Thyroid conditions are extremely common, and the most prevalent undiagnosed condition I encounter. This is largely due to the wide reference ranges provided on blood tests for TSH, T4 and T3. Interpreting these results in a different way often reveals quite a different picture to what clients have been told by mainsteam doctors.
Common Signs & Symptoms of a Slow Thyroid
- Brain fog
- Weight gain
- Dry skin
- Low blood pressure
- Poor memory
- Fluid accumulation
- Hair loss
- Temperature dysregulation
- Brittle nails
- Poor libido
- Muscle aches and pains
- Elevated cholesterol
- Adrenal fatigue
Thyroid stimulating hormone (TSH) is produced in the brain, and signals to the thyroid to make T4. T4 is a hormone made from tyrosine (which comes from protein), and iodine. Iodine is a naturally occurring element, which is present in seawater but land distribution is often low. In Australia, natural iodine levels are very low in the soils where we grow our vegetables, grains and graze livestock
Iodine in Australia
Globally, iodine deficiency is considered the single most important cause of preventable brain damage and mental retardation. It has profound effects on intellectual development. Iodine deficiency in Australia is well recognised and has been supplemented since the early 1900s in the form of iodine-containing sanitising agents used in the dairy industry (although this was not intentional), and then salt fortification in the 1920s.
The current average dietary intake of iodine does meet the recommended dietary requirement, as people are not consuming iodised salt, not eating enough seafood, and not supplementing in other ways.
T3 and T4
T4 does only 5% of the work for the thyroid. It’s T3 that does the rest of the heavy lifting and is considered the more active thyroid hormone. T3 has a higher affinity for thyroid receptors and is approximately four times more potent than T4. Converting T4 to T3 needs other cofactors, such as insulin, zinc, iron, and selenium. Unfortunately, individuals are often deficient in dietary selenium. Australian soils do not provide adequate selenium content for use to satisfy our needs. The best way to assess your thyroid, is to test for all of these cofactors, along with TSH, T3 and T4. Reverse T3 is another useful addition.
The Effects of Stress on the Thyroid
Stress is an important factor that needs to be considered, because this can cause T4 to shunt towards Reverse T3 (rT3). rT3 is antagonist to T3, so will bind to T3 receptors blocking the action of T3.
If the proportion of rT3 dominates over T3 levels, it will produce hypothyroid symptoms despite sufficient circulating levels of T4 and T3. Correcting elevated rT3 includes assessing adrenal function, and providing effective strageties to counter the dysfunction. This can come in the form of supplementation, but must include lifestyle changes as well.
Females and Thyroid
Every cell, organ, and system in the human body needs iodine, but the breast tissue contains the most iodine-thirsty cells. Breast tissue has a higher concentration of iodine than the thyroid, and uses the same iodine-transporting proteins used by the thyroid gland. Without sufficient iodine, breast tissue is susceptible to the stimulating effects of estrogen. This can lead to the production of microcysts, and those can lead to fibrocystic breast disease.
Iodine deficiency can also cause elevated prolactin, and menstrual tenderness and pain. It’s important to assess estrgoen when considering iodine suplemntation, because while testosterone can promote iodine absorption, estrogen has an inhibiting effect on iodine absorption. Clearing estrogen is a priority before iodine supplementation in cases of elevated estrogen.
Iodine Dietary Sources
Iodine food sources include brown seaweeds (kombu, wakame, and arame), oysters, salmon and other fish, sea salt, and fortified eggs. Levels are not consistent in every species of seaweed, and also change according to where the species are sourced. Figures below are the average amount of iodine in various types of seaweed.
- Nori 2.5mg (1 sheet) – Used for sushi = 0.02mg (20mcg) of iodine
- Wakame 2.5mg = 7mg (7000mcg)
- Kombu 2.5mg = 10.75mg (10,750mcg)
When considering thyroid testing, it’s important to test for TSH, T4 and T3. Often T4 levels are not checked, which is the most important marker to evaluate iodine levels. Urinary iodine can be included, and reverse T3 can also be investigated. Ideally, all cofactors are also assessed, which include selenium, zinc, and iron.
In many cases, doctors will not provide testing for all of these factors, and individuals need to pay for the added tests. This can provide much more useable data to help get your thryoid working again (without medications)
Nutrient deficiencies take some time to correct, and the length of time is dictated by what we find in the tests. Brain fog is the first symptom to shift, then motivation improves, mood picks up, weight loss starts to happen, and overall wellbeing follows.