Click here to listen to a reading of this blog:
Originally published on 28th March 2016 Last updated on 17th December 2018
The more I learn about hypothyroidism, the more I understand how big a part diet can play in the disease and helping our symptoms and recovery. Especially since gaining my qualifications in Diet and Nutrition.
Related article: What is The Best Diet for Hypothyroidism?
And an important note: as someone who personally has a history of eating disorders / disordered eating myself, I am aware that the information in this article could be triggering if you’ve previously / are currently restricting foods. Do know that I will never suggest that any of us HAVE to cut out ANY food types, so I present this info for each of us to make that decision ourselves if we still have ongoing thyroid symptoms or struggles to manage the condition.
Some people may begin removing one or two foods from their diet and enter down a slippery slope in to disordered eating behaviours, so if this is you, and you start to feel anxious about food or much of your time and energy is preoccupied with this, please seek out support from a trained professional and be cautious about altering your diet. Disordered eating needs to be taken more seriously and I don’t wish to contribute to more people struggling with this.
I’m not a fan of massively restrictive diets which can encourage disordered eating behaviours, and thus, create more stress which, in turn, isn’t great for our health either.
It is reported by many that if consumed in excess, goitrogenic foods can be problematic for thyroid function and even lead or contribute to the formation of a goitre (an enlarged thyroid) in some cases.
They are reported to inhibit the body’s ability to use iodine and affect the process of iodine converting to T4 and T3, which obviously isn’t good for our hypothyroid symptoms and overall thyroid function.
What are they?
Goitrogenic foods include:
- Brassicas, e.g. brussel sprouts and cabbage
- Bok Choy
- Bamboo shoots
- Canola Oil
- Choy sum
- Radishes (Horseradish)
- Soy and soy milk (soy ‘anything’ really)
- Pine Nuts
- Peaches (mildly)
- Pears (mildly)
- Spinach (mildly)
- Strawberries (mildly)
- Sweet potatoes (mildly)
But you don’t necessarily need to completely abstain from eating goitrogenic food.
The general consensus is to have goitrogenic foods in moderation and that it seems they’re only goitrogenic in their raw state. Therefore, many suggest that cooking them adequately removes the goitrogens, or at least a large majority of them. For example cooking goitrogenic vegetables like broccoli and sprouts until the ‘crunch’ has gone, can indicate that the goitrogens have also gone.
Whilst consuming fermented and cooked cruciferous vegetables is preferred, occasionally eating small amounts of them raw, should not aggravate autoimmune thyroid conditions.
The key is moderation really. I don’t actively avoid any goitrogenic foods but also do not eat large quantities of them daily.
Soy is a goitrogen that blocks the activity of the TPO enzyme, which has therefore been linked to the development of autoimmune thyroiditis and hypothyroidism. A lot of thyroid patients therefore choose to avoid or limit it.
And if you have Hashimoto’s Thyroiditis, seriously consider gluten, too.
You could have had the tests done by your doctor to check for Coeliac Disease, and it come back negative, yet you suffer from symptoms such as:
- Mood swings/Depression/Anxiety (Research and studies confirm that gluten intolerance can be linked to depression, anxiety and mood disorders)
- Brain fog
- Aches and pains
- Acid reflux
- Joint pain
- Skin issues
- Swinging lab results and feeling hypo then hyper and vice versa
- Poor gut health/Leaky Gut, also meaning low absorption rate of minerals and vitamins
- Rubbish immune system
- Dental Issues
Gluten is said to trigger the same autoimmune reactions that cause you to have Hashimoto’s in the first place, since supposedly, the cells of your thyroid are similar to the make up of gluten, and it confuses your body, increasing inflammation and antibodies as an attack on your thyroid is launched, destroying more thyroid tissue, and so worse/extra hypothyroid symptoms occur. As a result, many autoimmune hypothyroidism patients eliminate gluten from their diet, and see good results.
Worsening thyroid hormone levels over time as well as swinging test results, are thought to typically be due to the ongoing destruction of your thyroid gland, which obviously causes it to not work properly (hypothyroidism). Lowering thyroid antibodies is believed to stop or slow this down.
When Italian researchers also put subclinical or ‘borderline’ hypothyroid people with coeliac disease on a gluten-free diet for one year, thyroid function normalised in 71% of them, with another 19% normalising their thyroid antibodies. The researchers concluded that in some cases, a gluten-free diet may single-handedly reverse the abnormality. 
The Effect of Gluten-Free Diet on Thyroid Autoimmunity in Drug-Naive Women With Hashimoto’s Thyroiditis: A Pilot Study concluded that their results suggested a gluten-free diet may bring clinical benefits to women with Hashimoto’s. 
Consuming gluten can also lead to leaky gut, where holes form in the gut lining and when food is ingested, gluten in this instance, it allows small particles to leak into the bloodstream, leading to symptoms of gluten sensitivity like those listed above. The immune system sees these particles as foreign entities and creates antibodies and mounts an attack not only on the foreign protein, gluten, but also on thyroid tissue because of its close resemblance to gluten. Eek!
