Medical Evidence

In the second of a two-part series, Jim Ring looks at what evidence means to different people

Scientific evidence is often difficult to interpret, in medicine in particular. ‘An Unfortunate Experiment’ was the title given to the treatment for some women after screening for cervical cancer. In this case science was considered by the legal profession and apparently found wanting. The doctor involved was castigated and publicly humiliated for experimenting on humans. But no real experiments were ever done; it appeared he did not understand scientific methodology. Neither did the journalists and legal people involved. The point is that no proper controls were used so it was very poor science.

Were the women disadvantaged? It is difficult to tell, but many were certainly outraged. It generally escaped notice that the surgeon was responding to public pressure for less radical surgery and that a group of patients involved seem to have had on average a slightly better outcome than the norm.

One of the most unfortunate ideas that came out of the long legal case was the emphasis on privacy for the individuals involved which implied their records should not be available for medical study. There is a difference between privacy and anonymity. It is very important to explain to those involved in medical procedures that for medicine to progress it is essential to collect data. Women appeared on TV complaining bitterly that they had been used in an experiment without their consent. But all good medicine is experimental.

We are not much closer to determining whether mass screening for cervical cancer does improve the chances for the screened population and now we have another scandal in New Zealand. Public expectation of screening programs is far in excess of what they can deliver. Efforts to sue Dr Bottrill, and compensation claims from ACC, seem to imply that patients think a false negative reading is necessarily medical error. Women have appeared on TV claiming their lives have been devastated because they had a false negative. Surely this is wrong; they are rightly upset but this is because further tests show a medical problem. Of course some who died might have been saved if an early intervention had resulted from a correct positive reading; however this does not seem to be the main thrust of their complaint.

False Negatives vs False Positives

It is possible to reduce the number of false negative readings at the expense of an increase in the number of false positives. This may seem desirable but there is a cost. In Britain large numbers of women in a screening project reacted very badly to finding they might have a ‘pre-malignant’ condition. This included some members of the medical profession. There is a clear indication that patients were not well informed before screening.

Patients involved in any medical procedure are supposedly asked for their ‘informed consent’. It seems now obvious that ‘informed consent’ is largely lacking during mass screening for both cervical and breast cancer. Several of those involved in the public hearing are surprised to find that screening is less than 100 per cent accurate. All mass screening procedures are likely to have a high error rate as they are designed to be rapid, cheap and simple; leading to more precise testing if there is a positive result. Is a large and expensive inquiry, using legal methods, a suitable way of investigating scientific questions?

Cervical cancer, unlike breast cancer, is strongly correlated with environmental factors. The former is very rare in the general population with a relatively high incidence in a certain sector. However it is politically incorrect to target the high-risk population for screening because the risk correlation is with such factors as poverty, poor hygiene and sexual promiscuity.

A recent case of a gynaecologist accused of misconduct raises some interesting issues. The unfortunate patient would seem to be outside the high-risk group for cervical cancer, thus an assumption may have been made that the correct diagnosis was very unlikely. But no physical vaginal examination was made. Feminist literature once strongly criticised the medical profession for over-use of this procedure, which one writer described as ‘legalised rape’. It would be interesting to know the rate at which this procedure is used today compared with, say, 30 years ago. Is the medical profession responding to crusades in a way that disadvantages patients?

Objections to trials

Medical ethicists – now a profession – have objected to various drug trials saying it is unethical to provide some patients with a placebo that will not improve their condition. This is in effect a claim to certain knowledge – that the drug being trialed is the ideal treatment. Patients receiving a placebo are not disadvantaged when the new drug may do more harm than good. We can sympathise with terminally ill patients who know that they will die in the absence of treatment and where anything seems a better bet than a placebo. But it is essential that drugs be properly tested before being used routinely.

Experiments have even been done in surgery. In 1959 patients were randomly assigned, but all prepared for surgery and the chest cavity opened. Only then did the surgeon open an envelope and follow the instruction; either to perform the procedure or immediately close the chest. Although some ethicists have objected (one stated that such surgery would never take place in the UK), a double-blind study of brain surgery was recently done in the US. Not only did it pass an ethics committee but patients welcomed the chance to take part even though it involved drilling the skulls of both real and placebo patients. In this case there was considerable improvement in those under 60 who had the real operation.

This indicates people may be willing to give consent to risky experiments providing they are given good information.

Most evidence in medicine comes not from experiments but from epidemiology. This requires the collection of huge amounts of data and sometimes produces conflicting results. Two populations, which differ only in the factor under investigation, should be matched and this is difficult to achieve. Recently, in a world-wide study, doubt has been cast on the efficacy of breast-cancer screening. New analysis purports to show that when populations are matched correctly, the screened population has no better chance of survival than an unscreened population.

Demands for safety

Some demand that all medical procedures should be ‘safe’, though curiously this is not required of alternative medicine. Suppose a new drug has fatal consequences for one patient in 100,000. It is quite likely that this will not be discovered during testing. Should such a tiny risk preclude the use of a drug that gives significant benefits to the vast majority of patients? New medicines are introduced when they show a clear advantage over a placebo. When very large numbers are involved in a study it is possible for a drug to show a significant advantage, yet not be worth introducing. Significance is a technical term and it is possible to find an advantage of only 0.1% is ‘significant’, though it may not be worth taking such a product.

It was this confusion that bedevilled early experiments on ESP. Rhine in America and Soal in England recorded the success of subjects guessing unseen cards. The experimenters wrongly assumed controls were unnecessary; instead they compared guesses with a theoretical chance result. A few subjects scored correct guesses at slightly more than chance and because huge numbers of guesses were involved, statistical tests showed these results had ‘significance’. That is, there was a huge probability that the guesses were not simply ‘lucky’.

Enthusiasts then made the enormous leap to say that because the guesses were not due to chance they must be due to a previously undiscovered human faculty, extra-sensory perception or ESP. Disinterested observers, not just skeptics, should have concluded that other explanations, such as poor experimental design, badly recorded results, fatigue, or just plain cheating were more likely. A great deal of time, money and effort was spent pursuing this will-o’-the-wisp.

Placebos All in Researchers’ Minds?

The placebo effect has long been of interest to skeptics for its presumed role in alternative medicine. The Skeptics’ Dictionary (http://www.skepdic.com) has a lengthy entry, describing a placebo as an inert substance, or fake surgery or therapy, used as a control in an experiment or given to a patient for its probable beneficial effect. It goes on to add the effect has at least three components.

The first is psychological, due either to a real effect caused by belief, or to a subjective delusion – “if I believe the pill will help, then it will help.” Alternatively, the effect may be largely illusory – an illness or injury will often get better by itself, whether it is treated or not.

As a third alternative, the process of treatment, involving attention, care, and affection may itself trigger physical reactions in the body which promote healing, regardless of the nature of the treatment.

The second alternative has received a boost from a study published in May in the New England Journal of Medicine. Danish researchers Asbjorn Hrobjartsson and Peter C. Gotzsche performed a meta-study of 114 studies in which the experimental design included a genuine treatment, a placebo, and no treatment at all. In these studies, they found a slight effect of placebos on subjective outcomes, such as pain, reported by patients, but no significant effect on binary outcomes. Even the slightly positive subjective outcome result could be a reporting effect – patients want to please the doctor, so say they feel slightly better.

