Dara O’Briain holds a Sense About Science logo
Tracey Brown, Director of Sense About Science, has responded to my article which criticised part of her recent lecture (see The ugly truth about critics of “the ugly truth” in science). Her response is in the form of notes inserted into my article at the points she disagrees with.
Here I include those sections of my article she responded to – with her responses in red. Hopefully, this will give readers the context required – and if anyone wants more they can refer to my original article.
I answer Tracey’s comment in the next post Responding to Tracey Brown on fluoridation.
She made these points – and claimed that some of our social policies are based on insufficient information. My point was actually that we sometimes assume that there’s a stronger body of evidence than there is because we forget to question. I didn’t touch the question of what is sufficient. Or that we sometimes exaggerate the amount and quality of information we have to support these policies. That is the “ugly truth” she highlighted in her lecture.
Unfortunately though, her lecture was a practical example of another “ugly truth” – simple declarations are not enough. One’s criticisms of accepted knowledge are not necessarily correct or justified just because one is being critical. No, really? There is still the responsibility to base one’s criticism on facts – and to properly research the area before making critical claims. She based her criticism of at least one social health policy, community water fluoridation, on inadequate knowledge – claims from anti-fluoride campaigners she uncritically accepted. There is nothing in the relevant 4 minutes of my lecture to tell you this.
Tracey claimed that community water fluoridation (CWF) has very little empirical justification. She gave two reasons:
- The social health policy is based only on the original research which is over 70 years old and does not measure up to current scientific standards. This is different from what I said. I said that the US and UK’s adoption of 1 part per million as the level at which fluoride’s benefits are achieved and fluorosis avoided is based on studies conducted in the 1930s. I said that these studies did not have the controls in place that we usually expect today of evidence in public health.
- Data shows that the oral health of both fluoridated and unfluoridated countries has improved over recent decades and this has more to do with the use fluoridated toothpaste and improved health care than CWF. This is what I actually said: This near universal fall has been attributed to fluoride in toothpaste and improvement in dental hygiene and dentistry. Some argue that this masks residual problems for a socially deprived sub-population, and fluoridation is needed for them. That is a good argument and more generally an issue in public health – it is administered to everyone to produce benefits only for some.
These are, of course, two claims made again and again by anti-fluoride propagandists and campaigners. She could have taken her critique directly from one of Paul Connett’s political submissions to councils considering fluoridation. If she did so, she was irresponsible as there are plenty of experts who could have provided information of far better quality. But as I didn’t, this is irrelevant ad hominem.
I contacted Sense About Science and found out that Tracey used the following papers to “formulate” her comment on fluoride. A colleague sent you two papers, saying ‘that helped formulate’. It wouldn’t have been my description but it is clear that these were not all.
Peckham, S. (2012). Slaying sacred cows: is it time to pull the plug on water fluoridation? Critical Public Health, 22(2), 159–177.
Cheng, K. K., Chalmers, I., & Sheldon, T. a. (2007). Adding fluoride to water supplies. BMJ (Clinical Research Ed.), 335(7622), 699–702.
So, let’s consider Tracey’s claims about CWF
- The first claim is just silly. Of course, decision makers use the information available at the time – 70 years ago they used the information that was available then. But fluoridation decisions have been made again and again over the years and it is perfectly natural that decision makers will use the current information for thoseThe efficacy and safety of CWF have been investigated many times since it was first introduced. Science does not stop after a single study. If Brown had made a simple literature search she would have realised that (see Water fluoridation effective – new studyfor just one recent example – there are many others). Or, given that none of us have the time and expertise to be well informed about a wide variety of subjects, she could have consulted somebody with up-to-date knowledge and expertise on the subject. She certainly should not have relied solely on the very one-sided papers by Peckham (a well-known UK anti-fluoride activist) and Cheng et al. Solely? You’ve made that up. This also sets up a straw man to knock down. As above, I stated, briefly, that the one part per million figure originates from those old studies. Other parts of the world have rejected it in favour of different concentrations. My reading of the subsequent research on concentrations was that it was not possible to come up with a clear case for one part per million, as opposed to say 0.7 as used elsewhere, and that although the need for controls is better understood and sometimes applied, the multiple and variable sources of other contributors to dental health have made it harder to get a signal from the noise. In the lecture, I pointed out that it’s very difficult to control and measure the dose that people actually get from water. It’s not clear whether you disagree with this.
