Today I wanted to share with you some studies that link the consumption of certain protein foods rich in a certain type of amino acids to reduced thyroid function.

Thyroid health would be compromised if we eat these protein foods in excess, which is double our needs.
This is because some amino acids these foods are rich in lead to the reduction of thyroid peroxidase.

I then compared the most common protein foods in today’s diet with the data from the study researchers.

THYROID PEROXIDASE AND INHIBITION

To be clear, thyroid peroxidase is that enzyme that leads to the production of thyroid hormones.
People with hypothyroidism have a high number of anti-thyroid antibodies, including anti-peroxidase or anti-TPO antibodies.
The high number of these antibodies is found in thyroiditis, Hashimoto’s disease (autoimmune thyroiditis) and Graves’ disease.
However, even in diabetic subjects we can find elevated levels of anti-TPO (type 1 diabetes) and in other subjects suffering from autoimmune diseases.

Nutrition plays a fundamental role in the production of thyroid hormones.
Some foods naturally reduce thyroid peroxidase, inhibiting thyroid health.
These are foods rich in the following amino acids: tryptophan, cysteine, methionine and tyrosine.
To these are added histidine and phenylalanine.

Although many “pro-thyroid” supplements contain tyrosine, supplementing tyrosine if you fear a thyroid problem may have contraindications if tyrosine is taken in excess. In supplements this is a frequent problem due to overdose.
Because an underactive thyroid may not necessarily be caused by tyrosine deficiency, it is best to avoid taking certain supplements thinking about increasing thyroid hormone production and speak to an endocrinologist first.

In particular, cysteine ​​is the one that damages the thyroid the most , while the action of the other amino acids is linked to iodine, that is, it is more serious and permanent if there is also a deficit of foods that naturally contain iodine.
Going to see the foods richest in cysteine ​​we have: egg whites, cod, beef and pork, lupins, soy.
Egg whites, soy, aged cheeses, cod and meats also have high tryptophan contents, as does milk powder.

Clearly, no one eats 100 grams of Grana Padano a day, but 100 grams of meat or fish yes, and not just 100 grams.

Same thing for those who are vegan and heavily use tofu and soy protein powders.

So by checking these amino acids by dose, we see that high amounts of meat (i.e. slices, steaks), soy and soy products, cod, egg whites, chicken and pork all lead (in excess) to problems with thyroid health.

HYPERPROTEIN DIET AND HEALTH RISKS OF THE THYROID

Therefore, if I consider a high-protein or low-carb diet or the typical sportsman’s diet, where we have a lot of egg whites, a lot of meat, canned tuna or a lot of soy in the case of vegan athletes, the risk of inhibiting thyroid health becomes much more concrete.

A man of about 70 kilos has a daily requirement of just over one gram of cysteine. About half of tryptophan.

Which reaches with a portion of meat of 130 grams, one of fish of the same weight + milk or eggs or cereals such as oats or cheeses / dairy products.

However, if I double or triple the portions of meat and fish, add egg whites instead of eggs (100 grams of egg whites give me a quarter of a gram of cysteine), use protein powder, etc., I run the risk of having triple the daily requirement. . Same thing for tryptophan, which also comes to us from whole grains or legumes.

Therefore, a high-protein diet could inhibit thyroid health precisely because of these excess amino acids.

Sources:
Thyroid peroxidates are inhibited by some amino acids
Tryptophan, inflammation and fatigue
Micromolecules inhibit thyroid receptors