Posts Tagged health & medicine

are ‘alternative medicines’ really free of side effects? Alison Campbell Dec 16


Not necessarily. OK, most homeopathy’s just water (or sugar pills), but if a non-self-limiting disease goes untreated because someone is relying on homeopathy then, yes, this ‘remedy’ could be said to have side effects.

Similarly, using powdered rhinoceros horn – prescribed as an oral dose in Traditional Chinese Medicine – is unlikely to have side effects on the dosed individual; after all, we can’t digest keratin. Which makes this quote, from a post at, all the more poignant as it focuses attention on the wider impacts of magical thinking:

A common defense of Alternative Medicines is that they are side effect free. While the consumption of a tea made from a small piece of powdered rhinoceros horn may be as harmless and ineffective as biting your own fingernails, the side effects are far reaching and will be obvious for future generations who only know the rhinoceros from plaster molds along side those of dinosaurs in museums.


credulous reporting around cancer Alison Campbell Dec 02


This is a really difficult post to write. The word ‘cancer’ evokes any number of fears & unpleasant images, and I can’t imagine something worse than discovering that a child has cancer. (Nor can I be certain of my own reaction, if I should find myself in that position.) But that doesn’t excuse credulous reporting on the issue, most recently exemplified in this story (in the ‘Life & Style’ section) in the NZ Herald.

The story is about the use of plant-based compounds, called salvestrols, for children who’ve been diagnosed with a range of cancers. Now, a search for ‘salvestrols’ brings up a rather large number of websites making all sorts of claims for their efficacy, but a search for ‘scholarly articles’ narrows things down a bit. The first such paper to come up appears to be the one used to support the claims made by the Herald piece, & was published in the Journal of Orthomolecular Medicine in 2007. (It’s worth noting that this particular field of study is not widely supported by science-based medicine and that the journal itself isn’t indexed by Medline. I was intrigued to see that the editor of JOM has compared it to Medical Hypotheses, because really, that’s not a good advertisement.)

Those claims include the hypothesis that salvestrols are used by our bodies to destroy cancer cells (referencing an earlier study by the same authors) and that modern practices around food-growing & preparation reduce the amount of salvestrols in our diet (with little evidence for this cited in support). Unfortunately the Herald’s reporter simply presented these ideas as if they are widely-accepted facts:

they trigger a process in the body allowing it to kill diseased cells. But they have been depleted from food through modern farming and production techniques which have drastically altered diets.

The paper itself discusses case studies ie there are no controlled trials; while the case studies may suggest routes for future research they should be viewed as tentative, at best. Further, it makes the following claim:

First, it is not harmful. The toxins produced through the metabolism of Salvestrols by CYP1B1 are confined to the cancer cells and are exhausted through the destruction of the cell.

And yet GSK stopped a trial of a salvestrol (reservatrol) in cancer patients because not only was there no evidence of efficacy, there was evidence of harm (kidney damage). Hardly suprising as compounds such as reservatrol appear to have an effect on quite a range of metabolic pathways in our bodies.

Now, that information was fairly easy to find, so it was really, really disappointing to see the Herald’s reporter referencing the JOM – and the British Naturopathic Journal – as being the best source of information on this subject.

It’s also important to note that the people identified in the Herald story as successfully using salvestrols as a cancer treatment have also had surgery & in some cases chemotherapy as well. It’s entirely possible that the medical treatments alone have resulted in patients being in remission – and without properly-designed clinical trials there’s no way to identify any impact of the plant compounds. Nor is it enough to say that it’s “common sense” that they work; as a colleague’s said to me, blood-letting was also seen as a common-sense treatment for pretty much everything that ailed you.

This isn’t the first time that we’ve seen such poor reporting around such a serious issue; sadly, I suspect it won’t be the last.

weapons-grade foolishness from the ‘food babe’ Alison Campbell Nov 18

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Today, we move on to just plain, flaming, weapons-grade foolishness. Foolishness that is, unfortunately, spread to a rather wide audience.

Vani Hari is the self-described ‘Food Babe’, on a mission to ‘make America’s food safer’. According to Ms Hari, if you can’t pronounce a food item’s ingredients, you shouldn’t be eating it1. I guess she’s never seen information like this, then (graphic by the wonderful James Kennedy).

