I've recently become interested in the Blood Type diet (I am O+ I don't yet know my secretor status).
Looking at the Blood Type O diet from a perspective of Thyroid function and Iodine foods, there are a lot of connections. As Dr. D'Adamo writes "Type O’s tend to have low levels of thyroid hormone and often exhibit insufficient levels of iodine, a chemical element whose sole purpose is thyroid hormone regulation." http://www.dadamo.com/bloodtype_O.htm
What I find slightly odd is that Brazil nuts, a food high in selenium, "selenium helps to convert iodine into the thyroid hormones and Vitamin A is also important for the proper functioning of the thyroid gland" http://www.purelyhealthdirect.co.uk/i.html are an avoid for Type Os.
I'm concerned about thyroid function and it was very satisfying that the blood type diet and a diet to help thyroid function fitted together so well it's just slightly annoying that brazil nuts don't fit that pattern! Should I eat them or shouldn't I?
Life doesn't have to fit together and make sense, but it's nice when it does
At a guess, the answer lies in the fact that thyroid function isn't the only thing being taken account of on BTD - there's probably some other reason why brazil nuts are not a good move, which outweighs their selenium benefits. A number of the protein sources available on the O diet are pretty good sources of selenium.