Posts Tagged health & medicine

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.

on your bike Alison Campbell Feb 13


I drive a car. I also ride a bike to work a couple of days a week (an 18km round trip each time). And this is not a post on the science of either, but a plea to some car drivers for a bit more consideration (& road space).

Today I consider myself lucky to have got to work in one piece. To the driver of the white company van who came up fast on my right & turned left in front of me – yes, I know you indicated as you pulled alongside, but I still had to brake hard to avoid being collected as you shot down that side road. Were you really in such a hurry that waiting a couple of seconds for me to clear the intersection was going to cause an unbearable delay?

And the car driver who cut into the cycle lane ahead of me on that sweeping bend between 5 Crossroads & Southwell School – I wear a fluoro reflective jacket & have a cover of the same on my back-pack, there are reflective strips on my panniers, and my flashing lights were going front & back, so “I didn’t see you” would not have done you much good had you hit me with all the inevitable consequences of a heavy moving object hitting a much smaller one.

And don’t get me started on the idiots who think it’s a good idea to chuck bottles into the marked cycle-way, so that at rush hour cyclists have the choice of an almost inevitable puncture or to move onto the carriageway & take their chances with the cars.

Yes, there are cyclists who don’t obey the road rules & take foolish risks – just as there are car drivers who do the same. But most cyclists – like most motorists – are careful: we can imagine all too well the consequences if we aren’t. It would be wonderful if everyone thought about those consequences too – in an accident involving maybe 90kg of cyclist+bike travelling at 25kph, & a tonne or of car doing 50 (or even 25), the cyclist is always going to come off very much the worse for wear.

And I’d rather we all did our bit to avoid those consequences.


Actually, while I’m on my hobby horse erm, I mean ‘soapbox’ – could those cyclists who come rushing up at speed behind other cyclists (& behind walkers on the river paths) please please let those ahead know you’re coming? Ringing the bell would be good, or just calling out a cheery ‘excuse me’. It’s incredibly disconcerting to have someone whoosh past when you haven’t heard them coming (modern bikes really do run quietly). Thank you :-)

/vent over

you could probably sell anything with the right sales pitch Alison Campbell Nov 06


My post about zeolite & the supposedly ‘chemical-free’ nature of various dietary supplements containing the stuff led to some interesting comments, & generated a few ‘I wonder if…’ moments. After all, as Krebiozen said (in the comments thread to that post):  With the right sales pitch you could probably persuade some people that eating feline ‘tootsie rolls’ is good for them. They are 100% natural after all!

And goodness knows, if people will eat kitty litter itself (some brands are basically just zeolite) for its supposed health benefits **, he might just have a point. After all, how much of a step is it from coffee beans that have been through the gut of a civet to some of the other organic (see, that’s a Good word) materials emanating from the back end of a feline? As Herr Doktor said, there’s probably quite a bit of nutrients there, given that cats (being carnivores) have a relatively short gut & a reasonably rapid transit time (you will find perhaps more than you wanted to know about cats, their guts, & the products of said guts here): once ingested, food may reach the large intestine within 8 hours, although it may take well over a day to move on out from that point. (This was determined by giving cats capsules containing radioactive markers – after first emptying the colon using a series of enemas. Cats have an alarming array of sharp pointy bits – I would not care to try administering one enema, let along a series of them!)

Of course, much of the mass of faeces is actually bacteria: around 50%, in humans. So you’d want to scrub them out of the ‘tootsie rolls’, somehow. At first I thought you’d also need to remove the eggs from tapeworms and roundworms that would also be present in cat poo. But on second thoughts – why would you? After all, in newspapers from the early 1900s, you could find ads for diet pills containing tapeworm eggs (& there’s various urban myths around that may be based on this). And I was gobsmacked to find at least one website offering ‘diet pills’ that supposedly contain these eggs. (Whether they do or not is open to question.)

As for the roundworms… Well, any infection with a significant number of roundworms is going to leave you feeling rather the worse for wear. But an intriguing study from the University of Singapore suggests that a protein produced by a species of roundworm may possibly reduce the strength of allergic reactions. The impetus for this study was the observation that there seem to be fewer allergies in populations with a high burden of roundworms, something that’s also discussed in Robb Dunn’s entertaining book The Wild Life of Our Bodies: predators, parasites and partners that shape who we are today (2011, Harper Collins).