Ingredients of an All-Natural Banana

But I digress. Recently Ms Hari wrote a piece giving her advice around flying. (It’s since been removed from her site, but the internet has ways of ensuring that things don’t just disappear, so you can read the post in its entirety here – for as long as it remains there, or there’s a screen cap here.) The nature of some of her comments do not inspire me with confidence.

A few facts about what airplanes do to your body -

When your body is at seriously high altitude, your body under goes [sic] some serious pressure. Think about it – Airplaines thrive in places we don’t. You are traveling in a pressurized cabin, and when your body is pressurized, it gets really compressed!

I am still trying to get my head around the idea of inanimate objects like aeroplanes ‘thriving’. That aside, our bodies are not placed under greater pressure when at altitude. Yes, plane cabins are pressurised, but that pressure’s still less than what we’re exposed to at sea level.

Compression leads to all sorts of issues. First off your body’s digestive organs start to shrink, taxing your ability to digest large quantities of food. Secondly, this compression reduces the ability for your body to normally circulate blood through your blood vessels. Sitting down for long hours while this is happening, exacerbates these issues, leading to what they call “Economy Class Syndrome.” Economy Class Syndrome results the action [sic] of sitting in a cramped space for a long period of time, thus resulting in blood flow loss to the legs.

Yes, aeroplane passengers are subject to increased risks relating to poor circulation, but they’ve got nothing to do with ‘compression’ due to supposedly high cabin pressure & everything to do with simply sitting still in cramped conditions for prolonged periods of time. In fact, air travellers are advised to use compression stockings to help mitigate those risks. (Ms Hari does give some sensible advice on combatting this.)

The air you are breathing on an airplane is recycled from directly outside of your window. That means you are breathing everything that the airplanes gives off and is flying through. The air that is pumped in isn’t pure oxygen either, it’s mixed with nitrogen, sometimes almost at 50%. To pump a greater amount of oxygen in costs money in terms of fuel and the airlines know this! The nitrogen may affect the times and dosages of medications, make you feel bloated and cause your ankles and joints to swell.

This is such a basic science fail. Passengers don’t breathe in ‘everything the airplane gives off’ (details of where cabin air comes from are here). And Earth to Vani: the air you breathe has never been ‘pure oxygen’, whether you’re at ground level or 11,000m up in the air – probably just as well, really, given the reactivity of the pure stuff. This is so easily checked (image from

Now, this may seem laughable. Someone is ill-informed & shares that lack of knowledge rather widely. But that’s not doing any actual harm, is it?

Except, I think it is. Why? Because the Food Babe is encouraging and pandering to chemophobia and scientific illiteracy (and, sad to say, has a wide audience for this nonsense: several hundred thousand followers on FB, for example). And when you’re also spreading anti-vaccine misinformation to that number of followers then yes, you have real potential to do harm.


1 Sad to say, one of our local NZ companies has bought into the ‘no long words’ meme. It’s worth remembering that some ‘nasties’ have very short names, while the names of many important proteins are multisyllabic.

a tale of rare blood groups, or, ‘the man with the golden blood’ Alison Campbell Nov 03

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One of the topics we cover in first-year biology is human blood groups – it’s discussed during genetics classes & also touched on when looking at how immune systems function. I give the genetics classes and, being a regular blood donor myself, thought I knew a bit about at least the common blood groups and their inheritance. But there’s always more to learn, something I was reminded of when I read a fascinating story about people with truly rare blood types: “The man with the golden blood”.

There’s ‘Thomas’, for example: a man who lacks the Rhesus markers completely & so is classified as Rhnull  - in 2010 he was one of an exclusive global club of 43 individuals (of whom only 6 regularly donate their blood). And James, who is ‘Lutheran b negative’, and one of only 550 active donors for this blood type.

This makes known donors precious, in that if someone else with the same group needs a blood transfusion, there are very very few people around the globe who might be able to help them. And helping comes at a cost to the donors, for – as the story tells us – it’s actually easier in many cases to move people across borders than it is to move blood, but because many countries don’t pay donors, then that movement may well be at the donor’s expense. It’s also difficult for people like ‘Thomas’, with his vanishingly rare blood group: his blood can be used by anyone who’s Rhesus negative, but he can receive blood only from another Rhnull person, which means he has to be reasonably careful not to put himself in harm’s way (although he does still go skiing!).

