Although bladderwrack has been growing in cold ocean waters for thousands of years, its use as a health-supportive supplement is relatively recent. Rich in minerals like iodine and magnesium, the potential benefits of this seaweed are still being discovered, although it is used to support thyroid health, promote healthy mineral levels, support a healthy internal response, and more.

What is Bladderwrack?

Bladderwrack is a type of brown algae or seaweed that is typically found in the chilly waters of the Northern Atlantic and Pacific coasts of the United States, and on the Atlantic and Baltic coasts of Europe. Its name comes from the small, air-filled pods that grow along the thallus (main stem) of the plant and help it to stay afloat. The other part of its name (wrack) signifies something that is driven ashore.

Bladderwrack is known scientifically as Fucus vesiculosus, although it is also referred to as Fucus, seawrack, black-tang, rockweed, sea spirit, sea oak, and other names. It is a strong smelling seaweed with fan-shaped leaves and has a thin, leathery texture. It typically grows about halfway between the high- and low-water marks.

Bladderwrack and Kelp

Bladderwrack is part of the larger kelp family, which is the general term for 124 species of brown seaweed in the Order Laminariales, Kingdom Chromista. Typically, the thallus (or body) of kelp is made up of three parts: the blade, the stipe, and the holdfast. The blade refers to the leaf-like parts of the kelp, which are attached to the stipe, a stem-like structure. It is attached to the holdfast, which is a root-like structure that anchors the kelp to the substrate (the actual physical bottom) of the ocean. This helps the kelp to stay secure despite waves and currents.

Kelp live in dense “forests” that exist in cold waters (typically where the temperature is lower than 68 degrees Fahrenheit). Often, several species of kelp may live in a single forest, and these forests also function as their own ecosystems — fish, invertebrates, mammals, and birds live in and feed off the kelp itself and the smaller creatures that live in the kelp beds. Marine animals like starfish, crabs, and isopods also feed off the kelp, and gray whales sometimes use the kelp forest as protection from predatory orcas and sharks.

The most well-known kelp forests exist off the central coast of California. This kelp is home to sea otters, who feed on the red sea urchins that feed on the kelp. However, a number of environmental and outside factors may have a negative effect on these kelp forests. Fish like opaleye and halfmoon can damage the kelp forests (especially when growing conditions are unfavorable). The red urchins mentioned above can also do tremendous damage to the kelp when the otter population is smaller (which is often due to disease or oil spills). Other conditions like weather (such as El Niño), pollution, and overharvesting of the kelp can also contribute to unfavorable growing conditions. Luckily, kelp monitoring systems continue to ensure that kelp like bladderwrack continue to thrive.(1)

However, animals are not the only creatures that can experience the potential health benefits of kelp. Kelp and more specifically, bladderwrack, may have a number of potential benefits to support your health.

bladderwrack infographic

History of Bladderwrack Use

Bladderwrack has a long history of use, from being used as a fuel source, to winter feed for cattle. It is also a food source in cultures around the world. Some of the earliest evidence for humans using marine life as resources includes harvesting foods (like mussels and abalones) that are typically found in kelp forests. In the work “The Kelp Highway Hypothesis: Marine Ecology, the Coastal Migration Theory, and the Peopling of the Americas,” by Erlandson et. al., researchers suggest that the kelp forests may have contributed to the peopling of the Americas, since these coastal sites have remained unchanged for many years and may have provided food and resources for early people traveling along the coast, a migration that eventually resulted in permanent settlements.(2)

Scottish highlanders are also thought to have used kelp to produce “soda ash,” (also known as sodium carbonate, which has been used as a water softener and to make glass and gunpowder) from the ashes of kelp, and kelping was considered a common occupation. Bladderwrack was also thought to summon sea spirits and was sometimes carried to protect against age-related illnesses.(3)

Kelp harvesting reached a peak in 1919 when over 400,000 tons of wrack was used to make potash for gunpowder and fertilizer. In the 1800s, iodine was discovered, and it was extracted from seaweed, which eventually led to the use of bladderwrack as a supplement to support thyroid health and other health issues. Today, bladderwrack is harvested throughout the year to produce iodine, although it is thought that the most iodine can be yielded during spring and early summer. This is because the bladderwrack may have new growth, and it is thought that the iodine content is the highest in the young blades. Some of the traditional methods for extraction include sun drying.

Important Compounds in Bladderwrack

The most well-known compound in bladderwrack is iodine, although the amount of iodine in bladderwrack is dependent not only on harvest time but also on location. In the 1800s, a Parisian scientist named Bernard Courtois manufactured saltpeter (potassium nitrate) using seaweed ash as his primary source of potassium. After adding sulfuric acid, he noted the formation of purple fumes, followed by metallic-hued crystals. Courtois identified the element as iodine (from the Greek iodes, meaning “violet”), and debuted iodine at the Imperial Institute in Paris.(4)

Iodine is an essential component in the production of thyroid hormone and it supports overall healthy thyroid function. Iodine is not produced by the body — it must be obtained from your diet. Lack of iodine can cause swelling in the thyroid gland (colloquially called a “goiter”). Iodine also plays a necessary role in brain development, and it is especially important that developing fetuses get a proper amount of iodine from their mothers.

There have been several studies into the effects of bladderwrack-derived iodine on thyroid health. For example, in one study, researchers examined the effects of kelp supplementation on patients. They noted, “Short-term dietary supplementation with kelp significantly increases both basal and post stimulation TSH [thyroid stimulating hormone]. These findings corroborate previous studies on the effects of supplemental iodide given to euthyroid subjects for a similar period.”(5) As a result, many people choose to take a bladderwrack supplement to support healthy iodine levels.

