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Pundit’s Mailbag — Pesticides And Cancer

Our piece Pesticides Keep Pestering Us quoted a column in PRODUCE BUSINESS, a Pundit sister publication, that dealt with pesticides from a European perspective. Written by Marc DeNaeyer, Managing Partner, TROFI in The Netherlands, the piece focused on sterner standards now being imposed by continental retailers — especially German discounters who, previously, did not have the reputation, as did British retailers — for creating and enforcing uniquely rigorous standards. We wondered if these new standards might cross the Atlantic?

The piece prompted this succinct letter from a frequent Pundit contributor going to first principles:

Regarding Marc DeNaeyer’s statement, in the 6/1/07 Pundit article “Pesticides Keep Pestering Us”: “The only known fact today is no one has died due to pesticides residue.” This is similar to what tobacco companies said for years. After all, it isn’t the smoke, it’s the cancer that kills people.

The clear implication of my using tobacco as an analogy is that there is major harm being done, the problem is that research funding is 99% derived from companies with proprietary interests in the results.

However, it needs to be said that the importance of proprietary interests in funding research does not, in itself, say anything about the part that pesticides may play in contributing to countless diseases, many of which lead to early death. But I think it does justify some reservations about the truth of Marc’s statement.

As usual, I’m better at seeing problems than solutions.

— Bob Sanderson
Jonathan’s Sprouts
Rochester, Massachusetts

Seeing problems is always the start of seeing solutions but, here, we need to distinguish between a theoretical problem and one we actually have reason to think exists.

In its stalling on acknowledging a link between cigarette smoking and cancer, the tobacco industry was hanging its hat on the fact that we had not — and still have not — established a causal link between cigarette smoking and cancer. We had no way — and have no way — of establishing that any individual who begins smoking is going to get cancer.

This being said, there is an overwhelming correlation, established in hundreds of studies, covering hundreds of thousands of people, that smoking increases the likelihood of developing certain cancers such as lung cancer.

Though this is not “proof” that smoking “causes” lung cancer, the overwhelming weight of the evidence made clear that one significantly increased one’s chances of getting certain types of cancers by regularly smoking cigarettes.

On produce the situation is just the opposite. The Pundit was at the press conference that was held when the 5-a-Day program was being launched nationally. One of the people speaking at the conference was the head of the National Cancer Institute, which was the launch partner for the initiative. One of the reporters present asked this gentleman if the 5 a Day program shouldn’t require organic produce so as to avoid cancer.

He answered by saying that not only was there no evidence that pesticide residues on produce resulted in an increase in cancer in human beings, but that the research we had — which had been done on conventionally grown produce, not organic produce — indicated that rates of cancer could be reduced through a diet rich in fruits and vegetables.

Now this doesn’t mean that pesticides cannot contribute to an increased likelihood of getting cancer; it just meant that we have no reason to think so and, even if it does, it is a sufficiently small increase that the benefits of fruit and vegetable consumption can easily overwhelm this negative effect.

Besides, the question wouldn’t be, “Does synthetic pesticide residue increase the likelihood of getting a cancer?” Since there is no option to starve ourselves to death, we would have to compare produce grown under one system, in this case conventionally grown produce, to produce grown some other way, presumably organically grown produce.

Yet organically grown produce is not, contrary to popular perception, grown without the use of chemicals. It is grown without the use of synthetic chemicals. In many cases, because the organic compounds are less effective than the synthetic compounds, they are applied at a higher density.

So, for example, both copper and sulfur are organic and used in organic agriculture — is it just obvious to everyone that a lifetime of consumption of copper and sulfur residue is inherently healthier — because they are organic substances — than residue from a synthetic pesticide or fungicide?

It is very possible, even probable, that Marc’s statement was not accurate in a technical sense. It was only incorrect, though, in the sense that everything might cause cancer. It was a medieval monk named Paracelsus that stated the cardinal principle of toxicology: The dose makes the poison.

Although what he actually said was “Alle ding sind gifft und nichts ihn gifft. Allein die dosis macht das ein ding Kein gift ist,” which is typically translated as “What is not poisonous? Everything is poisonous yet nothing is poisonous. The dose alone makes the poison.”

This article on Paracelsus, from The Journal of Nutrition, applied this principle to some modern produce industry events:

A failure to perceive this elementary fact of nature causes many major problems to society. A trivial example is the “Chilean grape scare” of 1989. The FDA reported that it had found three micrograms of cyanide on each of two grapes imported from Chile.

In the ensuing panic, Chilean fruit was dumped into the garbage and a major economic crisis was precipitated in Chile.

The amount of cyanide on the grapes was less than the amount in a 1-g normal lima bean. But few people listened.

A distraught mother telephoned the highway patrol on March 15, 1989, to intercept the school bus, because her daughter’s lunch contained some grapes. Her request was dutifully obeyed: the lunch was removed and destroyed. At about the same time, school authorities were throwing apple pies into an incinerator because of the “Alar scare.’

A news story related that a young school pupil rescued one of the apple pies and ate it. In this, he was disciplined, truly a minor martyr to the cause of intuitive common sense.

In any case, we suspect Marc was not speaking of long term, theoretical consequences of exposure to synthetic pesticides, but speaking of the acute, readily observable consequences — and on that issue he was 100% correct.

In fact, the insistence of the organic community in allowing the use of composted manure, compost teas and other forms of manure in organic agriculture always leaves open the possibility that improper composting — or inadequate composting standards — could lead to the presence of pathogens on fresh produce such as E. coli 0157:H7, which can quickly cause serious illness or death to people at risk. It is hard to imagine any hypothetical, long-term, risk to health from pesticide residue on fresh produce that would outweigh that risk.

One issue on which we find common cause with our correspondent is the desirability of additional research. Since “the dose makes the poison,” we can benefit by deeper research into the effects of different doses. In addition we need to be mindful that there may be periods — such as pregnancy — in which there may be special vulnerabilities.

If we are going to fund research, though, we see no reason it should be confined to researching synthetic substances — a proper research program would evaluate all residues, both synthetic and organic. Who knows what we might learn?

Many thanks to our ever astute correspondent Bob Sanderson who always helps us look at issues with a sharpened focus. That is a very valuable friend to have and we appreciate his contributions.

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