Eating Raw Bean Sprouts Could be Hazardous to Your Health

The irony that health food could make you sick is not lost on anybody who writes about food borne illness. Uncooked, raw food has to be handled very carefully.

bean sprouts

Bean sprouts and other raw foods have gone mainstream. Raw foods have become a trend! If fast food chains are offering salads, you know it has gone mainstream! That seems great but what about the food safety considerations?

The rub is that uncooked food has to be handled very carefully to avoid sickness from bacteria and parasites. Here in the Caribbean, local people don’t eat salad. They may shred up a little cabbage and carrot to eat raw along with the stewed meats and boiled provision, but that is as far as they go.

Bean Sprouts, raw produce, and seed sprouts could be hazardous to your health!

I am one of those health conscience cooks, and I have eaten meals that were entirely concocted from living foods, specifically sprouted beans and seeds. Luckily that memorable meal  that included raw vegetable salad with alfalfa sprouts and hummus made from sprouted chickpeas made me feel great! It was the most energizing meal I think I have ever eaten. It was labor intensive because most of the ingredients were grown by the chef.

I mentioned in my last post (161–about how my green journey was progressing), that I had thrown caution to the wind and bought mung bean sprouts from Whole Foods to cook in a stir fry. I was inspired after ordering some Chow Mein from a local hole in the wall Chinese place and finding that it was at least half mung bean sprouts, along with shredded cabbage, etc. Apparently they know how to safely handle and cook bean sprouts because I experienced no ill effects at all after eating it. However, after I tried it myself, I felt pretty sick after eating, I admit. I don’t think those bean sprouts were considered tainted by anyone else, but I have a pretty sensitive stomach and digestion. I probably didn’t cook them at a high enough temperature.

Bean Sprout Research

I started researching bean and seed sprouts on the web and found an interesting video commentary by Dr. Raj Mody of the CDC.  Here are some excerpts from the video transcript, which was produced for the benefit of medical doctors in 2011 by

Hello, I am Dr. Raj Mody. I am an internal medicine and pediatric clinician and infectious disease epidemiologist at the Centers for Disease Control (CDC). 

So-called sproutbreaks have occurred every year in the United States since at least 1995 and have taught us that sprouts are a risky food to eat. Sprouts were found to be the cause of a devastating outbreak of Shiga toxin-producing Escherichia coli infections in Europe this summer. Ultimately, this outbreak caused more than 4000 illnesses, more than 900 cases of hemolytic uremic syndrome, and 50 deaths.
Why are sprouts a risky food, you might ask? Some people think of them as the ultimate healthy food — fresh and natural. In fact, raw sprouts can be anything but safe. Lessons from outbreaks have taught us that it is a good idea for people who want to lower their risk for foodborne infection to cook raw sprouts or avoid eating them raw.
Here is what we have learned:

Lesson 1: A sprouted seed is a perfect vehicle for pathogens.

A sprouting seed is as inviting and nourishing as Salmonella or E coli could want, and the warm, moist conditions in which sprouts are produced only make matters worse. A single Salmonella organism on the outside of a seed can easily grow to an infectious dose after it has sprouted. The bacteria in or on growing sprouts cannot be washed off. Because Shiga toxin-producing E coli (STEC) have a low infectious dose, sprouts are a great vehicle. Sprouts have also been the vehicle for Listeria, which causes a very dangerous infection for pregnant women and the elderly.

Lesson 2: Sprouts have caused many outbreaks of illness. 

Since sprouts were first recognized as a source of foodborne disease in the mid-1990s, they have become one of the “usual suspects” that foodborne disease epidemiologists look for when investigating an E coli or  Salmonella outbreak. Since 1998, more than 30 outbreaks have been reported to the CDC, due to many different kinds of sprouts — alfalfa, bean, clover, and others. In fact, CDC’s foodborne disease surveillance systems have identified 3 sprouts-associated outbreaks since June of 2010 that spread across multiple states.

Lesson 3: It is difficult to grow “safe” sprouts.

Once the potential dangers of sprouts became known, the US Food and Drug Administration developed guidance to help sprout growers reduce the risk for pathogen contamination in sprouts they produce and sell. Many sprouts growers have implemented practices to decontaminate seeds before sprouting, but no available method has proved completely effective. People who eat raw sprouts ought to know that they are taking a risk, including people who grow their own sprouts, because the contamination typically starts with the seed.