If you often have low levels in vitamins (B12, D, Iron etc.), it could well indicate Hashimoto’s and/or damage to the gut (leaky gut) caused by consuming gluten.
Thyroid Pharmacist Izabella Wentz conducted a survey amongst thyroid patients in May 2015, that showed that 86% of people who went gluten-free reported an improvement in digestive symptoms.  Notably, only 3.5% of the respondents were actually diagnosed with celiac disease, thus it confirms what a lot of thyroid advocates and specialist doctors have been saying all along: That you do not have to have coeliac disease to benefit from a gluten-free diet.
However, there are huge benefits in screening for coeliac disease before removing gluten. For example, diagnostic tests for coeliac disease require you to be on a gluten-containing diet so that the test can detect any antibodies to gluten. If you are already on a gluten-free diet when tested for coeliac disease, you will need to reintroduce gluten for several weeks before the blood test, in order to get accurate results. Having a formal diagnosis of coeliac disease, if you have it, is also important.
Also, if coeliac disease is confirmed, as well as lifelong, strict gluten-free diet a longterm treatment plan will also need creating by your doctor and dietician to ensure you’re still getting the right nutrients from other foods. Monitoring of any intestinal damage and healing, as well as vitamin or mineral deficiencies is also recommended.
Similar to gluten, many thyroid patients also find that they have an issue with dairy. Removing dairy from your diet for a while to see if any symptoms improve can be worthwhile. The thyroid symptoms a dairy sensitivity is often linked to include:
- Skin complaints such as acne and eczema
- Digestive complaints
- Brain fog
Sugar and Processed Foods
For obvious reasons, sugar and processed foods can be avoided or limited in everybody, not just thyroid patients, to promote better health. They drive inflammation and disease, something we can be wary of when we have thyroid disease, and can make symptoms worse. They can also contribute to poor gut health which is incredibly pivotal to our overall health. Addressing my gut health was one of the biggest interventions to managing my hypothyroidism and Hashimoto’s.
Alcohol and Caffeine
Both alcohol and caffeine can negatively impact your blood sugar. Blood sugar spikes cause cortisol to shoot up, which can tire out the adrenals and exacerbate hypoglycaemia, Hashimoto’s and adrenal dysfunction.
Caffeine may also irritate the gut lining and encourage acid reflux, migraines, poor thyroid hormone conversion and oestrogen dominance.
Many hypothyroidism and Hashimoto’s patients seemingly develop an intolerance or increased sensitivity to alcohol, too.
It could be due to your thyroid health and liver health working together, in balance, as we know that alcohol can be a stress on the liver (where a lot of thyroid hormone conversion takes place), which processes and metabolises the alcohol you consume, however, alcohol can also affect thyroid hormone conversion and reduce thyroid hormone levels.
Alcohol can contribute to oestrogen dominance and adrenal dysfunction also and deplete minerals and vitamins such as magnesium, zinc, folic acid, B Vitamins and Selenium. All of which are very important for thyroid health.
As always, if you wish to consume alcohol or caffeine, then do so in moderation and consider the overall effects on your health as well as your thyroid health specifically. If they contribute to you feeling worse, particularly in the form of a flare up of symptoms, consider whether it is best to avoid them in order to better manage your health.
Of course, this is only a guide with suggestions which may help you. Not all thyroid patients do well on the exact same dietary adjustments and what some find to be helpful in managing their symptoms, others do not. We’re all individuals after all! You must find what works for you. Please also refer back to the note at the start of this article about being wary of massively restrictive diets and behaviours.
Read about which foods are helpful for hypothyroidism here.
Do you avoid any of these for your thyroid health?
You can click on the hyperlinks in the above post to learn more and see references to information given.
AngelaFebruary 24, 2021 at 4:57 pm
Only a month ago I have confirmation I have low thyroid. Only just understanding about foods. Dear me found out the hard way ate pine nuts! All I can say any one reading this avoid , I have just been so ill tremendous stomach pains and something else which I can only describe as a long time on the t you know what. I am having to educate myself. Frankly I think I have had thyroid for decades only just been picked up in my case due to depression and pycosis at one point alarming in its self thankfully not too many of them. I had pine nuts a decade ago and they made me ill then but due to my foggy memory lose “brain forget”! I forgot. I was doing well with my diet just tripped up on the nuts boy did my system pay the price.
Misty M. WrightOctober 24, 2019 at 2:21 am
Can you help me PLEASE – I am on the thyroid medicine and all lab work is fine so taking enough its within range all test was done and I have them but I started this medicine May 9, 2019 and I am still lethargic every day since then and brain fog nervous and its EVERY day – can you give me some advice. Also, I am a plain eater I eat a salad no dressing at supper and 6 ounces of all natural peanut butter and I have been eathing that every day since the first of the year.
Rachel HillOctober 24, 2019 at 5:02 am
Hi Misty, if could be that your level/s are not optimal, which is different to just being within range. Have you also explored the possibility of adrenal dysfunction or low vitamin levels? Please see more info here https://www.theinvisiblehypothyroidism.com/im-on-thyroid-medication-but-still-feel-rubbish/