Seaweed has been hailed as a highly nutritional food source underutilized by people in the West.
Seaweed is loaded with minerals and fibers. Growing it can have environmentally positive impacts, such as absorbing carbon from the atmosphere, keeping oceans healthy and helping to tamp down methane emissions from cows.
But none of this is the reason seaweed had a viral moment for grocery store shoppers.
It came in 2023 from Hailey Bieber’s $20 Skin Glaze smoothie. The celebrity-backed beverage contained sea moss, a gelatinous semi- translucent gel seaweed scientifically known as Chondrus crispus. The edible red seaweed is found on rocky shores in the North Atlantic where it gains its other nickname, Irish Moss.
Bieber’s smoothie attracted new interest in sea moss. Champions applauded it as the next healthy superfood, claiming it can support heart, gut and immune health, clear skin and even help people lose weight.
More attention came earlier this year on Shark Tank when Mark Cuban invested in a sea moss gummy company. Recipes for ice cream and jams also have made it to Pinterest and direct-to-consumer brands have popped up around the ingredient.
But what are the true benefits?
Looking at the composition of sea moss, it is high in magnesium, iodine, iron, folate, calcium and vitamins, all important for a healthy body. It’s also low in calories, high in fiber and a good source of probiotics.
However, there are not many scientific, peer-reviewed studies of sea moss’ effects on humans. Some non-human studies have shown sea moss to enhance immunity in worms, have anti-cancer properties in mice and exhibit anti-inflammatory effects on isolated cells.
While sea moss in humans has not been studied extensively, there have been many studies on seaweed more generally. It has positively affected blood glucose metabolism, blood pressure and thyroid function, especially in those with type 2 diabetes. One study even showed seaweed to be beneficial for protecting against COVID-19.
The recommended dose of sea moss is no more than one or two tablespoons per day or no more than 1000 milligrams. Keeping to this serving size reduces the risk of heavy metal contamination and overdosing on iodine, which are elevated in sea moss. High levels of iodine can cause gastrointestinal issues and even serious thyroid complications.
One big concern with sea moss is that it’s not FDA-regulated. This means that not all sellers have been vetted and some might be selling questionable products. The claims have also not been corroborated by science.
“When something isn’t FDA regulated, it means that there likely haven’t been large-scale randomized control trials, which are the gold standard for this type of research,” Selvi Rajagopal, an assistant professor of medicine at Johns Hopkins University told Eater. “There are some studies out there, but the evidence is sort of sparse right now.”
