Seaweed has long been prized as an excellent
source of minerals. It provides an abundance of minerals, plus other
nutrients such as vitamins A and C (especially Konbu) and protein
(especially nori). It is also one of the very few non-animal sources of
vitamin B12, a lack of which can be dangerous as it leads to pernicious
Seaweed is therefore very useful for strict
vegetarians. It helps to prevent cancer and heart disease, lowers blood
pressure and cholesterol, and can even prevent ulcers and kill bacteria.
It also thins the blood. In one test, a
chemical from wakame seaweed was shown to be twice as effective as the
drug heparin at destroying blood clots.
These are the most common varieties of
seaweed eaten in Japan.
Konbu - This is very dark green,
almost black, and more rubbery in texture. Used for 'dashi' (basic
stock) and in nimono. Sometimes eaten with rice as shio-konbu, which is
dried and salted, either in small squares or in thin strands - more of
an 'acquired taste', rather like 'Marmite' or licorice.
Nori - This is also the most
palatable as it is dry and does not have a strong taste. It comes in
sheets, looking like dark green paper.
Wakame - This type of seaweed is
usually in the form of thin pieces, mid-green and not too strong, often
eaten in misoshiru (soup) or pickled with vegetables like thin slices of
cucumber in rice vinegar and a little sugar.
Hijiki - Thin, black strands,
sometimes fried (in sesame oil or vegetable oil). You can add thin
matchstick size pieces of carrot and/or bean curd and served as a side