Posts Tagged sciencesociety

overrun with creepy-crawlies? maybe not… Alison Campbell Mar 16

No Comments

I blog a fair bit about the way science stories are (mis)represented in the press. And when I do, I always wonder what the original press release (from the intitution to the media) would have been like. Now Ben Goldacre’s posted an excellent item on one such release.

The release in question came from a UK pest control firm, & it contained ‘data’ that seemed to show alarmingly high levels of pest infestation on London public transport. (Or, in the case of dust mites, surprisingly low. Only 500 of these tiny critters in a whole railway carriage?) Things like cockroaches, bedbugs, fleas. (Apparently bedbugs are raising their nasty little heads in New Zealand – not something I’d want to see gain a significant foothold here!). Cue a number of rather hysterical media articles.

Ben has done his usual thorough job of investigating this one. And he found – that the company did no studies whatsoever of in-service public transport vehicles. None. Zero. Zilch. Their scary figures were based on a model, which made a whole lot of unsupported & highly unlikely assumptions. As Ben hasn’t been able to track down the original release, we can’t be certain of its contents. But I have to say – to pretend some sort of scientific support for the numbers sent out to the media is to misrepresent what was done as good science. And that does none of us any favours.

 

how do we teach students to question what we say? Alison Campbell Mar 14

2 Comments

This is a re-post of something I’ve written for Talking Teaching. I’ve reproduced it here because I think the notion of teaching things like critical thinking & the nature of science are just as relevant here as they are in a discussion about teaching itself.

I’ve just been reading a post by Tim Kreider, over at Science-Based Medicine. Tim’s talking about the learning experiences of medical students, but a particular phrase caught my eye. I”m reproducing it here because I think it can be applied much more widely: students are in the habit of transcribing and commiting to memory everything uttered by the professors who grade them.

I’ve seen this happen myself. I remember talking with a class about fungi & saying that while most fungi are saprophytes (consuming dead material), some are predatory. And they all (well, all those I could see, anyway) wrote this down unquestioningly. ‘Hang on a minute,’ I said; ‘does this sound likely to you?’ They agreed that no, it didn’t really, it didn’t match with what they already knew about fungi. ‘Well then,’ I said; ‘why didn’t any of you call me on it?’ ‘Because,’ they said, ‘you wouldn’t tell us anything incorrect, would you?’ Which showed a touching faith but also a worrying lack of willingness to question things that didn’t sound right.

(Just as an aside: This was amply demonstrated one year when my class was sitting a lab test. One of the questions asked students to label a section of plant tissue, selecting their labels from a list that I provided. It happened to be April 1st – so I included the word ‘aardvark’ in that list. Rather worringly, about 30% of the class used it for a label – & when asked why they said well, it didn’t sound right, but they just knew I wouldn’t have used a word that didn’t belong… And not one of them questioned it at the time.)

Now, in his SBM post, Tim makes the point that med students in their pre-clinical training have to learn so much content that there isn’t a lot of room for rigorous skepticism (but make no mistake, he’s still arguing of the need to teach critical thinking). And I agree, there is factual content that I want my students to be able to remember (& my colleagues teaching at 2nd-year would like it too!) But at some point we must surely also want our students to develop a healthy skepticism: the ability to think critically about what they’re hearing & learning.  And I certainly don’t like the idea that my science students might regard me as infallible. Not least because that’s not a particularly good model for what science is like. They need to know that scientists can & and do make mistakes, get things wrong, interpret data in ways that subsequently (in the light of further data) turn out to be inaccurate. And they need to feel confident that it’s OK to ask questions. The thing is, how best to get this across?

Speaking for myself, I’m a firm believer in modelling this for my students. If I’m asked a question to which I don’t know the answer, I’ll tell them so, up front. But then I’ll say, but I can hypothesise about this – here’s what the answer might be, & here’s my evidence for thinking this. (If the classroom has web access – & most of ours do these days, we’ll often go on to check what I’ve said on the spot.) If it turns out that I’m wrong (which happens quite a lot, then that’s fine, & we’ve all learned something new.

