TCS Daily


How to Make Our Food Safer

By Henry I. Miller - November 6, 2006 12:00 AM

Food poisoning from food contaminated with microorganisms is very common: 76 million cases and 5,000 deaths annually in the United States, according to government figures.

A couple of recent outbreaks have garnered a lot of attention. During the past two months, there have been three deaths and approximately 200 cases of illness from E. coli O157:H7 (traced to fresh, bagged spinach), and about 200 illnesses caused by Salmonella typhimurium.

Federal officials investigating the spinach outbreak have narrowed their search to a handful of ranches in California's Salinas Valley and appear to be focusing on wild hogs as the cause of contamination. The source of the Salmonella contamination is as yet unknown.

Americans are wondering who will protect us from future outbreaks of contamination and food-borne illness.

First, it's clear we can't rely on growers of fresh produce to protect us 100 percent of the time. Modern farming operations - especially the larger ones -- already employ strict standards and safeguards designed to keep food free of pathogens. And most often they work: Americans' food is not only the least expensive, but also the safest, in the history of humankind.

However, there is a limit to how safe we can make agriculture, given that it is an outdoor activity and subject to all manner of unpredictable challenges. If the goal is to make a field 100 percent safe from contamination, the only solution that guarantees this is to pave it over and build a parking lot on it. But we'd only be trading very rare agricultural mishaps for fender-benders.

It has also become painfully clear that we can't rely on processors to remove the pathogens from food in every case. This most recent outbreak of illness demonstrated that our faith in processor labels such as "triple washed" and "ready to eat" must be tempered with at least a little skepticism. Processors were quick to proclaim the cleanliness of their own operations and deflect blame toward growers. But all of those in the food chain share responsibility for food safety and quality.

In fairness to processors, there is ample evidence to suggest that no amount of washing will rid all pathogens from produce. The reason is that the contamination may occur not on the plant, but in it. Exposure to E. coli or other microorganisms at key stages of the growing process may allow them to be taken into the plant and actually incorporated into cells.

Citing this, advocates of food irradiation have stepped forward to claim that their technology can provide the assurance consumers demand and deserve. To be sure, irradiation is an important tool to promote food safety and is vastly under-used, largely due to opposition from the organic food lobby and government over-regulation.

But irradiation is no panacea. Although it quite neatly kills the bacteria, it does not inactivate the potent toxins secreted by certain bacteria such as Staphylococcus aureus and Clostridium botulinum. This is a distinction you'd keenly appreciate should you become infected.

So, if consumers can't be protected by growers or processors or even irradiation, what can protect them?

There is technology available today that can inhibit microorganisms' ability to grow within plant cells and block the synthesis of the bacterial toxins. This same technology can be employed to produce antibodies that can be administered to infected patients to neutralize the toxins, and can even be used to produce therapeutic proteins that are safe and effective treatments for diarrhea, the primary symptom of food poisoning.

But don't expect your favorite organic producer to embrace this triple-threat technology, even if it would keep his customers from getting sick. Why? The technology in question is biotechnology, or gene-splicing -- an advance the organic lobby has vilified and rejected at every turn.

For organic marketers, the irony is more bitter than fresh-picked radicchio. The technology that affords them the best method of safeguarding their customers is the one they've fought hardest to forestall and confound.

Perhaps in the wake of at least three deaths and 400 illnesses from the recent E. coli and S. typhimurium outbreaks, the organic lobby will rethink its opposition to biotechnology. Perhaps they will undertake a meaningful examination of the ways in which this technology can save lives and advance their industry.

I'm not betting the farm on it. After all, admitting you're wrong is hard. Blaming others is easy.

