Why Raw Sprouts Can Be Riskier Than Raw Hamburger


Excerpts taken from Amazingribs.com

Everybody knows that undercooked ground beef is risky. But there is one innocent looking food that is probably riskier: Raw sprouts. Mike Doyle, director of the Center for Food Safety at the University of Georgia has been quoted as saying “I consider sprouts to be among the most risky foods sold at retail”.

How could this be? How could innocent crunchy, juicy, delicious sprouts be dangerous? Because they are grown differently than any other vegetable, in an environment practically ideal for bacteria. Let’s get a close look at the problem and consider solutions.

 In June 2011 vegetable sprouts from Germany contaminated with bacteria killed more than 30 people and sickened more than 3,000, and the outbreak has still not run its course.

The survivors had more than tummy aches. Many of their kidneys shut down, many were hospitalized, many were near death, and there almost certainly were thousands more who never reported their illness and just gutted it out at home.

In Germany it was Escherichia coli O104:H4 on the sprouts. Sometimes it is Escherichia coli O157:H7, sometimes it is Listeria, sometimes it is Bacillus cereus, but most often it is Salmonella on sprouts. Tangy tasty radish sprouts also caused one of the world’s largest food-borne illness outbreaks in Japan in 1996, sickening about 10,000 people (that we know of), many of them children. In the US there have been at about 40 outbreaks since 1990 according to Bill Marler, a personal injury attorney who specializes in food-borne illness.

Mark Bittman of the New York Times interviewed David Acheson, an MD who was the chief medical officer in Center for Food Safety and Applied Nutrition at the FDA. He said “only 5% of food-borne illness is linked to big outbreaks 95% is sporadic”. He told me Bittman that there are 1.5 million cases of salmonella in the US each year, and few are linked to outbreaks. Marler and Doyle and the Center for Disease Control and other safety experts only know when there is an “outbreak”, when many people get sick and when they go to a doctor and when their doctor does the right tests and then reports the results to the authorities.

Some probably thought they had the “24-hour flu”. Well there is no such flu. Look it up in WebMD. Zero hits. If you had the flop sweats and were on the toilet for a day or three, you probably had a food-borne illness caused by something you ate perhaps as long as a week ago. That’s one of the reasons it takes so long to trace the cause of an outbreak.

FDA says “If you purchase a sandwich or salad at a restaurant or delicatessen, check to make sure that raw sprouts have not been added”.

What makes them risky

Sprouts are seeds that have just begun to grow, usually less than a week old. Inside every seed is a “germ”, a sort of a baby plant, waiting for water and warmth to germinate. This is not a bad germ. It is part of the seed. Sprouts are easy to grow, and many people do it at home, you just soak the seeds in warm water until the germ is awakened, then rinse the seeds daily keeping them wet, and preferably warm and dark.

So how do they turn into high risk disease vectors? Alfalfa is a grass, that grows just like your lawn, but in a big field, and when you don’t cut it, it produces lovely lavender flowers that eventually are fertilized and go to seed. The plant reproduces itself by developing scores of new seeds per plant, and each seed contains the germ of another alfalfa plant. But the seeds can be contaminated right there in the field and it is pretty hard to prevent it.

The sources of contamination are myriad. Critters are a strong possibility. Birds flying over, rabbits munching on the green shoots, deer grazing in the field, raccoons, field mice, rats, even feral hogs can poop in the fields and it is impossible to prevent them. Heck, sometimes farm workers are the source. I know we want perfectly safe food for our children, but as long as food is grown outdoors it is impossible to prevent unwanted intruders.

Another possible source of pathogens is water. Rain is pretty safe, but irrigation may not be. Lakes, streams, and wells can host the bad guys easily. They can come from improperly treated human waste in sewage or seepage from septic tanks. It can come from runoff from livestock pastures, where rainwater mixes with manure and drains into the water supply. It can come from fertilizer made from manure that has not been properly pasteurized. And it is hard to pasteurize manure. Manure, of course, is the fertilizer of choice for organic farmers, so organic seeds may, in fact, be more risky than others.

