Many people struggle with thyroid issues. Common thyroid diseases include hypothyroidism, Hashimoto’s disease, and Grave’s disease. Thyroid conditions can cause a slow metabolism, trouble with weight loss, and regular fatigue. While many thyroid conditions or diseases can’t be entirely reversed or cured, there are measures you can take to help manage your symptoms. And your diet is a good place to start. The food you eat can affect the way you feel, help normalize your thyroid function, or just improve your symptoms.
We asked Luiza Petre, M.D., a board-certified cardiologist and weight management expert, to break down what exactly the thyroid is, what it does, and how your diet can impact thyroid health.
What Is The Thyroid Gland?
Also known as the butterfly gland, the thyroid gland helps produce hormones that regulate the body’s metabolic rate. It’s vital when it comes to the function of the heart, the digestive system, muscle control, brain development, mood, and bone maintenance. “Thyroid hormones are vital for optimal body function,” says Dr. Petre. “[They] regulate everything from metabolism, digestion, brain function, appetite, energy level, skin, nails, and hair quality. It’s estimated that as many as 40 percent of people will be impacted at one point. [Either] by a hypoactive thyroid or not enough thyroid hormone. Our food intake can have a big impact on thyroid function.”
There are two elements that have a big impact on how well your thyroid functions: iodine and selenium.
The Importance of Iodine
Proper functioning of the thyroid gland depends heavily on having a good supply of iodine from your diet. The gland takes iodine found in many foods and converts it into thyroid hormones: thyroxine (T4) and triiodothyronine (T3).
“Most water supplies are supplemented with iodine, but in some areas, iodine is lacking. So, it has to be added through diet,” Dr. Petre says. “Morton Salt started adding iodine for this widespread population supplementation. Still, 75 percent of our ingested iodine comes from processed foods or hidden salt.”
The daily recommendation is 150 mcg. According to Dr. Petre, iodine-rich foods include cranberries, sea vegetables such as kelp, strawberries, cheese, navy beans, and yogurt. She does caution, however, that high ingestion of iodine also can be harmful. “[It] has to be limited in some thyroid conditions.” For example, those who suffer from hyperthyroidism, which is when the thyroid produces an excess amount of a hormone called thyroxine, should avoid too much iodine.
The Importance of Selenium
“Selenium is the next most important mineral involved in converting T3 to T4. People with low selenium levels are frequently diagnosed with hypothyroidism,” Dr. Petre explains. “Examples of selenium-rich foods are Brazilian nuts, tuna, halibut, and beef.”
Similar to iodine, selenium is also a double-edged sword. Too much of it can be harmful. “We need on average 55 mcg per day. As a comparison, one [ounce of] Brazilian nuts has 542 mcg,” Dr. Petre says. “So refrain from eating too many.”
Still unsure about the exact foods you should avoid or consume to keep your thyroid health on track? Doctors and experts share a few lifestyle tips that can help you maintain proper thyroid health.
Foods That May Hinder Thyroid Function
Surprisingly, there are a number of healthy foods that may disrupt your thyroid function. For example, everyday cruciferous vegetables may present challenges. “Broccoli, cabbage, kale, and cauliflower are goitrogens (goiter inducers),” Dr. Petre explains. “[They] contain glucosinolates that are suspected to interfere with thyroid production of hormones. [This is] more accentuated in those with iodine deficiency or underactive thyroid.”
She explains that eating these vegetables in regular amounts is unlikely to cause any harm. Cooking them can also reduce any potential negative impact on the thyroid.
Those with thyroid dysfunction should also opt for organic produce whenever possible. “The chemicals in pesticides, organochlorines, can wreak havoc on your system,” Dr. Petre says. According to Lisa Hayim, an NYC-based R.D. and founder of The Well Necessities, research supports this claim. “A growing body of evidence supports a link between exposure to pesticides and thyroid problems. Research shows that people who ate the most toxins experienced a greater-than-normal dip in metabolism and had a harder time losing weight.” So, Hayim advises buying organic as often as possible.
Additionally, consume caffeine and soy in moderation. More than two cups of caffeine a day has been associated with an increased secretion of thyroid hormones. And reports reveal that soy ingestion can have a harmful impact on those with an iodine deficiency.
Foods That Support Thyroid Health
Nutritionist Jessica DeLuise recommends an anti-inflammatory diet to keep inflammation at bay and benefit your thyroid health. Omega-3-rich foods, including avocados, organic free-range egg yolks, salmon, and sardines, are good options. Additional anti-inflammatory foods include turmeric, ginger, garlic, beta-carotene found in red fruits and vegetables, and polyphenols found in purple and red fruits and veggies. Selenium-rich foods are key for their nutrients and necessary for the development of thyroid hormone. These include sea salt and seafood, such as tuna and shellfish.
“While maintaining a healthy body, it is important to start with the basics like a healthy gut and microbiome. Adequate flora can improve digestion, bowel regularity, weight loss, and nutrient absorption like the ones necessary for thyroid function,” DeLuise says.
Probiotics aid a healthy gut and support thyroid function. Foods with probiotics include grass-fed dairy, sauerkraut, miso, tempeh, kombucha, pickles, or apple cider vinegar. DeLuise emphasizes the importance of eating enough prebiotic foods to fuel probiotics. Prebiotic foods include cabbage, greens, and berries.
The thyroid gland is a small portion of the human body. However, it is a huge part of overall health. Making sure it is functioning properly is the first step of preventive care. If you feel you may be suffering from symptoms, be sure to make an appointment with an endocrinologist or another health care provider.