Henry I. Miller is a physician and fellow at the Hoover Institution. Barron's chose his most recent book, "The Frankenfood Myth..." one of the 25 Best Books of 2004. He headed the FDA's Office of Biotechnology from 1989 to 1993.
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9 Comments

admitting they're wrong
They will probably admit they're wrong as soon as Paul Erdman and his wife do; namely, never. Anyway, why would those health food luddite flakes want any new technique when they even oppose bodies like the FDA to check out foods, and food additives, etc? These are the same guys who are happy to see savages in tin pot backward countries starve instead of having GM frankenstein foods. These wealthy liberal food facissts are beneath contempt and I hope they choke on their fair trade double latte coffee as they lounge around Starbucks spending the money they've received from their cushy research grants.

They May Not Admit Their Wrong. . .
. . .but they'll sure kick up a ruckus demanding action if its food they regularly eat that ends up contaminated.

But it does get regularly contaminated
We've just had contaminated carrot juice and spinach, all "organic". They still don't kick up a fuss, somehow insisting that more of the same is what's needed. It's delusional to imagine that using manure for fertilizer can result in less contamination despite "triple washing" or some other window dressing, but it never stops the organic freaks. They have their mantra and nothing will convince them otherwise.

The ultimate motivator
A class action suit for damages would work wonders in changing persepectives and philosophies.

The science...
Rather than to indulge in our usual political bickering here let's talk about the underlying biology.

The proposition is that genetic engineers could drop chromosomes into the genome of, let's just say, a spinach plant. These genes would cause the spinach cells to produce an antibiotic protein. This molecule would specifically target a pathogen of interest or it might attack a broad range of bacteria.

If such molecules inhibited the vegetative stage of, for example, all E. coli then the raw spinach would also kill those varieties of E. coli populating the normal flora in the human lower gut. This would probably lead to intestinal tract distress for lots of people eating such a salad.

In general broad range antibiotics used in our food production processes are a concern because they select for antibiotic resistant strains of bacteria. They stop the easy to kill bugs and leave more room for the tougher strains. Of course, this is a serious public health problem worldwide. Bacteria that nothing can kill might, thereby, murder all of us.

As an example of our caution in this regard, dairy farmers must not mix milk contaminated with antibiotics from a cow under medication into their holding tanks. Milking machines are programmed to dump the milk taken from such animals (identified by ear tags). Residuals in meat from feedgrade antibiotics used in pork and chicken production are also a concern.

Alternatively, if the engineered molecule in our spinach plant should attack a particular pathogen (rather than all bacteria) then the fields to be cultivated must be surveyed in advance to identify the specific organisms we want to protect against.

Appropriate chromosomes would be prepared and introduced into the spinach stem-cell lines to be propagated. Large numbers of baby seed-stock spinach plants must be planted to yield enough seeds for each season. Then seeds must be carefully matched to the fields. Because bacteria mutate quickly the genetic engineering industry would need to respond continually with new seeds.

Nevertheless, most of the contamination that makes people sick eating raw spinach is residing on the surface of the plant rather than incorporated into its tissues. In this case genetic engineering would have no effect. A good washing to remove the dirt is, of course, the best approach. Cooking would also be a good idea for vulnerable young children and older people.

But let's look into the argument that, for example, Clostridium botulinum found its way into a spinach plant. Clostridium botulinum is anaerobic. The vegetative stage is killed by oxygen. Green leafy vegetables produce lots of oxygen as a byproduct of photosynthesis. Their tissues are literally saturated in high concentrations of oxygen. There is simply no chance that toxins from Clostridium botulinum would be found inside the tissues of spinach plants growing in the field.

Now let's look at this "triple-threat" argument. Genetic engineering and tissue culture techniques might be employed to produce antibodies to neutralize toxins, etc. or other organic medicines such as treatments for diarrhea. However, such pharmaceutical industry processes have absolutely nothing at all to do with organic farmers or any other spinach farmers, for that matter.

Biotech and genetic engineering are incredibly important to the welfare of man. The production of food enhanced via gene-splicing has up to now been successful and the produce has been safe to consume. Of course, it is possible to have a tragic outcome although a discussion of that is beyond the scope of this post. But the unknown risks with the spread of these techniques do justifiably concern all of us.