Plus, I actively encourage questioning during my lectures. (Pop quizzes & concept maps are good for encouraging the sort of conversations that lead to this.) Sure, I mightn’t get through as much content as if I didn’t do this, but the students’ learning experience is surely going to be a better one if they can follow up on things on the spot. And hopefully they learn from this that it really is OK to ask questions :-)

And – I’m all for telling stories. How better to help students learn about the nature of science than to use a narrative approach that lets them see how scientists viewed the world at some past point in time, & how science has led to a change in - or a reaffirmation of – that perspective?

what makes students stick at science? Alison Campbell Mar 11

No Comments

This is a very relevant question in the light of the government’s recent announcement of its intention to tie a proportion of tertiary funding to student completion and retention rates. (This decision is presumably driven, among other things, by relatively low rates of retention and passing papers/courses, which lead to questions about whether we’re getting value for money from our tertiary system.) Speaking personally, I find this a rather blunt instrument for rewarding performance as at least some of the factors affecting this are beyond the institutions’ control (e.g. Zepke et al. 2005). There’s quite a lot of literature around dealing with the whole issue of student retention, but I thought I’d be self-indulgent for once & discuss a study done here, examining the factors affecting completion & retention of students in science & engineering (Otrel-Cass et al., 2009).

This study used a combination of a questionnaire & focus-group interviews with returning 2nd-year students to examine various factors that could influence students’ decisions to stick with their studies. (One immediately obvious flaw is that we’d got no real way to find out why those who didn’t return, chose not to.) The questions we used in the survey were designed to elicit students’ opinions on their ability to cope with the varying demands they faced during their studies. We were interested in time management, learning strategies, how confident they felt at managing their learning in lectures & labs, communication issues surrounding their studies, information available about their programs of study (provided by staff in particular & the institution as a whole) and about assessment.

Rather alarmingly, only around half of the students we surveyed felt particularly confident about managing the workloads associated with tertiary study, while 70% felt that this was a significant issue in deciding to come back to uni. (And remember, these were second-year students, so they’d already managed to cope with the jump from school to university.). So – those of my readers who are intending to enter uni at some point – be aware that you’ll need to develop some strategies to handle the various demands on your time. I feel it’s also important for us to keep an eye on how our students are doing, & offer support when it’s needed, & in fact we’ve developed a system in my Faculty to do just this for first-year students. We need scientists & technologists & engineers, so it makes a lot of sense to support our budding technicians & researchers & teachers through the rocky patches as best we can.

If you’re studying science you’ll be in the lab, writing essays & reports, & using the library. Yet less than 20% of our respondents felt very confident in their ability to do these things well. (This bothered me more than a bit – we should be teaching them how to do these things in first-year! That’s actually one reason we include an essay in the assessment for first-year biology – to help students to learn the conventions of academic writing. And also to help prepare them for the essay-type answers in their end-of-year exams.) 

I mentioned labs – the students we surveyed placed a lot of importance on their lab work, in terms of learning various techniques but also because of the opportunities lab classes offer to interact with teaching staff. You get the chance to ask questions that you might not have wanted to ask during a lecture, and this helps to develop a more personal relationship with your lecturers. In fact, we found that [students] placed high value on the presence of academic staff in practical sessions,(Otrel-Cass et al., 2009), for thiis very reason.

Our respondents (in both the survey & the focus groups) recognised the value of lectures. They were particularly positive when they felt that lecturers valued what they were doing. They also felt strongly that it was easier to engage with a subject when the lecturers were themselves interested and enthusiastic – and when the teaching staff told personal stories in class. While these gave information about future careers, they also increased the students’ motivation. This was obvious in the students’ comments: One of the best [experiences] that I loved was how they give examples. You know, really amazing little things of weird little animals you never even knew about and you can actually go home and tell people, ‘Oh, I learned this today’ and that’s really cool. I always tell at home what I learned and why things happen too. 