Other Health-Supportive Compounds in Bladderwrack

In addition to iodine, bladderwrack contains phenolic compounds and mucopolysaccharides which may support overall health. These phenolic compounds include flavonoids like fucoxanthin, which is thought to have the highest antioxidant activity of any flavonoid in edible seaweeds. These antioxidants may work to protect cells from free radical damage. Mucopolysaccharides are long chains of sugar molecules and are sometimes called glycosaminoglycans. These compounds are sometimes taken as supplements to support synovial fluid and joint health. Mucopolysaccharides have also been studied for their effects on Candida and E. Coli.(6) However, studies on this topic are still ongoing.

Bladderwrack is also commonly used to maintain a healthy monthly cycle in women. In one study, bladderwrack was given to women who were determined to be at a “high risk of estrogen-dependent diseases.” and who experienced irregular monthly cycles. Conclusions from this small study were that “dietary bladderwrack may prolong the length of the menstrual cycle and exert anti-estrogenic effects in pre-menopausal women. Further, these studies also suggest that seaweed may be another important dietary component apart from soy that is responsible for the reduced risk of estrogen-related cancers observed in Japanese populations.”(7)

There has also been research into bladderwrack effects on cancer cells. It is thought that some of the therapeutic compounds in bladderwrack may have positive effects on breast cancer cells and colorectal cancer. A 2014 study examined this phenomenon and concluded, “Various therapeutic compounds from seaweed are able to induce apoptosis through different pathways and molecular mechanisms. Several studies indicated that fucoidan was able to induce apoptosis, inhibit angiogenesis, and suppress lung metastasis of breast cancer in vitro and in vivo.”(8)

Other Potential Health Benefits of Bladderwrack

  • Supports thyroid health
  • May promote a healthy hormone balance
  • Seeks to support a healthy internal response
  • May support liver health(9)
  • Supports healthy mineral levels
  • May promote healthy energy levels
  • May support a healthy metabolism
  • Seeks to support immune system health
  • May support joint health and cartilage health
  • Supports elimination and regularity(10)

While many of the beneficial effects of bladderwrack are still being studied, it seems apparent that it may have potential benefits for your health beyond simply supporting healthy iodine levels.

Other Uses of Bladderwrack

Bladderwrack is a source of alginates, which are biological compounds that form the cell wall of brown algae. Alginates were discovered in the 1880s by a Scottish chemist named E.C.C. Stanford, who derived them from wrack and British kelp.(11) These compounds are used as emulsifiers, meaning that they are thickening ingredients. Alginates are often added to ice creams and dairy products, toothpaste, and textiles to add viscosity, and there is also research to suggest that alginates may be used to support healthy cartilage and joint health.(12) Alginic acid is also a source of fiber, so it may support healthy elimination and may soothe the digestive tract.(13) There are a number of ongoing studies examining the effects of alginates on human health. Sodium alginate may offer support for a healthy weight by promoting healthy lipid levels, although the effects on humans are still being studied.

Bladderwrack also has cosmetic uses and is sometimes found in face masks and conditioners to support healthy looking hair and skin. It is thought that its antioxidant content may support healthy skin cells and promote overall health. There is also research that suggests bladderwrack may have positive effects on undereye circles. In a 2014 study, researchers concluded, “Fucus extract is a novel product that brings a quadruple approach to the treatment of under-eye dark circles.”(14) It is thought that bladderwrack may also soothe skin cells and support healthy collagen production.

In some countries, bladderwrack is used as a food source, and it is roasted to make crispy seaweed chips, or added to soups, salads, and sauces, although its strong flavor means that only a small amount of the seaweed is needed. It can be used in clambakes to add extra flavors to lobsters and steamer clams.(15) It is also made into tea, although because of the salt content, you may choose to blend it with mint, lemongrass, ginger, lemon peel, cinnamon, or allspice, and sweeten it with honey.

Should You Take a Bladderwrack Supplement?

If you are looking for a supplement to support thyroid health and promote normal thyroid hormone production, an iodine-rich bladderwrack supplement may make a difference for you. A healthy thyroid regulates your metabolism, weight, and more, so it’s important that you make sure you’re getting the iodine your body needs.

Bladderwrack also contains a number of trace minerals that are essential for overall health, including magnesium, calcium, potassium, and more. As the name suggests, trace minerals are present in very small amounts in the body, but they are critical to the body’s overall health and function. Some people choose to take a bladderwrack supplement in order to maintain normals levels of trace minerals.

However, some people have a sensitivity to iodine, so make sure you are aware of your iodine levels before you choose to take a bladderwrack supplement. It is also not advised to take bladderwrack if you have been diagnosed with hyperthyroidism. According to one article, a patient regularly taking a kelp supplement experienced issues with her thyroid, although such results aren’t typical.(16) It may be a good idea to consult with your doctor or a Certified Nutritionist before taking a bladderwrack supplement.

If you’d rather experience the potential benefits of bladderwrack for your skin, try an exfoliator or face wash that includes bladderwrack. As an ingredient, it supports healthy looking skin by promoting elasticity and healthy aging.

Bladderwrack supplements are typically available as capsules, although you can also find it in a powder. We have a number of bladderwrack supplements here at Natural Healthy Concepts, so if you’re interested in trying this supplement for yourself, you’ll find what you need here!