There is money to be made. Powerful interests wish to marginalize those who are resisting these technologies. However, the position that the organic crazies are costing us innocent lives because they will not let us add an antibiotic chromosome to our spinach plants is ludicrous and maliciously designed to frighten our easily confused citizens. Shame. You do know better.

underlying biology
The food naazzis don't care about biology or any science since they're 'out to save the world'. Science only gets in the way of their litany. Otherwise why wouldn't they want the FDA to check out their crappy, overpriced, usless food additives that they make their fortunes on?

Food irradiation
avoids all of these problems.

a few things
Forest,
First, one does not confer an antibiotic compound by transforming chromosomes into the genome, you insert a gene or genes into a chromosome. This is an important distinction.
"If such molecules inhibited the vegetative stage of, for example, all E. coli then the raw spinach would also kill those varieties of E. coli populating the normal flora in the human lower gut. This would probably lead to intestinal tract distress for lots of people eating such a salad." Assuming, of course, that the protein is present in large enough concentration and that it is not digested earlier.
"Alternatively, if the engineered molecule in our spinach plant should attack a particular pathogen (rather than all bacteria) then the fields to be cultivated must be surveyed in advance to identify the specific organisms we want to protect against." What's the big deal? This is how basic research is done.
"Appropriate chromosomes would be prepared and introduced into the spinach stem-cell lines to be propagated. Large numbers of baby seed-stock spinach plants must be planted to yield enough seeds for each season. Then seeds must be carefully matched to the fields." Unlikely. The number of transformed lines initially tested would be high. The number taken into seed production would likely be five or less. From then on, normal seed production practices would take over.
"Nevertheless, most of the contamination that makes people sick eating raw spinach is residing on the surface of the plant rather than incorporated into its tissues. In this case genetic engineering would have no effect. A good washing to remove the dirt is, of course, the best approach." Pathogens routinely find their way into the vascular system of plants, sometimes even into the seeds. The methods used by the organic crazies you refer to can exacerbate this problem because they use manure that sometimes contains the worst of these pathogens (E. coli O157). If this practice was eliminated and EXTREME care was taken to keep a safe distance between cattle ranches and fields of fresh produce, there might not be any need for a remedy.

Right...
Of course, you are correct that gene splicing techniques add DNA sequences (genes) into pre-existing chromosomes. Moving entire chromosomes around would be a very different matter. My bad.

Any antibiotic molecule produced by every cell in the spinach plant and present in a therapeutic concentration would be protected from most digestive processes by the cellulose of the cell walls and would then be drawn out into the large gut as the intestinal contents are dehydrated by the normal functioning of the colon. In any case, antibiotic compounds are designed to take a beating in the dosed organism and keep on killing or they would not work at all. If you had to design an antibiotic to be produced by your genes on my chromosome that would kill bacteria in the spinach leaf but denature when exposed to stomach acid...that's a more difficult design, isn't it?

The big deal about testing each field each season is precisely the same big deal we have each flu season when we need to prepare a cocktail of the specific viruses that are going to hit this year and some of them have mutated (at the antibody targeted active site) since the last time we prepared a vaccine for them. There would be far more than five seed varieties if we got pathogen-specific. Unless we prepared shotgun seeds without also making those new molecules into broad range antibiotics.

Pathogens might indeed find their way into the tissues of plants but is this happening enough to constitute a clinically significant exposure? Or are people actually getting sick from contaminated dirt on the surface of the leaf, for the most part?

Everyone uses manure on his fields. That's how we get rid of it! The piece of farm equipment involved is called a "manure spreader", it is pulled behind our tractors and the spreading mechanism runs off the tractor's PTO. You don't need to be an organic crazy to be a good farmer. Of course, we could test dairy barns and feed lots for the presence of dangerous strains and make sure that such manure stayed away from vegetable fields. That would seem prudent and manageable. Thanks.

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