Reaction to the report has been mixed. Some researchers have said it confirms what they’d suspected all along, there is no placebo effect, it’s an illusion due to the simple fact that people often get better without treatment. Others argue that the metanalysis used is inappropriate for such a disparate group of studies. But however it turns out in the end, the affair raises some interesting points. One is the origin of the oft-repeated claim that, on average, a placebo effect will help 35% of patients. This has attained almost the status of an urban legend, but Hrobjartson eventually tracked its origin to a single 1955 paper in the Journal of the American Medical Association. Its author, Boston anaesthesiologist Henry Beecher, based his claim on a review of 12 studies, and, like other articles read by Hrobjartsson, it did not distinguish between the placebo effect and the natural course of the disease.

It’s hard to accept there is nothing to the placebo effect at all. There are reports of people developing addictions to placebos, or demonstrating adverse side effects, and trials showing patients with placebos do better than others simply left on waiting lists. But it’s a complex, multi-faceted phenomenon. If we are going to assert that an alternative health treatment is “just a placebo”, we need to be careful about what we mean by that. Does it mean the patient is experiencing a subjective delusion, or genuine healing through care and support, or simply going through the natural course of an illness? The Danish study won’t be the last word on this subject, but it has very nicely focused an issue which has had some very fuzzy edges.

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Forum

More Brocken sightings

I enjoyed Jim Ring’s “the Spectre of Kahurangi” (Autumn 2001). In Kahurangi National Park there is a bridge called “Brocken Bridge”, quite close to Ghost Creek. Could this be an indication of supernatural forces emanating from this enchanting region?

As a NZFS park ranger there for two years, I discovered a more prosaic explanation, at least for the bridge. It seems that someone stampeded a herd of cattle on to the old bridge during a flood, and the cattle – and bridge – were lost in the floodwaters. The name then became “Broken Bridge”. We Forest Service staff were not renowned for our literary skills, and various track junctions started sprouting signs saying “Brocken Bridge”.

Rather disappointing, really.

Piers Maclaren

Homoeopathy test?

As a result of an accident on State Highway One recently a quantity of rat poison was tipped into the sea near Kaikoura. At first sight this seemed to me to be Mother Nature setting up a large-scale test of homoeopathy. My reasoning was as follows: we have a poison diluted with an enormous volume of water (tides are strong and the sea very deep off the Kaikoura coast), and we have succussion (see the surf breaking over the rocks). The rat poison, brodifacoum, like the better known warfarin, is an anti-coagulant, causing death by extensive bleeding. So, by homoeopathic principles, a very high dilution should have the opposite effect, causing strokes and heart failure among the seals, dolphins and whales, brought on by clottability of their blood.

I could see that measuring this effect could be difficult, but I persisted with my calculations. Sadly, I abandoned the project, chiefly because the concentration of rat poison in the sea turned out to be far too high. The amount of material dumped in the sea, 18 tonnes, was quite large, and even allowing for only a low proportion of active ingredient in the bait, and assuming it to have been instantly and uniformly dispersed in deep water of some thousands of square kilometres in area, the final concentration was in the order of one molecule of poison in ten litres of sea. This is, of course, far too high for homoeopathic work, where concentrations of one molecule in a volume equal to that of the Earth are normal. Regretfully, I shall not be issuing an invitation to marine mammals to volunteer for a study of the after-effects of this accident.

Bernard Howard

Sensitive Issues

In the last issue of the Skeptic (Autumn 2001), I quoted the reaction of the Commissioner for Children, Roger McClay, to the news of Liam Williams-Holloways death:

“Whether a different course of action would have been better, there’s not much point in worrying about it now.”

That response troubled me as it seemed so out of character, so I rang the office and asked Mr McClay about it. It seems that news of Liam’s death was sprung on Mr McClay while he was at a conference and he was asked to comment on the spot. The news upset him but he didn’t think it appropriate to take the family to task at that time, and this was the result.

The question now is, having had time to think about the implications of the whole saga, what will the office’s/commissioner’s response be next time? We’ll get a chance to find out at this year’s conference when an advocate from the Office will be speaking, so come to Hamilton with your own questions!

Vicki Hyde

Rebirth of Quackery

G B Shaw once said that the only difference between animals and humans was that humans like taking pills. It’s clear things haven’t changed since his time when you visit a library and see the number of books on how to be healthy.

Many quack medicine producers have made their money here out of our gullibles and have moved on. Bowel cleansers, hair restorers, nail hardeners, bust developers and fat loss treatments to name a few.

As one example, Black strap molasses’s only virtue was that due to insoluble matter it acted as a bowel irritant with laxative results. Now if you have a lot of molasses left over from sugar refining, use it to make rum or stock lick and get rid of the rest as a good health supplement.

When deer lose their antlers in the wild they recycle them, but when farmed the antler is a dangerous weapon so they are removed at the velvet stage. Now because the Chinese have used them for medicine for thousands of years there is money to be made out of this by-product.

Bee keepers and retired politicians are extolling the benefits of pollen, bee venom and propolis. Their claims for vitamin, mineral and amino acid content are way over the top. All the bee venom rubs which claim to be the panacea of all our skeletal and muscular remedies have added counter irritants which give the impression that this wonder of bee venom is being absorbed, which fortunately it is not. Finally, we come to propolis, bee glue, a dark brown resinous substance collected by the bee from trees. This phenolic resin is used to seal the hive and retain warmth, the antispetic properties of the resin will have some effect in keeping the bacterial integrity of the hive intact.

These are but a few of the nonsense claims to which we could add, electrical devices, magnets, emu oil, homeopathics and a plethora of herbals. If proof of efficacy could be established then such items would be added to the orthodox medicinal armoury. Meanwhile remember “ashes to ashes and dust to dust, if the liquor don’t get you the free radicals must”.

Alan Pickmere, retired pharmacist

Because Cowards get Cancer too

Because Cowards get Cancer too, by John Diamond, Random House, 1998

So John Diamond is dead; at age 47 killed by his tongue cancer. He may not be well known in New Zealand, but was a popular newspaper columnist and broadcaster in Britain. Soon after developing cancer in 1997 he used his weekly columns in the Times and the Daily Telegraph to report the course of his disease. This book, written after he had endured some terrible experiences, appeared when he was still unsure whether he was “cured”. Of the many books I have reviewed, this is the first to bring tears to my eyes.

Of special interest to Skeptics is that, to put it mildly, he was critical of “alternative” therapies. “…where I stand on alternative medicine is roughly where the Pope stands on getting drunk on the communion wine and pulling a couple of nuns.” Because of his public position, his candour on this brought in many letters of advice and abuse. He was particularly enraged by those which told him to take “a positive attitude”, or to “take control of his illness”.