Overall, it seemed clear to us that we (uni academics, & institutions) need to give our first-year students the message that we value them & take their educational needs seriously. This has a big impact on their attitudes to continuing with their studies. Letting students see staff as ‘people’ through personalised lectures, having academics (rather than senior students) in lab classes, being available to talk with students, keeping an eye on how students are handling things like workload – all these make students feel part of the uni community. This finding fits in with research findings elsehwere that stress the significance of staff: student relationships. The trick for us, of course, is to balance all this with the other demands on our time in a funding environment that places a high importance on research & attracting external funding. Achieving success is a juggling act for staff as well as for their students :-) But an act that’s rewarding, if we do it well.

K.Otrel-Cass, B.Cowie & A.Campbell (2009) What determines perseverance in studying science? Journal of Institutional Research 14(2): 30-44.

N.Zepke, L.Leach, T.Prebble, A.Campbell, D.Coltman, B.Dewart & M.Gibson (2005) Improving tertiary student outcomes in the first year of study. NZ Council for Education Research report.

the bca vs simon singh Alison Campbell Mar 05

No Comments

Over the last few months many science bloggers have been watching – with considerable interest – a libel case taken agains science writer Simon Singh by the British Chiropractic Association. Singh had used the word ‘bogus’ in describing treatments offered for a range of ailments, including asthma and ear infections. (Similar claims-by-implication are made in NZ.) While the UK’s libel laws allowed the case to proceed (it’s still before the courts), Singh’s view is supported by a number of meta-analyses of availble good-quality studies: for conditions other than musculoskeletal pain (eg asthma, & a range of childhood conditions)  such treatments perform no better than placebo .

Now it seems that the case appears to have sparked somethng of a backlash in the UK, with chiropractors advised by their professional body to remove from their websites & other publicity material any claims of the ability to treat conditions such as whiplash and colic. This is interesting given that the BCA had previously released what it described as a ‘plethora’ of evidence supporting those claims. However, as Edzard Ernst has noted, of the 19 references included in that list, it seems that 4 didn’t even contain data relating to chiropractic treatment. A further 8 are not based on controlled clinical trials, and the remaining 7 are flawed in methodology or conclusion – for example, a lack of double-blinding that doesn’t allow us to rule out the placebo effect, in a comparison of chiropractic vs an anti-colic drug.  (Ernst also points out that several robust, rigorous trials of chiropractic interventions, that don’t show any effect better than placebo, aren’t included in the BCA list.)

If the BCA is now advising that claims concerning ailments other than back pain should not be made, where to next for the case against Singh?

how i became a science teacher Alison Campbell Feb 20

No Comments

I’ve been reflecting on my teaching career lately, partly because I have to write a teaching portfolio. It occurred to me that talking about how I came to be where I am now might perhaps be interesting to some of you who are thinking about your future. In my experience, at least, things don’t always go according to plan :-) & it pays to be flexible.

With both parents working in science-related fields (mum a biology teacher, dad a technical officer for a government department) I suppose at least one of we four children was always going to be a scientist. By the time I was 7 or 8, I’d decided to be a doctor. I read mum’s biology books (well, OK, I looked at the pictures) & thought, as probably most kids who contemplate a career in medicine do, how neat it would be having a job helping people get well. A bit later on, though – maybe after mum showed me a dissection – it struck me that while it while it was probably fairly straightforward to open somebody up, putting everything back together so that it was still all in working order was a big ask. I crossed medicine off the list.

I studied the the sciences at school (and maths, & languages & geography up till the end of 5th form [year 11]), but didn’t really focus on a career until – I think – the beginning of year 13. With mum as my example, I decided on teaching (she’d moved into a teaching career relatively late in life). Way back then the government provided studentships to aspiring teachers: you got a rather decent monthly allowance for the duration of your studies, & in return you were expected to take up a teaching job at the end of your time at university. After an interview, I was awarded a studentship & trotted off to Massey to study biology.

