When it comes to thyroid diseases, hypOthyroid (not making enough thyroid hormone) gets all the press. But there’s another type of thyroid disease that sometimes flies under the radar: hypERthyroid disease, or making too much thyroid hormone. (The O and the ER aren't going to be bolded and capitalized for the whole post, because that would be really annoying, but pay attention to them, because the difference is huge!)
It’s true that hyperthyroidism isn’t as common. But it’s still serious and it does affect a lot of people.
Symptoms of hyperthyroidism are basically the opposite of the symptoms of hypothyroid:
- Inexplicable weight loss (meanwhile hypothyroidism typically causes weight gain)
- Constantly feeling agitated or irritable; unable to “turn off.” (Hypothyroidism typically causes extreme fatigue or inability to “turn on.”)
- Trouble sleeping (hypothyroidism typically makes people tired all the time)
- Diarrhea (hypothyroidism typically causes constipation)
- Sweating a lot, or being too hot all the time (hypothyroidism typically makes people cold all the time)
All of these are ultimately caused by having too much thyroid hormone, because thyroid hormone is a big regulator for metabolic rate. Too much thyroid hormone is basically forcing your metabolism and your whole body to run too fast and too hot. This is really uncomfortable for the person living with it (it’s not like a magic ticket to easy weight loss, unless you want to lose weight by feeling awful all the time) and it can cause heart failure, brittle bones, and vision problems down the line.
Hyperthyroid can have all kinds of causes. The most common is Graves’ disease, an autoimmune disease. Other infections can also cause hyperthyroid. Taking too much supplemental iodine or eating a diet extremely high in iodine can do it, too.
Links between Diet and Hyperthyroidism
The obvious link between diet and hyperthyroidism is dietary iodine. There’s reason to believe that dietary iodine can affect the likelihood of someone becoming hyperthyroid. But Graves’ disease also has an interesting connection via everyone’s old friend gluten – did you know that Graves’ disease is actually very tied up with Celiac Disease?
Diet can also be helpful for minimizing the damage of hyperthyroidism, especially bone loss.
Dietary Iodine and Thyroid Function
Iodine is a nutrient found mostly in sea foods. Fish has a lot, and sea vegetables are overflowing with the stuff. Iodine is important for all kinds of things, especially thyroid health. Basically, you need it to make thyroid hormone, so if you’re not getting enough iodine, you won’t be able to make enough thyroid hormones and you’ll end up being hypothyroid. Deficiency of iodine used to be a massive public-health problem in the US until we started putting iodine in the salt, and now it’s very rare to see someone with mental retardation or goiter (visibly swollen thyroid gland) from iodine deficiency.
But too much iodine isn’t necessarily better.
There have been some disturbing case reports of people getting hyperthyroid problems from eating way too much seaweed and other iodine-rich foods. Case reports are official medical reports of things that happened to individual patients. They’re at the bottom of the medical evidence tier - they’re basically really well-documented and professionally-confirmed anecdotes. But they’re still interesting.
- This woman became hyperthyroid after eating a marketed diet containing kelp. Afterwards, she had a rebound period of hypOthyroidism.
- This woman became hyperthyroid from drinking kelp tea.
Iodine deficiency early in life can make people more vulnerable to iodine-induced hyperthyroidism later on. This can cause big problems in developing countries, where a lot of people have pre-existing iodine deficiencies and governments or NGOs start an iodine supplementation scheme. Using high-dose iodine supplements for this is also associated with a higher rate of hyperthyroidism.
In the interests of not being alarmist: this isn’t a one-time effect. Almost all people have a temporary change in thyroid hormone levels if they eat a huge amount of iodine at once. It’s called the Wolff-Chaikoff effect, after the doctors who discovered it, and if it’s just a one-time thing, it’s no big deal. But chronically eating a high level of iodine can be dangerous.
The Celiac/Gluten Connection
Another interesting link between diet and the thyroid is the connection between Celiac disease and Graves’ disease. Celiac disease is an autoimmune reaction to gluten, a protein in wheat, barley, and rye. It’s very well recognized that Celiac disease is linked to autoimmune hypothyroid diseases, but an increasing amount of evidence is also connecting it to hyperthyroid autoimmunity, or Graves’ disease.
- Here’s a case study. The woman in question had Graves’ disease but didn’t respond to treatment. Her doctor screened her for Celiac disease and the result was positive, so she cut out gluten. After that, she started responding to her thyroid medication.
- Here’s another case study of another woman with Graves’ disease who got a lot better on a gluten-free diet. (that one is free to read if you want all the details)
Want something more substantial than a case study? In this study of 161 patients, patients with Graves’ disease had a much higher rate of Celiac autoimmunity than the general population. Here’s another one, with 115 patients. Celiac disease 4.5 times as common in patients with Graves’ disease as it is in the general population.
If you have an autoimmune hyperthyroid disorder, screening for Celiac autoimmunity might be well worth your time – and gluten elimination might be very helpful.
Other Dietary Factors
To wrap up dietary factors in hyperthyroid, here’s a mixed bag of studies that may be interesting.
This study makes it look like a vegan diet is protective against hyperthyroidism, but if you actually read the full text of the study, there’s a huge confounding factor: sex. Women get thyroid diseases much more often than men. So as the percentage of women in the group increases, the percentage of thyroid problems in that group will also increase. A group with 80% women will have more thyroid problems on average than a group with 20% women. In that study, the percentage of women was lowest in the vegan group, so of course the rate of hyperthyroidism was lower. The authors couldn’t come up with any solid link between veganism and thyroid health, so demographics seems like the most likely explanation here.
This study is also interesting. The researchers surveyed people in Pakistan, and found that the people who ate the most turmeric, milk, ghee, and chilies had the least hyperthyroidism. It’s an association and nobody can tell you if it’s causal or not, but turmeric in general is pretty good stuff, and so is ghee!
Eating for Hyperthyroidism
If the cause of your hyperthyroidism is diet (e.g. excessive kelp or supplements), then diet will obviously be a big part of the cure. If you have autoimmune hyperthyroidism, eliminating gluten might be helpful. But diet alone can’t cure hyperthyroid and nobody is claiming that it can: obviously, in either case your first stop should be a doctor’s office.
There’s one more thing to note about eating for hyperthyroidism : diet can help prevent the bone thinning that excess thyroid hormone often causes. If you have hyperthyroidism, bone health should be a top prority. Eating for healthy bones and teeth means…
- Getting enough Vitamin D (from sunshine, fatty cold-water fish, and/or supplements)
- Getting enough Vitamin K2 (from pastured meat and dairy)
- Getting enough calcium (from leafy green vegetables, dairy if you tolerate it well, and other sources)
- Getting plenty of high-quality protein and essential amino acids, from animal foods (meat and eggs) and bone broth.
Read up more on eating for bone health here. Of course, this isn’t a cure for the underlying thyroid problem, but it can help reduce the long-term symptoms.
Summing it Up
Hyperthyroidism often gets ignored next to its cooler and more popular cousin, hypothyroidism. But hyperthyroidism is also important, and diet does have an effect!
In terms of diet, finding the sweet spot for iodine is a good bet – deficiency is obviously bad, but there’s such a thing as too much. Gluten and gluten autoimmunity may also be one big factor that contributes to thyroid autoimmunity, so if you have hyperthyroid problems, gluten is a problem to watch. If you have hyperthyroidism , taking care of your bones is also important even after treatment, and diet can help with that.