It can be amplified in water tanks or hoses where the bacteria can reproduce rapidly. The problem is greater in areas that have less control over pollution, and many of the sprout seeds used in the US come from other countries where water quality can be very poor.

Once the bugs are on the seed, they can survive in a dormant state for weeks. They are harvested, mixed together in hoppers, and thus the seeds of a single plant that had bird poop on it can be distributed widely among millions of clean seeds. They are often then bagged in cloth, and stored in warehouses or sent overseas in the holds of ships where mice and rats have a chance to do their business on the seeds.

So why aren’t things like celery seeds used in our potato salad dangerous? Because the microbial load, which means the number of microbes, is usually very small on seeds. Even if you ingest them, there are usually not enough, and they don’t grow fast enough in our gut to do us any harm. Many spice companies, knowing that they sell a product that is easily contaminated, treat their seeds and leaves with a special grade of radiation that pasteurizes the product.

The problem is when the microbial load gets heavy. When microbes reproduce, they can double in 20 minutes, so within a few hours they can reach a deadly level. And that’s why sprouts are uniquely dangerous. Sprouts are grown indoors in a warm room. The seeds are soaked in water for up to 12 hours. The water is not always purified. The seeds can absorb up to three times its weight in water in this first phases. The seeds and water are stirred often to make sure they are all soaking properly, so if there are unwanted bacteria in the soup, they are spread among the whole mass. Warm water speeds the germination of the seed. The problem is, warm water also awakens the dormant bacteria. And the sprouting is often done under low light, away from the inhibiting effects of the UV light in sunlight.

The water is drained, and can then used to irrigate the fields. If it is contaminated, it becomes a source of further contamination.

Sprouting systems are essentially incubators, and it is very hard to prevent microbes from growing. They’ve tried chlorinated water and other purifying systems with only limited success. A solution may yet be found, and believe me, people in the sprout biz have tried just about everything.

Finally, the wet sprouts are bagged and shipped to stores. They are chilled to keep them from growing too large, and that inhibits both the sprouts and bacteria. But it doesn’t kill them. If the truck’s AC is on the fritz, or if they sit on the loading dock a while, things start growing rapidly. Sitting outdoors at the farmer’s market is a great way to grow pathogens. A food safety scientist I know calls the packaging a “germ culture chamber”. According to the scientists at FDA “Rinsing sprouts first will not remove bacteria”. And before you know it, people are falling face down in their salads.

Admittedly German authorities never found the smoking gun. All the contaminated sprouts had been eaten or destroyed by the time they got to the organic farm that probably grew them, but epidemiological research showed that it is highly likely that all the victims had eaten sprouts. Regardless, it doesn’t diminish the fact that sprouts are risky, especially to children, the elderly, and the immune compromised.

How big is the risk?

Vegetarians say that the risk is much less than eating burgers, but that’s because we eat so much more hamburger than sprouts. Nobody knows the odds for sure, but I’ll guess that it is probably less than driving your car, and probably more risky than eating eating raw burger, neither of which will I do.

If this number of deaths and illnesses were caused by terrorists, governments and the populace would be willing to spare no expense to cure the problem. But many people who love sprouts seem to be in denial, touting their taste and health benefits, and as I have learned in writing about the subject, they are having difficulty understanding the real risk.

Now you have the facts. Still want to eat raw sprouts? In the words of Dirty Harry “You’ve got to ask yourself one question. Do I feel lucky? Well, do you punk?

  • Anonymous

    I got the worst case of food poisioning from raw sprouts that were served at my staff xmas “buffet” dinner. I was only half way through my plate when it all started coming back up. Puked for 24hrs straight. Had to get I.V. fluids cause from dehydration. Doc said it was most likely salmonellla. I will never touch them again!!!!