Protein is an essential macronutrient (along with carbohydrates and fat), as it plays a structural role in the body (participating in muscle cell production, for example) and is involved in digestive and immune system metabolism; it is also the body’s only source of nitrogen. Seaweed is generally high in protein (though content varies depending on the variety, red seaweed being the richest), making this food a valuable additional source of this essential nutrient. Red seaweed, for example, contains more protein than soya even though the latter is usually regarded as the no. 1 plant protein.
Seaweed is particularly high in fibre, especially soluble fibre. An average 8 gram portion of seaweed covers up to one-eighth of our daily requirements for fibre. Dried seaweed is even better - up to 50% of its weight consists of fibre. Why is this an advantage? Because fibre affects satiety and therefore helps control weight (by regulating appetite), accelerates food transit, lowers ‘bad’ cholesterol and prevents cardiovascular disease and type 2 diabetes … According to a study published in 2000 in the journal Nutrition Research the fibre in seaweed may be more effective at controlling diabetes and cholesterol than that from other dietary sources.
Because it’s high in fibre, but very low in calories (around 40-45 per 100g on average) and low in fat, seaweed is a valuable aid to those watching their figures. It expands in the stomach and thus has a hunger-suppressing effect. Another benefit is its gelling properties. For example, as a substitute for gelatin, agar-agar helps produce ultra-light and tasty products (vegetable mousses, fruit jellies …) provided the right dose (4g per liter) is used. And seaweed’s slimming benefits are used in some dietary supplements (Fat & Carb Blocker), designed to aid weight loss.
This is particularly so with brown seaweed because it contains fucoidan. A large number of studies conducted across the globe over several years suggest this polysaccharide may boost the immune system.
Research conducted on rats suggests seaweed may have a protective effect against some types of cancer, particularly hormone-dependent forms such as breast or prostate cancer. Now human studies are needed to confirm these highly promising findings. Another study from 2010 showed that the plant sugar compound fucoidan present in brown seaweed may improve the efficacy of chemotherapy.
In general, seaweed is packed with vitamins, particularly A, B2, B9 (folic acid), B12 and K. The dulse and nori varieties have the highest vitamin content (except for vitamin K).
Seaweed contains carotenoids, vitamins, flavonoids, tannins … So many compounds with proven antioxidant benefits. However, these antioxidant properties vary according to the type of seaweed (colour or depth of colour plays a role), but the absolute ‘must-have’ variety is Ecklonia cava, a brown seaweed highly-prized in Japan and Korea, and the no. 1 choice for antioxidant power.
Seaweed is available in two forms: dried or fresh. When dried whole, it needs to be rehydrated (for 5-40 minutes depending on the variety) in a little warm water before use. It can then be easily incorporated into soups, salads, pasta or rice … In dry powder form, it can be sprinkled over salads or added to dishes. If using fresh seaweed, it should be rinsed thoroughly before use. It can then be eaten in salads or cooked al dente or until tender, according to preference. You can then add it to whatever recipe you choose.
Most of us are aware of the nori and wakame types of seaweed which feature prominently in Asian cuisine (nori is used to make maki sushi). But there are many other varieties of edible seaweed available, including here in Europe. Dulse, kombu, sea lettuce, kelp, hijiki, sea spaghetti, spirulina and agar-agar are all types of seaweed that can be consumed either as food or as dietary supplements (to benefit directly from their health properties).
Danish scientist Ole G. Mouritsen maintains that consuming 5-10g of seaweed a day may significantly lower your risk of developing cardiovascular disease. Why? Because it is high in fibre and antioxidants which reduce levels of the ‘bad’ form of cholesterol.