Best Foods for Thyroid Health (And What to Avoid)

Best Foods for Thyroid Health (And What to Avoid)

Your thyroid may be small, but it plays a huge role in your overall well-being. Located in the front of your neck, this butterfly-shaped gland regulates your metabolism, energy levels, heart rate, and even your mood — all by producing essential thyroid hormones. When the thyroid is not functioning properly, whether it’s underactive (hypothyroidism) or overactive (hyperthyroidism), the effects can ripple through your entire body.

But here’s the good news: your diet can make a real difference. At NHS Diagnostics, we believe that food isn’t just fuel — it’s medicine. By choosing the right foods and avoiding harmful ones, you can support your thyroid and help keep your hormones balanced.

Let’s dive into the best (and worst) foods for thyroid health.

Why Diet Matters for Thyroid Function

Before we talk about specific foods, it’s important to understand how your thyroid works.

Your thyroid needs key nutrients like iodine, selenium, and zinc to produce hormones such as T3 (triiodothyronine) and T4 (thyroxine). These hormones regulate everything from metabolism to temperature control. When your diet lacks these nutrients — or includes too many foods that disrupt hormone production — it can lead to thyroid disorders.

Common thyroid conditions include:

• Hypothyroidism – When the thyroid is underactive and doesn’t produce enough hormones.
• Hyperthyroidism – When the thyroid is overactive and produces too many hormones.
• Hashimoto’s thyroiditis – An autoimmune condition that damages the thyroid.
• Graves’ disease – Another autoimmune disorder that causes overactivity.

Now let’s talk about what to eat — and what to avoid — to support a healthy thyroid.

Best Foods for Thyroid Health

1. Seafood (Iodine-Rich Foods)

Why it’s good: Your thyroid uses iodine to produce T3 and T4 hormones. Iodine deficiency is one of the most common causes of thyroid dysfunction.

Best sources:

• Seaweed (kelp, nori, wakame)
• Shrimp
• Tuna
• Cod
• Sardines
• Iodized salt (in moderation)

Note: Don’t overdo iodine. Too much can also harm your thyroid, especially if you already have Hashimoto’s.

2. Brazil Nuts & Sunflower Seeds (Selenium)

Why it’s good: Selenium is essential for converting T4 into the active T3 hormone. It also helps reduce inflammation and supports your immune system.

Best sources:

• Brazil nuts (just 1–2 per day is enough!)
• Sunflower seeds
• Eggs
• Turkey
• Brown rice

3. Pumpkin Seeds, Chickpeas & Lentils (Zinc)

Why it’s good: Zinc plays a critical role in thyroid hormone production and immune regulation.

Best sources:

• Pumpkin seeds
• Chickpeas
• Lentils
• Beef
• Cashews
• Whole grains

4. Leafy Greens (Iron & Antioxidants)

Why it’s good: Iron deficiency can disrupt thyroid hormone production. Plus, leafy greens are packed with antioxidants that fight inflammation.

Best choices:

• Spinach
• Kale
• Swiss chard
• Arugula
• Mustard greens

Tip: Cook your greens slightly to reduce goitrogens (we’ll explain those shortly).

5. Eggs

Why it’s good: Eggs provide a combination of iodine, selenium, and protein, making them a thyroid superfood.

Include both the yolk and white to get the full range of nutrients.

6. Berries (Antioxidant Powerhouses)

Why it’s good: Berries help fight oxidative stress, which can worsen autoimmune thyroid issues like Hashimoto’s.

Best choices:

• Blueberries
• Strawberries
• Blackberries
• Raspberries

7. Greek Yogurt & Dairy (Iodine + Probiotics)

Why it’s good: Dairy is a good source of iodine and probiotics. The probiotics support gut health, which is directly tied to thyroid function.

Choose:

• Plain Greek yogurt
• Low-fat milk
• Cottage cheese

Lactose-intolerant? Go for lactose-free dairy or probiotic-rich alternatives.

