sarahkeenihan

Day 44. Don’t panic!

In September 2012 on September 25, 2012 at 11:49 am

If you saw any news headlines this past week quoting a recently published research paper linking genetically-modified food or weed killers with an increased risk of cancer, my advice would be,

DON’T PANIC.

The paper, published in the journal Food and Chemical Toxicology, contained statements suggesting that cancer in rats increased when they were fed genetically modified corn and/or water spiked with the herbicide Roundup.

Now I don’t have a subscription to that particular journal, and because the paper has been hidden behind a paywall ($31.50 for a single publication, you must be kidding me Elsevier! – for more on that see this Guardian article), I can’t do an analysis of the data myself. But  Australian cancer researcher Ashley Ng has, and he presents a compelling argument as to why the paper is close to useless from a scientific perspective.

His reasons can be summarised thus:

  • Inappropriate choice of study animals – the researchers worked with a strain of rats that is highly susceptible to cancer even under normal conditions;
  • Poor monitoring of and reporting about animals in the control group – you need to know what the health status is of animals which are not exposed to the test agent under analysis, so you have a baseline to compare with;
  • Failure to conduct statistical analysis of the data comparing number of deaths in the control groups to those in the groups eating the modified corn or drinking the spiked water. Statistics give data credibility – they allow scientists and independent observers to say with confidence the study conditions had an effect on numbers of deaths which was over and above that which may have occurred under normal conditions or by chance alone; and
  • Exclusion of some of the study data for argued reasons of space. You can’t just leave data out – the full story must be told. This begs the question why didn’t you show the full data set?

Unfortunately bad science sometimes sneaks through the peer-review process. It’s only via public, informed analysis of new publications that sensible conclusions can be drawn.

[photo thanks to Nate Steiner on flickr]

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