Edible seaweed doesn't usually come to mind when the stuff fouls our otherwise pristine white beaches or gets tangled up in our fishing lures or turns rocks into slippery dangerous places to step while beachcombing. After all aren't weeds a nuisance plant to be pulled up and thrown away. Well yes, but sea "weeds" is probably a misnomer when applied to a very beneficial form of life properly known as marine algae.
The term "edible" is reserved for those seaweeds that are mostly marine algae since most freshwater algae is toxic. Even so, some of the marine algae can irritate the GI tract and/or have a laxative effect.
It is probably a good idea to know what kind of seaweed one is consuming. No problem at the sushi bar, possible problem in "do-it-yourself" seaweed harvesting without having some advance knowledge of the edible seaweed types.
Types of Edible Seaweeds:
Pick your color. Marine algae are either red, green or brown multicellular organisms and seem to have developed independently, that is having no common ancestor.
All of them contain chlorophyll, a green pigment that employs sunlight to produce food, a process known as photosynthesis. Red and brown marine algae have chlorophyll but they also have other pigments that block the green color and yield varying shades of red and brown.
Common uses include fertilizer, compost, an ingredient in many medications, cosmetics, toothpaste, paint, industrial uses including paper, dyes, gels, explosives, fuel and, of course, food for people.
For our purposes, the nutrition and health benefits of edible seaweed will be the focus. And speaking of nutrition, here's a recommended book titled "Seaweeds: Edible, Available, and Sustainable" by Ole G. Mouritsen that covers everything we would want to know about these fantastic marine algae. Click the cover image to look it over.
According to the Canadian Museum of Nature, there are at least 10,000 different types of seaweed although they all fall into one of the three colors already mentioned. Around 32 of them are commonly named as edible seaweeds and of those 32, four seem to be the most popular: kelp, nori, kombu and wakame.A very recent issure of Food&Nutrition included a nice article on Edible Seaweed that included recipes, nutritional information and more. It's worth a look.
Marine algae, aka seaweed, contain a goldmine of nutrients. However not all edible seaweed contain the same nutrients nor in the same quantities. Consider some of the more widely consumed seaweeds:
Nori is red algae which are used extensively as a sushi wrap, in Japanese miso soup and some salads. It has the highest protein content of all the other seaweeds, in fact it is about 1/3rd protein and 1/3rd fiber. It also has high percentages of vitamins A, B12 and K plus high amounts of iron and usable amounts of copper, zinc, phosphorus and potassium. If you intend to make your own sushi rolls, be sure to buy the untoasted nori sheets since heating via toasting will degrade the nutrient content.
Wakame, which is also used in many soups and salads, is rich in EPA, an omega-3 fatty acid as well as a substance called fucoxanthin which helps the body burn fatty adipose tissue. It is especially high in calcium content and is recognized as a rich source of thiamine and niacin. It is usually purchased fresh or dehydrated; either way, it tastes best if hydrated in water prior to use.
Kombu is from kelp, an extremely large brown algae that grows into underwater forests and is known for it glutamic acid content as well as being a good fiber source. The Japanese have been using Kombu for hundreds of years as a flavor enhancer rich in minerals. Typically only a strip of the seaweed is added to other foods while cooking. For example it is added to beans to reduce gas and aid digestion and added to sprouts while soaking so that the sprouts will soak up the minerals in Kombu.
Kelp is a brown seaweed and is, by far, the most common marine algae found along ocean shores and beaches. Kelp is not normally eaten as food but its nutrients are often sold in supplement powder form.
Dulse belongs to the red algae family and is usually found in stores as flakes or whole. As many others, it is better soaked, drained, sliced and then added to your salad, veggies or soup.
Arame is known for its black, stringy appearance. It must be soaked for several minutes before being added to cooking foods since it will double in size. Recommended uses are with any grains, as well as in stir fry, soup, salads and curried dishes.
Hijiki is the last mentioned since it is not recommended for consumption. It has good calcium to magnesium balance, about 2 to 1 but if you like arsenic with your food then Hijiki is for you. It has such high inorganic arsenic content that several governments have warned against its dietary use.
Since cooking and preparation has been mentioned, here's another recommended book on that very subject titled, "Sea Vegetable Celebration: Recipes Using Ocean Vegetables" by Shep Erhart.
By now most everyone knows that seaweed is a source of iodine. Once upon a time, a lot of people were deficient in iodine but then iodized salt hit the market and the problem was solved. An iodine deficiency causes a goiter which is nothing more than an enlarged thyroid gland. The enlargement is due to the gland trying to capture more iodine from the blood stream.
Most notably, iodine is an essential component of thyroid hormones that control protein synthesis, enzymatic and metabolic activity. It is also required by infants and even fetuses for proper development of bones and the central nervous system. For iodine, think kelp, nori, kombu, wakame and any other type of seaweed you care to swallow.
Seaweed also contains complete protein or whole protein as it is sometimes called. Humans need all nine of the essential amino acids and we need them in certain proportions. It turns out that edible seaweed meets this requirement nicely.
Seaweed extract supplements
There are numerous seaweed supplements on the market from most of the more widely known supplement manufacturers. As with any dietary supplement it is best to stick with the well-known companies that follow good manufacturing practices (GMPs). This means good quality control, high quality ingredients, accurate and complete labeling information, standardization of the product and conformance with DSHEA requirements.
Typically, seaweed supplements are sold as fat burning or weight loss products or to address an iodine deficiency. Care must be taken with seaweed supplements not to take too much and end up with iodine poisoning. It is hard to get too much iodine from food but throw in supplements high in iodine and some serious side effects could happen including coma.
For packaged or even bulk seaweed, a good suggestion is to shop any of the Oriental food stores or Asian markets which are plentiful these days. For example take a look at the Asian Market by clicking on the banner below or following the link directly to their seaweed page.
In concluding this page on edible seaweed, a short summary list of why one should consider adding seaweed is offered below.
So get out there and keep our beaches clean; eat more seaweed;
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