June 14, 2023
Sea moss is gaining popularity after years of celebrities and influencers promoting the slimy goo – and its more natural-looking plant or powder counterparts – for its purported abilities to improve thyroid conditions, support gut health, aid weight loss efforts and boost one's immune system.
A search for sea moss on TikTok yields thousands of videos with a combined total of 1.1 billion views. Users have done 30-day challenges in which they try to take a few spoonfuls of sea moss gel each morning with breakfast or blend it into a smoothie recipe lauded by celebrities like Kim Kardashian and Hailey Bieber. Though many people gag at the taste and texture, others have embraced the nutrient-rich superfood as an aid for a variety of ailments.
Sea moss, also known as Irish moss or red seaweed, is a type of red algae that is harvested for its carrageenan, an ingredient used as a thickening agent in ice cream and other milk products. It's also available in its raw form as a sea vegetable or as a supplement, often jarred as a powder, gummy or gel, according to the Cleveland Clinic.
Sea moss is widely known as a nutrient-dense food, low in sugar and calories, but rich in calcium, magnesium, potassium, phosphorus and iron, according to the U.S. Department of Agriculture. It's low in fat, like other seaweeds, but most of its fat content is polyunsaturated fat, a nutritious type that can help reduce cholesterol levels.
"There seems to be quite a few benefits of sea moss, but they aren't heavily studied, and sea moss supplements are not approved by the U.S. Food and Drug Administration," Beth Czerwony, a registered dietitian, told the Cleveland Clinic in 2021. "Sea moss is a product of its environment, so its nutritional value depends largely on where it's grown. Unfortunately, there's no real way to know exactly what's in it or how much, and one batch may have higher potency than the next one."
Sea moss is most commonly associated with improved thyroid health because of its high levels of iodine, which is needed to make two key thyroid hormones, according to Harvard University's T.H. Chan School of Public Health. While most healthy adults in the United States receive their daily intake of iodine with a balanced diet, inadequate or overconsumption of iodine can lead to and worsen thyroid disease, VeryWell Health reported.
"Iodine is especially important to both thyroid and breast health and sea vegetables are excellent sources of natural iodine," Robin Foroutan, spokesperson for the Academy of Nutrition and Dietetics, told Parade earlier this year. "It could be especially helpful for those with low thyroid activity or even those whose thyroid labs look normal but have symptoms of low thyroid. I suspect the reason people think red sea moss may benefit weight loss is that seaweed in general is rich in iodine, and an adequate amount of iodine supports a healthy thyroid function, which supports healthy metabolism."
But while the iodine levels in sea moss and other seaweeds can be beneficial to those who don't get enough iodine in their regular diet, consuming too much iodine can have a negative effect on the thyroid, which can contribute to other health issues like thyroid cancer, nausea, vomiting, weak pulse, comas and burning of the mouth, throat and stomach, according to the National Institutes of Health.
The USDA recommends that people consume no more than 150 micrograms of iodine each day. Consuming about 2 to 4 tablespoons of sea moss in its gel or powdered form is considered safe and healthy, though it's important to discuss the potential benefits of sea moss with a medical provider, particularly for those with thyroid concerns.
A 2021 study on the effects of seaweeds, including sea moss, found that some components have the potential to act as prebiotics and support gut health, Forbes reported. Though additional research is needed to support its effectiveness in people, sea moss also contains healthy bacteria and is high in fiber, which can help balance gut bacteria and improve overall health.
A 2019 study found that Atlantic salmon that ate sea moss had a more efficient immune response than those that didn't. No similar studies have been conducted on humans to determine its effectiveness. However, the Cleveland Clinic notes that a healthy gut is widely associated with a healthy immune system, which may contribute to its effectiveness.
Still, sea moss may contain trace amounts of heavy metals like aluminum or cadmium, much like seaweed, depending on where it's grown. Regular exposure to low levels of cadmium have been linked to an increased risk of cardiovascular disease, according to the American Heart Association. While the heavy metals are not toxic in small amounts, experts warn against overdoing it, The New York Times reported.