The Health Benefits of Irish Moss, a Sea Moss Full of Nutrient-Rich Potential

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Nutrient-rich Irish moss—a type of sea moss that grows in chilly northern water—is becoming an increasingly buzzy superfood, as many tout its benefits. But that doesn't mean it's guaranteed to work: "Although it power-packs some vitamins and minerals, the science is not there to support whether this has a benefit on our health," says Amanda Kirpitch, RD, of Nutrition Perspective.

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What Constitutes Irish Moss

Officially known by its species name as Chondrus crispus, Irish moss can also be referred to as red algae or sea moss, says Kirpitch. The thin, flat, reddish-purple leaves branch out in a repeating pattern from a central stem and the plant grows primarily in the colder waters of the eastern and western northern Atlantic ocean. The plant also produces a thickening agent called carrageenan—inspiring another nickname, carrageen moss—which offers a vegan alternative to gelatin, though without the nutritional benefits of the plant form, says Kirpitch.

The Health Benefits of Irish Moss

Irish moss is a nutrient-rich plant with several potential health benefits, though not all of them have been scientifically proven. "It's marketed as a superfood with benefits to immunity, digestive health, [and] thyroid health," says Kirpitch. "It is high in iodine and iron. It has nutrients including potassium iodide that some have found to work as a decongestant." In a single study with rats, Irish moss had a presumed connection "as a prebiotic which could help improve the gut environment." Meanwhile, another study suggested that the gel could reduce ulcers, but no scientific studies have definitely linked Irish moss to those benefits, Kirpitch says.

How to Use It

Irish moss comes in a supplement form as a gel or powder that can be added directly to smoothies or other beverages. "In other countries they add it to beverages or make more of a pudding consistency, since it's a gel-like substance, but you may need quite a bit—which isn't really advised here, as we don't know much about potency," says Kirpitch. You can also eat it raw—but only after soaking it, she cautions.

What Else You Should Know

Like other supplements, Irish moss is not regulated by the U.S. Food and Drug Administration (FDA), and Kirpitch references "limited research" on how it affects people. "It seems fairly safe in small doses but would still be recommended to check in with a healthcare professional before taking," she says. "High levels of iodine can impact thyroid hormone levels—those with existing thyroid issues need to be cautious as the high levels of iodine can be dangerous and may interact with current treatments." Debate also surrounds the use of carrageenan. "There have been some reported concerns around inflammation of the GI tract with carrageenan, but it is categorized as Generally Recognized as Safe (GRAS) by the FDA in the non-degraded form," says Kirpitch. "The degraded form is not recommended for human consumption."