Sargassum Seaweed Benefits

Sargassum Seaweed
Latin Name

Sargassum muticum

Also Known As

Gulf Weed, Sea Holly


Tropical and temperate waters throughout the world

Parts Used

Whole plant

Traditional Use and Health Benefits

Sargassum seaweed is a genus of brown macroalgae in the order Fucales. Numerous species are distributed throughout the temperate and tropical oceans of the world, where they generally inhabit shallow water and coral reefs.

This unassuming seaweed recently hit the headlines for creating the biggest seaweed bloom in the world. In July 2019, a floating mass of seaweed stretching from West Africa to the Gulf of Mexico was picked up by satellites. As of June 2018, the "Great Atlantic Sargassum Belt" as scientists call it, extended 8,850km (5,500 miles) and was made up of over 20 million tonnes of biomass.

Sargassum seaweed is a nutritious food, rich in carotenoids, cellulose, protein, and aspartic and glutamic acids. It has a long history of traditional use and has been used in Asian traditional medicine systems for thousands of years.

Sargassum Seaweed Benefits

Thyroid Health

Just one 5 gram portion of Sargassum seaweed provides 100 percent of the RDA for iodine. Due to ongoing soil depletion, sea vegetables have long overtaken land vegetables in the iodine department, with Sargassum being no exception.

Iodine is critical to the thyroid; it forms a part of the thyroid hormones (T3 and T4) which are used in every cell of the body to regulate metabolism and weight by controlling the burning of fat for energy and heat. These hormones are directly responsible for controlling the body’s “base metabolic rate” which affects the efficiency and efficacy of many of the body’s organ systems, and regular processes including the absorption and biosynthesis of food into usable energy. Iodine is literally "food for the thyroid".

Iodine also displaces dangerous "halides" such as; fluoride, bromide and chlorine in the thyroid. It is antioxidant, promotes proper hormone balance, protects from radiation and kills bacteria and fungi.

When the thyroid is compromised, symptoms can include unexplained weight loss/gain, fatigue, hair loss and dry skin.

Source of Agar

Sargassum is one of the algae used in the production of Agar. This gelatinous substance benefits healthy weight loss as it is low in calories, fat and sugar. Promoting a feeling of satiety, it can also help to stabilise blood sugar and block the storage of fat.

Heart Health

Sargassum is extraordinarily high in the heart healthy mineral magnesium. One 5 gram portion provides more than double the RDA of this important mineral.

Magnesium helps to regulate heart rhythm, co-ordinating the activity of the heart muscle and the nerves that initiate heartbeat. Low magnesium levels can cause heart palpitations and arrhythmias (irregular heartbeats).

Magnesium also helps to keep the coronary arteries from having spasms that can cause the intense chest pains known as angina. It is relatively well known that a deficiency in magnesium is the most common cause of these spasms.

Also keeping blood pressure in check, magnesium relaxes the muscles that control blood vessels, allowing the blood to flow more freely. This can help to reduce high blood pressure – an important factor in decreasing the risk of a heart attack of stroke. Magnesium’s effect on high blood pressure is further enhanced because it helps equalize the levels of potassium and sodium in the blood.

Eye Health

A 5 gram serving of Sargassum seaweed provides around 40 percent of the RDA for vitamin A. The vitamin A found in this seaweed is in the form of beta carotene, a compound that has been shown to significantly reduce the risk of cataracts and macular degeneration.

A fat-soluble antioxidant, vitamin A also helps to protect the surface of the eye (cornea) and is a component of rhodopsin – a protein in the eye that boosts vision in low light conditions. One of the first symptoms of a deficiency in this important vitamin is “night blindness”, or nyctalopia. Furthermore, vitamin A maintains the integrity of the cells of mucous membranes, including those of the eyes.

Typical Use

Organic Sargassum Seaweed

To rehydrate: Soak in cold water for up to 5mins with a little salt Salted: Wash salt off thoroughly before use Fresh: Rinse thoroughly before use.

Can be eaten fresh (rehydrated) or boiled – do not boil for more than 15mins.

Folklore and History

Sargassum seaweed has a mythical, ominous image in Western culture. To mariners, it was bestial and hungry - prowling the waters of the Bermuda Triangle. Sailors have long imagined thick mats of seemingly endless Sargassum seaweed catching their ships, dooming the vessels to spiral with the seaweed along the currents until they disintegrate and sink together. 

In the East, it has an entirely different, more practical face. It is a component used in traditional Chinese medicine that dates to around the 8th century. It is said to be helpful for the treatments of bronchitis, laryngitis, infections and fevers, and can be used in poultices to treat wounds.

It is greatly appreciated in Japan, where seaweed has been used as an ingredient in foods for centuries.

Sargassum Seaweed

People with an iodine allergy should not consume seaweed. If you are taking any prescription medications, especially in the case of thyroid disorders, please consult your healthcare professional before consuming Irish Sargassum Seaweed.