What You Should Eat (And Avoid) To Improve Thyroid Health
You knew you had a thyroid issue. It just took your labs a couple of years to catch up. If you were lucky, you were prescribed magic pills and you shed your excess weight, your energy bounced back, your bowel movements became regular, and your bouncy, shining hair landed you in a Pantene commercial.
If you weren't so lucky, the pills didn't work. You felt like a frumpy, fatigued, and constipated version of yourself. Caffeine and sugar became your energy crutch. Dealing with thyroid issues can be confusing. As a nutritionist and a woman who reversed her own subclinical thyroid condition in three months, I'd like you to have a broader picture of food and your thyroid.
Here's what to eat to improve your thyroid function:
1. Cruciferous vegetables
Eat them raw, cooked, or juiced. I know you've been advised not to eat them raw, but doesn't it strike you as strange that plant foods with the richest source of cancer-preventing phytonutrients would inhibit thyroid function? It did to me. If this was true, what was the mechanism behind it, and where was the research on humans?
It turns out the concern has to do with iodine. Back in the 1950s, cruciferous vegetables were discovered to be potentially goitrogenic1, meaning they could suppress thyroid function, in animals. This is because the raw glucosinolates (the precise phytonutrients that are cancer-protective) might inhibit the intake of iodine, which is crucial for hormone production and normal thyroid function.
However, studies suggesting a strong link between cruciferous vegetables and thyroid disease are limited. Possibly because the amount of cruciferous vegetables you would need to eat to interfere with iodine far exceeds normal consumption levels. In fact, the vast majority of the research shows2 the consumption of cruciferous vegetables will not exacerbate or cause thyroid issues. So, no reason to miss out on the whole host of benefits from eating cruciferous vegetables.
2. Brazil nuts
These are the richest dietary source of selenium, which is essential for thyroid health. Selenium3 helps convert the thyroid hormone thyroxine to its active form, T3, for use in the body. It is also crucial for glutathione production, which can help decrease thyroid antibodies4 in those with Hashimoto's.
To support thyroid health5, try snacking on one or two Brazil nuts per day. Providing 90 micrograms of selenium per nut, or 129% of the daily intake recommended by the U.S. government, Brazil nuts are the perfect food-based supplement.
3. Sea vegetables
Sea vegetables are rich in iodine. Iodine6 attaches to tyrosine (an amino acid) to form thyroxine. If you have insufficient levels of iodine, it becomes a rate-limiting step in the production of thyroid hormones and you'll inhibit your thyroid function.
Snack on nori dusted with sea salt; make nori wraps filled with avocado, wild salmon, sweet potato, sprouts and mâche; add hijiki to a kale and pumpkin seed salad; eat wakame in a miso soup; or add dulse to a butternut squash soup.
Did you know heavy metals could be messing with your thyroid? Mercury, lead, and aluminum can all inhibit thyroid function7. In animal studies, chlorophyll8 has been shown to bind with heavy metals to rid them from the body. Try drinking a shot of chlorophyll upon waking to help boost energy levels and support thyroid function.
And some foods to avoid.
Of course, some foods can be triggering if you have thyroid issues. Below are foods to avoid to help heal your thyroid:
Gluten, a protein found in wheat, can wreak havoc on thyroid function. It can initiate thyroid antibody production10, causing inflammation and damage. Studies have shown that ditching gluten keeps Hashimoto's symptoms at bay11 in some patients. I've seen TPO levels drop from the 1,000s to less than 30 just from removing gluten.
Soy protein isolate
While the research on fermented soy and thyroid function is mixed, soy protein isolate12 should be avoided. Soy protein isolate is the extracted protein from soybeans that is used in many processed foods like soy cheese, soy yogurt, energy bars, soy burgers, and soy-based "meats."
The concern is that soy protein isolate may mimic the hormone estrogen in the body, disrupting thyroid functions. It can also interfere with the absorption of thyroid medications, so be sure to consult with your doctor about eating soy.
Noncaloric sweeteners such as aspartame, Splenda, and saccharin can change how glucose is regulated and the composition of the gut microflora for the worse. This can, in turn, trigger autoimmune disorders13 because the gut is tightly linked to the immune system.
It has been suggested that artificial sweetener use may be connected to the development of Hashimoto's. In one study, the use of sweeteners was weakly associated with increased levels of thyroid-stimulating hormone (TSH), a sign of hypothyroidism. In the same study, two-thirds of patients saw improvements in their TSH and thyroid antibody levels when they stopped using artificial sweeteners. More research is needed to fully understand the link between artificial sweeteners and thyroid function, but for now it's best to skip the sweet stuff.
By eating clean and smart, taking the right supplements, managing your stress levels, and avoiding environmental toxins you may be able to manage your thyroid condition. But you should also seek help from a medical professional to treat any symptoms you experience.
Dana James is a Columbia University–educated nutritional therapist and founder of Food Coach NYC. She holds her master's in clinical nutrition and is trained in nutrition biochemistry, functional medicine, and cognitive behavioral therapy. She believes that food should be viewed as nourishing, joyful, and fundamental to self-care. Her goal is to help women break their antagonist (and often obsessive) relationship with food and their bodies. She believes that true beauty stems from grace, dignity, and embracing our idiosyncrasies that make us unique and imperfect.
James created the "How to Ditch Sugar" video series for mindbodygreen. Check out the program here: How to Ditch Sugar.
James coaches one on one, runs workshops in NYC and LA, and holds tele-seminars on various topics that help women lead a more beautiful and balanced life. To connect more with James, check out her Instagram account and sign up for her biweekly Sunday-evening emails.