Bladderwrack (Fucus vesiculosus, Ascophyllum nodosum) is an alga with a variety of species. It usually grows up to 100 cm or more appearing in the small gas–filled vesicles which are paired or arranged in series on either side of a central midrib running along the centre of the strap-like frond. Since thallus has tough, air-filled pods (or bladders) to help the algae float, it is associated with the name given to the plant – the bladderwreck.
The sheltered shores from the middle littoral to lower intertidal levels are the preferred habitat for the bladderwrack. It sometimes grows on exposed shores where specimens develop short, stunted and without the air vesicles.
Bladderwrack is found on the Atlantic shores of Europe, the Baltic Sea, Greenland, Azores, Canary Islands and Madeira, on the Atlantic coast of North America from Ellesmere Island, Hudson Bay to North Carolina.
Thallus, the main stem of bladderwrack, is considered to be useful and used medicinally. It possesses antibacterial, antioxidant, diuretic, emollient, endocrine tonic, expectorant, and nutritive properties.
The plant is available at the markets in the forms of a tea, tincture, powder or capsules. It is also a component in the oil for topical application. The bladderwrack is commonly used in culinary purposes too. It is eaten raw or cooked, added into soups and grains for its salty flavor and rich mineral content.
The major chemical components in bladdewrack include mucilage, algin, mannitol, beta-carotene, zeaxanthin, iodine, bromine, potassium, volatile oils, and many other minerals. The bladeerwrack is used in herbal practicing medicine as a great source of iodine, an essential nutrient for the thyroid gland.
Since bladderwrack is beneficial to the thyroid gland due to the presence of these constituents, it shows a good effect on the symptoms associated with the thyroid functions (e.g. obesity). Alginic acid, the chemical found in high amounts in the plant, is used in medical formulas as the heartburn remedy. This acid is also proved to provide laxative properties. Fucoidan, a type of dietary fiber in bladdewrack, shows the results in lowering bad cholesterol levels, blood glucose levels and providing anti-inflammatory activities.
In traditional herbal medicine bladderwrack has a reputation in helping the relief of rheumatism and rheumatoid arthritis, when used internally and as an external application on inflamed joints. Laxative properties of the plant make it a remedy for digestive disorders. Bladdewrack is also used for treating atherosclerosis and strengthening immunity, although these uses are not supported by the scientific evidence.
As mentioned above, bladderwrack is an effective treatment for the thyroid glands disorder and is helpful for the overweight people. Except contributing to the healthy thyroid gland, the herb improves metabolism in general. Historical topical application of bladderwrack includes using it as the herb component for the bath aimed to reduce cellulite and support weight loss; lotions based on it possess skin-softening qualities.