2020 was a whirlwind so I didn't get to read and review as many articles as I would like. I am still combing through older research on Hashimoto's and probably will be for a long time!
I post about each of these studies on instagram as I review them and put it all together on this blog twice per year.
You can use the categories located to the right of this post and click 'Hashimoto's Research Update' to see all of the updates so far.
Unfortunately, Hashimoto's Thyroiditis (HT) is not well understood in conventional medicine and too often patients are dismissed. It's my hope that shedding light on this complicated condition will help patients feel more empowered.
You might already know that selenium can be very helpful for Hashimoto’s. It’s an antioxidant that supports the production of glutathione. Selenium is helpful in reducing anti TPO antibodies. This study compared patients using selenium alone and selenium with myo-inositol.
Inositol is involved in cell signaling specifically around TSH, FSH and insulin. You may be familiar with inositol’s benefit for some patients with polycystic ovarian syndrome (PCOS) and it turns out, it’s helpful for patients with Hashimoto’s as well.
This study found that using 600mg of inositol in combination with selenium was superior to selenium alone in reducing TSH levels and improving thyroid hormone concentration. TPOAb concentration decreased in both groups as expected. TgAb doesn’t tend to reduce with selenium supplementation alone and this study found that when adding myo-inositol there is a reduction in TgAb concentration! Patient’s also reported more symptom improvement when using a combination of selenium and myo-inositol.
Bottom line: consider talking to your provider about using a combination of selenium and inositol to support your thyroid health.
Nutraceuticals for Thyroid Health (2020)
This article is a review article which means the authors scoured the literature looking for all the information they could find on the topic. As the title indicates, most studies they looked at and discussed were done in animals. This article is full of great information about nutrients and their role in thyroid health. I am going to summarize some high points-
Vitamin D: Likely plays a protective role in preventing thyroiditis
Zinc: Positively impacts thyroid function
Selenium: Improves immune regulation
Inositol: This was the topic of last month’s review article, these authors reviewed that study among others that concluded inositol is beneficial in autoimmune thyroid disease.
Resveratrol: I’ve previously reviewed research exploring the mental health implications of Hashimoto’s disease and it appears that resveratrol might be useful. It improved BDNF and had antidepressant activity in hypothyroid mice. In addition, resveratrol appears to prevent the metabolic toxicity caused by fluoride exposure (drinking water) and restored the functional status of the thyroid.
Soy: There is no easy answer here. Soy likely has different impacts on human health during various life stages (ie the effects on a baby fed soy formula are different from a perimenopausal person) making animal models unreliable for humans. It also appears that the potential goitrogenic effect of soy is made worse with low iodine in the diet. (My opinion- deciding soy is ‘bad’ for the thyroid and completely avoiding it is a little bit like throwing the baby out with the bathwater. If we took ever food/nutrients that may inhibit thyroid function out of the diet we would have very little left to eat.)
They also reviewed several synergistic reactions which really interests me. It’s not often we find THE ONE nutrient that the body needs to function better. We are complex creatures and nothing works in isolation. They found melatonin’s benefits were improved with zinc, selenium’s benefits were improved with inositol, and vitamin E’s benefit was improved with curcumin.
There is much more to the article than what I summarized. It’s an open-access article available free online so check it out if you want more details :)
Cognitive functioning in Hashimoto's Patients (2018)
Something I hear at least weekly in practice is, “I am on levothyroxine/synthroid and my doctor says my thyroid is fine but I still have symptoms”. Well that is exactly the outcome from this study. They compared 139 patients with Hashimoto’s Thyroiditis (HT) who were properly treated with medication and 111 people who do not have thyroid disease. The TSH, FT3 and FT4 were no different between the thyroid patients and controls. You know what was different between the two groups? Symptoms. Global cognitive function, anxiety and depression scores were all significantly worse in the adequately treated HT patients. This isn’t surprising to those of us that treat thyroid disease holistically. Just replacing thyroid hormone doesn’t get to the root of the problem.
If you have Hashimoto’s and you’ve asked your conventional provider to check your antibodies (TPOAb and TGAb) you have likely been told that antibodies levels don’t matter. Well this study also helps disprove that long-held theory. The researchers found that TPOAb levels correlated with a lower quality of life in hypothyroid patients.
Bottomline: Just replacing thyroid hormone often doesn’t improve symptoms in Hashimoto’s patients and checking antibody levels is an important part of your care. If your provider isn’t on board, might be time to look for a new one.
Differences in food consumption between patients with Hashimoto’s thyroiditis and healthy individuals (2020)
I am pleased to see another study evaluating the relationship with food and Hashimoto’s Thyroiditis (HT) but unfortunately this study doesn’t give us very much clinically useful information.
The most statistically significant results were that folks with HT consumed more animal fat and processed meat that controls. Controls consumed more red meat, grains, plant oils and non-alcoholic beverages.
There was an association with elevated T3 levels in those who consumed more plant oil. The questionnaire used offered 3 options for fat intake: plant oil, olive oil and animal fat. So unfortunately, ‘plant oil’ covers a variety of oils and this nugget isn’t very helpful.
This study isn’t clinically useful for a variety of reasons. This is a cross sectional, observational study that is not designed to give a causal connection between the consumption of food groups and HT development. It is also very challenging to accurately measure food intake via questionnaires. Anyone who has filled out or reviewed a diet diary understands this! The questionnaire used in the study was not designed to collect quantitative data on dietary intake, only frequency of intake. If someone eats 1 TBS of animal fat vs 5 TBS of animal fat 3x per week, that’s a big difference and isn’t taken into account in this study.
Bottomline: Really nothing helpful here to incorporate into practice unfortunately. Again, still happy to see more research on diet and Hashimoto’s disease though!
- Nordio M, Basciani S. Myo-inositol plus selenium supplementation restores euthyroid state in Hashimoto's patients with subclinical hypothyroidism. Eur Rev Med Pharmacol Sci. 2017 Jun;21(2 Suppl):51-59. PMID: 28724185.
- Benvenga S, Ferrari SM, Elia G, Ragusa F, Patrizio A, Paparo SR, Camastra S, Bonofiglio D, Antonelli A, Fallahi P. Nutraceuticals in Thyroidology: A Review of in Vitro, and in Vivo Animal Studies. Nutrients. 2020 May 8;12(5):1337. doi: 10.3390/nu12051337. PMID: 32397091; PMCID: PMC7285044.
- Djurovic M, Pereira AM, Smit JWA, Vasovic O, Damjanovic S, Jemuovic Z, Pavlovic D, Miljic D, Pekic S, Stojanovic M, Asanin M, Krljanac G, Petakov M. Cognitive functioning and quality of life in patients with Hashimoto thyroiditis on long-term levothyroxine replacement. Endocrine. 2018 Oct;62(1):136-143. doi: 10.1007/s12020-018-1649-6. Epub 2018 Jun 29. PMID: 29959689.
- Kaličanin, Dean & Brčić, Luka & Ljubetić, Katija & Barić, Ana & Gračan, Sanda & Brekalo, Marko & Lovrić, Vesela & Kolcic, Ivana & Polasek, Ozren & Zemunik, Tatijana & Punda, Ante & Perica, Vesna. (2020). Differences in food consumption between patients with Hashimoto’s thyroiditis and healthy individuals. Scientific Reports. 10. 10670. 10.1038/s41598-020-67719-7.