Seaweed is a common ingredient in Asian cuisine that takes on different forms for soups, salads, snacks and entrees.
Here in the U.S., the names for each type of seaweed are generally more well-known by their Japanese monikers for reasons unknown to me. However, seaweed is very frequently used in Korean and Chinese cuisine as well. Below, I’ll list some of the most common seaweed types by the English names, followed by the Japanese name and the Korean name.
#1 Dried Seaweed / Wakame / Miyeok
Miyeok is often served as a cold salad, also used for Korean seaweed soup (miyeok guk)
#2 Dried Kelp / Kombu / Dashima
Dashima is often used to make broth, and sometimes used in salads.
#3 Dried Roasted Seaweed / Nori / Gim
Gim is often used to roll sushi or gimbap, or eaten with rice and vegetables. The little ones are usually salted, sometimes with olive or grapeseed oil, and can be enjoyed alone as a snack.
Seaweed is said to contain numerous beneficial nutrients (see this study) including vitamins C, B, A, and E as well as iron and iodine. This last nutrient is significant as seaweed is much higher in iodine than most foods. Iodine is an important nutrient but can be detrimental in high quantities. For this reason it has become controversial, particularly because of seaweed’s cultural significance in Korea for new mothers.
Korean mothers often make miyeok guk (seaweed soup) for their children on their birthday because it is eaten so often during the postpartum period (like, with every single meal). Miyeok has higher iodine levels than its counterparts, and while it loses some of it while it’s cooked, it’s still fairly high relative to other foods.
Iodine is useful for thyroid function; however, TOO much iodine is harmful for thyroid function. Too much iodine can cause hypothyroidism and some even speculate that too much seaweed consumption is linked to thyroid cancer. Because some Korean mothers eat miyeok guk up to three times a day after giving birth, some association is cautiously being linked.
My mom gave miyeok guk to me every day after I had my kids, telling me it would “clean my blood” and also help with milk production. There’s no actual evidence that it helps with milk production but it is commonly believed to do so among most Koreans. In terms of blood purification, I haven’t found much to back that up (if I’ve missed something please let me know) however, it is rich in iron which new mothers often need, and fucoidan which helps with blood circulation. Seaweed is also high in vitamin B12 which helps keep nerve and blood cells healthy and prevents certain types of anemia. Also, fucans (a carbohydrate found in seaweed) may help prevent blood clotting.
One other cautionary note on seaweed: it can absorb and store high levels of minerals which unfortunately can include toxic heavy metals when it’s pulled from the ocean. One study evaluated seaweeds from Asian and Europe, finding that exposure to toxic metals through seaweed consumption does not raise serious health concerns, but that organic seaweed had the lowest levels detected. Another study evaluated seaweeds from South Korea for toxic heavy metals and found contents to be low and non-threatening for both organic and inorganic species.
So, you probably shouldn’t eat seaweed for every meal no matter what your health condition. But it’s a nutrient dense food that is helpful in a lot of other ways and certainly safe to eat in moderation.
What are other health benefits from seaweed?
- Antioxidants: While vitamins A, C and E are all considered antioxidants, there are also flavonoids and carotenoids in seaweed shown to protect your body’s cells from free radical damage.
- Weight loss: Seaweed is high in fiber and low in starches and calories. There are also several animal studies with promising results from the contents of fucoxanthin (highly present in miyeok) that reduces body fat and blood sugar levels. The latter would also help with prevention of diabetes.
- Reduces heart disease risk: As previously mentioned, fucon in seaweed has a potential role in preventing blood clots, and also it may reduce blood cholesterol levels.
- Promotes a healthy gut – Algae provides gut-healthy prebiotic fiber which can help with constipation and diarrhea.
So, what’s the deal with seaweed?
Seaweed soup, seaweed salad, gimbap, sushi, a salty snack – there are many delicious ways to enjoy seaweed and reap the many benefits that it has. Admittedly, there can be too much of a good thing and seaweed is definitely no exception to that. Overall, you can feel good about enjoying any of these dishes in moderation. I know that I will.