Your thyroid gland produces hormones that help regulate metabolic functions, including your body temperature, energy and moods. About 20 million Americans have a thyroid disorder, according to a "Today's Dietitian" article published in 2004. While hypothyroidism causes deficient thyroid hormone production, hyperthyroidism causes excessive hormone production. Both conditions can be treated with medication. If you're taking thyroid medication, you should be aware that food intake can affect the absorption of the medicine.
Medication Function
Medications for hypothyroidism contain levothyroxine, a synthetic thyroid hormone. Levothyroxine helps bring your thyroid levels up to a normal, healthy range and helps reduce common symptoms, such as lethargy, depression, sleep trouble, constipation and weight gain. If you have hyperthyroidism, your doctor will likely prescribe one dose of liquid radioactive iodine, which slows production of thyroid hormones. This can trigger hypothyroidism, which is then treated with levothyroxine-containing drugs. Depressive thyroid drugs may also be used to manage hyperthyroidism.
Dietary Measures
Appropriate dietary changes, such as cutting back on refined foods like white bread, eating more antioxidant-rich foods and avoiding suspected food allergens, such as wheat or dairy products, may help reduce thyroid disease symptoms. Eating well may also help manage complications, such as undesirable weight loss or gain. Because certain foods can interfere with thyroid function and your medications, your doctor may also suggest avoiding particular foods.
Food and Medication Interactions
Foods containing natural substances called goitrogens can interfere with thyroid function, making it difficult for your medications to work. Many vegetables, fruits and nuts contain goitrogens. Consuming soy in excess can also offset your thyroid levels and lead to weight gain, according to Patricia Vasconcellos, a registered dietitian and spokesperson for the American Dietetic Association. You should also avoid soybean flour, cottonseed meal or walnuts when you take synthetic thyroid medications, because these foods can interfere with their absorption. Consuming too much fiber with your medications may cause similar effects.
Suggestions
Because many goitrogen sources are nutritious, talk to your doctor or dietitian about allowable portion sizes and suitable substitutions. Bell peppers, carrots, tomatoes, blueberries and squash provide antioxidant-rich alternatives to spinach, kale and strawberries, for example. Vasconcellos recommends that women with thyroid conditions limit soy to no more than one serving per day, equivalent to 2 tsp. of soy sauce, 8 oz. of soy milk or 4 oz. of tofu. Eating fiber-rich foods with meals you eat many hours before or after taking thyroid medications can help ensure digestive health and appetite control.
References
- "Today's Dietitian"; Thyroid Disease in Women --- Diagnostic Conundrum Today's Dietitian; Jennifer Sisk; October 2004
- University of Maryland Medical Center: Hypothyroidism
- University of Maryland Medical Center: Hyperthyroidism
- MayoClinic.com: Hypothyroidism Diet: Can Certain Foods Increase Thyroid Function?
