The Importance of a Healthy Thyroid

By Emmy Bawden

The thyroid regulates almost every action of every cell in your body, as well as your metabolism, heart rate and energy level. About 13% of women will develop a disorder of this butterfly-shaped gland, and the most common one is called hypothyroidism. Unfortunately, many patients aren’t receiving thorough nutrition and lifestyle guidance when they are diagnosed, which is why hypothyroidism is one of the most frequent health concerns I see in my clinical nutrition practice.

WHAT IS HYPOTHYROIDISM?

Hypothyroidism, or underactive thyroid, is when this gland doesn’t generate enough thyroid hormones (triiodothyronine, or T3, and thyroxine, or T4) to meet your needs. This decreases your metabolism (by a whopping 15-40%!) and cell activity and regeneration, which often results in:

• Hair loss, dry skin and brittle nails
• Enlarged neck
• Cold intolerance
• Infertility
• Weight gain
• Constipation
• Fatigue
• Depression

Risk factors for hypothyroidism include being female and/or over 60 years old, pregnancy, having thyroid nodules, autoimmune conditions like type 1 diabetes and a family history.

HOW IS HYPOTHYROIDISM DIAGNOSED AND TREATED?

Diagnosis involves assessing thyroid hormone levels; specifically free T4 (which is typically low in someone with hypothyroidism) and thyroid stimulating hormone (TSH, which is typically high). Your provider may also feel your neck to screen for thyroid dysfunction. Hashimoto’s disease, or autoimmune thyroiditis, causes more than 50% of hypothyroidism cases in the U.S. This is diagnosed by measuring certain thyroid antibodies and sometimes performing a thyroid ultrasound. If you’re diagnosed with hypothyroidism, the standard treatment is daily thyroid hormone replacement therapy.

HOW CAN YOU EAT TO SUPPORT YOUR THYROID?

A diet emphasizing whole, minimally processed foods, fiber-rich carbs (vegetables, beans, fruit and whole grains), lean proteins like poultry and fish, and heart-healthy fats while minimizing added sugars, saturated fat and fast food is key for managing hypothyroidism. This eating style helps reduce inflammation and complications like high cholesterol, optimizes digestion and nutrient levels (especially commonly deficient nutrients like vitamins D and B12), and maintains healthy blood sugar levels. However, balance is important, as restrictive weight loss diets will further reduce thyroid hormone activity.

Certain foods called goitrogens hinder thyroid hormone production by decreasing the thyroid’s uptake of iodine and shouldn’t be eaten excessively. These include cruciferous vegetables, leafy greens, soy, and coffee, among others. (Pro tip: Cooking these veggies decreases some of their effect.)

Certain nutrients are especially important for thyroid function. These include:

• Iodine: Absorbed by the thyroid to produce thyroid hormones. Find this in iodized salt, fish, dairy, grains and sea vegetables.
• Selenium: Involved in thyroid hormone activation, but excess intake may harm thyroid metabolism. Sources include Brazil nuts (two to three per day meets your needs!), tuna, sardines, mushrooms and barley.
• Zinc and tyrosine: Helps control thyroid hormone activation and release. Zinc foods include shellfish, meat and pepitas. Foods with tyrosine include spirulina (a type of algae, which is considered a superfood), soy, egg whites, cottage cheese and salmon.
• Copper: Required for transport, production and activation of thyroid hormones, and found in meat, eggs, nuts, seeds, legumes and grains.
• Vitamin A: Required for thyroid health, but those with hypothyroidism may not generate the active form of vitamin A (retinol) from beta carotene. Sources include turkey, orange fruits and veggies, and spinach. Vitamin A-rich foods include cod liver and egg yolks.
• Iron: Research shows a link between iron status and hypothyroidism. Include red meat, chicken, leafy greens and legumes regularly.

If you have hypothyroidism, you may be tempted to buy new supplements after reading this — but nutrient deficiency and excess have risks with hypothyroidism, so taking supplements could be damaging. It’s also generally best to skip thyroid support supplements as some have high iodine doses (which is not recommended for Hashimoto’s) and unregulated thyroid hormones. Always check with your provider before starting supplements for hypothyroidism.

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