Things began to unravel at the edges when I was invited to study for Honours, at the end of my 2nd year at Massey. This meant a further 2 years of study, which the Ministry of Education (who held my purse-strings) was quite happy with. But part of the final Hons year is your dissertation, where you spend a reasonable amount of time on a research study. I chose to look at mallard ducks – their behaviour was pretty well-described, but I wanted to know if there were any differences between the behaviour of mallards on the local lake (Centennial Lagoon) and a smaller population on a country pond. (There were.) I quite liked doing the research, & towards the end of that year I was asked if I’d like to work towards a PhD. Hmmm, teaching or study, study or teaching?

Study won out, & I went on to spend a further 3 years or so looking at the behaviour of black swans on a Manawatu dune lake. Mind you, I was also ‘teaching’ in the sense of demonstrating in undergraduate lab classes, but teaching as a career seemed a bit more distant. However, when I graduated I wasn’t immediately able to get into any research positions, and without that happening we weren’t going to leave Palmerston North as my husband had a secure & stimulating job there. So I applied for – and won! – a position as ‘assistant biology teacher’ at Palmerston North Girls’ High, & that was it. I was totally hooked on teaching. (I still am.) I loved, & love, the interactions with students, & also I get a real buzz from those times when you see something ‘click’ with a student.

(At this point I have to say that I really do think that good teachers are born as well as made. I took 4 extramural papers at ‘TColl’ while I was teaching, and after passing them & putting in another couple of years in the classroom I received my Trained Teachers Certificate. But still, a lot of what ‘worked’ for me in the classroom still seems to me to be instinctive.)

Anyway, after 8 years in secondary classrooms (& with our family expanded to include our 2 children), I ended up going back to Massey as a senior tutor. And I’ve remained in tertiary classrooms ever since. I have to say, I think I’m really lucky to have that secondary teacher training & experience – it’s given me an insight into the prior learning experiences of new students coming into my first-year lectures & lab classes. At the same time, the things I do with & for secondary teachers helps me to understand the classroom practices & processes that work for them & with which ‘my’ students will be familiar with when they join me at Waikato. And it’s also what got me into writing this blog – it’s a way of giving something back to those teachers, maybe encouraging their students to think more critically & read more deeply in the scientific literature, and hopefully helping to inspire their own journeys in science.

Because it is an ongoing journey, & I think that’s something you shouldn’t lose sight of – that you may end up in unexpected places in your passage through life :-)

meta-analyses – testing relationships Alison Campbell Feb 16

No Comments

One of the nice things about working at a university is that there is almost always an interesting talk to go to (supposing you have the time…). Yesterday I managed to go to a fascinating discussion of the use of meta-analyses by a Waikato graduate, Shinichi Nakagawa. (I suspect that Grant knows much more about this technique than I do, but Shinichi’s talk was very post-provoking.)

Shinichi began his studies here a year or so after I joined the University staff. He was invited to do a BSc(Hons), something reserved for the really able students, & it’s a sign of the quality of his research project (on zebra finches) that he’s since published five papers from it. After gaining his PhD at a UK university, Shinichi’s come back to New Zealand to work at the Universit of Otago. Over the last few years he’s begun to use meta-analyses more & more to identify relationships (or the lack of them) between data sets, & this particular research tool & its applications were the subject of his enthusiastic presentation. (He recommended Morton Hunt’s 1997 book How science takes stock: the story of metanalysis as an excellent introduction to the area, written by a journalist for a lay audience.)

