Foods That Improve Thyroid Function: How Do I Keep My Thyroid healthy?

You may have heard that thyroid disorders are often the result of autoimmune conditions, and think that there is not much you can do to improve your thyroid health through your diet — but that is not the whole story. Your diet plays an important role in keeping your thyroid functioning properly, whether you have a thyroid condition or are just trying to look after your general health and wellbeing. 

What exactly is the thyroid?

The thyroid is a hormone-secreting gland located at the front of your neck — just below the place where men have an Adam's apple. Made up of two separate lobes that together amount to the size of a large strawberry, this important gland has the job of producing, storing, and secreting two different hormones; thyroxine (T4) and triiodothyronine (T3). Together, they have important functions ranging from regulating your metabolism to helping control how the heart beats.

It is extremely important for your levels of these two hormones to remain within healthy ranges. When your levels of these two hormones are either too high or too low, the parts of the brain called the hypothalamus and pituitary gland will try to help your thyroid compensate by telling it to either boost or slow down the production and secretion of thyroid hormones. This is not always successful, however, and up to five percent of the population will have a thyroid disorder at any given time, something that may be temporary or permanent. 

What can go wrong with the thyroid?

When you think about thyroid problems, the main two that are bound to come to mind are hypothyroidism and hyperthyroidism. In hypothyroidism (also called a "slow thyroid"), in which the functioning of your thyroid gland is underactive and the thyroid isn't releasing sufficient T3 and T4, you can generally expect symptoms such as:

• Spontaneous weight gain
• Chronic fatigue
• Difficulty focusing ("brain fog")
• Dry skin and hair
• Muscle and joint aches
• Feeling cold easily, even when it isn't cold
• Feeling down, or even becoming clinically depressed
• In women, heavy periods

An overactive thyroid — hyperthyroidism — has a different set of symptoms, some the direct opposite:

• Spontaneous weight loss
• Hyperactivity, restlessness, jittery feelings
• Feeling hot easily, and sweating more
• Hair loss
• Trembling or shaking
• Heart palpitations
• Anxiety
• In women, missed periods

In addition to these common thyroid disorders, it is also possible — though rare — to develop thyroid cancer, as well as benign nodules or lumps. In many cases, thyroid disorders are the resulting of an underlying autoimmune disorder. Situations that unbalance your hormones, such as pregnancy and childbirth, may temporarily induce thyroid problems. When a thyroid disorder goes untreated for too long, complications can result. Hyperthyroidism may, for instance, lead to visual disturbances like blurred or double vision, and it may also cause miscarriages in women. 

What do you need to know about a 'thyroid-healthy diet' to improve your thyroid health?

Even people who have not been diagnosed with a thyroid disorder, nor have any of the symptoms of either a slow or overactive thyroid, can benefit from knowing more about how their diet can improve their thyroid health. That is because your thyroid hormones, T3 and T4, are produced with the help of the trace element iodine — and while your thyroid health is, really, the only known reason for which it's important to make sure you have iodine in your diet, that role is so vital that it's good to keep an eye on your iodine intake. 

While an iodine deficiency will cause your thyroid to grow in compensation, thus leading to hyperthyroidism, a high iodine intake can cause hypothyroidism once your immune system begins to react. Suddenly increasing your iodine intake after you've been deficient may, on the other hand, lead to temporary hyperthyroidism. 

Adults typically require 150 mcg of iodine to maintain healthy thyroid function. Many people who live in developed countries will be able to achieve this through their diet alone — foods such as fish, other seafoods, and (particularly) seaweeds are rich in iodine. Eggs, other dairy products, and foods artificially enriched with iodine (like some breads, pastas, and often salt) are other dietary sources of iodine. 

People who haven't been diagnosed with a thyroid disorder should make sure to get adequate — neither excessive amounts, nor too little — iodine through their diets, while those who have been prescribed thyroid medications should take special care to avoid excessive iodine intake, as this could interfere with their thyroid hormone levels. 

If you have hypothyroidism, you should further be aware that some studies have shown soy products — like tofu, soybeans, or soy sauce — to impair the absorption of thyroid hormones. While you will generally not be advised to avoid sot products altogether, it is important to ask your doctor about this. And, if your thyroid hormones are such that you are on the cusp of developing a clinically slow thyroid and your iodine intake is on the low side, eating a lot of soy-based foods may push your thyroid over the edge. In these cases, the advice would be to increase the amount of iodine you get, either by way of supplements or through foods. 

Besides these two areas of note, the best diet for people who want to keep their thyroid healthy would be one that is generally considered balanced and nutritious. That means:

• Choosing a wide variety of foods from all food groups. 
• Limiting your intake of processed, fatty, and fast foods severely — anything that will raise your cholesterol levels is also detrimental to your thyroid health.
• Make sure  that you get enough dietary fiber, from sources like fruits, vegetables, and wholegrain products. 
• Alcohol, especially when abused chronically, has a myriad of negative health effects. It also slows down the function of the thyroid. To improve thyroid health, avoid habitual alcohol consumption. 

In conclusion, the best way to look after your thyroid health if you don't have a thyroid disorder is simply to eat a healthy, balanced, and responsible diet that contains enough iodine, but not too much. If you have been diagnosed with a thyroid condition, on the other hand, this is still true — but in addition, it is also important to discuss your diet with your physician, as it may affect the doses of medication you will be prescribed.