How to improve thyroid hormone conversion with naturopathy
Do you take thyroxine but still suffer from low thyroid function symptoms such as weight gain, brain fog, and/or low mood?
Do you have normal levels of thyroid hormone T4 but low levels of thyroid hormone T3?
Is your T4 to T3 ratio less than 3:1?
Been told you have high levels of reverse T3?
If you have answered yes to any of the above questions, you may have a thyroid hormone conversion issue that can be effectively treated with the help of naturopathy so you can finally feel well.
What is a thyroid hormone conversion issue?
There are 2 types of thyroid hormone, T4 and T3. The inactive form T4 needs to be converted into the active form T3 for the body to use.
T4 to T3 conversion occurs through a process called deiodination, by enzymes called deiodinases. T4 is converted to T3 in the liver and kidneys by type 1 deiodinase and in the muscles and brain by type 2 deiodinase. T4 can also be converted to an inactive form of T3 called reverse T3 by type 3 deiodinase.
If you have diagnosed low thyroid function (hypothyroidism), your thyroid can no longer produce an adequate amount of T4 hormone. You are prescribed a synthetic form of T4 called thyroxine to replace what your thyroid can’t make itself. However, many people have difficulty converting thyroxine into T3, meaning they still experience low thyroid function symptoms such as low mood, weight gain, brain fog, temperature dysregulation, dry skin, and hair loss, despite having adequate T4 levels.
Even if you don’t have diagnosed low thyroid function, you may still experience low thyroid symptoms due to a thyroid hormone conversion issue. The thyroid produces 94% T4 and only 6% T3 and 85% of T3 is produced from the conversion of T4 to T3. If you have difficulty converting T4 into T3 effectively, you may not have adequate T3 levels causing you to suffer from low thyroid function symptoms, even though your test results look ‘normal’.
T3 is needed to regulate body temperature, metabolism, and energy levels and affects digestion, cognition, skin hydration, reproductive function, cholesterol levels, and more. So, if you have a thyroid hormone conversion issue you may continue to feel unwell, no matter how much T4 your thyroid makes or what dosage of thyroxine (synthetic T4) you take.
How do I found out if I have a thyroid hormone conversion issue?
GPs usually only routinely test for TSH alone or TSH and FreeT4, however it is essential to include Free T3 to be able to assess if you have a thyroid hormone conversion issue. You need to ask a GP or naturopath to test for TSH, Free T4 and Free T3 every time you get your thyroid function reviewed.
If your T3 levels are lower than the normal range but your T4 is within normal range, then it is likely that you have a thyroid hormone conversion issue.
Even if both thyroid hormone levels are within the normal range, if your ratio of T4 to T3 is higher than 3:1 you may have a problem with converting T4 to T3. For example, if your T4 is 15, you need a T3 level of at least 5. Anything less than 5 indicates you may have a thyroid hormone conversion issue.
If you have diagnosed low thyroid function, increasing your thyroxine (T4) dosage is not likely to improve low thyroid function symptoms caused by impaired T4 to T3 conversion.
Regardless of whether you are diagnosed and take thyroxine or remain undiagnosed, if you have normal T4 but low T3 or a T4 to T3 ratio higher than 3:1, you need to work on improving your T4 to T3 conversion to help reduce low thyroid function symptoms such as weight gain, brain fog, and low mood.
You can also test reverse T3, an inactive form of T3 that cannot be used by the body. It is a test that can be ordered by your naturopath or GP that you pay a private fee for because it isn’t covered under Medicare. It usually costs between $85 to $95, depending on which lab you go to. The main cause of high reverse T3 is elevated cortisol levels, which occur in response to chronic stress on the body.
Chronic stress is one of the four main causes of a thyroid hormone conversion issue that I will now discuss. Naturopathy can help with both identifying and treating these cause/s to assist in improving T3 levels and to help reduce low thyroid function symptoms.
What are the 4 main causes of thyroid hormone conversion issues and how do I treat them?
Chronic stress
Long term mental and/or emotional stress increases the production of the stress hormone cortisol from the adrenal glands. Elevated cortisol levels can cause your body to convert T4 into reverse T3, instead of T3.
Stress due to ongoing physical causes such as chronic pain, long-term illness, and over-exercise also elevates cortisol levels, increasing reverse T3 levels and decreasing T3 levels.
Dietary practices such as prolonged fasting and severely low carbohydrate and/or low kilojoule diets also cause physical stress on your body, increasing cortisol levels which causes T4 to be converted into reverse T3 rather than T3. They also make your body think you are experiencing famine, causing it to protect itself by reducing both T4 and T3 production to slow down metabolism and conserve energy.
This is why extreme dietary restriction and excessive exercise often do not facilitate weight loss in people with low thyroid function. In fact, these practices will only further slow down your already sluggish metabolism, meaning you could even gain weight. If you want to lose weight with low thyroid function, it is best to work on lowering cortisol levels to improve your T4 to T3 conversion.
Working on stress reduction techniques can help to reduce cortisol levels, increasing T3 production and decreasing reverse T3 production. This includes:
implementing a healthy diet and exercise regime
improving sleep hygiene
practising time management
seeking social support through trusted friends, family, and support groups and/or professional support from a counsellor or a psychologist
engaging in practices such as mindfulness, affirmations, and/or gratitude journalling
practising relaxation techniques including meditation, progressive muscle relaxation, and diaphragmatic breathing.
Fatty liver disease
Most T4 to T3 conversion occurs in the liver. A common health condition, fatty liver disease, can impair your liver’s ability to convert T4 into T3.
Fatty liver disease is caused by:
toxin exposure including cigarette smoke and excessive alcohol consumption
certain medications
metabolic health conditions such as metabolic syndrome (a combination of high blood sugar, high blood pressure, and high cholesterol levels), type 2 diabetes, insulin resistance, and PCOS
being overweight or obese, especially if you carry excess visceral fat around your abdomen.
