Seaweed is a member of the algae family and most commonly categorized by three color varieties: brown (e.g. kombu, wakame), red (e.g. nori, dulse), and green (e.g. sea lettuce). Each variety of seaweed is sourced from a different geographical region and has a signature shape, texture, and taste.
Seaweed is really a sea vegetable! It grows in nutrient-dense ocean waters and offers a broad range of minerals and vitamins, most notably calcium, iodine, copper, magnesium, phosphorous, potassium, and zinc, as well as vitamins A, B, C, E, and K. Historically, seaweed has been enjoyed in a range of Asian cuisines, often in sushi, salads and soups; and with its rising popularity, it’s showing up in a variety of snack foods such as crackers and crisps. With less than 10 calories per 2 tablespoon (10-gram) serving, seaweed is a popular low-calorie, nutrient-rich snack.
But remember, you can always have too much of a good thing. For instance, high consumption of vitamin K, a natural blood thickener, can work against the intent of warafin, a blood-thinning medication. Also, as a natural source of iodine, seaweed can be beneficial for thyroid health; yet, excess intake can lead to an underactive thyroid. With a current recommended daily intake of 150 micrograms (mcg) per day and an upper tolerable limit of 1,100 mcg, different varieties contain different amounts of iodine. For instance, a 10 gram serving of nori contains approximately 120 mcg of iodine, while one serving of kombu may contain up to 26,600 mcg.
What’s the takeaway?
From a crunchy roasted snack to a savory soup, seaweed can be a fun and flavorful addition to your diet. It’s a nutritious sea vegetable that offers a variety of nutrients, but that doesn’t mean you should eat an ocean’s worth — moderation is key.
Read more about seaweed here.