The milky way to iodine deficiency

Some of you might have the impression that the path to a healthy diet is full of cunning side passages and contrived corridors. Well, that isn’t that far from the truth, indeed. If you exclude red meat because of all the nasty facts you’ve read in the newspaper, then you’ll need to make sure you get the right amount of iron, zinc, and proteins from other sources. If, on the other hand, you stop eating gluten because you have celiac disease, you have to make sure you don’t end up navigating an ocean of heavily-processed gluten-free products, which might cause you more trouble than joy.

Let’s face it, the solution to one problem is often the cause of another one. And, according to a recent study, iodine deficiency might be the perfect textbook example of this fact.

For starters, let me tell you that the WHO considers iodine deficiency the world’s most prevalent yet most easily preventable cause of brain damage. And the type of milk you choose might play a role.

But what has milk to do with iodine deficiency? According to a recent study published by the University of Surrey in the UK, milk alternative drinks only contain 2% of the iodine usually contained in cow milk. And cow milk appears to be the main source of iodine for the British population[1]. Can you see the connection now? Many people think that cow milk is not as healthy as the dairy industry propaganda back in the old days wanted us to believe, and they have now started to replace it with vegetal alternatives. However, the fact that these products come in the form of milk does not necessarily imply that they replace all of the nutrients contained in milk. Apparently, this is particularly true for iodine.

Lower IQ in children whose mother was iodine-deficient has actually been observed previously, since thyroid hormones appear to be fundamental for in-utero brain development. As a confirmation of this, pre-birth exposure to endocrine disruptors such as PCBs (which can disrupt the functioning of the thyroid hormone) can cause similar effects in newborns. Besides brain damage, other symptoms of iodine deficiency include goiter and hypothyroidism. Unfortunately, iodine deficiency is usually tested in populations rather than individuals by measuring urine iodine secretion[2].

What can non-milk drinkers do to prevent all this? Use iodized salt or other iodine-fortified foods, of course. Foods which are naturally rich in iodine include kombu algae, eggs, and some types of wild-caught fish.

Milk has become one of the most controversial foods, and its health properties are still a matter of harsh debate among nutrition experts. In one of my latest publications with the university of Gothenburg, my former co-workers and I showed that milk intake was associated with increased risk of mortality in two separate studies. One of the two studies, in particular, included about 100,000 subjects from North Sweden.

To reduce the consumption of cow milk seems, therefore, at least partially justified. But if you decide to do so, make sure you don’t forget your daily dose of iodine.

[1] These British researchers analyzed 47 milk replacement drinks, excluding those targeted to children, such as soya, coconut, hemp, rice, almond, oat, hazelnut milk.

[2] American Thyroid Association: https://www.thyroid.org/iodine-deficiency/.