The vast majority of thyroid hormone converts from T4 (storage form) to T3 (active form) in our gut. That conversion can be thrown off if the gut isn’t functioning properly—namely, if you have a leaky gut, which is when the junctions in the intestinal lining break apart, and particles including toxins and undigested food escape from your intestines and travel throughout your body via your bloodstream. Another consequence of a leaky gut: We aren’t digesting and absorbing nutrients properly, and we need proper nutrients (tyrosine, zinc, selenium, iodine, B vitamins, vitamin A, vitamin D) for the conversion of T4 to T3. Often, when the problem is that the body simply isn’t making the conversion from T4 to T3, it’s really due to nutrient deficiency, which can be fixed with diet and supplement changes.
The main causes of leaky gut are gluten (and other inflammatory foods, i.e. processed and sugary), infections (such as candida overgrowth and intestinal parasites), medications (acid-blocking, antibiotics, and ibuprofen) and toxins (like mercury and lead). Gluten is particularly problematic because the gluten molecules look very similar to our thyroid tissue. Through a process called molecular mimicry, when we eat gluten—particularly if we have a leaky gut—the gluten slips into our bloodstream and our immune system goes on high alert, warning that the gluten should not be there. But because gluten looks so similar to our thyroid tissue, our immune system inadvertently attacks our thyroid, trying to rid the body of gluten. This is one of the theories behind autoimmunity and thyroid dysfunction.
What kind of diet do you recommend for people with hypothyroidism and hyperthyroidism?
The diet that I recommend to patients is something I call The Myers Way ®, which was born out of years of experimenting on thousands of patients and myself. Early on in my functional medicine practice, I used the standard elimination diet from the Institute for Functional Medicine, which included getting rid of toxic (alcohol, sugar, and processed) and inflammatory (gluten, dairy, eggs, and corn) foods. The diet helped many of my patients recover from conditions such as allergies, IBS, headaches, and weight gain. But as I started to see more complex patients, especially those with autoimmunity (including thyroid), chronic fatigue syndrome, and fibromyalgia, I realized that there were additional dietary changes that could help reverse these chronic conditions. I experimented on myself first by removing all grains, legumes, nuts, seeds, and nightshade vegetables (tomatoes, potatoes, eggplant, peppers) for a few weeks, and the results were dramatic. I started using this same protocol with all of my autoimmune patients and the results were again astounding.
I’ve found that eliminating grains and legumes, in particular, is a really good thing for most people. Grains and legumes contain certain amino acids and proteins that can be very irritating to the gut if you don’t soak and cook them properly. Also, many of my patients have small intestinal bacteria overgrowth (SIBO) or candida (yeast) overgrowths and the way to get rid of these infections is to really starve them out by getting rid of carbs, even the healthy ones.
Neither the diet or lifestyle components of my recommended treatment plan differ much for people with hyperthyroidism and hypothyroidism, because we aren’t trying to treat a problem of the thyroid; we are treating a problem of the immune system that happens to be affecting the thyroid. With autoimmunity, the problem is in your immune system, not a particular gland or organ (and indeed, more than one can be affected).
I also recommend the same general treatment plan for thyroid dysfunction even if you haven’t been diagnosed with an autoimmune disease. You may not have hit autoimmunity yet (it’s also hard to diagnose in the first place), but your body is still vulnerable to the same things (for instance, toxins). And you’ll want to do the same general things to heal the thyroid and immune system: Repair the gut, relieve stress, and so on. Many women find that they can add back in some of the foods they eliminated after going through the program, but everyone can benefit from it.
What about supplements?
Supplements are one area of the program that differs depending on whether a patient has hypothyroidism or hyperthyroidism. With hypothyroidism, you need key nutrients such as selenium, zinc, and iodine to support the conversion of T4 to T3—so a high quality multivitamin is very important. There are a host of supplements that are specific to hyperthyroidism, which help replenish the nutrients that the body is burning through. Also, rather than taking harsh medication to shut down the thyroid (which is what I initially did when I was diagnosed), there are a number of calming thyroid herbs that are safer and can help to suppress an overactive thyroid, like motherwort, bugleweed, and lemon balm.
Which toxins are problematic for the thyroid?
In your cleaning and beauty products, you especially want to avoid parabens (preservatives) and phthalates (plasticizers), which are both endocrine disruptors, meaning that they affect estrogen and other hormone levels. These toxins are harmful because they look and act like estrogens in the body, and as a result more proteins are secreted, which bind to your thyroid hormones. When the thyroid hormones are bound they cannot go into the receptors in our cells where they do their job, potentially leading to hypothyroidism. So using these chemicals can have a large impact on your estrogen levels and your thyroid.
What’s your stance on iodine?
The thyroid needs iodine to produce its hormone and to function optimally. Humans used to eat a diet rich in iodine (with sea vegetables, seafood, iodized salt), but the modern diet is iodine-deficient. On top of that, environmental toxins—including bromine, chlorine, and fluoride, which are all halogens—displace iodine in our body. Bromide is in our food, clothes, mattresses, sofas, and rugs. Chlorine is in our water, and fluoride is in toothpaste, medication, and water. Conventional medicine can make iodine seem taboo to those with thyroid dysfunction, but I’ve found that supplementing the body’s iodine intake can be very helpful—along with eating a diet rich in seafood/seaweed, limiting exposure to halogens and endocrine disruptors by doing things like putting a water filters on your shower, choosing nontoxic products and mattresses, and avoiding packaged foods. You need to be cautious with iodine supplements, but I often recommend a multivitamin with micro amounts of iodine to my patients because most of us are very deficient.
What about stress?
The Myers Way Thyroid Connection Plan addresses the five factors that I’ve found to be at the root of thyroid dysfunction: Diet, leaky gut, toxins, infections, and stress. There’s a twenty-eight day recovery plan in the book, with each day laid out for readers, including recipes, gut-healing and stress-relieving techniques.
Stress is a bigger part of the puzzle than I initially recognized. We can’t get rid of our stress entirely, but we can learn to relieve it. Things like how you prepare for bed are important—in addition to helping your body’s natural detox abilities, a good night’s sleep decreases stress levels. The first step in the morning (after you get up and drink two cups of water with lemon juice to get rid of toxins) is doing something calm and centering for yourself—and this is also how you should end the day. My plan has stress relieving options for everyone—there are simple and free tips that only take a few minutes each day, as well as more comprehensive ones to try weekly or monthly, such as neuro-feedback, massage, acupuncture, or going to a float tank.
Dr. Amy Myers is the founder and medical director of Austin UltraHealth, a functional medicine clinic based in Austin, Texas. Dr. Myers specializes in women’s health issues, particularly thyroid dysfunction. She is also the New York Times bestselling author of The Autoimmune Solution and The Thyroid Connection.
The views expressed in this article intend to highlight alternative studies and induce conversation. They are the views of the author and do not necessarily represent the views of goop, and are for informational purposes only, even if and to the extent that this article features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment, and should never be relied upon for specific medical advice.