The trouble started with a lump. No need to worry, said the doctors, you have a 92% chance it’s harmless. Unfortunately, Diamond was of the other 8%. The lump became a tumour; no need to worry, said the doctors again, radiotherapy will give you an x% chance of a cure. Again unfortunately, Diamond was of the (100-x)%. And so, to the surgery, described in almost unbearable detail. Because of the effect of the surgery on his speech and ability to swallow, this man, who previously had spent much of his working day in a broadcasting studio or on the telephone, was reduced, in his words, to “a honking, dribbling fool”. A dreadful fate.

Despite the fact that conventional medicine did not, in the long run, save him, Diamond never accepted that alternative treatments would serve him better. Although he earlier admitted that, in extremis, he might visit “that well of alternative solace”, there is no sign that he ever wavered in his opposition to those he called “scatterers of pixie dust”.

Diamond’s writing is full of insights expressed with wit. What text-book could explain for the general reader the difference between cancer cells and normal cells as pithily as this:- “A cancer cell is the one that never grows up…[it] bears all the nastier traits of reckless youth…[a member] of some wacky religious cult obsessed with immortality.” And metastasis: “.. spreading the good word round the body…to share the secret of eternal cellular life with other cells.” These apparently light-hearted words were written by the “honking, dribbling fool”.

He disliked the warlike metaphors used in discussing disease; “battle” and “brave” he avoided in his writing, claiming that this stigmatised those who succumbed to the disease as cowards or losers.

The Canterbury Public Library has five copies of this book, and I have had to join a longish queue of borrowers. It is gratifying that the author’s views and experiences are being widely read; I hope readers are as impressed as I, and accept the message. No doubt some of us who hold “alternative medicine” in derision will also die of cancer. Let us look to John Diamond as our inspiration when courage and steadfastness may falter.

Telling Lies for Father Moon

Reviewed by Bernard Howard with acknowledgement to Ian Plimer

Icons of Evolution: Science or Myth? Why Much of What We Teach About Evolution is Wrong, by Jonathan Wells

This is an important book. Look out for it, for example, in places where young minds could be influenced, such as high school libraries, or other places where creationists might care to spend US$27.95. The text may be unremarkable, the usual misquotations, selective omission, distortions, etc. The important thing is the credentials of the author; surely the holder of a doctorate in biology from one of the USA’s finest universities cannot be wrong?

However, there is more to Dr Wells than his biography in the book tells. Thanks to some astute websearching on the part of the biologist who reviewed it for Nature, we are now aware of the following:

  1. Wells has been a member of the Unification Church (the Moonies) for upward of 25 years.
  2. He was chosen by the founder of the church, Sun Myung Moon, to study for a Ph.D., in preparation for his life’s work, destroying Darwinism.
  3. He appears to have gone through the entire post-graduate programme of course work and a substantial research project without his teachers or supervisor knowing of his beliefs and intentions.

Distasteful though it may seem, it could be possible for a student to go through an undergraduate course, passing examinations on existing knowledge without accepting its validity. The situation is greatly different when tackling a research project for a post-graduate qualification. Those of us who have been through this academic mill know the dedication required, not only of time, but of the mind, to the search for new knowledge. I find it hard to credit that one could do research in developmental biology, as Wells did, while believing that growth of a life is something quite different.

But perhaps one should not be surprised. With the example of Australian geologist Dr Andrew Snelling before us, who believes the Earth is billions of years old when writing for geological journals, but only a few thousand when concocting creationist literature, the capacity of creationists for deception or self-deception seems limitless.

In preparing this note, I am indebted to Dr J. Coyne, University of Chicago, for his excellent review in Nature, and for subsequent correspondence.

Forum

Chelation Study

Ian McWilliam’s comments on the Dunedin Chelation Study [Forum, September] indicates the many difficulties in understanding medical research papers. In consideration of his critique of the study:

Re the number of patients:

  1. Whilst 32 is not many, they were all typical claudication sufferers, being mainly smokers, male, and average age 67.

  2. Van Rij et al arrived at this number in the correct method: using “power” and type error and allowing for detecting a predicted significant improvement in the order of 10% in terms of walking distance. Thus the study would easily detect the sorts of improvement that would be clinically significant (ie the 50-100% touted by some chelation clinics).

Re Mr McWilliam’s doctor friend’s analysis:

  1. His statement that only 12% of the controls achieved 100% walking distance improvement versus 26% for the chelation group is poor presentation of statistics: We don’t know how many of the controls achieved 99% or similar walking distance improvement.

  2. Van Rij et al quote a change in the average walking distance to pain (ie how long before the patients stopped walking because of pain) in the order of 25 metres improvement for the controls verses only 12 metres for the chelation patients. In other words the chelation group did worse. An average is a better statistic in this case than the ones quoted by Mr McWilliam.

  3. Mr McWilliam’s statistical analysis (95% confidence limits) is irrelevant given no explanation of the statistical method used and who performed the test.

Comments that “Those who supply the expensive drugs, equipment and surgery would lose much if research into other simpler, less expensive…” ignores the extensive research by the “heart industry” into the likes of aspirin and warfarin, hardly expensive medications.

I have found the results of the Dunedin Chelation Study significant for my clinical practice: It has reaffirmed my clinical observation of several patients who have undergone chelation; they all feel significantly better for the extensive attention they receive and the improvements they achieve in their lifestyle — i.e. enhanced placebo effect. Unfortunately the cost of this “placebo” is excessive, its long-term effects questionable and I have a degree of unease when I consider the number of chelation-treated patients I have had die from their heart and circulation disease within two years following therapy.

Jim Vause, Blenheim

Hokum Locum

No Medical Ghetto

In the last issue I warned of the dangers of a medical ghetto developing on the Auckland North Shore. Fifty new doctors set up practice in Auckland last year and even more overseas doctors are pouring into New Zealand. There has not been a corresponding drop in consultation fees in a local aberration of the law of supply and demand. Fortunately, the Northern Region Health Authority has moved to cap any further increases in doctor numbers which have already cost an extra $20 million in subsidy claims. (Christchurch Press 24/4/95)

Dietary Delusions

Retired British policeman Peter Bennett claims that criminal behaviour can be controlled by dietary manipulations. Following a shooting spree in the US, an offender claimed that he was temporarily insane due to excessive dietary sugar (the Twinkies defence, named after a proprietary candy bar). After a special diet, it was claimed that nine recidivist criminals showed a dramatic improvement in behaviour.

Such claims have been made before in connection with children’s behaviour and shown in placebo-controlled trials to be wrong. What Mr Bennett has overlooked is that changes in diet are associated with a change in management, and it is this that has the effect rather than the diet. (Dominion 3/4/95)

Magic Mushrooms in Fiji

Following its importation by a soldier returning from overseas, Fiji has been in the grip of mass hysteria over the magical properties of a tea made from mushrooms. As with most other quack remedies it is claimed to cure everything from baldness to diabetes.

The mushroom, which looks like a bloated, gelatinous pancake, is floated in sweetened black tea and the fermented brew is drunk a week later. The brew is also known as “kombucha” and is gaining popularity in the US and some other Asian countries, and has been touted as an AIDS remedy. (NCAHF Vol 18, No 2) It is in fact a symbiotic colony of yeast and bacteria. I wonder how long before the brew arrives in New Zealand. (Marlborough Express 10/4/95)

Naughty Children?

