Iodine in Organic v Conventional Milk

Does the news that organic milk contains less iodine than non-organic mean mean you should switch? Headlines about a recent study from Reading University being cited in the Guardian and Telegraph today would certainly make you think so. While the journalists themselves have attempted to balance the story with quotes from some experts, it seems sub editors just can’t stop themselves from penning frightening didactic headlines.

The fact that this isn’t actually news,  but evidence to be added to an ongoing area of study is rarely mentioned in the stories either. Food science is a continuum, and the problem with pumping out stories that represent one piece of a large and ever growing puzzle does little for consumer confidence or understanding. Whether it results in positive behavioural change could also be debated. My experience is that it usually confuses people or radicalises them to choose one or other side of the debate without consideration of all the facts. As a nutritional therapist trying to advise people on how to improve their diet while taking many differing factors (preferences, micronutrient needs, personal ethics) into account, this can be incredibly frustrating.

To see how complicated this can be let’s just take a random review study from 1979 , which pointed out that iodine feed supplement had caused an increase in milk iodine levels and warned that adults consuming more than even ½  litre could supply more than the recommended adult daily dose. It’s an old study and by no means gold standard, but I’m cherry picking to illustrate a point – that being, are there some additional questions we might want to ask when deciding what to make of media reports.

For example, have things changed markedly since the late 70s in the dairy industry? How do accepted levels of iodine then compare with today? Is there a recommended level of iodine in milk that has been agreed on by public heath experts?  If so, does this take individuals’ widely varying needs into consideration? Does focusing on iodine levels in milk detract from other potential sources in a healthy diet? Are the benefits of increased iodine offset in any way? Or even a basic question such as – does supplemented grain feed trump grass fed milk across a variety of important nutrients? The Soil Association thinks not.

You can begin to see how it would take years of study and and a PhD in dairy farming and food science to begin unravelling answers to these questions. Thankfully, there are people trained to do just that.

My point isn’t that we should ignore such studies – I personally find them fascinating. It’s just that we should expect the media to be more responsible about reporting them because what many will take from the articles is not a balanced review of the pros and cons of organic v non-organic or the importance of including other food sources of iodine etc., but a sense that somehow they will be damaging their child’s intelligence if they give them organic milk!

Journalists could begin by acknowledging the background to an issue and placing latest results of one particular study into context. Scary headlines about a complicated subject (especially those directed towards pregnant women who have enough to deal with already) need a longer, more intelligent analysis. Issues that involve financial interests on both sides of the organic v inorganic farming debate are especially troublesome. And if the journalist hasn’t got enough time to devote to this then they should either provide more links in the story to those that do and have a stern word with their sub-editors.


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