Tag Archives: science

I don’t “believe” in science – and neither should you

We should be very careful about naively accepting claims made by the mainstream media – but this is also true of scientific claims. We should approach them intelligently and critical and not merely accept them on faith

I cringe every time I read an advocate of science asserting they “believe in science.” Yes, I know they may be responding to an assertion made by supporters of religion or pseudoscience. But “belief” is the wrong word because it implies trust based on faith and that is not the way science works.

Sure, those asserting this may argue that they have this belief because science is based on evidence, not faith. But that is still a copout because evidence can be used to draw conclusions or make claims that are still not true. Anyway, published evidence may be weak, misleading or poorly interpreted.

Here is an example of this dilemma taken from the Vox article Hyped-up science erodes trust. Here’s how researchers can fight back.

The figure is based on data published in Schoenfeld, J. D., & Ioannidis, J. P. A. (2013). Is everything we eat associated with cancer? A systematic cookbook review. American Journal of Clinical Nutrition, 97(1), 127–134.

It is easy to cite a scientific article, for example, as evidence that wine protected one from cancer. Or that it, in fact, causes cancer. Unfortunately, the scientific literature is full of such studies with contradictory conclusions. Usually based on real data and statistical analyses which show a significant relationship. But, if it is easy to find such studies which can be claimed as evidence of opposite effects what good is a “belief” in science? All that simple “belief” does is provide a scientific source for one’s own beliefs, an exercise in confirmation bias.

This figure should be a warning to approach published findings in fields like nutritional epidemiology and environmental epidemiology critically and intelligently. One should simply not take them as factual – we should not “believe” in them simply because they are published in scientific journals.

Schoenfeld, & Ioannidis (2013) say of the studies they investigated that:

“the large majority of these studies were interpreted by their authors as offering evidence for increased or decreased risk of cancer. However, the vast majority of these claims were based on weak statistical evidence.”

They discuss problems such as the “pressure to publish,” undervaluation or not reporting negative results, “biases in the design, execution and reporting of studies” because nutritional ingredients “viewed as “unhealthy” may be demonized.” 

The authors warn that:

“studies that narrowly meet criteria for statistical significance may represent spurious results, especially when there is large flexibility in analyses, selection of contrasts, and reporting.”

And:

” When results are overinterpreted, the emerging literature can skew perspectives and potentially obfuscate other truly significant findings.”

They warn that these sorts of problems may be:

“especially problematic in areas such as cancer epidemiology, where randomized trials may be exceedingly difficult and expensive to conduct; therefore, more reliance is placed on observational studies, but with a considerable risk of trusting false-positive”

These comments are very relevant to consideration of recent scientific studies claiming a link between community after fluoridation and cognitive deficits. Studies the are heavily promoted by the anti-fluoridation activists and, more importantly for scientific readers, by the authors of these studies themselves and their institutions. I have discussed specific problems in previous posts about the results from the Till group and their promotion by the authors.

The merging of pseudoscience with science

We seem to make an issue of countering pseudoscience with science but in the process are often oblivious to the fact these to tend to merge – even for professional scientists. After all, we are human and all have our own biases to confirm and our jobs to advance.

This is a black and white contrast of science with pseudoscience promoted by Skeptics. It’s worth comparing this with the reality of the scientific world.

Do scientist always follow the evidence? Don’t they sometimes start with the conclusion and look for evidence to support it – even clutching at the straws of weak evidence (statically weak relationships in environmental epidemiological studies which are promoted as proof of harmful effects)?

Oh for the ideal scientist who embraces criticism. Sure, they are out there but so many refuse to accept criticism, “circle the wagons” and end up unfairly and emotively attacking their critics. I describe one example in When scientists get political: Lead fluoride-IQ researcher launches emotional attack on her scientific critics.

Are claims always conservative and tentative? Especially when scientists have a career or institution to promote. And institutions with their press releases are a big part of this problem of overpromotion. Unfortunately, in environmental epidemiology, some scientists will take weak research results to argue that they prove a cause and then request regulation by policymakers. I discuss this in . Specifically, there is the case of weak scientific data from Till’s research group being used to promote regulatory actions to confirm their biases.

Unfortunately, scientists with biases to confirm find it quite easy to ignore or downgrade the evidence which doesn’t fit. They may even work to prevent publication of countering evidence (see for example Fluoridation not associated with ADHD – a myth put to rest).