Attention deficit disorder (ADD) is alleged to be an organically based condition where children are impulsive, overactive and have a short attention span. ADD has previously been known as minimal brain dysfunction, hyperactivity, hyperkinesis and Strauss syndrome, to name but a few.

In fact, ADD is yet another example of the expansionist activities of health professionals who “convert” ills into illnesses. This is the very activity which Illich warned about with respect to the medical profession.

ADD is far more likely to be simply a description of badly behaved children. Instead of concentrating on the behaviour (an effective strategy), people form support groups and look for organic causes which is a waste of time and resources. (GP Weekly 14/4/95)

Occupational Health Delusions

In a landmark decision, a company was fined after admitting a charge that they failed to take steps to protect an employee against occupational overuse syndrome. The employee had been in the new job for four days. I wrote to the company urging them to defend the case but they chose to plead guilty.

After this ludicrous decision I wrote to the Dominion but they chose not to publish my letter. I have also written to the occupational health publication Safeguard but I am not confident on seeing any expression of opposition to the absurd idea that anyone can develop OOS after four days in a new job.

There are, however, some glimmerings of understanding creeping into the literature. A judge in the UK rejected the concept of OOS and in the US a court rejected a claim that computer keyboard design causes it.

Writing in Safeguard (No.30 1995) Alan Boyd lamented the fact that ergonomic changes in the workplace had not lessened the prevalence of OOS. This is not at all surprising to me as no amount of ergonomic posturing can lessen the prevalence of a psychogenic (produced as a result of psychological stresses) condition such as OOS.

In Safeguard Update (27/3/95), Chris Walls acknowledges that anxiety and depression are common in New Zealand, affecting 13% of the population. Exercise is prescribed to relieve anxiety and reduce the chance of OOS. I find it ironic that in their own literature, all the clues are there for a proper understanding of OOS but occupational health workers continue to miss the bigger picture.

When a job becomes too difficult and less socially enjoyable, people start to focus on their symptoms. Attribution to work then means that the problem is the fault of the employer and the availability of compensation validates the “illness”. OOS can only be understood by looking at the historical record of psychogenic illness. This is brilliantly examined in a new book, From Paralysis to Fatigue by Edward Shorter (The Free Press, 1992) which is supported with superb clinical examples from the medical literature.

A striking theme is the gullibility of doctors who validated such presentations as fits and paralysis. It is interesting to find that patients have always resisted the concept of psychogenic illness and have tended to find more socially accepted labels. This is why neurasthenia has been replaced with chronic fatigue syndrome, and Charcot’s hysteria with other conditions such as total allergy syndrome and multiple chemical sensitivity.

I recommend this book to all readers interested in medical history. It should be required reading for health professionals.

The (Un)laying-on of Hands

A physiotherapy technique known as cupping has been suspected of causing the deaths of five babies and brain damage in eight others. The technique involves tapping the chest with a soft latex cup in an unproven method of clearing chest secretions. Like many physiotherapy techniques, this method of treatment has never been subjected to critical analysis.

The use of the term “cupping” for the procedure is a little unfortunate. Cupping used to be a medieval practice of applying suction cups to the skin to cause localised counter-irritation to some disease process or symptom. Acupuncture and moxibustion are other examples of counter-irritation quackery. Lancet 25/2/95 Vol 345 p510

Case-management Flunks

In the US, case-management became the central tenet of the care of people with severe mental disorders. The case manager takes a full and comprehensive responsibility for the client. This concept spread to the UK because it was believed to be effective.

However, a randomised trial found virtually no difference in outcome for case-managed clients compared with a control group. The authors concluded “it is unfortunate, in view of the limited effectiveness we have shown, that social services case-management was not evaluated in randomised controlled trials before its implementation in the UK.” (Lancet 18/2/95 Vol 345 p409-412)

Once again, this article demonstrates the absolute necessity of critically evaluating new treatments. This process should be extended to evaluate many of our existing treatments across the whole health area.

Udder Nonsense?

In a form of primitive immunotherapy, Herb Saunders injected his cows with patients’ blood and then sold the bovine colostrum (“first milk”) with the claim that it would cure cancer and other serious diseases.

Saunders sold each patient a cow for US$2500, but not only kept the cow on his farm but charged the patients $35 a bottle for the worthless nostrum. He was charged with practising medicine without a licence but the jury were unable to find a majority verdict of guilty. In my opinion Saunders was definitely guilty of milking his patients!

Chelation Abuses

The California Medical Board has been attempting to prevent the use of chelation therapy for unapproved indications. At a meeting, dozens of patients gave impassioned personal testimonials claiming cures after chelation treatment. It was noted by observers that the “tense atmosphere did not lend itself to rational decision-making.” Despite several impeccable trials that showed no benefit, chelation therapy continues to be offered in New Zealand.

With respect to the dramatic improvements claimed, it is more likely that there has been a fraud rather than a miracle. When confronted with the ravages of arterial disease, people often make profound health and lifestyle changes. They quit smoking, lose weight, exercise and make substantial changes to their risk-factor profiles. These same people are also the ones most likely to seek out chelation therapy. How ironic that they end up paying out thousands of dollars for a treatment whose benefits have been produced entirely by their own effort. (NCAHF Vol 18, No.2)

Pseudoscience in the FOREST

Lately — my last few airline flights — I’ve been listening to the in-flight comedy channels. This was how I discovered Bob Newhart and his monologues. These are things where he takes one side of a conversation and leaves you to imagine the rest. There’s one that shows up quite often, where he takes one side of a conversation with Sir Walter Raleigh, who has just discovered tobacco and is sending eight tons of it over to England as an early sample.

Now, as Newhart points out, the uses of tobacco aren’t exactly obvious: you stick it up your nose, or roll it up in paper, stick it in your mouth, set fire to it, and breathe in the smoke. One wonders exactly how these uses were discovered. But these days smokers are a persecuted species, we know that. And I have a suggestion: I think smoking should be reclassified as a religion. In some ways this is already beginning to happen in any case.

Take FOREST, for example. According to FOREST, there is no medically proven link between passive smoking and lung cancer. Twenty years ago, the tobacco industry generally was saying the same thing about smoking itself, even, as the 1970s book Smoke Rings points out, in the face of medical evidence showing the opposite. This article of belief is both pseudoscientific and incomplete: lots of other medical conditions such as heart disease and emphysema are either caused by or worsened by exposure to tobacco smoke, and the children of smokers are well known to have more bronchial and respiratory problems. But point this out, and you run the risk of being labelled a “health fascist”, although this term is mostly reserved for government ministers and doctors who set targets for reducing smoking.

Reclassifying themselves as a religion would solve a number of problems for smokers at a stroke. For a start, there could be no more talk of government proposals setting targets for reducing smoking: we don’t set targets for reducing the numbers of Jews, Christians, Muslims, or even Hare Krishnas, who like smokers practice their religion publicly and sometimes disruptively.

