“I think my thyroid function is low.” This sentence is frequently stated and yet even more frequently gets ignored, poorly assessed and is under treated. So much amazing research has taken place in the last 20 years, uncovering a deeper understanding of this mysterious thyroid yet much of this research gets ignored. Several studies exploring how medical literature changes the way doctors practice medicine have shown that a proven medical concept or idea that is accepted as true and factual will take 15 to 20 years to penetrate into the broad habits of the medical community. Said another way – things change very very slowly in medicine. Well, that might satisfy some “standard of care” somewhere but it’s not good enough for you and I. Life is happening NOW and we need solutions that work NOW, not in 20 years.
Endocrinologists are doctors that specialize in the treatment of hormone issues, yet as stated above, many are slow to adopt new thinking and still engage concepts introduced decades ago. Thyroid is a hormone that interacts with every other hormone in our body and in fact thyroid hormone stimulates every cell in our body to do its specific job properly. How the body regulates thyroid hormone is very complex given its intertwined actions with all the other hormones. For example, our stress level and cortisol production have dramatic impact on thyroid activity. Our genes are no different than our caveman forefathers and so if we experience constant daily stress, (link to Adrenal INTRO) our caveman genes don’t know “why” we are stressed it simply knows that stress means “fight or flight” so prepare to fight or run away. This “ready to fight” body is VERY different from the body that is relaxed and poised to live long. Stress for a caveman might be famine, can’t find food, and the body is wired for survival. So, how do you survive a famine? Reduce your thyroid activity so your cells don’t burn up all of your valuable fat. If you use up your fat in the face of a famine you perish. So, stress = low thyroid = weight gain.
Modern stress comes in many forms: menopause, diabetes, high cholesterol, endurance sports, fasting, aging, obesity, depression, heart disease, hormone imbalance, low testosterone, nutrient deficiencies of B vitamins and minerals, alcohol, and medications such as beta blockers and statins. Any of these stressors will trigger the body to slow down the conversion of your inactive T4 thyroid hormone into the active T3 form thus essentially hitting the brakes. Our body needs to convert our inactive T4 thyroid hormone into the active T3 form in order for it to do its job of stimulating the cell.
Therein lies the challenge. Endocrinologists are smart people but we aren’t taught in medical school how to integrate all of these variables. We say silly things like, “well, you are in menopause so it’s natural to feel sluggish, have a low mood and gain weight”. Then you get offered a prescription for Lexapro or Prozac as if this will fix the thyroid issue. Don’t just cover up my mood issues with a drug that makes me more fatigued – please get to the CAUSE.
Thyroid function is fascinating as the brain literally assesses the environment to determine how much demand or stress we have and makes adjustments in 2 ways. The brain can send a signal called Thyroid Stimulating Hormone (TSH) to the thyroid to kick it into action to make T4, the inactive thyroid hormone. Note that TSH is NOT a thyroid hormone, it is simply a signal from the brain. Therein lies our first challenge, the brain lives in a “gated community” in a different protected environment than the rest of the body. The brain’s ability to sense the level of thyroid hormone is different than what your heart, muscles and other bodily parts see but more on that later.
Once TSH is released from the brain it stimulates the production of T4, the inactive thyroid hormone. A lack of nutrients, low levels of tyrosine and iodine will make this task more difficult. Once T4 is made it enters the blood for delivery to your tissue. But for T4 to even enter the cell it requires energy from the cell. But what if your cells are fatigued and aren’t making adequate energy to do this? Let’s say T4 did make it into the cell, now it has to get converted by the proper enzyme (deiodinase) into T3 which is the ACTIVE form. But we aren’t done yet. Now T3 has to engage the nucleus of the cell the stimulate that cell’s function. What if the receptor for T3 has a genetic alteration? What is the receptor is gummed up with pesticides, herbicides, plastics or metals?
As you can see this process is not simple. On top of this, if T4 can’t enter the cell and it stays in the tissue or worse gets taken back to the liver, it will get converted into something called “Reverse T3” and as you might assume by the name it has the opposite effect of T3. Reverse T3 blocks the receptor for T3 so even if you took a bucket full of T3 it can’t easily get into the receptor to do its job. This is the classic “braking effect” that the body employs in time of constant stress. If we think of T3 as the gas pedal for cell function and energy, then Reverse T3 acts as a brake.
Now let’s add thyroid antibodies. What if you have had gut issues like gas and bloating, heartburn, constipation? Your gut (intestines) are the heart and soul of your immune system function. If your gut has been a mess or you have eaten years of highly allergic foods such as wheat and dairy, then this immune system gets irritated and can begin to throw defense antibodies into the blood stream that land on your thyroid and we develop an auto-immune disease where our immune system is attacking our own body. More detail here is discussed in the article on Hashimoto’s thyroiditis. But the very presence of these antibodies can sit in the thyroid receptors and block the T3 from doing its job. Ouch.
Given all that is presented here you can easily see that simply measuring a TSH, which isn’t even a thyroid hormone, can’t begin to assess your full thyroid function. In a study done by Fraser et al. way back in 1986 they reported that the “positive predictive value” of the TSH was determined to be only 16%. In other words, TSH accurately reflected thyroid status and the impact of treatment only 16% of the time. TSH as a test is MISLEADING 84% of the time. Further studies in 2003 by Meier showed the same thing. They reported that “TSH is a poor measure for estimating the clinical and metabolic severity of primary overt thyroid failure”. Furthermore, they stated that signs and symptoms (how the patient FEELS) of thyroid effect and not the TSH should be used to determine the proper replacement dose. What? You mean actually listen to the patient? YES!! What you feel is a better predictor than lab alone. Your symptom complex should be valued as half the equation and the other half is a COMPLETE thyroid panel that explores T3 and Reverse T3 and antibodies to fully see the picture. To do anything less would be to work in the dark with marginal hope of lasting success.
In summary, yes the thyroid is complex but also easily assessed with proper testing and exploration of physical symptoms. This is so critical as the thyroid is responsible for influencing every system and every function in your body. An undiagnosed or under treated thyroid issue leads to poor health, poor quality of life, weight gain, low mood and all of the following issues occurring at higher rates:
- Heart disease and congestive heart failure
- Diabetes and insulin resistance
- Sleep disorders
- Lethargy and gross fatigue
- Anxiety and depression
- Psychiatric issues
- Gut issues like constipation, gas/bloat, undigested food, heartburn
- Cognitive decline and Alzheimers
- Weight gain and obesity
Integrative physicians have a keen sense of the inter-related nature of our body’s systems and can offer a deeper dive into your health concerns.