At the weekend, the Scotsman on Sunday carried an article claiming that a posited increase in thyroid problems in Scotland was down to an increase in vegetarianism.
It claims that:-
Experts believe a lack of iron from reduced red meat consumption and large amounts of soya in some vegetarian meals has contributed to the increase of more than 300 per cent in Scotland’s thyroid drug bill.
What experts? I presume this is one:
Lyn Mynott, chief executive of charity Thyroid UK, said a lack of proper nutrition and a meat-free diet were contributing to a rise in the numbers of people seeking support.
She said: “We know there is an increase in cases of thyroid problems as we have an increasing number of people coming to us. You can also look at prescription cost analysis to see this trend.
“Your thyroid needs iron and a lot of people don’t eat meat and are eating a lot more soy.”
I do not know what Lyn Mynott’s scientific expertise is and frankly it is not relevant as no evidence to support these assertions is provided. The on-line version of the article does contain an embedded link which is claimed to lead to the statistics behind the story. In fact it just leads to the Information Services Division Scotland home page. None of the available links support the article’s contention so I tried the search function, with the following results:
Your search -thyroid vegetarian- did not match any documents.
No pages were found containing”thyroid vegetarian”.
Your search -vegetarian diet and thyroid – did not match any documents.
No pages were found containing”vegetarian diet and thyroid “.
My own investigations of the iron content of food found this which while showing that meat and fish are the richest sources of iron, it is still possible to get sufficient from a varied vegetarian diet and this which is more extensive but also would support the notion that it is possible to get sufficient iron from a vegetarian diet. It also says that while beef (for example) has roughly 1 to 3 mg of iron per portion, soybeans have roughly 4 to 8 which does kind of sink the notion that eating less red meat and more soya is leading to iron defficiency.
Icidently, I had always been under the impression that thyroid problems were caused by iodine defficiency, not iron defficiency. On that subject this research concluded that:
U.S. vegetarians are iodine sufficient. U.S. vegans may be at risk for low iodine intake, and vegan women of child-bearing age should supplement with 150 μg iodine daily. Environmental perchlorate and thiocyanate exposures are not associated with thyroid dysfunction in these groups.
It is starting to look suspiciously like the writer has taken two trends (decrease in meat eating, increase in thyroid problems) and assumed that they are connected, which is ridiculous – on that basis one could conclude that the decrease in tobacco use has caused the increase.
Fair is fair though, it is possible that the article is based on some statistics which my google-fu is too weak to find so I sent the following email to the newspaper:
Subject:Article linking thyroid problem with vegetarianism
I read the above article (http://www.scotsman.com/scotland-on-sunday/scotland/vegetarian-diet-blamed-for-thyroid-issues-1-2209159) with interest but I note that the alleged link does not go to the stats as claimed but merely to the Information Services Division Scotland home page. This contains no links to the stats, nor does the search function provide any.
I would be most grateful if you could provide me with a link to the stats to which the writer refers.
I will blog any response.
(thanks are due to the good people on Bad Science who supplied a couple of the above links)