Trawling through my ‘blogging’ folder, wondering what to write about, I came across a paper from the New England Journal of Medicine that discusses problems with contaminated dietary supplements in the US (Cohen, 2009). I’ve previously written about the recall of ‘natural’ treatments for impotence, & Grant’s talked on more than one occasion for the need for ‘truth in labelling’ for such supplements & other forms of complementary & alternative medicine. So I thought it was about time for a follow-up.

Every so often the issue of regulating complementary & alternative health products comes to the fore in NZ. And when it does there are usually fairly strident arguments made against the suggestion. I’ve never really been able to understand why, given the evidence that these products can be adulterated, or aren’t standardised in terms of dosage. I’m also at a loss to see how some (many?) of these products can be described as ‘natural’, and held to be much better for you than those made by ‘Big Pharma", when in fact they’re often (as we shall see) not all-natural & also often produced by the same pharmaceutical companies that make prescription drugs.

Cohen’s paper begins with the cautionary tale of an American police officer who took what was presented as a ‘natural’ weight-loss supplement to help him lose some excess kilos. The supplement also lost him his job – it contained amphetamine, which was detected in a routine urine test & led to him being fired. Apparently, by August 2009 the US Food & Drug Administration had identified more than 140 ‘natural’ products containing active pharmaceutical ingredients, most of them marketed as dietary supplements – & this is regarded as the tip of the iceberg.

Apparently, before 1994 herbal products fell under the rubric of food additives; manufacturers had to prove their products were safe before they could market them. These days, since the 1994 US Dietary Supplement Health & Education Act, it’s assumed that supplements are safe & there’s little control over their marketing. However, it seems that this deregulated environment isn’t well understood by either consumers or doctors. The majority of consumers believe that the supplements they take have been approved by the relevant government agency, & must carry warning labels about any side effects that may exist. (The absence of such warnings is then taken to mean that the product is safe, where in fact they may simply be missing.) Similarly, a survey of doctors in training found that a large minority also believed that the products had to have FDA approval, while most didn’t know that adverse events had to be reported to the FDA.

Cohen’s list of contaminants found in ‘health’ products on the US market is alarming. While poisonous plant materials, heavy metals, & bacterial contamination are commonly found, what’s even worse are the many supplements – touted as ‘natural’ – that contain ‘prescription medications, controlled substances, experimental compounds, or drugs rejected by the FDA because of safety concerns’ (Cohen 2009). They’re most often detected in products sold to enhance sexual or athletic perfomance, or for weight loss but are also found in supplements aimed at people with serious health concerns, such as diabetes. In the light of all this I find it more than a little ironic that a New Zealand natural health products website – arguing against regulation of these products in NZ – says that "the status quo, mirrored in the USA, has been shown over many years to be safe, inexpensive and efficacious. Existing legislation protects consumers from dangerous products and misleading advertising." As Cohen has pointed out, this is a long way from reality. 

Given patients’ tendency not to tell their GPs what supplements they are using (unless the doctor asks fairly specific questions), & the fact that some supplements can act as antagonists to prescription medicines**, & that the contaminants themselves can have serious health effects, such widespread contamination may well represent a significant public health risk in the US (where it’s estimated that 114 million Americans use some sort of dietary supplement: Cohen, 2009)). And in New Zealand. You might argue that ‘our’ products are much better formulated – but remember that many supplements are readily available on-line from overseas sellers, or are imported from overseas and, as the recent withdrawal of sexual enhancement products shows, may be subject to the same serious problems as those discussed by Cohen.

Personally, I think there’s a good argument for regulation of dietary supplements & other over-the-counter health products. You may argue that it’s a case of ‘buyer beware’ & individual freedom to choose – but there’s likely to be a significant cost to the individual and to the public health service when (& it is when, rather than if) things go wrong.

** For example, Oneschuk & Younus (2008) note that while some ‘natural health products’ may have the potential (based on animal & in vitro studies) to help cancer patients manage the side effects of chemo- & radiotherapy, others significantly reduce the effectiveness of chemotherapeutic drugs.

PS (23/06/2010) Anyone interested in a more detailed coverage of the US situation should have a look at Steven Barrett’s post on Quackwatch.