So, there’s our marketing ploy: all-natural, organic (& therefore ‘chemical-free’), & not only an excellent nutrient supplement but also a slimming aid & something that ‘supports your immune system.’ What’s not to like?

Except… if I can think of it, you can pretty much guarantee that somewhere, someone else will have beaten me to it. (As, indeed, the ads for tapeworm-egg diet pills demonstrate.) And also, imagination is one thing, & humour is good, but if you consider yourself a good, ethical person – & I do – then you’ll never go any further down that road.

** As Herr Doktor Bimler found out (see his first comment), at least one site selling ‘liquid zeolite’ promotes it as a means of removing teh ebil aluminium from your body. One suspects the person or persons making this claim are not chemists – for zeolite is an alumino-silicate mineral, & consuming the stuff is more likely to add to your overall aluminium load than it is to reduce it! (I would prefer to think that the sellers are ignorant of chemistry, as the alternative is that they know damn well what it is & don’t particularly care.)

deconstructing zeolite Alison Campbell Nov 02


Years ago, when my old dog Bella was still alive, I was the happy recipient of several doggy haiku verses. One of them read:

The cat is not all bad./She fills the litter box/with tootsie rolls.

I was reminded of this when reading the comments thread on a recent post by Orac. Some commenters were discussing claims that the mineral zeolite has enormous healing powers and other health benefits. Going by the amount of the stuff that Bella would have ingested along with the aforementioned ‘tootsie rolls’, perhaps it’s no surprise that she reached the advanced (for a labrador) age of 15…

However, the comments left me with alarming mental images of people also chomping through kitty litter, albeit in a finely-ground form and without the organic inclusions that so delighted Bella (& which also delight young Ben-the-poodle). You can certainly find the stuff widely promoted on-line (at, for a start). And yes (alas!) there are purveyors in New Zealand as well, although the outfit that came up tops on a google search sells it in liquid form.

I really should send them a bill for a new irony meter. For on reading the promotional blurb, one is told that It is chemical free: LIQUID ZEOLITEâ„¢ is processed without chemicals. This, on the same page that proudly proclaims the actual materials in this wonderful product:

humic acid/fulvic acid complex, ultra-cleansed volcanic zeolite (clinoptilolite) and a blend of angstrom-sized trace minerals, phyto-nutrients, macro-nutrients & micro-nutrients,DHQ (Dihydroquercetin), “M-Water”, citric acid, Preservative: potassium sorbate.

You can see why the meter went kablooie :-)

Humic & fulvic acids are produced by the breakdown of dead organic matter, & are widely used in agriculture as soil supplements. Since to the sellers of ‘natural’ health products the word ‘chemicals’ is used for teh ebil ‘artificial’ substances, I suppose I can see why they would classify these acids as ‘non-chemical.’ Clinoptilolite is the technical name for zeolite, & from the seller’s blurb the ‘ultra-cleansing’ has been done by treating it with concentrated humic acid. So that’s all nice & natural too.

I’m intrigued by the idea that the product contains ‘angstrom-sized trace minerals’, since angstroms are definitely on the nano-scale and people do have concerns about the health implications of products containing nanoparticles (not an issue I want to address here). Goodness knows what the ‘phyto-nutrients’ et al. are, so it’s not possible to check how they are extracted – in commercial quantities – from the source plants…

DHQ is apparently one of the most potent [antioxidants] in the whole world, or so this site tells us, & it has all sorts of claimed health benefits. (With a name like dihydroquercetin, I thought, it sounds like something you’d get from oak trees – turns out that it’s extracted from larches.) I’m always a bit puzzled about the promotion of antioxidants – the process of oxidative phosphorylation is key to production of energy in our mitochondria, & that’s definitely not something I’d want to stop! Extraction of DHQ, however, definitely involves those nasty chemicals, in the form of organic solvents. Do the liquid zeolite folks know?

“M-water” – this is pure comedy gold in its own right. Honestly. I couldn’t make this stuff up if I tried, which I suppose suggests a certain failure of the imagination. Apparently M-water is much better at hydrating your cells than the stuff that comes out of the tap & – as one of Orac’s regulars remarked – is obviously much better than the nasty dehydrated water that you get when the tap’s turned off. He was right on the button, if the M-water sellers are to be believed: apparently most other functional water products will actually cause dehydration instead of improving hydration. As I said, you couldn’t make this stuff up.

