Evidence supporting the use of: Kelp (unspecified)
For the health condition: Goiter
Synopsis
Source of validity: Scientific
Rating (out of 5): 3
Kelp, a type of seaweed, is used to support or treat goiter primarily due to its high iodine content. Iodine deficiency is a well-established cause of goiter, which is an abnormal enlargement of the thyroid gland. Historically, populations living far from the sea had higher rates of goiter, which decreased markedly with the introduction of dietary iodine, including iodized salt and iodine-rich foods such as kelp. Scientifically, iodine supplementation is considered an effective and evidence-based treatment and preventive measure for goiter associated with iodine deficiency. Kelp has been used in both traditional and modern contexts for this purpose, but scientific support is specifically tied to its iodine content rather than kelp as a unique substance.
However, the direct use of kelp as a treatment is not universally recommended because the iodine content in kelp can be highly variable and sometimes excessively high, leading to the risk of iodine-induced thyroid dysfunction (such as hyperthyroidism or thyroiditis). Most clinical guidelines prefer standardized iodine supplementation over kelp due to these safety concerns. Nonetheless, the scientific rationale for kelp’s use in iodine-deficiency goiter is strong, as the causative link between iodine intake and thyroid health is well established. Studies and reviews (such as those cited by the World Health Organization) confirm that iodine supplementation reverses and prevents goiter, and kelp is a traditional dietary source of iodine. Thus, kelp’s use for goiter is scientifically validated, but caution is required regarding dosing and safety.