Goiter is a fancy term that refers to an enlargement of the thyroid gland, a butterfly-shaped gland that sits at the lower part of your neck. Although the thyroid gland is normally pretty small, it has some really big jobs in your body. In order to perform these jobs to the best of its ability, your thyroid gland requires access to certain nutrients, like iodine.
Getting too little iodine can interfere with thyroid function, causing a goiter. However, too much iodine can do the same thing. Other foods, classified as goitrogenic foods, can also contribute to a goiter. In addition to developing a proper treatment plan with your doctor, there may also be some foods to avoid for a goiter.
What Your Thyroid Does
Thyroid hormones mainly act on your metabolism, controlling your weight and your growth and development. The thyroid gland also plays a role in helping you maintain your body temperature and keeps your heart, brain, muscles and other major organs working properly.
Proper functioning of the thyroid gland relies on a combination of hormones and nutrients in certain delicate balances. Your thyroid gland produces three major hormones:
- Thyroxine (T4)
- Triiodothyronine (T3)
In order to make your thyroid produce these hormones, the pituitary gland, an endocrine gland in your brain, produces and releases another hormone called thyroid stimulating hormone, or TSH. The proper functioning of these hormones, especially T3 and T4, also relies on access to iodine, a trace element that's naturally found in some seafood or added to iodized salt.
Why Is Iodine Important?
Iodine is a major component of both the T3 and T4 hormones. When you consume iodine, it travels through your digestive system, eventually moves into your blood, then is carried to your thyroid gland where it's used to produce the right amounts of the hormones you need. Depending on your energy needs and what else is going on in your body, sometimes you need higher amounts of iodine to make more hormones, and sometimes you need less.
Because your body can't make iodine, you have to get it from your diet somehow. The problem is that there aren't a lot of foods that naturally contain high amounts of the element. Because of this, manufacturers started adding a supplemental form of iodine to salt in 1924, in an effort to prevent goiters, a condition that was affecting lots of people.
What Is a Goiter?
A goiter is a noncancerous enlargement of the thyroid. According to the American Thyroid Association, iodine deficiency is one of the leading causes of goiters in the world. When your body doesn't have access to enough iodine, it can't make sufficient amounts of the thyroid hormones T3 and T4. When the levels of these hormones in your blood drop, it prompts the pituitary gland to tell the thyroid to make more by sending out TSH.
When TSH reaches your thyroid gland, it directs it to make more hormones. However, if your thyroid isn't functioning properly, it can't respond to this demand. As a result, more TSH is sent out, which keeps hitting your thyroid gland, eventually causing it to grow in size. For some, this is enough to overcome the thyroid deficiency, and further problems don't develop. Others may progress to a thyroid disorder.
It's important to note here that since manufacturers started adding iodine to salt, the prevalence of goiters in the United States has decreased dramatically. Now, the most common cause of goiters in the U.S. is Hashimoto's thyroiditis, a type of hypothyroidism (or underactive thyroid) that's caused by an autoimmune disease. In Hashimoto's, goiters develop in the same way, but the underlying mechanism isn't always known.
Symptoms of a Goiter
The most common sign and symptom of a goiter is an enlargement of the thyroid gland in the lower part of the neck. For some people, this may be the only sign of a problem, while others may experience:
- Breathing difficulties
- Cough or wheezing
- Swallowing difficulties
- Dizziness when the arms are lifted above the head
- Prominent neck veins
Balancing Your Iodine
Even though too little iodine is one of the major causes of goiters worldwide, a report in PLoS One in October 2014 notes that too much iodine in the diet may also cause a goiter. That's why it's important to balance your intake of the element. The current recommendation for iodine is 150 micrograms per day for all adults. If you're pregnant or breastfeeding, your needs go up to 220 and 290 micrograms, respectively.
In addition to getting enough iodine, it's important not to overdo it. If you have a goiter due to too much iodine, you may want to completely avoid high-iodine foods or limit them in your diet, depending on what your doctor says. The major sources of dietary iodine include:
- Seaweed (dulse, nori, kelp)
- Baked cod
- Plain, low-fat yogurt
- Reduced-fat milk
- Enriched white bread
Iodized salt is also a major source of iodine. One-fourth teaspoon contains about 71 micrograms, or almost half of your needs for an entire day. However, unlike iodized salt, sea salt and pink Himalayan salt don't contain any added iodine. If you're watching your intake of iodine, you may want to switch to one of those.
Goitrogenic Foods and Goiters
There's also another class of foods described as goitrogenic. According to a report published in Journal of Clinical and Diagnostic Research in January 2016, goitrogenic foods are certain types of foods that can reduce the absorption of the T4 thyroid hormone and negatively interfere with the way the thyroid hormones work. Goitrogenic foods may be especially problematic for those with Hashimoto's thyroiditis, since they're known to increase the mechanisms of autoimmune diseases.
Examples of goitrogenic foods include:
- Brussels sprouts
- Mustard greens
- Cassava root
- Lima beans
- Sweet potato
- Soy and soy products
- Green tea
You don't have to completely eliminate goitrogenic foods, which offer other health benefits, from your diet, but it's best to avoid eating them raw. According to the report in the Journal of Clinical and Diagnostic Research, washing, cooking and boiling can reduce the amount of goitrogens present in these foods and make them safer for you to eat if you have a goiter.
On the other hand, there are some other foods and nutrients that are classified as thyroid-healing foods. If you have a thyroid problem, no matter what the cause, you may want to increase your intake of these nutrients:
- Tyrosine (amino acid)
- Vitamins B2, B3 and B6
- Vitamin C
- Vitamin E
A Note of Caution
Although a goiter is noncancerous, it is a sign that your thyroid, which is vital to your health, is out of whack. If you have a goiter, or something seems off, make an appointment with your doctor before trying to correct it yourself with diet.
In addition to identifying an underlying cause, your doctor can work with you to develop a comprehensive treatment plan that includes proper nutrition. Your doctor may even be able to provide an appropriate thyroid diet chart that you can reference on a daily basis.
- Journal of Clinical and Diagnostic Research: "Various Possible Toxicants Involved in Thyroid Dysfunction: A Review"
- National Institutes of Health Office of Dietary Supplements: "Iodine"
- Nutrients: "History of U.S. Iodine Fortification and Supplementation"
- Institute for Quality and Efficiency in Health Care: "How Does the Thyroid Gland Work?"
- UCLA Health: "Thyroid Goiter"
- EndoText: "Dietary Goitrogens"
- American Thyroid Association: "Goiter"
- American Thyroid Association: "General Information/Press Room"
- Nature Reviews Endocrinology: "Consequences of Excess Iodine"
- PLoS One: "Prevalence of Goiter and Thyroid Nodules before and after Implementation of the Universal Salt Iodization Program in Mainland China from 1985 to 2014: A Systematic Review and Meta-Analysis"
- Mayo Clinic: "Goiter"
- Today's Dietitian: "Thyroid Disease and Diet — Nutrition Plays a Part in Maintaining Thyroid Health "