In an effort to stay up to date on one of our favorite ocean food trends, we recently asked two registered dietitians about the science-backed health benefits of sea moss, and learned that all edible forms of seaweed can, in fact, offer gut and heart health benefits, helps maintain a strong and healthy immune system, stimulates cognitive functioning, and fights inflammation. In short, consuming algae is a pleasure both for the palate Y our bodies, and we should be consuming it in much more than just shake form.
However, as sea moss rapidly grows in popularity, we can’t help but wonder: What other nutrient-dense forms of sea vegetables should we be eating? Researching some of the best sources of seaweed around the world, it was no surprise when we landed (figuratively speaking) on the shores of Okinawa, Japan, known to be home to some of the world’s longest-living people. In the Blue Zone region of Okinawa, brown seaweed, also known as mozuku, is an everyday staple in the centenarian diet. We spoke with a registered dietitian to learn more about mozuku, including its health benefits and how to incorporate it into meals.
What is mozuku seaweed and what are its health benefits?
According to Lauren Manaker, MS, RDN, LD, CLEC, CPT, a Charleston-based registered dietitian, a few things set Okinawan seaweed mozuku apart from the rest. “If you’ve seen seaweed that is browner than the classic green color many of us are used to, then you may be feasting your eyes on mozuku, a nutrient-rich seaweed that offers unique health benefits,” says Manaker. While most forms of seaweed for sushi and dried nori sheets come from a species of red seaweed known as pyropia (included P. yezosis Y p. tenera)Okinawa mozuku is derived from the genus Cladosiphon okamuranus.
According to Manaker, unlike green or red algae, brown algae is the only type that contains fucoidan, which is a natural compound that has a host of health benefits. “Fucoidan has been shown to have antioxidant, antitumor, anticoagulant, antithrombotic, antiviral, and anti-inflammatory effects,” she says.
Although more studies are needed to look at the health benefits of mozuku, Manaker says preliminary data suggests that consuming the seaweed may offer heart health benefits. Another study examined the anti-inflammatory effects of fucoidan in relation to quality of life in advanced cancer patients and found that proinflammatory cytokines were significantly reduced after two weeks of fucoidan ingestion.
So does this mean we should start eating more brown algae? “The data shows that eating fucoidan, even in large amounts, is safe for generally healthy people,” says Manaker. “Nutrients can vary between different seaweeds. But generally speaking, seaweed is a natural source of iodine, a nutrient that helps maintain thyroid health. It is also a natural source of fiber, which can support gut health,” he adds. However, that does not mean that it is suitable for everyone. “If you have a thyroid disorder, it’s important to ask your health care provider if seaweed can be part of your diet, as certain varieties may contain too much iodine for your needs.”
How do Okinawans commonly eat mozuku seaweed?
The brown seaweed is often hand-harvested in warm, shallow waters off the coast of Okinawa and then rinsed to remove any remaining sand or hidden sea creatures. To preserve its health benefits, Okinawans often eat mozuku raw, seasoned with sweet vinegar, or combined with other gut-healthy ingredients such as nattō, also known as fermented soybeans; however, it can also be eaten fried (as tempura) or in soups. The best way to get your hands on (literally) the freshest form of seaweed would be to harvest it yourself, but you can also find packaged mozuku in Japanese grocery stores or on Amazon, like this dried version.
Mozuku is not only a large part of the Okinawan diet, but is also considered an “under the sea treasure” that is an integral part of the local economy. According to the Okinawa Institute of Science and Technology (OIST) Graduate University, in 2006, the Japanese Cabinet Office estimated a production of 20,000 tons, with an economic value of billions of yen. However, in the last decade, rising sea temperatures have jeopardized the production of this valuable crop (and a source of income for many Okinawans). After all, 99 percent of this seaweed is produced in Okinawa and almost entirely farmed by humans. That’s why scientists are working tirelessly to find the best ways to preserve this aquatic gem, which is a staple in the Okinawan diet.
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