Medical practitioners who refuse to treat smokers for illnesses linked to smoking would be guilty of religious persecution. Better still, smokers could have their own medical practitioners, just like Christian Scientists do, who understand and cater to their religious practices.

Best of all from the smokers’ point of view, they would be able to make a persuasive argument that the government would have to stop taxing cigarettes and tobacco, since that would be equivalent to taxing religious practices. The money thus saved could be collected by the temples smokers would set up for their religious services (which would no doubt replace singing hymns with ritualistic smoking) and used to fund a variety of smoking community needs.

All this would have useful implications for other types of drug use and addictions. Marijuana smokers, for example, could claim status as a heretical sect, as could crack smokers (these might be the dangerous fanatics that all religions have to have). Alcoholics would have to found their own religion, of course.

All this would mandate changes for the self-help movement, too, some of which already has some religious aspects. Members of any 12-step program, for example, call on the help of a Higher Power (defined however each individual member likes, so it doesn’t have to be specifically a god-like figure) to help them stop doing whatever destructive things they’ve been doing — drinking, gambling, overeating, smoking, or inflicting their chaotic emotional states on their loved ones.

Such self-help groups rarely talk about scientific evidence: telling someone smoking or drinking is bad for them generally doesn’t help them stop in any case. They rely instead on shared experiences first of all to show that quitting is possible and second of all to help members with specific problems by giving them a chance to hear how other members have coped with the same problems.

In this sense, reclassifying smoking as a religious practice merely confirms the setup we already have, except that smokers and anti- smokers could battle it out among themselves without reference to anything or anyone else. They don’t need science for this, and don’t use it. The time society at large now spends getting wound up in these battles could be given to finding homes for the conscientiously objecting non-smoking children of smokers, say. Meanwhile, the tobacco industry would be saved a lot of marketing costs, since the temples would obviously want to do their own missionary work to find new members; they could take over the third-world outreach work already set in place by the tobacco companies.

They would do well to take as their role model in all this the Catholic Church, which deems the health risks of pregnancy and overpopulation irrelevant in its campaign against birth control on moral grounds. You’ll have to decide for yourself whether that’s better or worse than their present role model, which seems to be those creationists who insist that “evolution is only a theory” and classify their own theories as scientific.

Hokum Locum

MSG Myth Laid to Rest

Another sacred cow from my medical school days has been laid to rest. A letter in the New England Journal of Medicine in 1968 triggered a rash of anecdotal reports about facial flushing allegedly caused by monosodium glutamate (MSG) in Chinese food. “Chinese restaurant syndrome” had entered the popular medical mythology. Finally, 26 years later, two Australian scientists conducted a double-blind placebo controlled trial and found that some reaction to MSG was experienced by 15% of the subjects but the same reactions were also experienced by 14% of the placebo subjects. The scientists believe that the true cause of Chinese restaurant syndrome are histamine compounds found in fermented ingredients such as soy sauce, black bean sauce and shrimp paste. New Scientist 15 Jan ’94 p15

Poppycock

A US plastic surgeon found that the majority of his patients presenting for operative penile enlargement were motivated by anxiety over the size of their privy member rather than its performance. In fact one patient’s partner reportedly phoned the surgeon before her husband’s operation and told him she would rather have a fur coat! (GP Weekly) The procedure of penile enlargement was developed in China by the appropriately named Dr Long Daochou.

This absurd operation is not at all unusual in a culture where people also have silicon inserts into their muscles in order to look good at the beach. In fact, Ken and Barbie dolls are good models for such people who prefer plastic moulding to the real thing. Speaking of which, Barbie now has her own spiritual “channeller” (Barbie:”I need respect”!) and a “Barbie Channelling Newsletter”. Sadly, Barbie’s cries for help were treated with derision by Mattel Corporation who threatened the channeller with a multi-million dollar lawsuit. Sunday Star Times 5 June ’94

Naturopathology?

I was absolutely stunned to read in the Christchurch Press (12/8/94) that the Aoraki Polytechnic in Timaru is planning to offer a three-year Bachelor of Applied Science in naturopathy. Incredibly, the Qualifications Authority (QA) will be visiting the polytechnic to assess the course. The list of “basic sciences” to be studied includes herbal medicine (Kentucky fried medicine) and homeopathy (dilutions of grandeur). Is there anyone out there with any influence on the QA? Should market forces be allowed to dictate what constitutes a “basic science”? These are serious questions.

Psychobabble?

Can anybody help me come to an understanding of post-traumatic stress disorder (PTSD)? I know it is the new term for what used to be called “shell-shock” but can anyone tell me if the condition is seen in societies which do not have compensation available and are therefore not subject to Welch’s law (see NZ Skeptic 32).

Three passengers on the cruise liner Mikhail Lermontov were awarded a total of nearly $300,000 compensation for PTSD and a further 18 plaintiffs are waiting for their pot of gold. In order for PTSD to have a valid aetiology there must be an equal incidence of cases in the NZ passengers.

I briefly mentioned similar cases related to military service (NZ Skeptic 32) and most people will have heard about “Agent Orange” and alleged links with ill-health in Vietnam vets. It proved cheaper for the manufacturer to settle out of court but this decision has now entered the popular mythology as proof of causation.

Gulf War veterans (something of a misnomer since very few saw any active service) are claiming that symptoms such as fatigue and memory loss constitute a syndrome for which they will no doubt be claiming compensation. (NZ Skeptic 31) I have been following this saga in the medical literature, and investigators are coming up with ever more fanciful theories to explain what is nothing more than mass hysteria. Christchurch Press 14/6/94

Medical News

A therapist who become famous through treating Diana, the Princess of Wales, has been ejected from his Harley St consulting rooms because his claimed medical qualifications were found to be bogus. Presumably he must have had some success with his treatments but the real Harley St doctors were offended and he had to go. What about the opposite situation — real doctors who persist in offering bogus treatments? We have plenty of these in New Zealand and a medical registration system which can do absolutely nothing about the situation!

There will be no sensible policy on smoking in Israel because the acting health minister, Prime Minister Rabin, is a chain-smoker and refuses to sign a bill prohibiting smoking in public places!

Finally, a common inclusion in 17th century Dutch paintings of women visiting the doctor is a charcoal burner and string. The string was burnt near the nose of hysterical women so the fumes can drive the “wandering uterus from the woman’s upper body back to its proper place in the pelvis.” A quaint theory which has been replaced in our time with food and multiple chemical allergy, RSI, CFS. Have we made any progress? Lancet Vol 343 p 663, BMJ Vol 308 p606, International Express 31/8/94.

Mass Hysteria

Some of you will have noted the derivation of hysteria from the Greek “hysteros” for the female uterus which was thought to wander about the body causing hysteria.

Many of you will remember two cases in the US (where else?) where “poisonous” patients caused ill-health to their medical attendants. The first case concerned a 31-year-old woman receiving chemotherapy for cervical cancer. Following the taking of a blood sample in the emergency room, a nurse noted a smell and promptly passed out followed by other emergency team members. Following exhaustive tests no toxic chemical was found and I quote “no one seems to have seriously attributed the mystery illness to hysteria”. The second case followed a similar course.