Quite an eye-opener – and a tale I’ll be including in next year’s class.

helicobacter pylori and the complexity of the human microbiome Alison Campbell Jul 24

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In their first-year microbiology lectures. our students hear about Helicobacter pylori, the bacterium associated with the development of gastric ulcers (a discovery that eventually saw Barry Marshall and Robin Warren receive the 2005 Nobel Prize for Physology or Medicine). The trouble is, I suspect that this is all that they hear about a story that is considerably more complex.

The story of H.pylori is just one part of Jessica Snyder Sach’s highly readable and thoroughly-referenced book, Good Germs, Bad Germs, which introduces the reader to the complexities of the human microbiome: the intricate microbial ecosystems found on and within the human body.

Good Germs, Bad Germs: health and survival in a bacterial world. Jessica Snyder Sachs (2008) pub. Hill & Wang. ISBN (e-book): 0809016427

The book begins with the harrowing tale of a young man’s death from a rampant MRSA infection, and of a child living with multiple life-threatening allergies.- two tales linked by the unforseen effects of our overuse of anitbiotics and our fixation on hygiene. (Actually, the former was not entirely unseen: in his 1945 Nobel Prize lecture, Alexander Fleming commented on the possibility that overuse of penicillin could see the development of resistant bacteria. Unfortunately, at the time this warning went unheeded – if indeed it was really heard – for example, penicillin was available as an over-the-counter drug in the US for almost a decade after its introduction in the 1950s, which would undoubtedly have contributed to the development of resistant strains of microbes.)

Then, after an introduction to the “war on germs” and scientists’ search for the ‘magic bullets’ that would (it was hoped) allow us to vanquish them forever, it’s on to “life on man”. Wherein I learned heaps, including the thought-provoking suggestion that there may be some adaptive significance to the fact that babies usually exit the vagina with their heads face backwards, towards the mother’s anus. For babies guts are colonised by bacteria very soon after birth – & they may receive an inoculum of faecal matter on the way out, to join the lactobacilli  from the vagina itself and bifiobacteria from breast milk.

Incidentally, while all this may sound uncomfortably germy, there’s good evidence that the gut microflora are essential for survival. Lab animals reared in absolutely germ-free conditions, & whose guts never develop a microbial flora, fail to thrive. What’s more, Snyder Sachs  comments that the combined acction of several species of intestinal bacteria “liberate as much as 30 percent of the calories a person absorbs from food, especially from high carbohydrate meals.”

Reading on – and it was really hard to put this book down! – you’ll hear about the hygiene hypothesis, which suggests that many of the inflammatory diseases that plague us today are an unforeseen result of lives that are too clean. Along with this is the ‘dirt vaccine’: the idea that vaccination with a mycoplasma may help to redirect the overzealous immune response underlying many allergies. Then it’s on to a deeper look at the development of antibiotic resistance and the rise of the superbugs, which has been exacerbated by the widespread use of antibiotics in farm animals. (Encouragingly, Snyder Sachs notes that banning this use, as in the Netherlands, can lead to a reduction in ‘superbug’ prevalence.) And finally, we look at our options for the future, and whether we can find a way to live in balance with our burgeoning microbial ecosystems.

And H.pylori? It turns out that this particular bacterium has been with us for at least 60,000 years, something that’s been used to track human migration patterns that began when Homo sapiens first left Africa. H.pylori colonises the stomach in the first few months of life, before gastric acid secretion really ramps up, and can actually affect that acid secretion, lowering the pH enough that Helicobacter can survive but most other species are killed. There is a plus to this: the lowered pH reduces the effects of acid reflux & the development of oesophageal cancer. But then, there’s those gastric ulcers – which apparently didn’t really become an issue until the 1830s, when this was mainly a disease of the upper classes, possibly linked to a decline in colonisation related to improved sanitation and the use of early antibiotic products. And gastric ulcers

remain virtually unknown in undeveloped regions of the world such as Africa, where most people become colonised in infancy. It may be that delaying or disrupting H.pylori colonisation with water sanitation or antibiotics has somehow altered the immunological ‘truce’ that this microbe forged with our immune systems over thousands, possibly millions, of years.

