Ep 63. The Thyroid System & the Impact of Stress | Marek Doyle

Apr 21, 2022 | Podcast Episode



You’re going to want to take notes as you listen to this episode (you could make them in the journal that’s in My Thyroid Box ). This is a nice and meaty discussion about the thyroid SYSTEM and the impact that stress has on it.

Marek Doyle is a nutritional therapist in the UK (love having a UK expert on the show) and he’s all about individualise health, which, let’s face it, we need when we have a thyroid condition because it can be complicated and we all experience it differently. Dogma – or blanket statements about thyroid health are not at all helpful. There is no thyroid protocol that will work for everyone. There are themes, common aspects to consider, but there is not ‘ultimate thyroid plan’. Oh I wish there was!

The Thyroid System

Thyroid function is much more than about the thyroid gland itself.  It’s a whole system. Here are the 4 stages of the system that Marek tells us about on the show:

  1. The thyroid gland itself. It has to respond to signals from the brain, then it has to manufacture and release thyroid hormones (mostly T4 which is the INactive thyroid hormone.
  2. Metabolic conversion of T4. This is where the body uses deiodinase enzymes around the body to convert T4 into the active T3 hormone. It’s very common to have issues at this stage. We discuss whether T3 replacement medication is helpful at this stage and why it’s important to look at WHY your body isn’t converting T4 into T3 well.
  3. Entry of thyroid hormone into the cell. This is highly energy dependent.
  4. Binding of the thyroid hormone in the cell with thyroid receptors. This is the end goal!

There can be problems at each step along the way, so it’s important to work with a practitioner to hep you identify where and what’s going on (or not as often the case is).

The impact of stress

In the podcast discussion Marek talks a lot about the adrenal response, cortisol  and the connection with thyroid health. He covers the importance, not of ridding our bodies of stress, but in becoming good at managing stress and our body’s response to stress. We need to get better at regulating stress and having heart rate variability (which can be measured via apps and tools like an Oura ring) .

Reducing stress is simple, but it’s not easy.

Things that can stress the body can include – food intolerances, chemical exposure, gut health.

Other key discussion points

  • The deiodinase system
  • Key factors in poor T4 to T3 conversion – stress, inflammation, oxidative stress, mitochondrial function and more.

Thank you Marek for a stimulating conversation.

related podcast episodes

If you enjoyed this episode and are looking for similar discussions, check out these episodes:

#57 Dr Anshul Gupta – on mitochondrial health

#58 Dr Eric Balcavage – for more on the stress response & cellular hypothyroidism.

Meet Marek Doyle

Marek is a functional nutritional therapist who has spent the last 16 years building a model of personalized nutrition, based on the data of over 3,000 individual outcomes, 11,000 test results and extensive use of the scientific literature. Based in London, he offers one-to-one consultations for clients as well as training for practitioners. He holds an MSc in Personalized Nutrition.

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