How does the thyroid work? Episode 26.

Nothing in life is to be feared, it is only to be understood. Now is the time to understand more, so that we may fear less. - Marie Curie

Welcome to Episode 26. Today, inspired by someone in the Help For Hashimoto’s Facebook group we are talking about how the thyroid works. You are getting a hopefully easy to understand lesson in thyroid anatomy and physiology. I’m keeping it simple here so don’t worry. 

If you are dealing with hypothyroid symptoms then you know, this tiny little gland runs the show. It rules our body and when it isn’t functioning, we really feel it. 

The symbol for the thyroid is the butterfly and with good reason. It is shaped kind of like a butterfly and it wraps itself around our trachea and sits just below our voice box. It has these little sacs within it where the thyroid hormones are produced. 

The thyroid is part of our endocrine system and it is responsible for increasing our basal metabolic rate which is our ability to gain or lose weight. Our basal metabolic rate rises when we make cellular energy (called ATP) which provides us with heat causing our body temp to rise.  This is why when our system of producing thyroid hormones breaks down somewhere along the way, we can end up with cold hands and feet or just feeling cold in general. You might literally feel cold in your bones. 

Thyroid hormones stimulate the creation of proteins at the cellular level which involves making DNA which is part of how we copy and make new cells. Remember we are cellular beings. Our cells make up tissue which make up organs which make up systems which make up us as an organism. 

Thyroid hormones help us use glucose or sugar and fats for energy and they help break down triglycerides so they can be eliminated as needed. 

Thyroid hormones help us grow as kids and particularly help in the growth of the nervous and skeletal system. 

So you can see, this little gland has a big job. 

The thyroid gland is really sensitive and will respond to messages pretty quickly when called upon as long as it is working properly. It kind of speeds things up or slows things down as needed. So if you are cold, its job is to tell the body to create more heat so you can be warmer. 

If your hands and feet are always cold or you have that cold bones feeling, then something isn’t working right along the way. This is not happening because your body wants it to, but rather because it doesn’t have the tools to do it properly. Or something is broken down along the way. 

What can break things down? Well, chronic stress, poor diet, blood sugar dysregulation, the wrong medication or the wrong dose or the inability to process the medication, not enough- you get the idea. 

You must ask yourself WHY this pathway has broken down somewhere instead of what can I take to make it feel better. 

How is your thyroid supposed to work?

It starts in your brain. The hypothalamus works in concert with the pituitary gland. The hypothalamus is the controller here. The very tiny part of the brain controls much of the function between our nervous system and our endocrine system. In fact, all that the hypothalamus and pituitary do together control most of the growth, development, metabolism and balance throughout the body. The two are attached in the center area kind of under the big parts of the brain. 

Through a negative feedback loop like the furnace or air conditioner in your house, your body sends a message that it needs some regulation. We are using the example of being cold and needing to warm up. 

Your hypothalamus sends out a hormone called Thyroid Releasing Hormone or TRH which gets sent to the pituitary gland. 

TRH tells the pituitary gland to release Thyroid Stimulating Hormone or TSH which you will be familiar with because that is probably what your doctor tests for. Funny they don’t test for actual thyroid hormone in our blood. Just this stimulatory hormone. TSH gets sent to your thyroid where it tells the thyroid to make thyroid hormone. 

In the thyroid, some chemical reactions occur and Thyroid Peroxidase gets a message to make T4 and T3. Thyroid Peroxidase is one of the things that creates antibodies in Hashimoto’s. Remember Hashimoto’s is first an immune system problem rather than a thyroid problem. We are going to cover that next week. 

T4 and T3 are being produced in the thyroid. Mostly T4 and a small amount of T3. This gets taken through the blood on a binding protein and is held captive until it gets where it needs to be when it is released or free.  Much of the T4 our thyroid makes needs to be converted to T3 before our cells can use it so about 60% of what is made in the thyroid goes in to the liver and is converted to T3 there and about 20% is converted to T3 in the gut or small intestine area. 

Again, once they get to the cells they are released as free. This is the hormone your cells can use. See why it makes sense to test the free levels or hormone?

Your liver has a big job. It works hard for you every day.  It has to help manage blood sugar, it makes bile so we can break down and use dietary fats. Bile also carries toxins out of our intestines and eliminates them in our waste. The liver processes hormones like excess estrogen, and it processes toxins or chemicals for elimination as well, not to mention processing alcohol. Do you think your liver can work on your hormones if it is processing toxins and chemicals and managing blood sugar all day long? I think it gets backlogged and has to prioritize things and guess what- converting thyroid hormone is not always at the top of the list. 

I mentioned conversion of T4 in the gut. Those good gut bacterial are vital to our health in a lot of ways, one of which is conversion of T4 to T3 for our cells to use. What if those gut bacteria are destroyed due to antibiotic use or there are more bad guys than good guys? How much conversion of thyroid hormone is happening? Antibiotic use is not the only thing that affects our gut bacteria. Remember that stress, especially chronic stress can alter the gut bacteria population which will affect our ability to convert T4 to T3. 

When things are working properly, the Free T3 will get to your cells and turn on or off the genes needed for each situation presented- in our case today, we want to feel warmer or be warmer so we are turning on the metabolic process of creating more heat with the tiny increase in TSH happening all the way back at the brain and pituitary gland. 

Let’s do a quick review of these hormones. 