Fatty liver disease doesn’t always have symptoms, especially in the early stages, but they can include:
fatigue
nausea
itchy skin
upper right sided abdominal pain.
You can ask your naturopath or GP to order a blood test for elevated liver enzymes but be aware that you can have normal levels and still have fatty liver. The best way to find out if you have a fatty liver is to have a liver ultrasound.
Fatty liver can be improved or even reversed by:
reducing alcohol and quitting smoking
asking your GP if there are suitable drug alternatives to medications that affect your liver function
improving your diet by decreasing processed foods, sugar, and trans fats and increasing unprocessed, whole foods including lean protein, healthy fats, whole-grain carbohydrates, fruits, and vegetables
losing weight by focusing on the above dietary changes as well as committing to regular exercise
managing metabolic syndrome and other metabolic health conditions with naturopathic principles plus pharmaceutical medication, if required.
dysbiosis and leaky gut
About 20% of T4 to T3 conversion happens in the gut by an enzyme called intestinal sulfatase, produced by beneficial bacteria.
An imbalanced gut microbiome (dysbiosis) reduces the production of intestinal sulfatase, lowering T4 to T3 conversion.
Leaky gut (intestinal permeability) which can occur in the most common cause of low thyroid function, the autoimmune condition Hashimoto’s thyroiditis, can also impair T4 to T3 conversion by:
disrupting the gut microbiome, causing dysbiosis
increasing inflammation, elevating cortisol levels that increase reverse T3 production
preventing absorption of nutrients needed for T4 to T3 conversion, selenium and zinc.
You can help to treat both dysbiosis and leaky gut by:
avoiding gluten and dairy as they can be both triggers and drivers of leaky gut
increasing foods containing beneficial bacteria (probiotics), including non-dairy coconut yoghurt and kefir
increasing prebiotic and soluble fibre intake to feed beneficial bacteria including vegetables (especially onions, garlic, and leeks), fresh fruit, legumes, and non-gluten whole-grains
decreasing processed foods, sugar, and trans fats
decreasing the use of antibiotics.
Supplements such as glutamine, zinc, collagen, and curcumin from turmeric can all help to treat leaky gut, but it is advised to seek guidance from a naturopath or pharmacist rather than self-prescribing as they can check for drug/herb/nutrient interactions as well as contraindications in certain health conditions.
Probiotic and prebiotic supplements can help to treat dysbiosis, but again it is recommended that you seek the advice of a naturopath or pharmacist to get the most appropriate type, strength, and dosage for your unique health needs.
However, one supplement I commonly recommend for dysbiosis, due to it being relatively safe and well tolerated by most people, is partially hydrolysed guar gum (PHGG).
PHGG is a good soluble fibre source and prebiotic that also has the added benefit of improving constipation, a common side effect of low thyroid function.
PHGG is odourless, easily dissolves in liquid, and has no taste making it easy to take.
As it ferments slowly, PHGG is less likely to cause gas and bloating compared to other prebiotic supplements. It is also gluten and dairy free, and suitable for low-FODMAP diets.
However, some people may experience mild gastrointestinal side effects when consuming large amounts, especially when first commencing supplementation. Therefore, it is advisable to start with a low dose and gradually increase it to assess personal tolerance. I suggest starting with 2.5g and gradually increasing to 5g daily to help reduce side effects.
Nutrient deficiencies
Selenium and zinc deficiencies can impair T4 to T3 conversion.
Selenium is an essential component of the deiodinase enzymes that convert T4 to T3 and a deficiency can prevent their synthesis. Food sources of selenium include Brazil nuts, seafood, meats, and poultry.
Zinc is needed for deiodinase enzyme function to convert T4 into T3 effectively. Food sources of zinc include shellfish, meats, poultry, legumes, seeds, and nuts.
You can ask your naturopath or GP for a blood test to check selenium and zinc levels. If you are deficient, you may benefit from supplementation. You want to aim to get your levels in the top end of the normal reference range and you should retest your levels in 12 weeks to see if you have achieved this.
A safe daily dose of selenium is 150mcg and the Therapeutic Goods Administration (TGA) warns that selenium can be toxic in higher doses. It is essential to check all of the supplements you are taking to ensure you are not exceeding a daily dose of 150mcg daily.
A safe daily dose of zinc is 25–50mg daily with food, as zinc on an empty stomach can cause nausea. It is essential to check all of the supplements you are taking to ensure you are not exceeding a daily dose of 50mg. The TGA recommends that zinc not be taken in high dosages long term, so it is best to seek the guidance of a naturopath or pharmacist about safe zinc supplementation duration.
Lastly, check if there is Vitamin B6 in your zinc supplement. The TGA has recently lowered the recommended daily dose of Vitamin B6 from 200mg to 100mg due to an increase in reported cases of peripheral neuropathy from Vitamin B6 supplementation. Vitamin B6 is often added to zinc supplements so it is essential to check all of the supplements you are taking to ensure you are not exceeding a daily dose of 100mg daily
Whilst there can be more causes of thyroid hormone conversion issues, the four I have discussed today, chronic stress, fatty liver, dysbiosis and leaky gut, and selenium and zinc deficiency are some of the more common ones. By treating these causes, you can help to increase your T3 levels and lower your reverse T3 levels so you can reduce low thyroid function symptoms such as brain fog, fatigue, and weight gain.
want to find out how I treat thyroid conversion issues?
As a naturopath, I can develop a personalised treatment plan for you to treat thyroid hormone conversion issues, to help you feel energised, shift weight, and think clearly. Take a look at my Thyroid service page for more info…