Despite its recently trendy, superfood status, seaweed has been used all over the world for thousands of years, but has most notably been a prominent part of Asian diets for the longest period of time, particularly in Japan, Korea, and China. There are thought to be over 10,000 species of seaweed, reflecting its immense diversity, both in flavor and nutritional properties. The most popular seaweed species are nori, which is dried in sheets and widely used to make sushi. Other common varieties include dulse, arame, wakame, kelp, and spirulina. Sea vegetables also have a long history in ancient medicine, folklore, farming and food growing in Europe, particularly in Ireland.
Sea vegetables are full of nutrients. Coming in a multitude of colours, textures, shapes, and sizes, all types contain a rich supply of minerals, most prominently calcium, copper, iodine and iron. They are also rich in protein, fiber and vitamins, specifically vitamin K and folic acid while being low in calories and fat.
Thanks to their impressive nutritional profile, seaweeds are beneficial to health and are thought to help the body fight illness and disease. The Japanese have one of the highest life expectancies in the world, and one significant, standout dietary habit is their regular consumption of seaweeds. Seaweeds contain a molecule known as fucoidans, which are believed to be responsible for these impressive health benefits, contributing not just to overall life expectancy, but also to immunity and cardiovascular function.
A 2011 review of 100 studies on the benefits of seaweeds, published in the American Journal of Agricultural and Food Chemistry, reported seaweeds may be used to help lower blood pressure and promote heart health.
The quest for umami – or the fifth taste – by chefs and foodies alike has highlighted another key component of seaweeds – their high glutamate content, an amino acid, necessary for normal brain function. Dashi, a traditional Japanese broth, heralded as the ‘mother’ of umami, has seaweed as a core ingredient. Research suggests that it’s the high glutamate content of certain seaweeds that provides the umami flavoring.