Here are the top three foods that promote a healthy thyroid.

Your thyroid is a small, butterfly-shaped gland that sits at the base of your neck and helps regulate your metabolism, temperature, heartbeat, and more. An underactive thyroid—when the gland fails to produce enough thyroid hormone (TH)—can bring on weight gain, sluggishness, depression, and increased sensitivity to cold. An overactive thyroid, on the other hand, happens when your body produces too much TH, and can cause sudden weight loss, irregular heartbeat, sweating, nervousness, and irritability.

Your thyroid needs iodine to work properly and produce enough TH for your body’s needs. If you don’t get enough iodine, you run the risk of hypothyroidism or a goiter (a thyroid gland that becomes enlarged to make up for the shortage of thyroid hormone). Most Americans have no problem getting enough iodine, since table salt is iodized, but if you’re on a low-sodium diet like many Americans are for their heart health, or follow a vegan diet, you may need to increase your intake from other sources.

Genetics, an autoimmune condition, stress, and environmental toxins can all wreak havoc on your thyroid—and so can your diet. Here are the top three foods that promote a healthy thyroid.

1. Yogurt – According to recent research in the journal Nutrition Reviews, dairy products are often full of iodine (and in more manageable amounts). Part of the reason is because livestock are given iodine supplements and the milking process involves iodine-based cleaners. Plain, low-fat yogurt, or Greek yogurt is a good source—it can make up about 50% of your daily intake of iodine.
   
2. Milk – Much of the iodine in the average American diet comes from dairy products, according to a recent study by researchers from the Food and Drug Administration (FDA). However, our consumption of dairy has been declining slowly over time. By drinking one cup of low-fat milk, you’ll consume about one-third of your daily iodine needs. Choose milk that’s been fortified with vitamin D. Recent research suggests that people with hypothyroidism are more likely to be deficient in D. 
   
3. Brazil Nuts – Brazil nuts are packed with another nutrient that helps regulate thyroid hormones: selenium. In a recent study by researchers in France, women who consumed higher amounts of selenium were less likely to develop goiters and thyroid tissue damage than those who didn’t. Plus, it may also help stave off long-term thyroid damage in people with thyroid-related problems like Hashimoto’s and Graves’ disease, according to a review in the journal Clinical Endocrinology.