]]]]]]]]]]]] PROF. BRUCE AMES REBUTS CBS [[[[[[[[[[[[[[[ (10/3/1989) [From Priorities, Fall 1989, pp. 38-39] [Published by the American Council on Science and Health, 1995 Broadway, 16th Floor, New York, NY, 10023-5860, (212) 362-7044] [Kindly uploaded by Freeman 10602PANC] Dr. Bruce Ames, noted biochemist and Chairman of the Department of Biochemistry at the University of California, Berkeley, was also interviewed by Mr. Bradley. His comments to ``60 Minutes'' were also distorted, as CBS did their best to discredit him. Specifically, the producers misquoted Dr. Ames -- and then brought on Dr. William Lijinsky and allowed him, uncritically, to challenge the distorted statements attributed to Dr. Ames, without allowing Dr. Ames a rejoinder to clarify points. Below is the letter Dr. Ames wrote to Don Hewitt, ``60 Minutes'' producer, following the [14 May 1989] airing of the interview. June 29, 1989 Mr. Don Hewitt Executive Producer 60 MINUTES CBS NEWS 524 West 57th Street New York, N.Y. 10019 Dear Mr. Hewitt: SCIENCE vs. ``60 MINUTES'' ``60 Minutes'' interviewed me for its second program on Alar, which was shown on May 14, 1989. Mr. David Gerber, the producer, and Mr. Ed Bradley, the interviewer, grossly distorted the scientific arguments I presented, thus dishonestly discrediting me. The program dealt both incompetently and dishonestly with a scientific issue and was therefore unprofessional. I assume that such an egregious mistreatment of a scientific issue was made by ``60 Minutes'' in order to buttress its previous scientifically flawed coverage of the Alar issue [broadcast on 26 February 1989], rather than to pursue the truth. The focus of my discussion in the interview was that the fear of cancer from the breakdown product of Alar was based on misinterpretation of the meaning of animal cancer tests. Below, I briefly summarize the relevant facts, which are documented in greater detail in the enclosed papers. I also indicate how Gelber distorted the facts to make his case. Of all chemicals tested at high doses in both rats and mice (about 400 chemicals), about half are carcinogens: thus, carcinogens, as defined by such tests, are extremely common. Synthetic industrial chemicals account for almost all (-85%) of the chemicals tested. However, despite the fact that more than 99.9% of the chemicals humans eat are natural, only a small number (about 70) of natural chemicals have been tested in both rats and mice; again, about half are carcinogens. These results imply that synthetic chemicals, except in the case of high-dose occupational exposure, are unlikely to be responsible for much human cancer. This is in agreement with the conclusion of the epidemiologists who study human cancer: only a minuscule proportion, if any, of cancer is likely to be due to pesticide residues. Nature's pesticides are one important group of natural chemicals that we have investigated. All plants produce toxins to protect themselves against fungi, insects, and predators such as man. Tens of thousands of these natural pesticides have been discovered, and every species of plant contains its own set of different toxins, usually a few dozen. In addition, when plants are stressed or damaged, such as during a pest attack, they increase their natural pesticide levels many fold, occasionally to levels that are acutely toxic to humans. We estimate that 99.9% of the pesticides we eat are all natural. Surprisingly few plant toxins have been tested in animal cancer bioassays, but among those tested, again about half (20/42) are carcinogenic. Even though only a tiny proportion of plant toxins in our diet have been tested, natural pesticide carcinogens have been shown to be present in the following foods: anise, apples, bananas, basil, broccoli, brussels sprouts, cabbage, cantaloupe, carrots, cauliflower, celery, cinnamon, cloves, cocoa, coffee, comfrey tea, fennel, grapefruit juice, honeydew melon, horseradish, kale, mushrooms, mustard, nutmeg, orange juice, parsley, parsnips, peaches, black pepper, pineapples, radishes, raspberries, tarragon, and turnips. Thus, it is probable that almost every plant product in the supermarket contains natural carcinogens. The levels of the known natural carcinogens in the above plants are almost always much higher than the levels of man-made pesticides, and many are in the range of thousands to millions of parts per billion. I pointed out to ``60 Minutes'' that a glass of the suspect Alar-contaminated apple juice