8. Olive Oil & Fatty Fish (Healthy Fats)

Why it’s good: Healthy fats support hormone production and help reduce inflammation, especially in autoimmune thyroid disease.

Great options:

• Salmon
• Mackerel
• Sardines
• Extra virgin olive oil
• Avocados

Foods to Avoid for Thyroid Health

1. Soy-Based Products (in Excess)

Why to limit: Soy contains compounds called isoflavones, which may interfere with thyroid hormone production — especially if you have hypothyroidism or are iodine-deficient.

Avoid large quantities of:

• Soy milk
• Tofu
• Edamame
• Soy protein powders

If you’re eating soy, keep it fermented and in moderation (like tempeh or miso).

2. Cruciferous Vegetables (Raw)

Why to limit: These vegetables contain goitrogens, substances that can disrupt thyroid hormone production by interfering with iodine uptake.

Examples:

• Raw broccoli
• Cabbage
• Cauliflower
• Brussels sprouts
• Kale

Tip: Cooking cruciferous vegetables reduces goitrogenic effects, making them safer in moderation.

3. Processed Foods & Refined Sugars

Why to limit: Highly processed foods often contain harmful trans fats, high sodium, and sugar — all of which can trigger inflammation and worsen thyroid conditions.

Avoid:

• Fast food
• Packaged snacks
• Sugary beverages
• White bread and pastries

4. Gluten (For Autoimmune Thyroid Patients)

Why to avoid: People with Hashimoto’s thyroiditis often have gluten sensitivity. Gluten may increase intestinal permeability (“leaky gut”), worsening autoimmune reactions.

Consider a gluten-free diet if:

• You’ve been diagnosed with Hashimoto’s or Graves’ disease
• You have digestive symptoms like bloating or IBS

5. Excessive Caffeine & Alcohol

Why to limit: Both caffeine and alcohol can disrupt adrenal and thyroid balance, worsen anxiety, and impair sleep — all of which affect hormone health.

Cut back on:

• Coffee (more than 2 cups/day)
• Energy drinks
• Alcoholic beverages

Instead, try:

• Herbal teas
• Water infused with lemon or mint
• Bone broth for gut healing

Bonus Tip: Gut Health = Thyroid Health

Did you know that up to 20% of thyroid hormone conversion happens in your gut?

If your gut is inflamed or your microbiome is out of balance, it can disrupt thyroid function. That’s why probiotics and fiber-rich foods (like oats, apples, flaxseeds, and yogurt) are so important.

A healthy gut supports:

• Better hormone absorption
• Stronger immunity
• Reduced inflammation

Summary: What to Eat & What to Avoid

Eat More Of	Limit or Avoid
Iodine-rich seafood	Soy (in excess)
Brazil nuts & seeds	Raw cruciferous veggies
Zinc-rich legumes	Processed & sugary foods
Leafy greens (cooked)	Gluten (if autoimmune)
Eggs & dairy	Excess caffeine/alcohol
Berries & whole fruits	Trans fats & fried foods
Healthy fats (olive oil, fish)	Artificial additives

Get Your Thyroid Checked with NHS Diagnostics

If you’re experiencing symptoms like unexplained weight changes, fatigue, mood swings, or hair loss, your thyroid could be the cause. A simple thyroid blood test can help diagnose issues early — and guide the right dietary or medical treatment.

At NHS Diagnostics, we offer:

Accurate thyroid panel testing (TSH, T3, T4, and more)
Expert consultation and guidance
Home sample collection for your convenience
Fast and confidential reporting

Conclusion

Your thyroid is sensitive, but with the right nutrition, it can thrive. By focusing on whole, nutrient-dense foods and avoiding thyroid-disrupting ingredients, you can support hormone balance and feel your best.

As always, consult your doctor or a qualified nutritionist before making major dietary changes — especially if you’re managing a thyroid condition. Ready to take control of your thyroid health?
Book your thyroid test today at nhsdiagnostics.com or call us for expert support and home sample collection.