Lesson 4: Sprouts can make even young and healthy people ill. 

This is one of the biggest lessons learned from the outbreak in Europe in 2011 and from our experience with outbreaks in this country. Sproutbreaks in the United States predominantly affect healthy persons aged 20-49 years. A typical victim may be an especially health conscious person in the prime of life. Nevertheless, illnesses from sprouts can be particularly severe in vulnerable populations, such as young children, older adults, pregnant women, and people with compromised immunity.

Lesson 5: It can be hard for those who become ill to remember having eaten sprouts. 

We have found in our investigation of outbreaks that were ultimately linked to sprouts that people often do not remember having eaten them, because they are often just a garnish or just one of many ingredients in a food dish. It is not necessary to eat large quantities of sprouts to make a person sick. An ill person’s inability to accurately recall what they ate sometimes makes it difficult to pinpoint an outbreak of sprouts.

The part of all of this interests me is how do the seeds get contaminated in the first place? The answer I found is that the contaminating pathogens are usually found in the water used to irrigate the seed crop, or in waters that flood a field by accident. Most farms use some sort of manure and organic farms use a lot of manure as fertilizer instead of using petrochemical fertilizers.

Bean Sprouts, Manure, and Compost

Only thing is, and I know this because I am an organic flower gardener, the manure needs to be composted at a high enough temperature to kill off pathogens in the manure. The germs that came out of the cow or chicken by way of manure have to be killed to produce a healthy fertilizer, especially to use on food. In England they call this “well-rotted”. (When I first started learning about gardening from books, that “well-rotted” manure was perplexing. Where to buy that in United States? If you are buying composted manure in bags, as many city gardeners must do, that manure should not smell like manure anymore, and it should be pleasurable to touch and handle (with gloves is recommended even so). If the manure you buy makes you kind of grossed out, it isn’t well composted or well-rotted and you should be very careful with that and probably return it for a refund.)growing bean sprouts

A proper compost heap inside reaches temperatures well beyond 240 degrees minimum temps needed to kill most bacterial germs. Most farms have manure piles at least, or have livestock in addition to fields of vegetables and grains. Just like in our home and commercial kitchens, separating these two things is really important. Cross contamination must stop at any cost. That means sacrificing a crop grown in a field that is accidentally flooded with water from another part of the farm, which most likely contains traces of fecal matter.

Okay, so we in United States and Europe have the luxury of refusing to eat food that is irrigated on purpose or by accident by gray or wastewater. But people in the developing world don’t have that luxury. In fact, the World Health Organization issued a report in 2006 called ‘Guidelines for the Safe Use of Wastewater, Excreta and Greywater’ in the growing of food. The issue is that in places other than the developed world, like in Africa for instance, water shortages and droughts mean that people often have no choice but to use wastewater to irrigate their crops. The International Water Management Institute (IWMI) did the research for the WHO report. It is based in Accra Ghana where wastewater farming is going strong.

Food Waste

While I’m once again on this topic of food safety, and because this is my blog about all things green and healthy, I’d like to comment on the immorality of a country like ours, the United States mishandling it’s abundant food supply to the extent of having to recall and destroy vast amounts of food because the food has become contaminated. I don’t have a statistic about just how much food is destroyed, but I’m sure one could search and find a number pretty quick.

To think that while so many people in the world are hungry, underfed and even starving, that we continue down this path of centralized, industrialized food production and distribution, only to have it result in so much waste. It’s not just the food that is wasted either, it’s all the energy that goes into producing the food that is wasted.  And when the recall is for a product like beef, well that is in my opinion just about criminal, since everybody should know by now that beef cattle use enormous amounts of water and grain and energy to become food. Cattle also release lots of methane gas which contributes to Global  Climate Change.

I recently read an article in Onearth, a quarterly publication of the National Resources Defense Council of which I am a member, written by Jocelyn C. Zuckerman called The Constant Gardeners. Immediately my eye was drawn to an excerpt that stated, “10 percent of the global population regularly eats produce that has been irrigated with untreated wastewater.” This was astounding to me, since I was just worrying about a few contaminated sprouts, kind of luxury food for the well fed.