Both of these cases are in fact classical examples of mass hysteria which is an unfortunate term with connotations of misbehaviour. Mass hysteria is better described as a contagious psychogenic illness. Psychogenic refers to the production of physical symptoms under conditions of stress and should not be confused with neurosis or malingering. The classical sequence of events begins with a generalised belief about a toxic substance in the workplace followed by a precipitating event, typically, as in the above example, a smell. This perceived threat to health and safety leads to psychological arousal and typical symptoms and signs such as dizziness and fainting. There have been many examples of mass hysteria in New Zealand — the Parnell civil defence emergency 1973 (NZ Med J April 28 1982 p277 and also Australian and NZ Journal of Psychiatry 1975 9:225) and the ICI Chemical fire. Occupational overuse syndrome and sick-building syndrome are good examples of mass hysteria in the workplace.

See Scand, J., Work Environ Health 10 (1984) 501-504) for a good review on the subject.

Bioenergetic Medicine

An advertisement for a course in bioenergetic medicine in GP Weekly (25/5/94) recently caught my attention. The location was the same place where I did a week-long basic acupuncture course in 1987. I spent a week and about $1,000 in total expenses learning a practice which is totally unscientific and can be taught in about half an hour to any intelligent skeptic.

During my course the tutor introduced a market-gardener with alleged “allergy” to tomatoes. The patient was connected up to a Vega machine or equivalent and we were given a demonstration of how his muscle strength was diminished when exposed to the killer tomatoes. A container of steroid was then introduced into the circuit and the muscle “weakness” was cured.

Unfortunately one of the other skeptics in the room had actually removed the vial of steroid from the box and revealed it at the conclusion of the demonstration. Incredibly, the tutor was unfazed and attributed the “improvement” to steroid residues (presumably homeopathic) in the box! Truly a graphic demonstration of the power of belief, one which got me interested in active skepticism as a scientific philosophy highly relevant to my own chosen area of medicine.

I suspect that bioenergetic medicine is very similar to applied kinesiology (AK) where muscle strength is tested while a person is subjected to various influences such as foods, vitamins, homeopathic remedies etc. Controlled studies of AK have repeatedly shown that responses are random under conditions where both tester and test subject are unaware of the substance being tested. My own anecdote is a good example of this. NCAHF Vol 17 No 3 has a brief overview

Fraudulent Food & Drink

Yuri Tkachenko, of the resort town of Sochi, has been given permission by city authorities to “magnetise” the Sochi river and thereby lessen the flow of pollutants into the Black Sea. As the river water quality is obviously a little suspect you might like to try some of his “magnetic” vodka which is guaranteed not to cause hangovers.

On the other hand, if you are mainly worried about getting rid of heavy metals, look no further than a new Hungarian oat-bran extract guaranteed to soak up lead and radioactive strontium carried in the blood stream. The pill, Avenan, has been developed by Lajos Szakasi who needs few lessons in the marketing of quack remedies. Avenan will go on sale as a health supplement rather than a medication because “it can be approved after a simple registration procedure”. To quote Lajos again “I believe the product will be successful because…people will always spend on their health.”

More fantastic still is a report from Japan where Kazu Takeishi has been arrested for giving medical advice and medicines without being properly qualified. It all began with his “healthy” vegetable soup which can be mixed with urine to become a miracle medicine, particularly effective against AIDS and cancer. Kazu claimed to make his diagnoses by touching patients’ knees and the palms of their hands. Like all good quacks Kazu is sure of his market and it’s a good one — $30,000 a day and a two-month waiting list (must have been getting behind on the urine supply). Cancer is a taboo subject in Japanese culture and doctors are even protected in law from informing patients about such a diagnosis.

Now, if I could get the recipe for this soup, I could mix it with urine and treat cancer patients for $300 per consultation and there is nothing the medical council can do — because I’m a doctor!

Scary Headlines, Dodgy Science

The New Zealand Herald of 5 September carried the headline “Ozone gap to lift skin cancer 7 per cent”.

Then followed a report from Dr Richard McKenzie of the National Institute of Water and Atmospheric Research at Lauder. He said that ozone loss in the past 15 years had caused an increase of 8-10% in the amount of harmful ultraviolet rays reaching Otago and Southland, and that UV levels were expected to rise another 2-3%, reaching a peak in about five years.

So far so good. We have no reason to question the quality of the research and his findings that ozone depletion over the southern region has increased UV penetration over the South Island plains. But Dr McKenzie is then reported as saying that:

Cancers caused by past depletion were only now beginning to appear as the disease often developed some years after exposure to the rays.

And that:

Small changes in UV can have large effects on life. There will be extra skin cancers and earlier deaths will result.

Surely Dr McKenzie has moved beyond his field of expertise. The recent increase in skin cancer is almost entirely attributable to the craze for sun-bathing and sun-tans which began in the 1920s and reached a peak during the early ’70s. Any impact of increased ultraviolet penetration is insignificant when compared to this “life-style” choice which encouraged young children to play at the beach all day, fully exposed to the sun, and teenagers to bask in full summer sun for hours on end in their quest for the perfect tan.

Furthermore, changes in the level of ultraviolet light reaching the ground are much more dependent on cloud cover, general atmospheric pollution, and geographic latitude than on any recorded or predicted variations within the ozone layer. A move from the Arctic to the equator increases annual exposure to UV by 4,000%. If Aucklanders are worried about a 10% increase in UV penetration they should move 200 km south to, say, Taupo.

I am prepared to bet $1,000 to $1 that there will be no increase in skin cancers attributable to increased UV over the next few years. The increases which occur will be attributable to the sun-burned baby-boomers growing up and contracting melanoma. This will peak and decline as a new generation of parents encourage their children to wear hats and use sun-blocks.

If Dr McKenzie can set up an experiment using a control population which stays where it is, in an atmosphere which remains as clear as it is today, and in which no-one reduces their exposure to intense sunlight or increases their use of sun protection, then that population might record the increase he forecasts. But such an experiment would be totally unethical, so the predicted outcome cannot happen. Hence my confidence in the bet.

In an interview Dr McKenzie conceded he was no expert in public health. Maybe he should have stuck to his field and let someone else draw the public-health conclusions. People have to deal with daily predictions of doom from all directions. There is no need to add a fear of UV-induced melanoma epidemics to the list. His forecast sounds unavoidable — and it’s not.

Bruce Ames: Environmental Prophet or Apostate?

What is the link between chemicals and cancer?

Forty years ago, Bruce Ames was a young microbiologist working at NIH in the day and enjoying Scottish country dancing in the evening, when he had an inspiration: to use the rapid growth of bacteria as a method for determining whether a particular chemical was able to cause mutations. If the chemical was positive — i.e., was mutagenic — it might be considered as a possible cause of cancer. This method, soon called “the Ames test”, became widely used. It was cheap, fast, and sensitive. One of the first discoveries was that a dye commonly used in children’s pyjamas had mutagenic properties. Bruce Ames became a hero to the environmental movement when he led a successful campaign to ban such dyes.