I like the full, more complex story; it’s so much more satisfying than the ‘helicobacter – bad’ version, and it’s a much better reflection of the dynamic relationship between humans and the microbes that call us home.

the science-based medicine blog on fluoridation Alison Campbell Jan 22

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This is something that I posted on Making Sense of Fluoride, but thought I’d re-post here; it deserves to be widely read. I’ve highlighted some of the main points made by the authors as they address issues frequently raised by those opposed to community water fluoridation.

The Science-Based Medicine blog is an excellent resource and well-worth adding to your regular reading list. A few days ago Clay Jones (a paediatric hospitalist) & Grant Ritchey (DDS) posted an article entitled “Preventing Tooth Decay in Kids: Fluoride and the Role of Non-Dentist Health Care Providers“. It’s reasonably long but contains a number of key points.

The first is that “there are a number of stumbling blocks that prevent children from receiving appropriate dental care” – including distance from/accessibility to a provider, not to mention the costs involved.

Secondly, that the majority of people will be affected by caries: ” [r]oughly 90% of us will have some degree of tooth decay during our lifetime”; that this prevalence increases over time, and that – sadly but unsurprisingly – it is most marked in poorer sectors of society. Interestingly they also characterise caries as infectious – because the bacteria involved can be & are spread from mouth to mouth. (Consequently they advise against ‘spit-cleaning’ a child’s dummy, which sounds just about as insanitary as popping it straight back in from a sojourn on the floor.) And there’s also a genetic component, which means that “[t]ooth decay truly is a complex, multifaceted process that clearly isn’t as simple as forgetting to floss every day or even the socioeconomic status.”

There’s a description of the effect of fluoride on tooth enamel, which says quite explicitly that “when exposed to fluoride either systemically during tooth development or topically via toothpaste, fluoridated water, or professional application, becomes strengthened.” Jones & Ritchey agree that dental and skeletal fluorosis are problems when ingesting higher levels of fluoride, but add a caveat that bears repeating: “It must be emphasized that skeletal and severe fluorosis of the teeth do not occur as a result of any sort of community water fluoridation, or because of fluoride in toothpastes or professional fluoride treatments [my emphasis]. They occur in areas with naturally occurring fluoride levels far in excess of what is safe, and are rare in the United States. In these areas, a defluoridation process must be undertaken to return the water concentration of fluoride to safe and optimal levels.”

And they have some strong words to say on the so-called ‘fluoride controversy’.

As I said, it’s a long-ish piece but well worth reading in its entirety.

For those interested in reading more on this issue, my colleague Ken Perrot has written extensively on fluoridation over at Open Parachute: here, for example.

secrets from an ancient graveyard Alison Campbell Dec 16

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One of my current favourite TV programs is Time Team – I enjoy learning little bits of history & Tony Robinson’s happy enthusiasm is so contagious (but I still think of him as Baldrick). So you’ll understand that I was happily distracted this morning when, while looking for something else (isn’t that usually the way?), I stumbled across a fascinating piece about an ancient graveyard in the Italian town of Badia Pozzeveri.

Published on Science magazine’s site, the article tells the story of the ongoing excavation of a medieval graveyard. The dig is providing a wealth of information on things like the dietary differences between nobles, monks, & peasantry (based on isotope analysis of their teeth) & the impact this had on health. What’s more, using ancient DNA (aDNA) techniques, the scientists leading the dig are hoping to identify the presence of various pathogens, such as Yersinia pestis (the bacterium linked to the Black Death, and which still causes cases of plague in the US today) and Treponema pallidum, which causes syphillis and has already been found in 16th-century mummies from Naples.

