Used for thousands of years in Asian cooking and Chinese medicine, seaweed is a wonderful addition to a healthy diet. It is incredibly versatile, making a delicious snack, condiment, sushi wrap, salad ingredient or stock addition. The possibilities for its use are endless, and the health benefits numerous.

There are many different kinds of edible seaweed, most of which are very high in antioxidants and essential nutrients. Though these essential nutrients may vary between seaweed types, generally seaweed is a great source of iodine, magnesium, calcium, folate, and vitamins A, K and B12, as well, as fiber and protein.

• Iodine is a necessary part of all thyroid hormones produced by your body. The proper construction of these hormones is necessary for many important physiological processes within the body including normal growth, healthy brain development, and metabolism regulation.
• Magnesium is essential in the construction of proteins and in energy production and cell signaling pathways. It also plays a structural role in our bones and muscles.
• Calcium is essential to the structural integrity of both bones and teeth. It also plays a role in cell signaling and communication.
• Folate plays many important roles in the body, but it is especially important in protecting our cells from damage. If cells do become damaged, folate also helps to mark these damaged cells so that our immune system can get rid of them. This system helps to keep damaged cells or those that are cancerous from growing and spreading.
• Vitamin A supports your internal antioxidant pathways and helps your metabolism run efficiently These nutrients are particularly important in supporting a healthy, robust immune system and helping to prevent cell damage caused by free radicals.
• Vitamin K plays a role in bone health, as it is vital for bone calcification, but also helps to prevent unwanted blood vessel calcification. It also part of necessary blood coagulation systems and is involved in regulating cell function.
• Vitamin B12: Vitamin B12 is found in abundance in animal sources, but seaweed is considered the only naturally occurring plant source of vitamin B12. This makes seaweed an extremely vital part of vegan and vegetarian diets. Vitamin B12 plays an important role in maintaining correct DNA structure and function, help to facilitate communication between brain and nervous system cells, and promotes healthy neurotransmitter synthesis in the brain.

There is ongoing research regarding the potential anti-cancer properties of seaweed. While there isn’t conclusive evidence that seaweed can fight or cure cancer, as more research must be done before we can apply these current preliminary findings produced in cell studies and make specific dietary recommendations for humans, it is a great idea to add seaweed to your diet. You can enjoy its versatility and capitalize on all the wonderful health-promoting nutrients it brings.

Here are some of the most common types of seaweed for cooking and snacking.

Nori: Nori is what most sushi-loving Americans are used to. Nori is often used to wrap sushi and can also regularly be found dried on its own in snack form and in miso soup. One sheet of dried nori has more fiber than a cup of spinach. Nori also contains heart-healthy omega-3 fatty acids, but is not considered a reliable source, given the typical amount consumed and the low total fat content of seaweed.

Kombu: Kombu is edible kelp. It is often used to make rich-tasting and delicious stocks for soups. Because kombu has so much flavor, one sheet can be used multiple times to flavor stocks. Kombu can also be added to beans during the soaking step to help promote digestibility. Kombu has been treasured for years as an important source of iodine, which helps regulate thyroid function.

Arame: Arame usually comes in dried dark brown strands and is usually reconstituted and added to salads and soups. It has a very mild flavor so it can be used in many different ways. It’s a great source of potassium, which is necessary to maintain proper muscle function.

Wakame: This seaweed is commonly found fresh and tossed with sesame oil in seaweed salad. It often comes in thin green somewhat crunchy strips. It is rich in calcium and its mild flavor is a great addition to soups.

Hijiki: Hijiki resembles dark noodles when dried and has a mild flavor. It can be used in stews, casseroles, and salads. Although it is a great source of calcium and fiber, it has unfortunately recently been found to contain high levels of inorganic arsenic and may be harmful if consumed in any quantity. It is best to avoid hijiki.

Agar-Agar: Agar-agar is a vegetable gelatin that comes from red agarophyte seaweed.  It is used all over Asia to make edible jellies and deserts, and is also a staple in research labs where it is used to grow cultures. Agar-agar is a great addition to vegetarian and vegan diets. It is especially useful for desserts since it has little flavor and is a perfect way for seaweed novices to start adding it to their meals. Agar-agar is sold in white spongy looking bars, or in powder form.

Chef Tips

Seaweed can be an acquired taste, but the minerals and vitamins it adds to the diet make getting familiar with it well worth the effort. Many grocery stores now carry seaweed in their health food sections. If they don’t have it, look in the macrobiotic section of your local health food store where they will definitely carry everything on our list.  Seaweed can also be found at specialty Asian markets.

Most seaweeds are sold dried and are best stored in an airtight tin. Nori, in particular, needs to be kept away from moisture. Its thin papery sheets can pick up moisture in a heartbeat, so it’s a good idea to store it with a silicone pack to help keep it dry and crisp.  Kombu as noted, is a great base for soups and stocks. Keep any reconstituted kombu in the fridge. Kombu can be re-used up to three times before it loses its flavor.  After the third time, shred the kombu and add it to your soup.

We love all the health benefits of seaweed and the delicious flavor it can give to soups. It can be great as a condiment, too. Try lightly toasting a sheet of nori and crumbling it over plain boiled rice.

Classic Miso Soup is made with dashi, a broth that starts off with a large piece of kombu. For a truly nutrient-rich, healthy soup try making Oden, a classic Japanese comfort food. For a more westernized way to use kombu, try making our healthily cooling Watercress and Seaweed Soup.  And for dessert, try our Blueberry and Rosemary Kanten to get a simple, sweet intro to agar-agar.