posed only 1/10th the possible carcinogenic hazard of the average peanut butter sandwich and 1/50th that of a mushroom, as well as other relevant comparisons [see ``Pesticides, Risk, and Applesauce,'' Science, May 19, 1989]. Furthermore, we need not be alarmed by the presence of low doses of synthetic toxins and a plethora of natural toxins in our food. Humans are well protected by many layers of general defenses against low doses of toxins -- defenses which do not distinguish between synthetic and natural toxins. In addition, new research suggests that conventional worst-case extrapolations from very high-dose rodent cancer tests to very low-dose human exposures to chemicals, such as the NRDC performed, enormously exaggerate the possible hazards. Additionally, there is a fundamental trade-off between nature's pesticides and man-made pesticides. We can easily breed out many of nature's pesticides, but then we will need more man-made pesticides to protect our crops from being eaten by insects. In contrast, growers are currently breeding some plants for insect resistance and unwittingly raising the levels of natural pesticides. Although I am considered one of the world's leaders in this field, and I devoted a day of my time to explain in detail the above points to Gelber/Bradley, they chose to ignore most of these facts. The points that were covered on the air were handled in the following incompetent and unprofessional manner. (1) My discussion of natural carcinogens was grossly misquoted: Bradley: ``Dr. Lijinsky disputes Ames' claim that 99.9% of all carcinogens come from natural foods.'' This obviously incorrect claim was never made by me. Gelber/Bradley made it up. What I stated was that 99.9% of chemicals we ingest are natural. It is well known that 30% of human cancer is due to smoking and another large percentage of cancer is due to viruses, hormones, sunlight, alcohol, dietary imbalances, radon, and occupational causes. Thus, Lijinsky rebutted a statement made up by Gelber/Bradley, and, as a consequence, publicly discredited me. When I asked Gelber where he got that statement from, he couldn't come up with an answer. (2) Gelber/Bradley grossly misquoted me again and publicly discredited me in two unjustifiable ways. Bradley: ``Well, who's right? This is the most recent listing of carcinogens published by the U.S. government's National Toxicology Program. That's the agency which determines which chemical compounds are known to cause tumors in animals or humans. It does not support Dr. Ames' claim that there are tens of thousands of carcinogens in natural food. He believes further tests will show he's right. But for now, the national toxicology survey lists just 148 substances, and the compounds in celery and broccoli aren't among them. One compound that is, is the one produced by Alar.'' (a) The attribution to me of the statement ``there are tens of thousands of carcinogens in natural food'' is not right. (b) Bradley's statement that the natural carcinogens in celery and broccoli aren't listed by the National Toxicology Program (NTP) is not correct. In the ``60 Minutes'' interview, I said that Brussels sprouts, cabbage, broccoli, and celery contain carcinogens. Gelber later phoned me asking what these carcinogens were. The information on three of these foods was in the article ``Pesticides, Risk, and Applesauce,'' which I had sent to Gelber and which he had promised to read before he came to interview me, and which has since been published in Science. Nevertheless, I told him on the phone that allyl isothiocyanate is in cabbage, Brussels sprouts, and broccoli, and that 8-methoxypsoralen is in celery, and that both plant compounds were found to be carcinogens by the NTP in its own bioassay program. Bradley said in the quote above that these compounds are not in the latest NTP list of carcinogens, thus discrediting me. The list he waved was years old. The compounds are, in fact, on other lists that NTP sends out to all interested parties several times a year: allyl isothiocyanate was evaluated by NTP as positive for carcinogenesis in 1982 and 8-methoxypsoralen in 1988. Gelber/Bradley could have clarified this easily of they had wanted to, but, apparently, scientific truth was not on their list of priorities. (3) Gelber/Bradley turned the Alar issue into a question of motives rather than of science. For example, they attempted to tie me to the ``bad guys'' -- the American chemical industry -- by introducing me