I’ve referred to meta-analyses myself, from time to time. The Cochrane Collaboration, for example, makes use of them in examining the (claims for) efficacy of various medical treatments. Essentially the technique involves combining the data from a range of studies (allowing for sample sizes & so on), producing summary results that may allow recognition of a statistically significant pattern in the data. (It may equally show that there’s no real relationship between a set of factors, as Shinichi noted. Alternative treatment modalities such as acupuncture & homeopathy, for example, have been shown to perform no better than placebo as an outcome of  meta-analyses.) The larger sample size afforded by a meta-analysis allows greater confidence about the results.

The technique does have its disadvantages: you could be accused of comparing apples with oranges, for example, although this could be overcome by proper selection of the studies for inclusion in the analysis. There’s perhaps a greater problem (Shinichi described it as the ‘file drawer’ problem) whereby studies with a non-significant result are less likely to be published, thus biasing the pool of studies available for inclusion in a meta-analysis. Shinichi described how he’d had difficulty publishing a paper on sparrow parental care because it had a negative result. Now, there’s nothing wrong with this, & a fairly large proportion of experiments would come up with such an outcome, but unfortunately this doesn’t make good headlines:-) And the editorial attitude described here both skews publications in a particular direction & also skews public perceptions of how science is done.

We then heard about a few research areas where meta-analysis had been applied to a large body of data to test prevailing views. Should we take antioxidant supplements, for example? Not according to a 2007 study, that found an increased mortality rate associated with their use. While this particular study had its critics, a paper published last year in Nature found evidence that antioxidants can actually help cancerous cells to grow. (Mind you, there is a need for caution in interpreting studies like this last one, given that it was done on cancer cells in vitro – there needs to be a fair bit of follow-up work to see if this holds true in the body.)

The final example in Shinichi’s talk looked at the widespread view that a restricted calorie intake can prolong life. (Obviously there would be limits to this one & it’s not a case of living longer & longer on less & less. Eventually there’d be a point in which the lifespan was shortened rather abruptly. And terminally.  Rather like the work of Famine in the wonderful Good Omens by Terry Pratchett & Neil Gaiman.)

Anyway, individual studies of rats & monkeys, fruit flies & nematodes, & even yeast, seem to bear out this idea – it looks like a general biological phenomenon. Our speaker seems to enjoy doing meta-analyses – he commented that a preliminary review f the literature, & an introductory analysis, shows no conclusive evidence that calorie restriction has any positive effect on the length of life, not as a general principle. He found there was no consistency in the data for different species. In the discussion at the end, someone pointed out that almost all the work in the area of dietary restriction’s been done in lab-bred animals, and might not reflect what happens in ‘wild-type’ individuals. And it’s more important to look at the carbohydrate/protein balance in the diet, rather than the overall reduction in calories.

And, of course, the sting in the tail – from an evolutionary point of view, if you don’t produce fertile offspring & thus pass on your genes, the length of life is actually irrelevant. If you lived to 120, but left no fertile children, you’d be an evolutionary non-event…

an update on facilitated communication Alison Campbell Feb 16

No Comments

A while ago now I wrote about Rom Houben, who’d been in a vegetative state for 23 years but who, it was claimed, was really conscious inside an immobile body & now able to communicate via something known as ‘facilitated communication’. I and many others were sceptical of this claim – it looked too much as if the ‘facilitator’ was controlling what was going on. (That’s not to say they didn’t genuinely believe that they were assisting Mr Houben to communicate.) And there were simple ways to test this, which at the time the lead researcher in the case seemed to feel unnecessary.

Now Steve Novella reports that such a test has been done. Mr Houben was shown several objects while the ‘facilitator’ was out of the room, & subsequently asked to name them with her assistance. He got none of them right. Not one. This very strongly suggests that the facilitator, consciously or otherwise, was imposing her own words & understandings on Mr Houben, and supports Dr Novella’s characterisation of ‘facilitated communication’ as a pseudoscience. (My fellow Sciblogger Darcy Cowan has also posted something about this.)

