The Gut – Thyroid Link

Hands up if you can locate your thyroid?

Double points if you can not only find where your thyroid lives but can also explain what the thyroid organ actually does?

If you answered – A) at the base of your throat, below your Adam’s apple (also known as thyroid cartilage) and B) just about everything?! Then you would be correct!

This butterfly shaped organ is the metronome of the body. This means it keeps the tempo or speed of our bodily functions by producing hormones that are important for regulating a range of metabolic functions. Our thyroid hormones work on a feedback mechanism – our brain sends hormones and messages to our thyroid and vice versa. Depending on what our bodies need, the thyroid will speed up or slow down the release of hormones to initiate the desired response. For example; during periods of growth, pregnancy, even when we are cold, the thyroid will produce more hormone to facilitate more energy and when we’re
stressed, get an infection or eat inflammatory foods, our thyroid will reduce the amount of hormone it produces to slow things down so our body can attempt to heal.
You could say that the thyroid is a pretty important organ. Sadly, I am seeing more and more patients in clinic with thyroid dysfunction and in many of the cases of diagnosed thyroid conditions, there were early warning signs that were overlooked by other healthcare providers (to read more about this click here). Unfortunately in these instances, the feedback mechanism was affected in some way and the symptoms or warning signs were missed. It’s not all doom and gloom though, there’s a lot you can do to ensure your thyroid is functioning optimally and one of the simplest things is understanding how the gut (yes, the gut again!) and thyroid are inextricably linked.

Intestinal microbiome
We now know that gut bacteria is integral to our health. We need a diverse microbiome to properly digest dietary fibres and synthesise nutrients. We also need a healthy balance of microflora to ensure our immune system (70% of which resides in the digestive tract) functions efficiently. When we have a bacterial imbalance otherwise known as dysbiosis, we experience intestinal permeability (aka leaky gut) and inflammation and our immune system can falter. If this happens we are at a risk of our immune system becoming overactive and attacking healthy tissue. So how does this relate to the thyroid? An autoimmune condition
called Hashimoto’s thyroiditis. This is where the immune system begins attacking the thyroid, leading to hypothyroidism; where the thyroid begins to slow down the amount of hormone it is producing resulting in weight gain, constipation, fatigue, hair loss and muscle weakness. Research has shown a direct link between intestinal permeability, dysbiosis and autoimmune conditions, such as Hashimoto’s.

Digestive function
Thyroid hormone T4 (inactive) is converted to T3 (active) in both the liver and gut. When there is liver and gut dysfunction like sluggish digestion, food intolerances or inflammation, our ability to convert these hormones is impaired. When this happens we also begin converting T4 into reverse T3 (rT3), which can then block T3 from working. Why is that a problem? T4 is responsible for your metabolism, mood and body temperature and T3 is needed for digestive and metabolic function and bone health. So, if either of these are out of balance (and they usually go hand in hand) then you can begin to experience symptoms.
If T4 and T3 are reduced due to poor digestive and liver function, then this sends a message to our pituitary gland (the control centre) to produce more TSH; our master thyroid hormone that determines how much T4 and T3 to make. If there is too much TSH, it actually down regulates production of T4 and T3 even more and symptoms can become exacerbated – weight gain, brain fog, lethargy, menstrual changes, dry skin, bloating and sensitivity to coldness. So you can see by producing less T4 and T3, our brain increases TSH production, which then further suppresses T4 and T3 production and this vicious cycle continues.

Inflammatory Foods
Understanding what foods may be a trigger for you is imperative when it comes to thyroid health and a great place to start is with the main offenders. Wheat and gluten are synonymous with thyroid dysfunction and there is a direct correlation between coeliac disease or non-celiac wheat sensitivity and autoimmune thyroid conditions such as Hashimoto’s. This is due to the damage that these foods cause to the intestinal barrier, leading to inflammation and leaky gut, which as mentioned above can activate our immune system but it can also lead to nutrient deficiencies, particularly, essential thyroid nutrients such as iodine, selenium, iron and zinc.

What to do?

Optimising thyroid health all begins in the gut. Whether you’ve been diagnosed with a thyroid condition, suspect you may have thyroid dysfunction or are looking to ensure your thyroid stays in tip top shape there are some things you can do:

• Cut out the inflammatory foods – wheat, gluten, dairy and sugar are a great place to start. Ideally following an anti-inflammatory diet to ensure you are optimising your thyroid loving foods and eliminating any foods that may cause systemic inflammation is key. This can be restrictive so it is best to chat with a natural health practitioner to ensure you are meeting your nutritional and energy requirements.
• Increase zinc and selenium rich foods – zinc and selenium are essential for conversion of T4 to T3. A simple way to improve your thyroid function is to
  incorporate foods such as oysters, beef, pumpkin seeds, cashews and chickpeas which are all rich in zinc and brazil nuts, sardines, turkey and beef liver all of which are high in selenium.
• Minimise stress – when we are stressed our cortisol spikes and cortisol loves to steal the limelight. It takes priority over other bodily functions, like converting T4 to T3. When we’re in fight or flight, our thyroid hormones slow right down because digesting food and staying warm isn’t important when we’re running from a sabre tooth tiger; or at least that’s what our body thinks! Stress reducing techniques that resonate with you are important – yoga, meditation, exercise, walking in nature, anything that lowers your stress response is key.
• Speak with one of our practitioners – we love the thyroid! And we love helping our patients understand how the thyroid works and how to optimise its function. Our practitioners can refer you for a full thyroid test to measure your exact hormone levels. We can then treat you holistically to improve your thyroid function using food and lifestyle medicine, nutritional supplementation and herbal medicine.