| ||Food for Thought || |
Last reviewed by Faculty of Harvard Medical School on February 24, 2010
By Marc C. O'Meara, R.D., L.D.N, C.D.E
Brigham and Women's Hospital
Food safety has been making news again with five multi-state outbreaks of produce-related illnesses in the past 5 months. Over the last 10 years, foodborne diseases from meat and poultry, including E. coli, campylobacter and listeria, are down about 30%, but foodborne illnesses from produce has more than doubled during that time.
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Produce - Culprit in Recent Outbreaks
E. coli was the cause of two separate outbreaks in December 2006. One outbreak occurred at Taco John's restaurants in Iowa and Minnesota and sickened 54 customers. The second outbreak occurred at Taco Bell restaurants in the Northeast where 71 people became sick. Federal health officials think that E. coli-contaminated iceberg lettuce grown in California was responsible for both outbreaks.
But E. coli isn't the only culprit. Fresh tomatoes contaminated with salmonella caused about 400 people to get sick last October and November. Norovirus, a group of viruses that cause the "stomach flu" and is often associated with cruise ship outbreaks, was blamed for an Olive Garden restaurant outbreak in December 2006 that caused vomiting and diarrhea in 370 people. (Noroviruses are highly contagious and can spread easily from person to person.)
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Which Foods Are Risky?
Any food that is handled by people can become contaminated, as the Olive Garden outbreak shows. The rest of the recent outbreaks have been traced to produce contaminated by infected animal feces from nearby farms. (The E. coli outbreak linked to fresh spinach in September 2006, which sickened more than 200 people and killed 3, was traced back to feces tracked by wild pigs from a ranch onto nearby spinach fields.)
The foods that have the most potential for contamination are:
- Leafy greens, such as spinach and lettuce
- Sprouts (bean and alfalfa)
- Unpasteurized juices and cider
That's because these foods:
- Grow close to the ground or fall to the ground (apples)
- Are not cooked before eating
- Are not acidic (foods like citrus fruits are acidic and can fend off bacteria better than produce that is neutral or basic)
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Symptoms and Treatment of E. coli
E. coli symptoms usually show up 3 to 4 days after eating contaminated food. (Other bacteria and toxins can cause symptoms minutes after eating or may take up to a week for symptoms to strike.) Severe abdominal cramps and bloody stools are the most common symptoms of E. coli infection. If diarrhea is bloody or doesn't resolve in 3 days or if it's accompanied by a fever over 101.5° F, you should call your doctor. Most illnesses and outbreaks (when two or more people become ill) never get reported to the Centers for Disease Control and Prevention (CDC) because people think they just have the flu and they don't go to the doctor. There is usually no fever with E. coli and it resolves on it's own in about 5 days. But it can also cause:
- Kidney failure
- Red blood cell damage (hemolysis)
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Efforts To Prevent Future Outbreaks and Illness
The food industry and regulators don't want people to be afraid of their food. Currently, the U.S. Food and Drug Administration (FDA) relies on growers (farmers), processors, packers and distributors to follow voluntary food safety guidelines. New guidelines to prevent food contamination from fresh produce are expected from the FDA in April. They will include how to keep produce safe through growing, harvesting, packing, processing, and distribution until it reaches the dinner table.
It's estimated that the FDA oversees the safety of about 80% of our food supply. That's almost everything we eat except for meat, poultry and processed egg products, which are regulated by the U.S. Department of Agriculture (USDA). Yet their food safety budget is less than half of the USDA's and they have only about a quarter of the number of inspectors. Budget cuts and a shortage of operating funds at the FDA has left the division short-handed. So rather than prevent outbreaks, it can only react to them. Several Senators want to replace the patchwork system of federal food regulation with a single agency in charge of what people eat.
States such as New Jersey and California are trying to prevent future outbreaks by setting new standards for food safety and labeling. In New Jersey, where small family farms were hurt by the spinach ban, they plan to set up a task force for food safety standards. In California, where most of the nation's green leafy vegetables are grown, farmers are looking to approve new labeling for stricter growing of greens.
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What You Can Do
The tips below may help you get the health benefits of eating fresh fruits and vegetables while avoiding foodborne illnesses.
- Wash hands with warm water and soap for 20 seconds before preparing food.
- Refrigerate or freeze leftovers within 2 hours of cooking.
- Eat refrigerated leftovers within 4 days or throw them out.
- Reheat foods to 165° F and reheat soup until boiling.
- Heat food to 160° F to kill E. coli.
- Remove outer leaves of lettuce and cabbage before preparing.
- Don't eat raw sprouts (bean or alfalfa).
- Wash produce even if you are going to just peel it or slice it. The knife can transfer bacteria from the outside to the inside as it slices through.
- Wash fruits and vegetables under running water just before eating, cutting or cooking. (Washing fruits and vegetables with soap, detergent or commercial produce washes is not recommended.)
- Remove the outer leaves of leafy vegetables. Processing plants wash leafy greens three times in chlorinated water before bagging them. But bacteria are sticky, so even thorough washing may not remove all contamination.
- Organically grown produce is not necessarily safer than conventionally grown produce.
- Canned and frozen spinach are safe to eat.
For more information on food safety go to the U.S.D.A.'s Food Safety and Inspection Service.
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Marc O'Meara, R.D., L.D.N., C.D.E. is a senior nutritionist at the Brigham and Women's Hospital and the Roxbury Heart Center, and also works in the lipid clinic at Children's Hospital Boston. He graduated from the University of Vermont in 1991 with a bachelor of science in dietetics. He completed his dietetic internship at Beth Israel Deaconess Medical Center in 1992.