TCS Daily

Remembering a Berry Scary Thanksgiving

By Elizabeth M. Whelan - November 24, 2004 12:00 AM

Forty-five years ago this week, in November, 1959, most Americans celebrated Thanksgiving sans cranberry sauce. Earlier that month, Health, Education and Welfare Secretary Arthur Fleming had announced that traces of the weed killer aminotriazole--a chemical that caused cancer in rodents--had been found in the cranberry crop. The spokesman urged housewives to "be on the safe side" and refrain from buying cranberries because the rodent data suggested that the "contaminated" cranberries could pose a human cancer risk. New York City's health commissioner, among others, joined the chorus of those who advised "against the use of berries until they could be tested for contamination."

Headlines in newspapers across the country read "Government Warns Cranberry Buyers" and "All Cranberries Face nationwide U.S. Test" and "Cranberry Sales Curbed; U.S. Widens Taint Check."

Cranberry growers were furious. While most industries and manufacturers under attack by environmental critics today remain mute, just hoping the scare will go away, back then the agricultural community -- and the manufacturer of the weed killer in question -- fought back fiercely.

For example, in New York, Ambrose Stevens, executive vice president of Ocean Spray Cranberries Inc., held a press conference to announce that he had sent a telegram to Sec. Fleming expressing the ire of his industry:

"In justice to thousands of cranberry growers and distributors and millions of consumers, we demand that you take immediate steps to rectify the incalculable damages caused by your ill-formed and ill- advised press statements yesterday. You are killing a thoroughbred in order to destroy a single flea. You must know that there is not a shred of evidence that a single human being has been adversely affected by eating allegedly contaminated cranberries."

The Massachusetts Farm Bureau Federation telegraphed President Eisenhower demanding the resignation of Sec. Fleming, noting that his statement, made just before Thanksgiving, was "callous and harmful."

Dr. Boyd Shaffer from American Cyanamid, manufacturer of the agricultural chemical in question, stated that the production of thyroid cancer in rats had resulted from "continued administration over the lifetime of the rat at relatively high dosage." He added that similar experiments with dogs had produced no cancer whatever and he declared that a human "would have to eat l5,000 pounds of (contaminated) cranberries a day for many years" to sustain any ill effects.

The cranberry scare of 1959 marked the beginning of a modern wave of "chemicalphobia" and a government assault on synthetic chemicals that at high doses caused cancer in laboratory animals. This "war on carcinogens," which is still in full force today, had its legal origins in the Delaney Clause, a 1958 amendment to the Food, Drug, and Cosmetic Act that prohibited the presence in food of any synthetic chemical that caused cancer in animal studies. Cranberry phobia, which burst on the scene a year after the Delaney Clause was passed, was soon followed by a spate of other chemical scares, including those focused on nitrite in bacon, the sweeteners saccharin and cyclamate, and the agricultural chemicals EDB and Alar. More recently, questions have been raised about the safety of French fries (and other high-starch foods cooked at high temperatures) because the process can generate acrylamide. All of these "carcinogen du jour" scares were based solely on the observation that the chemical in question caused cancer in rodents.

But is there sound scientific evidence that high-dose animal tests can accurately predict human cancer risk? Many scientific studies and scientific experts tell us that the resounding answer is "no."

America's "war on carcinogens" was predicated on a number of assumptions -- all of which we now know are false:

-- Only a small number of chemicals are carcinogenic -- so let's get rid of them.

Actually, a surprisingly high percentage of chemicals--50% in some tests--test positive in animal carcinogenicity studies, and a likely explanation for many of these positive results is that toxicity at high doses, not the chemical per se, leads to increased cell turnover, which in turn increases cancer risk.

-- If it causes cancer in one species, it will cause cancer in all animals -- including Man.

In reality, not all substances that induce tumors in one species do so in another. In many instances, findings in mice do not predict cancer risk in rats, two species that are far more closely related to one another than either is to humans.

-- Since chemicals that cause cancer in people (mainly in occupational exposures) also cause cancer in animals, the predictions work the other way as well.

Not so. Very few chemicals shown to be animal carcinogens have ever been linked later with human cancer risk.

-- Only synthetic chemicals are carcinogens, not natural chemicals.

Wrong again.

For example, our upcoming 100% natural Thanksgiving dinners will be brimming with carcinogens, including the hydrazines in the mushroom soup, heterocyclic amines, acrylamide, benzo(a)pyrene, safrol and quercetin in the roast turkey and stuffing; coumarin, acetaldehyde and methyl eugenol in the apple and pumpkin pies; and benzofuran, caffeic acid and 4-methylcatechol in the after-dinner coffee. None of these substances pose a health hazard. Similarly, none of the chemicals that have been the focus of carcinogen scares over the years -- the cranberry scare in 1959, the Alar/apple scare in 1989, the acrylamide/French fry scare of 2003, and all the scares in between -- posed a risk of cancer or any other health problem.

Animal testing is essential to biomedical research. But so is common sense. A positive result in a few high-dose animal tests is not sufficient evidence to allow us to conclude that a chemical poses a human cancer risk.

Over-reliance on animal carcinogenicity testing as a predictor of human health risks has diverted both public attention and resources from important and proven causes of cancer. Unfounded cancer scares cause economic disruption as useful, safe products are banned -- and replaced with more expensive, inferior alternatives (the 1959 cranberry panic had a devastating effect on the growers). Earlier this month, the Bush administration, in addressing environmental policies for the President's second term, pledged "to employ the best science and data to inform our decision-making." The elimination of the scientifically baseless mantra "if it causes cancer in animals it must be assumed to be a human cancer risk" would be an excellent place to start.

Dr. Elizabeth M. Whelan is president of the American Council on Science and Health, and an editor of ACSH's forthcoming book, "America's War on 'Carcinogens': Reassessing the Use of Animal Tests to Predict Human Cancer Risk."


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