Vol. 10 No. 5 October 1990



This special edition of the Environmental Toxicology Newsletter will hopefully reach you before you start to get questions about a new book titled Diet for a Poisoned Planet. I was fortunate (I think) to have had the opportunity to read an advance copy and wrote a review of the book. The review makes up this special edition of the newsletter. Because of limitations in the length of the review, I could not address all of the misinformation in the book, so if you have specific questions, please write or FAX them to me. If you need a copy of the FDA "Residues in Foods: 1989", call us. As with all of the information in the Environmental Toxicology Newsletter, please make use of it in any way you desire. Good luck, this should be an interesting experience for all of us.

Book Review

Diet for a Poisoned Planet -- D. Steinman

This book does not offer any new or startling information about our food supply. It is a repetitive rehash of lots of old misinformation and selective presentation of newer information from the FDA Total Diet Studies. The author portrays the book as the results of exhaustive research, and it is not. It is the result of selective background research and inappropriate data analysis to support his view. Borrowing some of the favorite terms of the author, this book is "saturated" with misinformation, "laced" with misconceptions, and "soaked" in the selective presentation of outdated, unsubstantiated, and anecdotal reports. In the first chapter of the book Steinman states "Unfortunately, most doctors know little about the impact of chemicals in food and water. Most have no training at all in chemical toxicology". This statement is even more applicable to the author of Diet for a Poisoned Planet.

There are many serious flaws in Steinman's approach, but the biggest flaw is the lack of application of the principle of dose- effect relationships. He does indeed acknowledge that such a relationship exists, but then proceeds to dismiss it only two pages later when he develops his "red, yellow and green light" approach to safe foods based on the number of residues found in the FDA Total Diet Study not on the levels of the residues. Results of the recently published 1989 FDA Total Diet Study present the daily intake of residues compared to the Acceptable Daily Intakes (ADI) set by FAO/WHO. The ADI is the level of intake which is calculated to cause no adverse effects if consumed throughout a lifetime. The 1989 Total Diet Study data show the average intake of pesticide residues to be only 0.23% (1/400th) of the ADI. Do the levels (low ppb) found in the Total Diet Study imply "saturation" with pesticides? Hardly.

Steinman ranks peanut butter and raisins as "dangerous" foods based on his own risk assessments. He includes in the book cancer potency values (actually Unit Cancer Risk values) calculated by EPA and presents the results of his own risk assessments using data from the "FDA Total Diet Study, April 1982-1986 Dietary Intake of Pesticides, Selected Elements and Other Chemicals". It is impossible to evaluate his methodology since he presents only his results, thus only general comments about this can be made. Steinman states that these risk assessments are "objective" benchmarks of hazard and therefore useful for ranking safety. In fact they are highly uncertain measures of risk, and should be viewed as such. The Unit Cancer Risk (UCR) values set by EPA for simplified risk assessment are based on the 95% upper limit slope of the linearized multistage model used in risk assessment. In plain English this means that the highest estimates of potency are taken from a risk assessment model known to overestimate risk. The difference between the upper bound estimates and the most probable (median) estimates is usually factors of ten or greater, thus there is considerable uncertainty about these numbers. In general Steinman ranks foods with predicted risks less than 7 x 10-6 as green light (eat all you wish), 7-20 x 10-6 as yellow light (okay to eat occasionally) and greater than 20 x 10-6 as red light (dangerous foods). Because risk assessments are so uncertain, and the confidence intervals at these levels would overlap considerably, this subjective rating scale is completely without value.

Another error that Steinman makes many times in the book is the transformation of predictive data (predictive risk assessment values) into actuarial data (body counts). This common error is a form of "math abuse". Risk assessment predictions from animals cannot be multiplied by the exposed human population to establish actual numbers of human cases. In addition, predictive risk assessment estimates should always be presented with their confidence limits. When this is done, it is easy to see that a prediction with an upper bound confidence estimate of 20 per million will usually have a lower bound confidence estimate of 20 per billion or less.

An in-depth listing of the outright errors and selectively quoted research results would be as tedious as the book itself, so I will only present a few examples to show the lack of expertise of the author. Steinman plays loose and fast with the term carcinogen and makes many statements to the effect that "chemical X is a known human carcinogen". He confuses or ignores carcinogen classification systems used by consentual scientific bodies, and makes his own pronouncements. In chapter 15, "The Nontoxic Home" Steinman makes another factual error in relation to auto batteries, "Batteries are a prime source of methyl mercury accumulation in the environment." Auto batteries do not contain methyl mercury, it is lead that is the concern with car batteries. In the next chapter, "Pregnancy and Toxic Chemicals" under a section on nitrates and nitrites, Steinman misstates the cause of nitrate toxicity in babies, claiming they are converted to "mitrosemines" (such chemicals do not exist). In another section a proven relationship between food additives and human behavioral problems is presented. This is an example of the selective presentation of studies that only support his view because in fact many double-blind studies have shown no such relationship. The factual errors are a result of inadequate background research. The use of numerous anecdotal reports and testimonials to prove his points is simply not scientific. Such personal accounts provide human interest, but no basis for establishing fact.

There is one error in the book that I consider egregious. Steinman blames the dairy industry for causing the heptachlor contamination problems in Hawaii and Missouri, and unequivocally states that they do not deserve our trust. He portrays the dairy industry as the perpetrators of the problem rather than the victims of it. He seems to think that the dairy people in these states intentionally fed contaminated feed to their animals. This is simply not the case. The dairy industries in both instances were truly the victims of contamination.

As a toxicologist, I cannot evaluate the potential health effects of Steinman's proposed diet. The "detoxification" recommendations could indeed be hazardous, as the author himself recognizes, and thus deserve caution. It should be noted that the use of these programs is quite controversial, and not inexpensive. The premise for detoxification is that the low level contaminants in your system are having real effects on your behavior and performance. This premise is established solely on the basis of testimonial reports. The incidence of placebo response to medical treatments is from 25-50%, and real treatment effects have to be measured using objective performance criteria. The presence of a chemical in body fat , does not mean it is having an effect. Dose-effect relationships hold true for all chemicals.

A better title for this book would be "Diet for a Paranoid Person" since the book is filled with paranoid ideation. The first example occurs in the first chapter in which Steinman states "Many people today have no conception of true mental clarity. We have all been exposed to low-level chemical residues for so long that it is difficult to conceive of life without their subtle neurotoxic effects". Other examples include "People who care about their health but regularly drink tap water.....may be making a deadly mistake." "We all have chemical sensitivities." "Do you see the omnipresence of our enemy? It is virtually everywhere!" "None of us is immune. Some of us cannot adapt, even imperfectly, to the chemical onslaught." Our enemies are the tiny, cumulative poisons in everyday life, nemeses disguised in banality." I'm sure you get the idea.

Fortunately the book is tediously repetitive, and written in a rambling style. It is doubtful that anyone other than a reviewer would even read the whole thing. This book is not even interesting reading. The book abounds with contradictory ideas, often presented within the same paragraph. This is not surprising considering the author's simplistic, naive, and unscientific approach to the subject matter. It is also an indication of the incomplete and selective background research upon which the book is based. The recommendation to eat fruits and vegetables is certainly a good idea, but not for the reasons put forth by Steinman. This book gets a "thumbs down" evaluation. For those people that do buy it, or are given copies to read, be sure to recycle it when you are finished. It would be nice for the book to have some practical use.

Arthur L. Craigmill, Ph.D
Toxicology Specialist
University of California
Davis, CA 95616
(530) 752-2936
(530) 752-3394 (FAX)