as follows: Bradley: ``At the urging of the agricultural chemical industry, we spoke with Dr. Bruce Ames, chairman of the Biochemistry Department at Berkeley. Dr. Ames says he is completely independent and does no consulting for industry.'' Gelber/Bradley, of course, could as well have chosen to say that I am a member of the National Academy of Sciences, or have received a long list of scientific honors from numerous countries. In any scientific controversy, a professional reporter wishing to obtain an unbiased view should ask advice from the leading scientists in the field. Gelber did not do this in the first Alar program. If Gelber had wanted to obtain a professional scientific opinion on Alar he could have assembled a list of outstanding scientists in the field by consulting Nobel prizewinners or other leading scientists who are familiar with the field. If these scientists were asked to name leaders in the field, I am confident that I would be near the top of everyone's list -- not just the agricultural chemical industry's. I doubt if Lijinsky would be on anyone's list. Lijinsky, who was the scientist given the most time on the program, was introduced as the head of a chemical carinogenesis lab at the National Cancer Institute (NCI), yet Lijinsky is not an NCI employee. Gelber didn't talk to any of the leading chemical carcinogenesis people at NCI, e.g. Richard Adamson, the head of Cancer Etiology, for their opinions of either Lijinsky or myself or Alar. The theme of the ``60 Minutes'' program seemed to be that anyone who has consulted for or is connected with industry is biased, without considering that bias can exist on both sides. Although I do no consulting for industry or law firms, I am aware from my experience in 20 years in toxicology that the American chemical industry is extremely competitive and consistently tries to get the best toxicologists in the country to advise them because it is in their self interest to do so. On the other hand, my experience with the environmental organizations is that they specialize more in ideology than in expert science. The activist lawyers of the NRDC and similar organizations choose scientists who are selectively interested in rodent carcinogens that are produced by chemical companies, and they believe that anyone connected with a chemical company or industry works only for greed (profit) while they work for altruism. Perhaps feeling virtuous compensates for their lack of success in being competitive in science. Such scientists can profit very well from their ``altruism'' by testifying for a generous fee in the flourishing toxic torts industry. For example, testifying that a few parts per billion of some man-made rodent carcinogen will, as Lijinsky phrased it, ``put someone over the edge and they'll develop cancer'' can be very lucrative. But Lijinsky's or the NRDC's possible biases did not interest ``60 Minutes''. I won't elaborate on the many inaccuracies in your treatment of Elizabeth Whelan. The American Council on Science and Health (ACSH), directed by Dr. Whelan, is that rare creature, a ``public interest'' organization that is based in science. Dr. Whelan has assembled an impressive list of knowledgeable people on her scientific advisory board. I have been as impressed with the scientifically sound pamphlets that ACSH has published, as I have been unimpressed by the scientifically unsound claims of the NRDC. There are many important issues concerning cancer that ``60 Minutes'' could tackle without bankrupting apple farmers and falsely convincing the public that their apples are poisonous. One real issue in environmental cancer is how a few ideologue lawyers and second-rate scientists working through the media have convinced many Americans that pesticide residues, water pollution, and ``toxic chemical'' pollution are serious causes of cancer or birth defects, and that what this misdirected effort costs the country by diverting attention from real to trivial problems. A final thought: Reed Irvine of Accuracy in Media (AIM) was a pleasure to deal with, in contrast to Gelber. He was a stickler for detail and cared about scientific integrity. When I was first contacted by him, I didn't know who he was, but he deserves more than a brushoff. He raised a lot of issues that need answers, and so does my letter. Yours truly, Bruce N. Ames Professor and Chairman Department of Biochemistry University of California * * *
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