Ames was more interested in reducing the death toll from cancer than he was in attacking new chemical technology. As more results from the Ames test accumulated, he realised that many naturally occurring chemicals were also giving positive results. Even more disturbing, the number of chemicals that seemed to be positive in high-dose tests on mice and rats was, he felt, excessive. In an extensive series of important reviews, published in prestigious journals such as Science and Proceedings of the National Academy of Sciences, he has attempted a quantitative estimate of the difference in human cancer. Because his figures show manmade chemicals in food and the environment to be quite insignificant compared to natural or self-inflicted factors, the name of Bruce Ames is now anathema to the same environmental movement that once applauded him. Nevertheless many professional scientists believe that Ames’ position is basically correct. If the inventor of the Ames test now says that most methods for detecting carcinogenicity are invalid, it is certainly not a case of sour grapes. This article is an attempt to summarise his beliefs. Those who are sufficiently interested should read some of the papers listed in the bibliography.

(1) What do we know about the incidence of cancer?

First, cancer risk increases according to the 5th power of age. That is, a 40-year-old is 100,000 times more likely to be cancerous than a 20-year-old. There are more cancer cases per 100,000 population simply because we are living longer and no longer dying of infectious diseases.

Second, the age-corrected mortality (death rate) from cancer has been declining since 1950 except in those over 84. Overall decline has been 13%. Naturally much of this decline is caused by improved detection and treatment. The only exceptions are lung and skin cancer, clearly caused by tobacco smoking and by increased exposure to sunlight. There are occasional claims that certain types of cancer are increasing slightly, but improved methods for detection are probably responsible.

Thirdly, some mostly unknown environmental factors have a major influence on the types of cancers that are likely. Japanese, for instance, have a high incidence of stomach cancer, yet Americans and Japanese-Americans have a low incidence. On the other hand, American men have much more likelihood of prostate cancer than do Japanese.

(2) What are the major known causal factors in cancer?

The single most important factor is smoking. This accounts for one-third of all US cancer deaths, not to mention one-fourth of heart disease. Each year, smoking causes 400,000 premature deaths in the US and 3 million deaths around the world.

Chronic infections contribute to about one-third of cancer on a world- wide basis. As mentioned below, any factor that causes body cells to divide increases the likelihood of cancer. Hepatitis B and C infect 500 million people, mainly in Asia and Africa. This liver infection is a major cause of “hepatocellular carcinoma”. Two different Schistosomiasis worms infect Chinese colons and Egyptian bladders, being associated with increased cancer risk in those two organs. Liver flukes cause chronic inflammation of the biliary tract, hence risk of cholangiocarcinoma. A bacterium, Helicobacter pylori, is adapted to living in the human stomach and is now believed to be a major cause of stomach cancer, ulcers and gastritis. (So much for the classical psychogenic explanation for ulcers!)

Overall about 70% of cancers might be caused by environmental factors, but pinpointing the exact causes is very difficult. There remains some 30% that cannot be ascribed to any factor other than age and bad luck.

(3) How does cancer develop?

The first requirement is that a dividing cell suffer some sort of damage to its DNA. (DNA is the basic material of our genes.) DNA damage occurs all the time, but our bodies have excellent repair mechanisms to detect and destroy damaged DNA. Based on the amount of DNA breakdown products in the urine, Ames and co-workers estimate about 10,000 “hits” on DNA every single day in an adult. These repair mechanisms are not 100% perfect, and some damaged DNA does escape.

DNA damage is mostly caused by oxidants. The oxidants in turn arise from both internal and external sources. Internal oxidants come from mitochondria, peroxisomes, cytochrome P450 enzymes, and phagocytic destruction of infected cells. The production of oxidants when infected cells are destroyed may be a factor in the connection between chronic infection and cancer. External sources of oxidants include the nitrogen oxides of tobacco smoke, iron and copper salts, and natural plant phenolics like chlorogenic and caffeic acid.

If oxidants are bad, then antioxidants should be good. They are: antioxidants protect against disease. Natural antioxidants include ascorbic acid (vitamin C) and tocopherol (vitamin E). Synthetic antioxidants are also good. One worker estimated about 5% reduction in cancer because of approved antioxidants added to our food.

The health benefits of antioxidants, provided mostly by fruits and vegetables, are statistically highly significant. The quarter of the US population with the lowest intake of fruits and vegetables has double the cancer rate of the quarter with the highest intake. This applied to “epithelial” cancers (lung, mouth, larynx, oesophagus, stomach, pancreas, cervix, bladder, and colorectal) plus ovarian cancer. Breast and prostate cancer, on the other hand, is less affected by fruit and vegetable diets. (Although there is at least a statistical link between fat/calorie intake and breast cancer.)

Persons taking daily tocopherol or ascorbate had one-third the risk of developing cataracts. In contrast, smoking and radiation (both well known oxidative stresses) are strong risk factors for cataracts. Smoking seems to destroy ascorbate: smokers need to take double or triple amounts of ascorbic acid to achieve the same blood levels as non-smokers. Incidentally, smoking by the father seems to affect sperm production and health; smoking fathers increase the risk of birth defects and childhood cancer in their offspring.

Excess food, at least in rats, is “the most striking rodent carcinogen ever discovered”. Even a 20% increase in calories over the optimal results in shorter life, with more endocrine and mammary tumours.

Excessive cell proliferation (cell division) is a very important factor in cancer production. This has been mentioned above in relation to chronic infection. Major dietary factors, such as salty pickles in the Japanese diet, have been hypothesised to be involved in the high rates of stomach cancer in this population. Even table salt, at high enough concentrations, can cause stomach cancer.

That cell proliferation predisposes to cancer is a major source of false positives in chemical screening as normally carried out. Test chemicals are repeatedly applied to animals at the “MTD” (maximum tolerated dosage). This is like chronic wounding, “which is known to be both a promoter of carcinogenesis in animals and a risk factor for cancer in humans”. Many chemicals that purportedly have caused cancer at high dose (MTD) levels, may therefore not be true carcinogens. The infamous saccharine tests are a case in point: only female mice dosed with nearly toxic levels of saccharine showed an increase in bladder tumours.

For these chemicals that “cause cancer” at high doses only by tissue irritation, a tenfold reduction of dose in a rat or mouse experiment would show much more than a tenfold reduction in risk. This seems to have been confirmed. One analysis of 52 tests showed that two-thirds of the purportedly positive results for carcinogenicity would not have been found if the dosage had been cut even by one-half! (I suspect that commercial cancer-screening laboratories get new contracts in direct relationship to how many “successes” they have had previously.)

(4) How do synthetic and natural chemicals line up as causes of cancer?

The conventional cancer-screening techniques are, as stated above, too sensitive. There are not merely a few chemicals that show up as carcinogenic. Instead, nearly one-half of all chemicals tested seem to be positive in these tests. The ratio is the same for both natural and manmade chemicals, even though very few natural chemicals have been tested. Thus we cannot generalise that natural chemicals are inherently safer or riskier than synthetic chemicals. We must look instead at the quantities of chemicals ingested.