I feel intensely sorry for Mr Houben & his family in all this. If Mr Houben really does suffer from ‘locked-in syndrome’ (one possible diagnosis), then imagine how that must be for him, day after day. And imagine how profoundly frustrated you would be, in that context, if some well-intentioned person began claiming to help you to ’speak’ – and got it all wrong. And his family – his mother had insisted for years that her son really was alert inside his unresponsive body. To be told that he was, to have him ’speak’ to her, and then to have all that taken away by the lead researcher’s admission that he’d got it all wrong – to me this is indescribably sad.

It also saddens me that people will continue to cling to the hope – exemplified by one of the commenters on Dr Novella’s post – that facilitated communication really does offer the chance of communicating with people who are otherwise cut off from their loved ones (eg children – & adults – with severe autism). But, as the Houben case shows, the words will be those of the facilitator, regardless of their beliefs or intent. (And in case you think I’m being too harsh here, the Houben case is not the only one where the idea of facilitated communication has been shown to be false.)

armed and dangerous… Alison Campbell Feb 13

No Comments

… the intriguing title of a brief news item in the latest edition of Science. The story (anon, 2010) outlines some of the most serious plant & fungal threats to agricultural production. One of them is the potato blight fungus, Phytophthora infestans. The leaves & stems of an infected plant blacken & fall, & the tubers themselves basically turn to mush:

Potato blight

I mention potato blight in my first-year lectures, when I talk about the impact of plants on human history. The organism causing potato blight is infamous for its role in the great potato famine in Ireland, which ran from 1845 to 1851.  On a global scale it’s probably still the most significant threat to potato crops: In developing countries P. infestans causes crop losses worth around $US2.75 billion every year (Anon. 2010).

Potatoes have been cultivated in South America for thousands of years, and were introduced to Spain in 1570, following the Spanish conquistadores’ arrival in Peru. The humble spud slowly spread through the fields & gardens of Europe & reached Ireland by the 1600s. Perhaps surprisingly, potatoes were often greeted with suspicion; Russian peasants, for example, viewed them as sent by the devil. It took a while for the idea of actually eating them, rather than tearing them up or feeding them to animals, to sink in.

Once this had happened, food production increased & this in turn meant that human populations also began to rise. This can be seen to greatest effect in Ireland: between 1780 & 1841 the Irish population went from 4 to 8 million people, based almost entirely on the widespread cultivation & consumption of the humble spud, which with milk or water was the dietary staple of most Irish peasants. Apparently a working man might eat 5-6kg of potatoes a day. (This should all be put in its social context, which you can read about here.)

Phytophthera infestans apparently arrived in Ireland in September 1845, blown across from fields in England, or in ships from the American colonies. The Irish potato crop failed in a matter of weeks, leading to widespread famine among the peasantry. (The UK wasn’t affected as badly because people were not so heavily reliant on a single food crop.) Unbelievably, at the same time as people were starving, Irish cereal crops (wheat, barley & oats) were being exported to England…

With nothing else to eat (the price of cereals was out of the reach of your average peasant, & efforts by the British government to supply corn at the beginning of the famine were fairly ineffective), people turned to eating turnips, weeds, seaweed, even grass. Death rates soared, although at least as many people died of infectious diseases (typhus, disentery etc) as from starvation. Understandably, many peasant farmers could no longer pay their rent, & there were wholesale evictions; many of those who were turned off the land ended up being transshipped to Canada & the US. Eyewitness accounts of the time make harrowing reading. The combination of migration and deaths due to starvation & disease saw the Irish population plummet: somewhere between 500,000 & 1.5 million died, and more than 1,000,000 people emigrated, during & immediately after the famine. Even after it was over the population continued to fall, getting down to about 4 million by 1911.

There’s a lesson for us all in the story of the Irish potato famine. Just 15 crop plants provide about 90% of the world’s food energy intake, with three of them (rice, maize & wheat) making up 2/3 of this. These three crops are the staple foods for more than 4 billion people. And as the story in Science shows, P.infestans & other biological threats to our food security are still with us.