TRH- Thyroid Releasing Hormone

The body sends a message it needs something- like to warm up- this is a message to kickstart your metabolism. The message goes to the hypothalamus which talks to your nervous system (important for adrenals health) and to your endocrine system (thyroid, blood sugar regulation, sex hormones) and releases TRH as a message to your pituitary gland which releases: 

TSH- Thyroid Stimulating Hormone

This is released in response to the message from TRH. TSH goes to the thyroid gland with iodine where Thyroid Peroxidase, an enzyme that is made in your thyroid gland does some chemistry and makes T4 and T3 with a protein called thyroglobulin. 

T4- Thyroxine

Is called T4 because it has 4 molecules of iodine attached to it. It is bound to thyroglobulin until it reaches its final destination at your cells where it is released and is Free. 

T3- Triiodothyronine

This is the main thyroid hormone used by the cells. 

What can go wrong?  A lot. Are you on hormonal birth control?  If so, this can interrupt the functioning of your thyroid. Very simply explained, your body ends up overloaded with estrogen which will cause confusion in your pituitary gland. The pituitary is where the TSH is released and the excess estrogen will create extra binding proteins so your thyroid hormone will be bound instead of free which means less for your body to use. You can then have labs that look like you are releasing enough TSH but it is all bound up so it isn’t getting to the cells and this creates symptoms when labs look fine. 

Even if you present with high enough TSH to get put on medications you and your doctor should be asking WHY is the TSH high? Where is the malfunction at? Where is the breakdown? 

The breakdown could be in the hypothalamus/pituitary axis. Some sort of dysfunction there. It could be in the gut, maybe in the liver.  Maybe your body is overloaded with toxins from the environment- either poor quality foods with high amounts of chemicals in them, body care products and makeup or you work around chemicals. We live in a toxic world, it is just a fact of life. We need to make sure our liver can keep up with the chemical burdens we face daily. If not, thyroid function can be affected. 

Chronic stress- physical or emotional stress can reduce the amount of T4 in the cells without the pituitary gland being affected much at all- again- this would mean you have symptoms but blood tests might look normal. Remember we convert T4 in our tissue mostly and that might not be happening under conditions of chronic stress. What are the stories you have going on in your head? 

Iodine deficiency- I am not an expert in this area so I will only touch on this briefly. We need iodine to make T4 and T3. If you eat real food and you eat high quality food, you are likely getting all the iodine you need to make thyroid hormones. Not everyone agrees with this and you can check out Dr. Brownstein for more information. He believes iodine therapy can be very helpful. Dr. Kharrazian believes iodine therapy is like fueling the fire, especially if you have hashimoto’s. I don’t feel knowledgable enough to comment one way or the other on it. There have been some people who suffer with low body temperature and therefore are cold all the time that have benefited from iodine therapy and have also found an increase in their energy. Do not supplement with iodine unless you are under the care of a knowledgeable practitioner. 

Childbirth- this is where I was diagnosed with hypothyroidism with a TSH of 150. This happens in about 5-10% of new mothers. I also had a genetic predisposition and I epigenetically turned on these genes with poor diet and lifestyle. So this was the beginning of my knowledge of thyroid problems for me. I likely began the breakdown of my body long before that. 

Heavy metals- cadmium, lead and mercury have all been linked to thyroid dysfunction and mercury in particular with thyroglobulin antibodies which is significant in showing a relationship between mercury and hashimoto’s. I had a mouth full of mercury fillings. 

Chlorine, fluoride and bromine are halogens. They all affect the thyroid in different ways. Chlorine keeps iodine from making T4, fluoride decreases T3 and T4 while increasing TSH in the blood. Bromine displaces iodine increasing TSH in the blood and keeps the thyroid from functioning well. Getting a filter for your shower at the least can help with the fluoride/chlorine issue. Bromine is in bread products.  You need a lot of exposure to these chemicals to really be affected. It is just one small piece of the puzzle. 

There is so much going on here and so much that is at play. This is why there is no one quick fix. No one supplement, no one thing that will work to make you feel better. There are general recommendations, of course that will definitely get you on the road to feeling better but you have to remember that it took time for your body to get to the point of breakdown where you are noticing symptoms and so it will take time for things to get back to normal. 

As always, I start with diet and very little supplementation. Get cooking, eating real whole foods, manage blood sugar and stress. Get good sleep. These are things you can do before you seek the help of functional medicine testing. Save yourself some money on supplementing with things you aren’t even sure you really need but think you do because someone has said that selenium or zinc is good for your thyroid. I’ve even said it- these things are needed for good thyroid function but maybe you don’t need them. Try cleaning up your diet first and then hire someone to help you figure out what might be best for you. In the long run you will save yourself thousands of dollars. 

Ok. That is it for me for today. Next week we will talk bout Hashimoto’s and why it is first an immune system problem with consequences for the thyroid. 

Until then, head on over to my website and get my ebook- Five things your doctor won’t tell you about hypothyroidism. Join the facebook group, Help For Hashimoto’s and please tell other people about the podcast so they can stop getting bad information from people in these support groups. I see so many people being told such bad information and it breaks my heart. 

I would really appreciate it if you could leave a rating and review on iTunes so more people can find the podcast. I do this for you guys so you don’t have to go through what I have. 

Find me on Instagram @stephanieewalsntp and at Out of The Woods Nutrition on Facebook. I should streamline all that stuff so it’s all the same. Anyway, I sent out a recipe in the newsletter this week. If you are not on the list, that is the place to be. I am done with biochemistry now- whew. I survived and so I will be putting more time in to better content in the newsletter. That is the best place to be. 

See you next week. Thanks for listening.