Citric acid – well, I suppose someone could be squeezing a lot of lemons for this product, & since lemons are natural then they must also be chemical-free. But potassium sorbate? It’s obtained by neutralizing potassium hydroxide with sorbic acid, an unsaturated carboxylic acid that occurs naturally in some berries. Yup, they definitely owe me for a new meter!

And that’s even without going into the various health benefits claimed for consuming zeolite in its various forms. One of which is that it chelates various ‘toxins’ including mercury. A search of pubmed using ‘zeolite chelation’ as the search term produces just 2 references, neither of which looked at zeolite in a human-health context. ‘Nuff said.

weird ‘science’ letter of the week Alison Campbell Apr 28


Some of my colleagues over at Sciblogs (NZ) publish the occasional ‘crazy science’ letter. I thought I would join them, having just read the following in one of our local free papers.

Fluoride and Viagra – what do they have in common? As it turns out, a lot.


Well, no, only to those armed with little biological knowledge & a tendency to conspiracy theories.

Water fluoridation was sold to us as the ‘magic pill’ to prevent tooth decay. The sugar producers were thrilled. Now we could eat as much sugar as we liked and not worry about our teeth.

Nice straw man there. I doubt the sugar producers were ‘thrilled’, & to my knowledge no-one promoting fluoridation has also advocated eating a poor diet.

But whoops – what happened next? Diabetes. But don’t worry, there is a ‘magic pill’ for diabetes. The more insulin we take, the more sugar we can eat.

No evidence here of cause-&-effect. We’re not provided with data that might show any putative relationship between the uptake of fluoridation and an upswing in diabetes. There is a link between ‘westernised’ diets (not simply sugar intake) & diabetes: Nauru has one of the highest incidences of diabetes in the world, much of it related to diet although there also appears to be a genetic link. But I could find no indication that Nauru’s water supply is fluoridated…

Plus there’s a lack of distinction between the two types of diabetes. While type 2 diabetes is related to – & to a certain extent, can be controlled by – diet, type 1 diabetes is not. The writer also appears unaware that insulin is not a magic bullet: insulin-dependent diabetics have to be very careful indeed regarding their diet & certainly don’t see it as a means to gobbling sugar.

Pharmaceutical companies were thrilled – no need to change our diet and cure ourselves of diabetes. Bring on the sugar.

Again, a straw man argument. Not to mention that changing the diet won’t provide a cure for type 1 diabetes. On the other hand, doctors will actively encourage those at risk of developing type 2 to change their diets (& exercise regimes) as in some cases this can eliminate the need for drug treatments.

But whoops – 10 years on, diabetes drugs have taken their toll and there is something not up in the bedroom. No problems – where’s the Viagra ‘magic pill’? And bring on the sugar while you are at it.

Actually it’s the untreated diabetes that is more likely to have the implied effect… And of course, our writer is ignoring the fact that a multitude of factors – including simply growing old – can impact on bedroom performance. Some may use Viagra to help deal with this, some may not.

Isn’t there something wrong with this picture? How about we do what we are supposed to do – eat properly. Tooth decay is nature’s way of giving us a timely message. Tooth decay is easier to fix than diabetes, heart disease, cancer, high blood pressure.

Nice attempt there to imply that all the health problems listed are a direct result of fluoridating a water supply.  There is, however, a reasonably strong correlation between at least three of them and aging. I wonder what nature’s message there might be?

How about we nip our health problems in the bud and stop focusing on the wrong things? Water fluoridation is not about tooth decay. Hexaflurosilicic acid is a waste product that is being disposed of in our drinking water. Ask Mr Google and find out for yourself.

Perhaps the writer would care to tell us what water fluoridation is ‘about’?

world blood donor day Alison Campbell Jun 14

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Today (June 14) is World Blood Donor Day. Blood’s not a product that keeps particularly well (about a month, if we’re talking whole blood) & blood banks are always looking for new donors. In New Zealand, around 3,000 donations per week are needed in order to meet the demand.

So, if you’re been considering giving blood, put the thought into action & rock on down to your nearest NZ Blood Service centre. Giving blood’s a straightforward process & can make a profound difference to the lives of others.

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