- From the audio Brown appeared to use this graphic (below – left image) from Cheng et al., (2007) which is very similar to the one promoted by the anti-fluoride propagandist organisation Fluoride Action Network. I have discussed this graphic in several articles and in my debate with Paul Connett (download the pdf) It is based on extremely limited WHO data (hence the straight lines), makes comparisons which ignore the multiple factors influencing oral health, and ignores the within-country data which show the efficacy of CWF (such as for Ireland in my second figure). Yes, I hope you don’t mean that we shouldn’t show WHO data if they have been used by a campaign we disagree with. As my point was simply to show that the data for countries with and without fluoridation is a fairly similar downward trajectory, which is surprising to people, including me, who expected to see greater variation, I can’t understand what is objectionable here. Whether it ignores in-country differences is irrelevant. National data ignore in-country differences in natural fluoridation, access to dentistry, use of toothpaste too. As I went on to say, these data may mask problems for socially deprived populations.
You’re responding as though I’m campaigning against fluoridation, when I am simply showing that the case for it is not as clear cut as many of us might expect. I pasted above and paste again here, my actual words: This near universal fall has been attributed to fluoride in toothpaste and improvement in dental hygiene and dentistry. Some argue that this masks residual problems for a socially deprived sub-population, and fluoridation is needed for them. That is a good argument and more generally an issue in public health – it is administered to everyone to produce benefits only for some.
Unfortunately, the “ugly truth” Tracey Brown demonstrated was that even scientists, and supporters of science, can be fooled by the claims of anti-science campaigners if they are too lazy to do their own checking. Perhaps she also demonstrated that even scientists, and pro-science people, can suffer from confirmation bias – just like anyone else. They can sometimes adopt a partisan position which restricts them to considering only the misinformation and distortions peddled by anti-science campaigners. This is rude. It is also immensely brittle on your part, despite the grand statements at the start of your piece about not being defensive. My overall point was that this is surprisingly not as clear cut and well-established as we might expect, as indeed I expected. And you’ve drawn from this that I have adopted a partisan position which restricts me to considering only the information and distortions of the anti-science campaigners. Even based on the papers you know I looked at, never mind the many others, do you consider Iain Chalmers, a founder of the Cochrane Collaboration, to be an anti-science campaigner?
The dilemma is that we, as individuals, can not be experts in everything. We are not capable, individually, of making a well-informed critical and objective judgement on all the issues we may have to face in preparing a lecture like Tracey’s. We have to be careful about relying on our own biases or poorly informed memories. We have to recognise our limitations and not be afraid to consult experts for clarification, updating knowledge or even just getting one’s head around complex issues. I didn’t actually have such memories: as I said clearly in my lecture, I recently looked into it and was surprised. If I had a bias it was that the evidence was surely stronger and clearer than it turned out to be. My observation that it is weaker does not mean there is no case for fluoridation. I used this example to show that we tend not to question things that have been around a long time. I went on to say, especially when the madcap arguments appear to be on the other side. Throughout this piece you seem to refer to anti-fluoride campaigner statements (I’m assuming you’re accurate about them – I’ve not read them) in precisely that way: as an indicator of what is most likely to be correct.
In this example, I have sufficient knowledge about the science behind CWF to judge this aspect of Tracey’s lecture and see she was mistaken. But what about the other subjects she covered? For example, she claimed that current health advice on cholesterol relies on inadequate research and could be wrong. Do I take her word for it? No! Of course not! That is the whole point of my lecture. I certainly don’t feel I should – if she is wrong about CWF she may be just as mistaken about cholesterol.
That also makes me wonder if the Sense About Science organisation is as credible in its pronouncements as I used to think it was.
I respond to Tracey’s comments in my next post Responding to Tracey Brown on fluoridation.