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

Therefore hardly surprising to find foods high in Iodine, foods from the sea, such as Kelp http://www.dadamo.com/typebase4/depictor5.pl?213 & Cod http://www.dadamo.com/typebase4/depictor5.pl?3 as beneficial for Type Os. (see http://www.iccidd.org/pages/iodine-deficiency/sources-of-iodine.php).

It also follows that goitrogens, foods that block iodine absorption, are avoids. Such as Peanuts http://www.dadamo.com/typebase4/depictor5.pl?288 and Soy http://www.dadamo.com/typebase4/depictor5.pl?385

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 :-)

thank you

Will

Hi Idiopathic,

if you look here http://www.dadamo.com/typebase4/depictor5.pl?73 you'll see that brazil nuts are an avoid for Type O because of other reasons: "Flocculates serum or precipitates serum proteins."

So it seems that brazil nuts aren't well digested by Type O's and should therefore be avoided, regardless of thyroid function they're not beneficial for your bloodtype.

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.

Thank you both for your replies, I will look at other sources of selenium