pack, that way it can be used to make more than one salad.  That may be beneficial in the short run but not in the long run.

FACT:

Lettuce is best consumed while it is fresh.  Lettuce cannot be consumed after freezing.  It can be placed in the freezer, but the retained water within will then cause ice crystals to form.  The taste will be drastically changed, making it unappealing.  Lettuce should be stored in an airtight container to extend its shelf life.  It should be stored n the proper vegetable drawer in the refrigerator and kept at a temperature of 32 degrees.  It should never be stored in a temperature higher than 41 degrees.  It is also best to keep it away from apples or grapes, as they let off ethylene gas that can cause the lettuce to rot quickly.

MYTH 5:  BAGGED LETTUCE MUST BE WASHED BEFORE EATING

Bagged lettuce or bagged salad greens are so convenient.  Many people make the mistake of washing the greens again before consuming them.

FACT: 

Studies have found that people actually increase the likelihood that they’ll get sick if they clean prewashed greens at home.  Why?  Cross-contamination from not washing their hands or the sink can add bacteria.  Washing the product will not make it clean compared to the triple washed process.  Prewashed and bagged greens are ready to eat and should be treated as such.

ALL THINGS LETTUCE

Lettuce is one of those things that people take for granted.  It is used in many things from salads, sandwiches and juices.  While all produce is subject to bacterial contamination, lettuce appears to be especially vulnerable.  Be sure to pick the freshest lettuce.  Wash your hands before handling.  When in doubt, throw it out.

 

Resources:

http://www.businessinsider.com/washing-bagged-salad-produce-triple-washed-2016-7

https://www.webmd.com/diet/features/lettuce-learn-wash-produce-properly#2