The thyroid, a small butterfly-shaped gland at the base of your neck, is small but mighty: It produces hormones that control your metabolism and can influence your energy levels. It’s important to keep it working efficiently, and you may have heard that certain foods can help or hurt that process. We asked two experts to weigh in on these claims.
The claim: Eating too much broccoli, cauliflower or Brussels sprouts can interfere with thyroid function.
The facts: It’s true that these foods, which are described as goitrogenic, can make the thyroid function less efficiently, says Dr. R. Mack Harrell, an endocrinologist with Memorial Health Systems in Hollywood, Fla., because they can prevent the thyroid from getting enough iodine to function properly. But you don’t really need to avoid them. “Those foods would have to be eaten in huge quantities and mostly raw to do anything,” Harrell says.
The claim: People who take a synthetic thyroid hormone for hypothyroidism (underactive thyroid) should avoid calcium- and iron-rich foods like spinach and kale.
The facts: These foods can interfere with the absorption of iodine. But Harrell tells his patients not to completely avoid those healthy foods, which are low in calories and high in fiber. Instead, he suggests they alter their thyroid medication schedule. His advice: Continue to eat those foods but eat them earlier in the day, and then take your medication at bedtime. (The same goes for iron and calcium supplements, or antacids that contain calcium.)
The claim: Your giant soy latte habit could be hurting your thyroid.
The facts: Soy compounds could interfere with the absorption of iodine, so you may need to be more mindful about when you indulge, but only if you have a thyroid condition. Harrell recommends spacing out products that contain soy by at least four hours so you’re not absorbing too much at once.
The claim: Certain foods will boost your thyroid function.
The facts: There’s not really a specific diet that will boost your thyroid function, says dietitian Joy Dubost, spokesperson for the Academy of Nutrition and Dietetics (formerly the American Dietetic Association).“It’s really just a generally healthy diet that you should follow,” she said. “To eat a healthy diet in general is going to support a healthy thyroid.” Instead of concentrating on a few specific foods, your diet should mostly consist of whole grains, low-fat dairy, fruits and vegetables and lean protein, she added.
The claim: You should make sure you get enough iodine in your diet, or you might develop a goiter.
The facts: In the past, a goiter — swelling in the neck caused by enlargement of the thyroid — was linked to diets deficient in iodine, but that hasn’t been a widespread phenomenon in the United States in decades. “That’s because we use iodized salt,” Dubost says, noting that most people consume too much sodium, rather than not enough.
That means that for most people there’s no need for iodine supplements. Beware of advertisements for iodine or kelp (a type of seaweed high in iodine) supplements, Harrell warns. None of those are necessary, and large doses of extra iodine can actually be harmful, especially if you have autoimmune thyroid disease or a family history of it.