Conclusion

I could go one taking each point in order. But, in reality, I think such absolute claims about science are just not realistic. The scientific world is not that perfect.

In the end, the intelligent scientific reader must approach even the published literature very critically if they are to truly sift the wheat from the chaff.

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Bottle fed infants: fluoridated water not a problem

Parents need no longer be concerned about using fluoridated water for baby formula. Photo credit: Life insurance for your heirs

New recommended fluoride dietary intakes by infants and young children in Australia and New Zealand were recently published. The updated values are available online at Nutrient Reference Values for Australia and New Zealand.

This is a regular update – the Australian National Health and Medical research council advises these recommendations be reviewed every 5 years. But the new recommendations are interesting because the upper limit for fluoride intake for infants and young children is substantially higher than the previously recommended upper limit.

Public health policy in Australia and New Zealand aims to adjust fluoride intake at the population level to be high enough to prevent dental caries but low enough not to cause moderate or severe dental fluorosis or other adverse effects. But health professionals have noted an anomaly in recent years.  Dietary intake of fluoride by children may exceed the previously recommended upper levels – even when community water fluoridation levels are within the recommended targets. Despite this the occurrence of moderate or severe dental fluorosis in Australia and New Zealand was rare.

This led to health authorities acknowledging that, for example, bottle-fed infants may sometimes exceed the upper limits for dietary fluoride intake – but still recommending this was harmless. Anti-fluoride activists misrepresented this advice by claiming health authorities were recommending that fluoridated water not be used for preparing formula for bottle feeding. Their claims are incorrect and alarmist. The “warning” simply provided advice that there was no risk of harm but the if parents were concerned they should occasionally use non-fluoridated water to make up baby formula.

In part, this current report is a response to that conundrum.

Why the change?

Anti-fluoride propagandists will no doubt attack this change. They have made capital out of the situation in the past by claiming that infants and young children are getting dangerous levels of fluoride in their diet. They, of course, ignore or hide the fact that despite this, levels of moderate and severe dental fluorosis have not been a problem. They, also misrepresent the situation regarding dental fluorosis and its causes – see Dental fluorosis: badly misrepresented by FANNZ and Water fluoridation and dental fluorosis – debunking some myths.

However, the expert working group who reviewed the literature and came up with the new recommendations did have their reasons. And these were more than just the absence of moderate and severe dental fluorosis.

They also concluded the previous recommendation was not consistent. This is because it was based on the US Environmental Protection Agency’s use of mean dietary intake and not the higher percentile fluoride intake which should have been used for the upper limit.

Consequently, their recommendation for the upper limit of fluoride intake for children up to 8 years of age is 0.20 mg F/kg bw/day (kg bw = kg body weight). The previous limit was 0.1 F/kg/ bw/day. This produces the following upper limits for children of different ages.

In Australia and New Zealand, the estimated upper range of total daily fluoride intake for different age groups ranges from 0.09to 0.16 mg F/kg bw/day – considerably lower than the new recommended upper limit of 0.2 mg F/kg bw/day.

Conclusion

Will anti-fluoride campaigners top claiming that bottle-fed infants consume dangerous levels of fluoride if their formula is made with fluoridated water?

And the rest of us should not longer make the concession that intake levels are above the recommended upper limits – because they aren’t.

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Earthquakes and twitter

New Zealand climate change denial defeated

The High Court decision on the Judicial Review of NIWA’s New Zealand temperature record was issued today. I will comment in more depth next week but interested readers can download and read the judgement themselves.

In short – the arguments made by the climate change denial/sceptics/ contrarian groups were tossed out and costs will be awarded against them.

Here is the judgement’s summary:

“[185] The plaintiff does not succeed on any of its challenges to the three decisions of NIWA in issue. The application for judicial review is dismissed and judgment entered for the defendant.

Costs
[186] The defendant is entitled to costs. Given the time involved and the steps taken, costs on a category 2 time band C would seem appropriate. However, if the parties are unable to agree I will receive memoranda and deal with the issue of costs on the basis of such memoranda.”

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The reality of scientific research

I don’t think simple definitions of scientific method really catch the reality of how research is carried out. That is why I prefer not to use an algorithmic description of scientific method. Instead the definition suggested by Neil deGrasse Tyson appeals:

“Science is doing whatever it takes to avoid being fooled by reality”

Here’s a nice little cartoon outlining how real science can often be a frustrating and messy process.
Click on the image for a larger version)

With thanks to Biology Update (@BiologyUpdate)