Anon. (2010) Armed and dangerous. Science 327(5967): 804-805 DOI: 10.1126/science.327.5967.804

but it does no harm… Alison Campbell Feb 09

No Comments

Over on Code for Life, Grant’s recently put up some posts concerning homeopathy (here & here, for example). He’s also suggested that homeopathic (& other) remedies should carry disclaimers to do with their active ingredients (or lack thereof) and what they can & can’t do.

Anyway, one of the common responses to articles critical of homeopathy & other ‘complementary & alternative medicines’** is that, even if they ‘work’ only via the placebo effect, at least they do no harm. I would argue that if the placebo effect masks an ongoing problem, then it is doing harm. And the same is true if patients are led to stop taking necessary medication. But – & I think more seriously – here’s an example where following a homeopathic prescription may do considerable damage: homeopathic vaccinations.

The article I’ve linked to (posted  by Peter Bowditch of ratbags.com, for purposes of serious critiquing) makes the following claim:

Homeopathic immunisation is effective against poliomyelitis, chickenpox, meningococcal disease, hepatitis (all types),Japanese encephalitis, Hib, influenza, measles, pneumococcal disease, cholera, smallpox, typhoid, typhus, whoopingcough, rubella, mumps, diphtheria, malaria, tetanus, yellow fever, dysentery, and many other epidemic diseases.

Well, they’re pretty safe in making this claim for smallpox as that’s been eradicated in the wild, but the rest are still with us in various parts of the world. These are pretty extraordinary claims for products that, by their very nature, usually contain no molecules whatsoever of their supposed active ingredients. Most of the diseases on that list can be fatal if left untreated, & can leave survivors with ongoing physical problems. So you’d expect to see some decent evidence that homeopathic ‘vaccines’ actually perform as claimed – good, solid evidence-based data on patient outcomes. Not vague statements that lack names, dates & other data, which is all the article provides. Yet hard evidence appears to be lacking.

Take influenza, for example. Here’s an evidence review from our Ministry of Health – a meta-analysis of a number of studies examining claims for a homeopathic ’remedy’ called oscillococcinum (made from the liver of a dead duck, by the way, although it’s so highly diluted that you would be hard-pressed to find any evidence at all of duck in your liquid or pills). Oscillococcinum is prescribed by many homeopaths as both a prophylactic & treatment  for flu. The Ministry’s evidence summary examined data from a systematic review & a total of 7 clinical trials (representing 3459 patients). Three of the trials (2265 patients) found that the oscillococcinum preparation did not prevent the flu. The other 4 trials looked at its efficacy in treating flu – oscillococcinum shortened the length of the illness by about 6 hours. In other words, this particular homeopathic remedy didn’t do what was claimed for it; it acted as neither vaccine nor treatment. (There did appear to be some reduction in severity of flu symptoms, but as such data tend to be self-reported it’s hard to be sure how much represented actual effect of the preparation & how much reflected patient expectations that they’d get better.)

But that’s just the flu – what about the other claims made in that article? Since they’re extremely vague, & cite no evidence whatsoever in their support, it’s rather difficult to judge. But a scirus search for published data on the claimed efficacy of homeopathic treatment during a a supposed polio ‘epidemic’ in Buenos Aires turned up nothing. And frankly, if the stuff was that good I’d expect to see hard evidence of that fact. Given the potential severity of polio, I’m sure doctors around the globe would love to have an addition to the treatments available to them. But then, it seems that most individuals affected by polio don’t progress to the severe paralytic form of the disease – so many of those Buenos Aires patients claimed as success stories for the homeopathic ‘vaccine’ may in fact have had the less severe infection, easily confused with the flu. With no actual data in the article, how can we tell?