And like many episodes of Time Team, the tale has a twist at the end: a bit of fashion-based detective work showed that at least some of the burials were not medieval at all.

chocolate! & just in time for easter Alison Campbell Mar 27

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For years the husband has insisted that chocolate is a health food. He’s also spun me the line that eating it is good for the rainforest, as the mature cacao trees apparently grow in mature forest. So he’ll be happy with the Herald‘s story on his sweet treat, which has the enticing title of “Sweet news: chocolate is good for you”, and comes direct from the Daily Mail, that fount of all things good in science reporting. (Not.)

Me? Not so much. Like cautious investors, I tend to subscribe to the view that if something sounds too good to be true, it probably is.

The item begins:

Just in time for Easter, it’s the news chocolate lovers have dreamt of – official confirmation that their favourite guilty pleasure can be good for you.

New research shows that eating just a single chocolate bar has a direct effect on the brain and may cut the risk of stroke.

The research on which the Daily Mail‘s story is based was published last week in the journal Neurology, to which – alas! – we don’t have a subscription. The brief excerpt I can see indicates that the researchers were building on an earlier publication:

Larsson et al. investigated the association between chocolate consumption and risk of stroke in men, concluding that moderate chocolate consumption may lower the risk of stroke. We performed a prospective mechanistic study that may suggest a potential mechanism for this observation.

A prospective study is one that takes a group of individuals & follows them for some period of time, studying the impact of various factors on that group; ‘mechanistic’ means that the researchers would be looking to explain their findings in terms of physical or biological causes. In this case they were interested in the impact of eating chocolate, & apparently found that this had an impact on blood vessels; specifically, on the stiffness of the vessel walls. It would be interesting to read the actual paper because I’d like to know, for example, which blood vessels were studied, & how they determined the ‘impact’ of chocolate on brain cells. It’s notable that there’s no indication of what constituent of chocolate might be involved in any possible outcomes, so it’s a very broad-brush, preliminary outcome.

In its timing this mirrors an earlier story, published just before Easter 2010. However, the 2010 story is much more balanced in scientific terms, pointing out the shortcomings of the earlier research (and that most newspapers Got It Wrong) & noting that while it was possible that eating a small quantity of chocolate might confer some benefit, the association between choccy consumption & health wasn’t particularly strong. (And in fact, reported chocolate consumption appeared awfully low – the ‘high intake’ group reported eating a mere 7.5g/day!)

In this week’s Daily Mail story, the lead researcher is quoted as saying that

We think a reduction in stroke risk may be caused by chocolate changing how brain blood vessels behave.

It’s a real pity that the DM left this next part of the message until the very end of the tale, but at least the paper does note that

chocolate also has a high sugar and fat content which can cause obesity – a definite risk factor for strokes.

Sounds like swings & roundabouts to me. I hate to dash the husband’s hopes, but it would be a leetle premature to add this putative benefit to his list of reasons to eat his favourite Whitaker’s bar :(

another silly homeopathic product Alison Campbell Jun 22


Checking my in-box today I came upon this offering:

HCG Diet Direct – hCG Diet Drops – Homeopathic Drops

HCG Diet Direct – Lose weight on the homeopathic HCG Diet without heavy exercise or without frozen or prepared foods to buy. HCG Diet Direct – a brand you can trust

HCG = Human Chorionic Gonadotropin, a hormone produced during pregnancy. Quite how it would help you lose weight, I am not sure. The idea that it could do so appears to be based on claims that – in combination with an ultra-low calorie diet (around 500 cal/day) – use of this hormone would help obese individuals lose weight. However, there is no clinical evidence to support this claim, & I see that in the US over-the-counter sales of ‘homeopathic’ HCG diet products were banned by the Food & Drugs Administration - something our advertiser gets around by being based in Russia. (Although I see you can also buy the stuff here in NZ.)

I suppose you could argue that since the highly diluted nature of most homeopathic products means that they contain no active ingredients, then all you are ingesting is water or sugar pills (the latter, of course, are not going to help with weight loss!), so the product’s hardly going to do any harm. It’s not unknown for homeopathic ‘remedies’ to actually contain physiologically-active levels of various drugs & other chemicals (think Zicam), and this may have influenced the FDA’s ban, but more likely they were working from the viewpoint that there is no way such a weight-loss product could do what is claimed for it. Low-cal diets – yes, the weight should come off (although whether it will stay off is another matter). After all, the original claims about HCG’s efficacy in weight loss saw it combined with that very low caloric intake. So why bother with the additional water/sugar pills? Anyone buying such products in the expectation that the kilos will melt away without any additional effort on their part is likely to be sadly disappointed.