Plants contain surprisingly large quantities of natural pesticides. One of Ames’ greatest achievements, in my opinion, has been to compile convincing evidence about how many natural chemicals have pesticidal functions. (In my youth, the question of the function of different “secondary” plant products was much debated. Some thought that products like alkaloids and lectins were mere accidents of metabolism, a plant process gone wild. I personally thought that the main role of these chemicals was to provide research material for young biochemists.) Ames pointed out that up to 5% of the fresh weight of vegetables can be natural pesticides.

The list is very long, and a sample limited just to non-toxic plants would include: the sharp flavours of mustard and other cabbage-family crops; piperine (10% of weight of black pepper); light-sensitising psoralens in parsnip and celery; chlorogenic and caffeic acid in coffee beans; nerve-poisoning alkaloids in potatoes, tomatoes and eggplants. The cat-attracting chemicals in catnip are actually very good insect repellents. The vast majority of plants are inedible by us. Even so we are at risk of poisoning if cattle or sheep graze on them. Abraham Lincoln’s mother died when she drank milk of cows that had grazed on snakeroot. A California infant was born deformed when fed milk from a goat that had been eating lupin. The concept that “natural is harmless” is simply false.

Ames has published numerous estimates of the amounts of natural pesticides that we eat every day. He calculates that we eat about 10,000 times more natural pesticides than synthetic pesticides. More usefully, he and his coworkers have attempted to estimate the relationship between the amounts of different chemicals we are exposed to, and their potency as carcinogens. After all, it is the dosage that makes the poison, to coin a phrase. Some of his calculations are shown in Table 1, rewritten from Ames et al., 1987. The last column (HERP%) is a relative risk. A 5% HERP doesn’t mean a 5% risk of cancer!

Material Carcinogen, dose to 70kg person Rodent Potency Risk (HERP%)
Tap Water Chloroform, 85 ug 90 0.001*
Contaminated Well water Trichloroethylene, 2800 ug 940 0.004
Home air Formaldehyde, 598 ug 1.5-44 0.6
PCB’s, daily PCB’s 0.2 ug (US average) 1.7-9.6 0.0002*
DDT/DDE, daily DDE, 2.2 ug (US average) 13 0.0003*
Bacon, cooked Nitrosamines, 0.4 ug 0.2 0.003-.006
Peanut butter Aflatoxin, 64 ng/sandwich 0.003 0.03
Brown mustard Allyl isothiocyanate, 5 mg 96 0.07
Mushroom, 1 raw Hydrazines 20-300 0.1
Beer, 350 ml Ethyl alcohol, 18 ml 9110 2.8*
Wine, 250 ml Ethyl alcohol, 30 ml 9110 4.7*
Comfrey-pepsin tablets, 9/day Comfrey root 626 6.2
Diet Cola, 350 ml Saccharin, 95 mg 2143 0.06*
Phenacetin pill Phenacetin, 300 mg 1246-2137 0.3**
Phenobarbital, 1 sleeping pill Phenobaribital, 60 mg 5.5 16***
Formaldehyde, industrial Formaldehyde, 6.1 mg 1.5-44 5.8
EDB, industrial exposure Ethylene dibromide, 150 mg 1.5-5.1 140

Table 1: Calculated risk factors for common chemicals.
* Material not believed to be gene-damaging; that is, acting as a carcinogen only by irritation or damage at high concentrations.
** Some evidence for increased kidney (renal) cancer after long-term use.
*** Apparently no cancer risk to people taking it for decades.

How then do these theoretical risks relate to the “real world”? A few links can be found. There have been perhaps dozens of cases of liver damage from comfrey-pepsin tablets, although this has been as “hepato-occlusive disease” rather than cancer. These comfrey-pepsin tablets have a risk factor (HERP%) of about six.

Although alcohol is a low-potency carcinogen, large quantities are consumed by some people. Alcoholics have significantly increased risk of cancer in the mouth and throat. Thus HERP’s around five seem to be genuine risks. On the other hand, the HERP value of 16 for one phenobarbital sleeping pill is apparently not connected with any risk of cancer. (Note that phenobarbital is one of the numerous so-called carcinogens that shows up as positive only at tissue-irritating concentrations.)

One interesting point is that TCDD (the dreaded “dioxin” of milk cartons and teabags) is known to cause most of its effects by reacting with an animal component called “Ah receptor”. There are chemicals in broccoli, mainly indole-carbinol, that also react with the Ah receptor. Both chemicals can protect against cancer if administered before challenge with a carcinogen. Both chemicals can promote cancer if administered after the carcinogen has already acted.

Taking potency into account, a 100 g portion of broccoli has 20,000 times more effect on the Ah receptor than a legally allowable TCDD intake of six femtograms/kg/day. (Perhaps it is not surprising, then, that experiments in which rats given a carcinogen were protected by including broccoli or cabbage in their diet. There is evidence that humans too are protected by these vegetables: People who are high-crucifer eaters are significantly less likely to wind up in cancer wards.)

(5) How pesticide regulations and chemical scares diminish public health.

Diet is one of the key routes to better health. Only 9% of the US population eats sufficient fruit and vegetables, higher consumption of these would decrease cancer as well as other diseases. There is plenty of margin to increase fruit and vegetable eating.

To discourage consumption of vegetables and fruits is to diminish public health. Excessively strict limits on harmless levels of synthetic pesticides act to increase vegetable and fruit prices, by reducing production and by increasing cost of production. Thus these regulatory restrictions may well be harming health rather than helping it.

Similar comments could be made about the attacks on Alar a few years ago, when apples disappeared from the lunchboxes of many children.

This then is one reason why Bruce Ames is hated by many “environmentalist” groups. He has shown that they are, in all likelihood, damaging public health under the guise of protecting it against non-existent or unimportant risks.

Acknowledgement:

This review was inspired by an article by Dr Arthur B Robinson in Access to Energy, April 1994.

References

B.N. Ames. 1983. Dietary carcinogens and anticarcinogens. Science 221: 1256-1262.

B.N. Ames, R. Magaw, and L.S. Gold. 1987. Ranking possible carcinogenic hazards. Science 236: 271-280.

B.N. Ames and L.S. Gold. 1990. Environmental pollution and cancer: some misconceptions. In: Science and the Law (Ed. Peter Huber).

B.N. Ames and L.S. Gold. 1990. Too many rodent carcinogens: mitogenesis increases mutagenesis. PNAS 87: 7772-7776.

B.N. Ames, M. Profet and L.S. Gold. 1990. Dietary pesticides (99.99% all natural), mitogenesis, mutagenesis, and carcinogenesis. PNAS 87: 7777-7781.

B.N. Ames, M. Profet and L.S. Gold. 1990. Nature’s chemicals and synthetic chemicals: comparative toxicology. PNAS 87: 7782-7786.

B.N. Ames, M.K. Shigenaga and T.M. Hagen. 1993. Oxidants, antioxidants, and the degenerative diseases of aging. PNAS 90: 7915-7922.

B.N. Ames. n.d. Does current cancer risk assessment harm health? Published by The George C Marshall Institute, 1730 M Street, N. W., Suite 502, Washington, D. C. 20036-4505. ($US 5.00) [Not seen by me yet — JDM]