People with diabetes (either type 1 or type 2 diabetes) have a higher risk of thyroid disease than people without diabetes. If you have type 1 diabetes, which is an autoimmune condition, you are at risk for hyperactive thyroid (called Grave’s disease) or underactive thyroid (called Hashimoto’s). In fact, the American Diabetes Association recommends that everyone who has type 1 diabetes be tested for hypothyroidism shortly after a diagnosis of diabetes. And research shows that hyperthyroidism and hypothyroidism are more common in people with type 2 diabetes than in people without diabetes.
Thyroid disease and its effect on diabetes
According to the American Diabetes Association, when your thyroid isn’t working as it should, it can make managing your diabetes more challenging. Here’s why:
Hyperthyroidism (too much thyroid hormone)
This thyroid disorder can increase your metabolism and cause your diabetes medications to be metabolized (go through your body) more quickly. As a result, your blood sugars may increase because there isn’t much of your diabetes medication left to do its job. Also, symptoms of hyperthyroidism, such as sweating, pounding heart, muscle weakness, and trouble concentrating, can also be signs of low blood sugar (hypoglycemia), so it’s important to check your blood sugar when you get any of these symptoms.
Hypothyroidism (too little thyroid hormone)
This type of thyroid disorder slows down your metabolism; as a result, your diabetes medications may stay in your body longer and may lead to low blood sugars. If you have hypothyroidism, you may need to decrease the amount of your diabetes medication.
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Role of nutrition in thyroid health
If you have either hyperthyroidism or hypothyroidism, medication may likely be part of your treatment plan. While good nutrition won’t cure your thyroid condition, it can help you manage your symptoms and feel your best. Let’s take a closer look.
Low energy and weight gain can occur with hypothyroidism. Also, you have a higher risk of getting heart disease with hypothyroidism. Here are tips to help you deal with these issues, while managing your blood sugars at the same time:
Get your iodine levels checked.
Iodine is a mineral that is essential for proper thyroid function. While iodine deficiency is uncommon in the U.S., too little can lead to thyroid issues, as can too much. Iodized salt provides iodine, as does eating seafood. Avoid taking iodine supplements unless advised by your health care provider.
Get enough selenium.
Selenium is a mineral that plays a role in converting T4 hormone to the active T3 hormone. Seafood, poultry, beef, eggs, whole-wheat bread, fortified cereals, and legumes are good sources of selenium.
Get enough zinc.
Zinc is a mineral needed for thyroid hormone production. Not getting enough zinc can lead to hypothyroidism. Good sources of zinc include oysters, red meat, poultry, lobster, whole grains, fortified cereals, and dairy foods.
Get enough vitamin B12.
About 30% of people with Hashimoto’s disease can be deficient in vitamin B12. Make a point to include vitamin B12-rich foods in your eating plan, including lean meat, fish, dairy foods, fortified cereals, and nutritional yeast. Ask your provider if you should get your blood levels of B12 tested, too.
Soy contains plant estrogens, which can block the activity of enzymes that help to make thyroid hormones. Soy might also block the uptake of iodine and interfere with the absorption of thyroid medication. Tofu, tempeh, miso, edamame, and soy milk are sources of soy.
Watch the millet.
Millet is a gluten-free grain that can suppress thyroid function. You don’t need to avoid it altogether but eat it less often, and focus on other whole grains, instead, such as quinoa, farro (not gluten free), or brown rice.
Go easy with goitrogens.
Goitrogens are substances found in broccoli, cauliflower, kale, Brussels sprouts, strawberries, peaches, and other foods that can block the body’s ability to use iodine. They also inhibit the release of thyroid hormone, and in large amounts, can lead to a goiter or an enlarged thyroid. Cooking your vegetables and getting enough iodine and selenium can minimize the effects of goitrogenic foods.
Get enough fiber.
When your metabolism slows down, your digestive tract may slow down, too. Keep it running smoothly by eating foods that contain fiber every day. Vegetables, fruits, whole grains, and legumes are great ways to get fiber. Remember that eating high fiber foods may make it easier to manager diabetes, too.
Weight gain can occur with hypothyroidism, and that, in turn, can make it harder to manage your blood sugars.
Time your thyroid medication.
If you’ve been prescribed levothyroxine, a thyroid hormone replacement drug, you will likely be advised to take it on an empty stomach with a full glass of water at least 30 minutes before eating breakfast. You will also need to take levothyroxine at least 4 hours before or after taking some medications, such as antacids, orlistat, and iron and calcium supplements. Your provider or pharmacist can give you additional information on how and when to take this medication.
Hyperthyroidism is when your thyroid is overactive. Graves’ disease is the most common form of hyperthyroidism, and this happens as a result of an autoimmune response that causes the thyroid gland to make too much of the T3 and T4 hormones. According to the American Thyroid Association, hyperthyroidism may be treated with medication, radioactive iodine to destroy thyroid cells, or with surgery, which involves removing some or all of the thyroid gland.
Check on your iodine status.
You may or may not need to limit your iodine intake, so talk with your health care provider. Some iodine is usually fine, but go easy with iodized salt and don’t take iodine supplements unless advised by your provider.
Get enough vitamin D.
Hyperthyroidism may lead to bone loss, so getting enough vitamin D is crucial. Milk, eggs, fatty fish, and mushrooms contain vitamin D, but you may need to take a supplement, especially if your blood vitamin D levels are low.
Eat cruciferous vegetables.
Broccoli, cauliflower, and cabbage are part of the cruciferous vegetable family and they contain goitrogens, natural substances that can decrease the amount of thyroid hormone made by your thyroid gland.
Include protein at your meals.
If you’re losing or have lost weight due to hyperthyroidism, eating a high-protein food at each of your meals can help to ensure you build back and maintain muscle mass (plus, it helps with blood sugar management, too). Good sources of protein are poultry, lean meat, seafood, eggs, tofu, beans, milk, and yogurt.
Time your thyroid medication.
Thyroid medication needs to be taken on an empty stomach. Take your medication at the same time every day and wait at least 30 minutes before eating or drinking. Also, wait four hours after taking your thyroid medication before taking calcium or iron supplements, a multivitamin with calcium or iron, and antacids. Ask your provider or pharmacist for more information about taking thyroid medication.
Foods that may interact with thyroid medication.
Some foods can cause your thyroid medication to work less effectively, including fiber, grapefruit, soy foods, and walnuts. You don’t necessarily need to avoid these foods, but if you eat them, eat them consistently.
Whether you have hypo- or hyperthyroidism, always check with your provider before taking dietary supplements. If you are prescribed medication to manage your thyroid condition, ask how and when you should take it, and if any foods need to be limited or avoided. Also, keep tabs on your blood sugars. That means checking them with a meter or using a CGM (continuous glucose monitor). Doing so can help you and your provider know if your diabetes medications need to be adjusted
Be sure to get enough physical activity when you have a thyroid condition. Being active can help with weight management, blood sugar control, and improved energy and sleep, as well.
For more information about thyroid disease, visit the American Thyroid Association.