So it’s hard to see how the claims made in the article for homeopathy’s ability to prevent serious, potentially lethal, infectious diseases can be supported. What’s more, I wonder how those claims can sit with any code of conduct for homeopaths. After all, the Society of Homeopaths in the UK has a code of ehtics which clearly states that no advertising may be used which expressly or implicitly claims to cure named diseases. And another homeopathy site expressly states that TCAM practitioners are prohibited from… treating infectious, communicable diseases (which is pretty much everything on that list I cited). Where does the responsibility lie, if someone follows this advice, takes (for example) a malaria ‘vaccine‘, contracts the falciparum form of the disease, and dies?
…………………………………………………………………………………………………………………………………………………………………

PS CAM isn’t really the right term. If a treatment works, can be shown to work in a reliable manner, produces positive outcomes that can be confirmed by other workers in the field – then it’s medicine. If it doesn’t – whatever it is, medicine it’s not.

And Ben Goldacre has an excellent article on the subject here.

the 8-glasses-a-day myth Alison Campbell Feb 07

2 Comments

I was at the gym yesterday when I read something in a women’s mag that quite put me off my stride on the cross-trainer. (In my defence, I’d forgotten to take a book & the only other reading material on offer was car magazines.) The offending article contained the following factoids: you need to drink at least 8 glasses of water a day, if you don’t drink it your cells will be sloshing in dirty recycled water, tea & the like won’t do – but ‘lemon water’ will & is especially good because it will alkalise your blood & help you metabolise fats (which your cells store to protect them against acids…).

Hmmm. Let’s look at all this through the lens of science – or to put it another way

funny pictures of cats with captions

First up – the idea (very widely promoted) that you have to drink at least 8 glasses of water a day in order to stay healthy is actually a myth, not science. Yes, our bodies contain a considerable amount of water – around 60% of body weight, with a fair bit of variation between the individual organs (& between men & women), & we do need to replace that which is lost through sweating, urination, breathing, & in our faeces. These losses can amount to 2-3 litres per day. But that definitely doesn’t mean you have to drink at least 8 glasses of water a day on top of everything else – any fluids are OK and there’s a fair amount of water in food as well, particularly in fruit & vegetables. Not only do we get water directly from various foods, but there’s also a certain amount of water generated through the metabolism of the carbohydrates they contain. (It is possible to drink too much water. This can lead to ‘water intoxication’, when the body becomes hyponatraemic: cellular fluids become so dilute that normal biochemical processes don’t work properly, a state that can be fatal.) In normal circumstances, your body’s normal homeostatic mechanisms operate to maintain water balance: when you enter a slightly dehydrated state, not only are you stimulated to drink but your kidneys reduce the volume of urine they produce. Be slightly over-hydrated, & urine volume increases. (I can still remember getting a lecture about this in Christchurch airport, prior to flying down to Antarctica. The air is so dry down there that it’s easy to become a bit dehydrated, & we were told all about the warning signs in terms of urine volume & also colour – very pale straw, Good; brown, Bad…)

What about the concept that if you don’t drink those 8 glasses a day, your cells will be bathed in ‘dirty’ recycled water? Again, no. This one shows a basic misunderstanding of how kidneys do their job. And they’re certainly not flushing out yesterday’s ‘used’ water & replacing it with the nice fresh stuff you drink today, not in the way that article implied. Water is water, as far as your cells are concerned, & it doesn’t come stamped with a use-by date.

The lemon juice one I found rather puzzling. It’s hard to see how lemon juice (which is acidic) is going to ‘alkalise’ anything… In addition, your blood pH is already regulated in a rather tight range: between 7.35 & 7.45. Treatment for some illnesses (eg kidney stones) may involve the use of urinary alkalinisers – but these have minimal effects on blood pH. Urine pH is increased all right – as your body excretes excess bicarbonate ions in order to keep the blood pH at its normal closely regulated level. And a fat burner, lemon juice ain’t – my Significant Other will have to find another excuse for adding lemon to his G&Ts!

« Older Entries