Slow-Thyroid Foods to Avoid

Slow-thyroid foods should be avoided by people with hypothyroidism or low thyroid. Also called an underactive thyroid gland, hypothyroidism can lead to weight gain and fatigue. Following a low-thyroid diet can improve the function of the thyroid, which is to transform iodine from food into thyroid hormones for metabolism. Some of the slow-thyroid foods to avoid include foods with caffeine, sugar and compounds that are bad for the endocrine system.

Soy Products

Soy products contain isoflavones, which act as anti-thyroid agents and should be avoided by people on low-thyroid diets. Soy is a phytoestrogen that acts like a hormone. It can suppress thyroid function. Isoflavones are chemicals considered endocrine-system disruptors. The thyroid is part of the endocrine system.

Goitrogens

Goitrogens are substances that block the absorption of iodine, which is critical for thyroid function. Slow-thyroid foods to avoid include vegetables from the Brassica family that contain goitrogen, such as cabbage, turnips, broccoli, cauliflower and kale. Make sure to cook the vegetables instead of eating them raw, which has been shown to help.

Caffeine, Chocolate

Caffeine should be avoided since it is a stimulant that has been shown to alter thyroid-stimulating hormones in animals. Caffeine also zaps the body of calcium, which is important for hormonal balance. Avoid foods containing coffee, which has 40 mg to 180 mg of caffeine per cup. Also avoid bittersweet chocolate, which has 25 mg of caffeine per ounce. Brewed American tea has 20 mg to 90 mg of caffeine per cup.

Sugar, Milk

Avoid slow-thyroid foods that contain sugar. Sugar can impair the function of the thyroid and adrenal glands. Hypothyroidism slows down the body's ability to digest carbs, which is why many people with a sluggish thyroid gain weight. Too much sugar can lead to weight gain as well as blood sugar swings that cause fatigue and hunger. Milk is another form of sugar. The casein in milk is bad for the endocrine system. Also, some milk products contain hormones that interfere with the thyroid's ability to properly function.