Seaweed and Thyroid Health
During the winter months, as I have mentioned a few times, we want to support our own internal sources of energy production. One of our primary hormone producing centers in the body is the thyroid. Generally speaking, the thyroid helps to regulate how “fast” the body runs. A good way to illustrate this is to talk about what happens when the thyroid gets out of balance: too much thyroid hormone will make the heart beat too quickly and cause weight loss from increased metabolism. Too little thyroid hormone will cause weight gain, slowed production of skin, hair and nails (causing hair loss, weak nails, and dry skin), weight gain, and constipation from slowed digestion.
Seaweed has traditionally been used as medicine for the thyroid. In Chinese medicine, it is seen as cooling and good for dissolving any type of swelling. In autoimmune thyroid conditions such as Hashimoto’s or Graves disease, it has been used to decrease inflammation and swelling. In hypothyroid, the swelling of the thyroid known as “goiter” has also been treated by seaweed. In Western medicine, this is assumed to be related to replacement of deficient Iodine.
The Iodine content in seaweeds varies depending on the variety, but is quite high in any type you find. Iodine is a critical component in the creation of thyroid hormone. In its absence or deficiency, the thyroid will swell to many times its normal size to try to create sufficient thyroid hormone. This swelling is called “goiter”. Before salt started being iodised in the United States in 1924, iodine poor areas had extremely high rates of goiter--a goiter rate of 47% of the population of Michigan was reported at that time.
Today, iodine deficiency is much more rare in the United States, but due to the increasing popularity of using non-iodized salts such as sea salt or kosher salt, many people are looking for another source of iodine. Seaweed offers the advantage of being a whole food source of iodine rather than a synthesized source, as well as supplying many other minerals and trace minerals important to optimal bodily function. The type of seaweed most utilized and researched specifically for thyroid support is bladderwrack (latin name fucus versicolor), but any type of seaweed will be high in iodine and generally beneficial for thyroid health.
Optimal dosage of iodine each day is variable depending on the individual, but the minimum daily amount needed to prevent goiter is 150mcg, and should not exceed 1000mcg. Studies in which people were given large daily doses of seaweed exceeding their daily need for iodine have shown to have decreased thyroid function, so it is important not to overdo it. The amount of seaweed that is beneficial will vary primarily depending upon where you live. People who live in coastal regions, particularly those who frequently consume salt water fish or shellfish will have greater iodine in their diet. Soil levels of iodine that will be incorporated into vegetables grown in the region will also vary. There have also been studies that indicate that people who live on the coast in areas with high seaweed growth actually absorb iodine that has been released in gas form from seaweed lying on the beach. In general, people living in landlocked areas will have lower iodine intake and will benefit more from putting more seaweed in their diet.