Kelp is a type of brown seaweed that is also called bladderwrack. The seaweed is taken from the Pacific and Atlantic coasts and is used in some dishes such as sushi. Kelp is sometimes used as an alternative treatment for an underactive thyroid gland, a condition called hypothyroidism. However, there is not enough evidence to prove kelp's benefits for an underactive thyroid, and it can even worsen your condition.
Causes of Hypothyroidism
Hypothyroidism is historically caused by a lack of iodine. Iodine is contained in sea salt and iodized table salt. Iodine helps your thyroid gland create hormones. In the United States, however, the American Thyroid Association reports that hypothyroidism is caused by Hashimoto's thyroiditis, certain prescription medications and from pregnancy. The American diet is rich in iodine, due to the salt content in prepared and packaged foods.
Indications
Kelp is naturally rich in iodine, which makes the seaweed an attractive form of treatment for an underactive thyroid. Medline Plus says that kelp is available to eat in its raw form as well as tablet supplements, tinctures and teas. Pills are the most common kelp supplements on the market. Medline Plus recommends a maximum daily dosage of 600 mg of kelp.
Evidence
Medline Plus gives kelp a "C" grade for thyroid disease treatment. This grade indicates that there is not enough scientific evidence to support the use of kelp for hypothyroidism and goiter. A goiter is an enlarged thyroid gland that can sometimes result from hypothyroidism. Weight gain from a slowed metabolism is a common side effect of hypothyroidism. Kelp is used in some weight-loss supplements, but Medline Plus says there is not enough evidence that kelp helps you lose weight.
Effects
Since hypothyroidism is not likely due to a lack of iodine in American patients, taking an iodine-rich supplement such as kelp is not likely to help an underactive thyroid gland. The American Thyroid Association recommends treatment with thyroid hormone replacements instead. An endocrinologist determines the appropriate dosage based on your thyroid hormone levels that are calculated through blood tests.
Considerations
Kelp should not be used as hypothyroid treatment without first consulting a doctor. According to Medline Plus, kelp can increase hormone levels, leading to abnormal thyroid function. Although this may seem good in theory, too many thyroid hormones over time can cause a hypothyroid patient to have an overactive thyroid gland, or hyperthyroidism. Medline Plus says there are other side effects associated with kelp, including abnormal bleeding, lowered blood sugar, kidney problems and diarrhea.