In other news: the Quackometer examines claims that homeopathic products are useful in dealing with sports injuries (worth knowing, I guess, as Olympics fever strikes).

anti-vaccination anti-science Alison Campbell Feb 25


At Respectful Insolence, Orac has a recent post discussing ‘anti-science’, and I thought of this when I finally got around to writing this piece (which Grant has kindly ‘left to me’, as it were!). Here’s how Orac defines the term ‘anti-science’:

It’s an imperfect term for people who reject well-established science. To get a flavor of what being “anti-science” means, take a look at people who reject evolution, reject anthropogenic global warming, reject vaccines, and reject scientific medicine in favor of quackery.

Which is a reasonable characterisation of some of the content from the IAS website that Grant’s deconstructed, leaving this bit for me (because I asked nicely):

When a well meaning friend or relative questions your decision [not to vaccinate], simply say “I fail to see how injecting heavy metals, foreign proteins, multiple viruses and many toxic substances into a body all at one time can keep someone well, can you explain it to me?”

“Heavy metals”: could they mean (gasp!) mercury? It’s hard to tell, with such a non-specific term. But if they do mean mercury, then this phrase can only be construed as intending to mislead: mercury (as thiomersal) was phased out of New Zealand’s paediatric vaccines in 2000. In reality, the “heavy metals” actually include some elements that are required for life (such as iron, molybdenum, & cobalt) as well as the harmful ones like lead & plutonium – and mercury.

Dose & chemistry also matter. When childhood vaccines in NZ did have thiomersal in them, the mercury was in the form of the organic compound ethylmercury. Unlike methylmercury, ethylmercury has a half-life in the body of around 7-10 days: it is converted to an inorganic form & then excreted. As for dosage, back when our vaccines contained ethylmercury, a 6-month-old child who had received all recommended vaccines would have received a grand total of 175 micrograms of this substance, well below World Health Organisation guidelines.

‘Foreign proteins”? Which ‘foreign’ proteins are we discussing here? Presumably it’s the antigens included in vaccines to elicit an immune response. Which are no more, & no less, ‘foreign’ than the self-same proteins on the surface of a bacterium or the coat of a viral particle. In any case, it’s worth remembering that proteins & large polypeptides from food can cross the gut wall to circulate in the bloodstream, & they’re equally ‘foreign’.

“Multiple viruses”? It’s correct that some vaccines contain viruses. “Live” vaccines contain viruses that are attenuated but which stimulate an immune response in the host. Examples are measles, mumps, rubella, & chickenpox. “Inactivated” viral vaccines (eg for polio & influenza) have had their ability to replicate destroyed – this further reduces the extremely small risk of a “live” vaccine inducing disease, but requires much higher doses to elicit the same immune response. There are also vaccines based solely on viral protein subunits.

Let’s assume that the IAS’s “multiple viruses” refers to the MMR vaccine. Three viruses at once – sounds bad! However, viruses are extremely common in many indoor environments, so daily exposure to viral particles may be many orders of magnitude greater than the 3 in that particular vaccination. Many pathogenic viruses are airborne, entering the body through mucous membranes, and some can persist for up to several months on dry surfaces. Overall, an individual’s daily exposure to antigens is many orders of magnitude greater than exposure via vaccines.

As for the “many toxic substances” part (oh noes, teh ebil toxins!) – it’s notable that many of those who cite the presence of toxins appear quite unable to identify what they are. The term ‘toxins’ is presumably sufficiently scary to put hearers off asking for elucidation. At a guess, IAS might be referring to formalin, squalene, & or aluminium. However, once more dose is important. None of these are toxic at the concentrations found in vaccines – in the case of aluminium daily exposure through food & drink is far higher (hardly surprising when you consider that it’s one of the most abundant elements in the earth’s crust). And our bodies make both formalin (formaldehyde) & squalene as part of their normal metabolic functioning.

So, sad to say, that particular anti-vaccine website could fairly be characterised as anti-science.

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