The recorded use of Fucus vesiculosus, also called "bladderwrack" or "sea wrack" dates back to at least the time period of the Eclectic Physicians of the 19th century. Historically these physicians used this seaweed for goiter (swelling of the tissue or cells of the thyroid) and for obesity. Published commentary by a turn of the century physician (Dr. J. Herbert Knapp) indicated that he had found this plant to be a specific remedy for both exophthalmic and uncomplicated goiter. In his experience bladderwrack worked best in individuals under age 30, a population for which he claimed a 100% success rate, and was less dependable for normalizing thyroid function in people beyond this age.
Fucus vesiculosus contains a wide spectrum of polysaccharides including fucoidans(,) and fucans (). In general, fucoidans are a family of high molecular weight sulfated polysaccharides, widely dispersed in the cell walls of brown seaweed. The core region (or backbone) of fucoidan is composed primarily of a repeating chain of fucose sugars. Fucose is also attached at branch points. Thus bladderwrack is a rich food source of fucose.
Similar to most plants grown in the ocean, this plant is also very high in iodine and other trace minerals.
One of the emerging fields of research with regards to microorganisms (and lectins) centers about an idea of adherence and anti-adherence. () Because of the high concentration of fucose, Fucus vesiculosis qualifies as an anti-adhesion therapy in particular for group O and ABH secretor individuals.
Anti-metastatic and anti-tumor activity
Bladderwrack, because of its fucose content, is a potent inhibitor of tumor cell invasion, with modest anti-tumor activity. (,,,))
The Fucoidan found in bladderwrack inhibits the growth of many unfriendly bacteria and viruses.() Some of the viruses this compound is antagonistic to include herpes simplex virus, human cytomegalovirus, and human immunodeficiency virus. Bladderwrack has been found to agglutinate the cells of several strains of Candida (). Bladderwrack also has a toxic effect on some strains of E. coli and all strains tested of Neisseria meningitidis.()
The complex sugar structures and other compounds found in bladderwrack have anti-HIV activity. (,,) Researchers have suggested that, since adhesion is the initial step in HIV infection, blocking adhesion might prevent HIV-1 transmission. In vitro evidence supports this suggestion with the complex fucose structures found in bladderwrack showing a capability to block HIV adhesion to cells. (,) These same blocking strategies with fucose sugars have also been used in studies of malaria to prevent its spread to additional red blood cells. Fucose sugars inhibit invasion of red blood cells by the malaria parasite. (,,)
L-fucose is a least partically responsible for the attachment of Helicobacter pylori to gastric mucins. ()
Immunomodulating activity and anti-inflammatory Activity
The fucose sugars in bladderwrack can beneficially impact immune system health by stimulating immunoreactions of the humoral and cellular types, and by enhancing the phagocytosis (or consumption of invaders) by your macrophages. Essentially they block the recruitment or inhibit an overly aggressive inflammatory immune response at sites of inflammation.
Fucoidans bind selectins which apparently enhances eosinophil recruitment. ()
Metabolism and thyroid function
The historical uses of Fucus vesiculosus were primarily as an agent to enhance thyroid function in cases of goiter and as an aid in weight loss for obesity. This remains the primary use of this plant today in natural medicine. (,,)