Vegetables You Should Avoid If You Deal With Thyroid Disease

Living with thyroid disease can be challenging. Depending on the severity of your condition, you may experience fatigue, joint pain, memory problems, and other symptoms. For example, hypothyroidism can cause weight gain, low energy, forgetfulness, and increased sensitivity to cold, notes the Cleveland Clinic. This condition occurs when the thyroid gland doesn't produce enough hormones. An overactive thyroid, on the other hand, can lead to rapid weight loss, mood swings, muscle weakness, sleep problems, and increased sensitivity to heat.

Thyroid disease is an umbrella term for several conditions affecting the thyroid gland. There's hyperthyroidism, hypothyroidism, Hashimoto's thyroiditis, Graves' disease, goiter, and more. These disorders affect about 20 million people in the US alone, according to the American Thyroid Association. The same source reports that about 12% of the population will experience thyroid problems at some point in life. On the positive side, you may be able to manage some of your symptoms through diet and lifestyle changes.

"Diet will not make your thyroid disorder go away and will not cause thyroid disorders," endocrinologist Dr. Ayla Bakar told Northwestern Medicine. While it's true that some foods can affect thyroid function, they are likely safe when consumed in moderation. "Like everyone else, people with thyroid disorders need to eat a healthy, well-balanced diet," says Dr. Bakar. However, there are some vegetables you may need to cut back on to keep your condition from worsening. 

Hypothyroidism, one of the most common forms of thyroid disease, occurs when your body produces too little triiodothyronine (T3) and thyroxine (T4), two hormones that regulate metabolism. This condition can have a variety of causes, including iodine deficiency, according to the Cleveland Clinic. Certain foods — especially those rich in goitrogens — can inhibit iodine uptake and affect thyroid function, explains a 2015 review published in Biochemistry & Pharmacology.

Goitrogens are substances that occur naturally in plant-based foods, such as cabbage, cauliflower, cassava, kale, radishes, and collard greens. Soy falls into this category, too, and it may cause an underactive thyroid in people with iodine deficiency, says Today's Dietician. These foods are safe for healthy individuals, but they can be troublesome for those with thyroid disease — especially when consumed in excess. "You would have to consume an excessive and unrealistic amount of these vegetables for them to interfere with iodine and thus hormone production in the thyroid," Dr. Bakar told Northwestern Medicine.  

Cooking these foods can reduce goitrogens by up to 90%, reports the Kresser Institute. Experts recommend steaming rather than boiling, which helps preserve more nutrients. The Kresser Institute also points out that fermented veggies, such as sauerkraut, are higher in goitrogens but lower in nitriles than raw or cooked vegetables. Cyanides, or nitriles, affect thyroid function to a greater extent than most goitrogens, so fermented foods are likely beneficial when consumed in moderation.