Kombu (Laminaria digitata), like most kinds of seaweed, is salty and nutritious. Along with wakame, kombu contains alginic acid, which removes radioactive substances and heavy metals from the gastrointestinal tract and bones, as well as removing strontium 90 from bones. The nutrients in seaweeds also have a higher bioavailability than those in most foods, and when used in recipes, they can increase your body's ability to absorb the nutrients in the dish's other ingredients.

One of the big ideas in nutrition these days, at least as it is put forth by mainstream magazines, is that people should shop by color for their fruits and vegetables. Each different major color of produce tends to provide something separate and important to the body; for example, orange and yellow fruits (and even root vegetables) tend to be high in vitamin C and E and potassium, whereas blue and purple berries tend to excel in providing antioxidants. The darker the shade, the more nutrition it provides, with dark blueberries and dark leafy greens being put forward as the most nutritious fruits and vegetables available (although one looks like a berry and the other is a leaf).

This theory would suggest that seaweed must be extremely nutritious, since it is so dark a green as to be almost black. And in fact it is: kombu, specifically, is an excellent source of potassium, magnesium, iodine, B vitamins, carotene, vitamin C, and fiber.

Admittedly this information is from Rising Tide Sea Vegetables at loveseaweed.com, but although they're selling it they're still required to provide accurate nutrition information.

They also note that the glutamic acid in a four-inch strip of kombu, if popped into a pot of beans, grains, or soup, will add nutrients and flavor and make beans and grain more digestible. This acid also thickens sauces and tenderizes beans, and the seaweed itself adds flavor the way MSG is supposed to without the side effects. Personally, I eat it raw; however, as this is something like chewing on tar paper, I don't really recommend it. It is, however, excellent for when you need a snack that none of your friends will try to get you to share.