P.A.Cohen (2009) American roulette – contaminated dietary supplements. New England Journal of Medicine 361(16): 1523-1525. doi 10.1056/NEJMp0904768

D.Oneschuk & J.Younus (2008) Natural health products and cancer chemotherapy and radiation therapy. Oncology Review 1: 233-242. doi 10.1007/s12156-008-0028-6 

In another few weeks it’ll be 27 years since my mother died of metastatic breast cancer. Not a nice way to go – but eased by a very caring family GP and the wonderful people at the local hospice, who helped her die with dignity at home.

I was reminded of this by reading David Gorski’s recent post on Science-Based Medicine: chemotherapy vs death from cancer. In the US at least (although I suspect here as well), ‘alternative practitioners’ offer a wide range of ‘therapies’ for people with cancer, claiming ‘natural cures’ & the option of ‘dying healthy’ if you must die at all. Unfortunately for those choosing this option, modern chemotherapy really is the best treatment option for many cancers (alongside radiotherapy & surgery, depending on how the disease manifests itself). If those alternative therapies worked they’d have become part of the mainstream pharmacopaeia by now. Dr Gorski agrees that yes, chemo can be quite brutal in its effects – but the cancers it is aimed at are at least as bad. (The reason chemo can have serious side effects is that it’s a fine line between killing the cancerous cells & killing normal tissues.)

Anyway, Dr Gorski’s article led me to think about the way that other proponents of ‘alternative therapies’ make special claims for their own products, and level all sorts of accusations against mainstream medicine. Over on SciBlogs, for example, a local anti-vaccination advocate was quoted in the comments thread for an article on vaccination that the sooner New Zealand drops all vaccinations, the better. In support of their views that vaccinations are Bad, Bad, Bad, the commenters on that thread trotted out all the usual claims: that vaccines cause autism (false – there are no data to support this claim); that vaccines contain ‘neurotoxic’ materials including formaldehyde (true, but our bodies make far more of this, during normal metabolic processes, than is contained in any dose of a vaccine); that vaccines contain ‘aborted foetal tissues’ & ‘monkey kidneys’ (serious scare tactics, these, & also false). These claims have been ably addressed elsewhere, both on SciBlogs & on overseas sites such as Science-Based Medicine & Orac’s Respectful Insolence.

But I wonder - do the people advocating a complete cessation of vaccination really seriously think about the consequences of this? My mother contracted polio as a teenager in the 1930s. She was lucky – the virus ‘only’ paralysed nerves in her hand and leg. She recovered, but for the rest of her life the muscles in those areas were smaller & weaker than on the unaffected side. She never had to spend time in an iron lung – and at the height of polio epidemics, some overseas hospitals had entire wards devoted to patients in these machines, which ‘breathed’ for people who could no longer breathe for themselves because the necessary muscles were paralysed. Mortality rates from polio – before the widespread availability of a reliable vaccine – were around 5%, with a further 35% of those infected suffering some level of paralysis.

Or what about diphtheria? The mortality rate for this bacterial disease is between 5 & 10%, & outbreaks still occur, even in industrialised nations. Diphtheria often has respiratory symptoms, due in part to severely swollen lymph nodes in the neck. But the bacterium (Clostridium diphtheriae) also produces metabolic by-products that can lead to damage to the heart & nerves, & it can sometimes cause serious secondary infections in the skin.

And there’s measles, whooping cough, rubella – while in the industrialised world, with its generally good provision of health care, most of those who contract these infections go on to recover, they are not trivial diseases. (I couldn’t believe one comment I read a few months ago, where the writer commented that whooping cough was a trivial illness; her child had ‘only’ had a serious cough for a week… & was unwell for several more.) All have a rate of serious complications, including death, that is several orders of magnitude higher than the unquestioned rate of complications due to vaccination.

And I wonder – are people so ready to advocate a return to a world where these diseases are common because they’ve never had first-hand experience of the effects? After all, the highest rates of illness occur in the ‘third world’, which is a long way from the experiences of most people in comfortably first-world New Zealand. And is part of it due to a failure on the part of scientists, doctors, the education system at large to help people understand things like relative risk, and how science-based medicine operates? And – a key part of this – how well do we communicate the idea that correlation does not equal causation: that because B happens soon after A, for example, this is not proof that A caused B?

I think we still have a long way to go on these things.

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PS And those with a genuine interest on what <i>is</i> in vaccines (as opposed to the wilder claims being made over at Sciblogs) might like to read this post from ERV:  – basically a group of researchers did DNA analysis on most of the main vaccines, looking for evidence of contamination from other sources (monkey tissue, foetal tissue, etc etc). The result: modern vaccines are clean.