Thyroid Health

Learn more about the latest research on thyroid health in the videos below.

A butterfly-shaped gland found low on the front of the neck, the thyroid is part of the endocrine system, which is made up of glands that produce, store, and release hormones into the bloodstream. Thyroid hormones primarily influence our metabolism, growth and development, and body temperature.

The mineral iodine, found predominantly in the ocean and in variable amounts in the soils of the world, is essential for thyroid function. To ensure everyone was getting enough, table salt was fortified with the mineral starting in the 1920s. Given that sodium is considered the second-leading dietary killer in the world, however, iodized salt should not be considered as a viable source (though if you do add salt to foods, use iodized salt instead of “sea salt” or other non-iodized varieties). The most concentrated, healthful source is seaweed, which has the iodine of seafood without the fat-soluble pollutants that build up in the aquatic food chain. Sea vegetables are the underwater dark-green leafies, and I encourage you to experiment with ways to include them in your diet. The recommended daily intake of iodine is 150 mcg, which is what is in about two sheets of nori, the seaweed used to make sushi, or a half-teaspoon of the seaweeds arame or dulse. I caution against hijiki (also spelled hiziki), because it has been found to be contaminated with arsenic, as well as kelp, which may have too much iodine. (Just a half-teaspoon of kelp could exceed the daily upper limit.) Too much iodine can cause excessive thyroid gland activity.

How else may we protect our thyroid health? One way is by minimizing exposure to pork products. Nearly 100,000 Americans are sickened each year by Yersinia bacteria. In every outbreak for which a source has been found, the culprit was contaminated pork. In most cases, Yersinia food poisoning leads to little more than acute gastroenteritis, but the symptoms can become severe and mirror appendicitis, resulting in unnecessary emergency surgeries. Long-term consequences of Yersinia infection include chronic inflammation of the eyes, kidneys, heart, and joints. Studies have found that within a year of contracting Yersinia food poisoning, victims appear 47 times more likely to come down with autoimmune arthritis, and the bacteria may also play a role in triggering an autoimmune thyroid condition known as Graves’ disease. How contaminated are U.S. pork products? Consumer Reports magazine tested nearly 200 samples from cities across the country and found that more than two-thirds of the pork was contaminated with Yersinia.

The information on this page has been compiled from Dr. Greger’s research. Sources for each video listed can be found by going to the video’s page and clicking on the Sources Cited tab. References may also be found at the back of his books.

Image Credit: ChesiireCat / Thinkstock. This image has been modified.