The article is about a new trend in Africa, Kenya and Ghana specifically, that has people seeding and growing food in the city. Since a majority of the world’s population now lives in cities and no longer in rural areas, food production is decreasing rapidly while cities are getting very crowded. This migration is especially true in sub-Saharan Africa where desertification is ongoing.

All over the developing world people are living in heavily populated shanty towns and barrios, often illegally and without the protections and rights that others have who live in legal settlements. So urban farming is becoming a way of life in these areas. Funny that growing your food is also a trend in the United States as well, although perhaps for different reasons. Here we are trying to return to a localized food economy to avoid tainted food supplies. There, urban farmers are staving off starvation. We are all, however responding to the increasing price of food. I swear every week Whole Foods raises the price of everything in their store by 10 cents.

In the article The Constant Gardeners  Zuckerman writes that wastewater is

Free and available year-round, it’s also rich in plant nutrients, which means less money spent on fertilizer. There are likely heavy metals in it too, though—things like cadmium, chromium, and lead—not to mention pathogenic microorganisms like bacteria and viruses, as well as parasitic worms . . . More than 10 percent of the global population regularly eats produce that has been irrigated with untreated wastewater.

But how are these farmers using wastewater to grow food and not becoming sick from that food? They have a few very low tech ways that may be working. According the one such farmer, Fuseini Bukari, :

When they get water from the pond they’ve dug to collect [the wastewater] they don’t wade into the pond with their buckets, they walk out on a plank and dip water from the top, so as not to disturb the contaminated sediment at the bottom. They store produce in ventilated buckets instead of plastic bags, and some stop watering the produce a few days before harvesting to allow the plants to dry off and the pathogens to die.

So, all of this is food for thought isn’t it? One man’s waste is another man’s treasure. I think we can learn a lot from these new subsistence farmers.  Why not give it a shot and try seeding and grow food in any spare plot of soil you may have in your backyard, or even in containers on your deck. It’s really an awesome feeling of freedom to grow something that you can eat! Just be careful sprouting your own bean sprouts!

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Julia has been practicing green cleaning for several years as the owner of As You Like It Home Cleaning and organic gardening for almost 20 years running Julia Houriet Custom Gardening. She studied landscape design at Radcliffe Seminars in Cambridge Massachusetts. Her expertise is gleaned from education and years of experience.

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  • Lala R

    The funny thing is I grew up eating cooked mung bean sprouts all the time, since they’re common in Asian cooking, and where I came from has a heavy Asian influence. No one ever talked about getting sick for all those years, and I’ve cooked with sprouts many times. (Those sprouts were probably locally grown, though, now that I think about it, and were just about always used cooked.) I wonder how often they have problems in Asia…some dishes just aren’t the same without sprouts, like Pad Thai or Pho or Chow Mein. A huge part of the planet is somehow eating sprouts on a daily basis.

  • immortelle

    Hi Lala, thanks for your comment! I’ve wondered the same thing about certain cuisines cooking with sprouts for a long long time and people aren’t dropping like flies from contaminated sprouts. My thoughts are that since say Asian cooks often use a super hot wok or pan to cook the dish, that high heat is enough to kill any bacteria on the sprout.

    Note that the warnings and illnesses blamed on sprouts are about eating raw, uncooked sprouts.

  • mostly raw

    I have really swollen lymph nodes and I think the culprit is sprouted raw hummus. Otherwise I don’t feel very sick-well, I have fatigue but that is normal for me. It’s been at least 48 hours now and I’m wondering when they are going to go back down….

  • baszia

    Hi, I have been spending a bit of time recently researching sprouting chick peas / garbanzos because a friend suggested I should always cook them before eating them. For me the point was to eat them raw and uncooked to preserve the crispness and freshness. I have now become concerned after reading dramatic accounts such as the one cited here.

    My own experience to date, and I have been sprouting chick peas for several years, has been an entirely happy one.But I guess it only takes one bad batch to alter that. I don’t cook my sprouts. I wash them first, then use a specially designed commercial sprouter which drains off excess water; I water them twice a day for four days or so and then rinse them thoroughly in cold water and dry them gently and refrigerate them. I usually marinate them in a vinaigrette, along with other salad ingredients, but also eat them plain.

    is it possible that sprouts simply carry the same risk as any other raw food and that the information below is a bit alarmist? Or have I just been lucky?

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