When choosing which seaweed to buy, it helps to think of seaweeds as vegetables, but just from the sea rather than land. Like land vegetables, seaweeds offer a wide range of colours, textures & flavours – each is unique. Within a species of seaweeds the variation in culinary application and nutritional benefits can be surprisingly large.
Because all seaweeds contain chlorophyll, they photosynthesize, using the sun’s energy to synthesize nutrients from carbon dioxide and water and releasing oxygen into the atmosphere. Depending on their depth in the water, their colour can vary. Typically green seaweeds are found in shallower water on near the surface, reds in deeper water (up to about 100m, because blue and violet wavelengths are able to penetrate deeper depths), and browns in the subtidal areas, about 1-2 meters below the surface where red and orange wavelengths of sunlight are absorbed.
So seaweeds are classified in 3 groups according to their pigment and their chemistry. Each seaweed has a unique profile, active ingredients and benefits, but seaweeds from the same groups do share some common traits.
Although grouped as ‘brown’, their colour may vary between orange, gold, khaki, dark green, brown and black brown. In addition to their high iodine content, they also contain other unique substances that are being researched for their beneficial impact on degenerative diseases for example:
- alginates (detox radiations & heavy metals),
- fucoidan (cancer & infections),
- laminarin (cardio-vascular health) &
- lignans (oestrogen related illnesses).
Brown seaweeds naturally contain a high concentration of minerals & trace elements, including calcium, magnesium, potassium & zinc. They also contain Omega 3 & 6 fatty acids in a favorable ratio (1/2).
The broad health benefits of brown seaweeds include:
- nourishing the thyroid gland & brain,
- balancing hormones,
- improving metabolism & facilitating weight loss,
- detoxing environmental toxins from the body,
- inhibiting cancer cell growth and
- facilitating bone & joint health
Red seaweeds are the oldest & largest group of macroalgae with over 6,000 species worldwide (roughly 570 species of which are found along the New Zealand coast). Examples of red seaweeds are Agar, Dulse, Nori, Sea Chicory and Irish Moss.
Their distinctive colour pigments allow them to survive at great depths. They vary greatly in size, shape and ecosystem, and despite their name, their colour ranges from pink through to crimson, purple and orange.
Red seaweeds are an excellent source of minerals, carbohydrates, antioxidants, enzymes and are generally very high in dietary fiber. They are also rich in carrageenan and have a positive potassium/sodium balance. Red seaweeds are an excellent vegetarian source of high quality, complete protein – containing all the essential amino acids the diet requires. They are also a source of heme iron (a form of iron that can actually prevent iron-deficiency anemia).
Red seaweeds are a good source of iodine, well suited to maintaining healthy thyroid function.
The broad health benefits of red seaweeds include:
- strengthening the immune system and boosting minerals
- promoting cardiovascular health & regulating cholesterol,
- nourishing the nervous system – improving resistance to stress
- relieving congestion in colds & flu
- reducing inflammation – they are naturally anti-viral, anti-bacterial, anti-parasitic, anti-biotic, anti-septic and anti-fungal, and
- soothing the skin and the digestive tract.
Green seaweeds grow closest to the shore and are most closely related to land plants. They are most often noticed because of their vibrant colours (various greens & yellows) but are fewer in number than the red or brown seaweeds (approx. 140 species in New Zealand). Sea Lettuce is an example of a green seaweed.
Green seaweeds are the emeralds of the sea and they contain a wealth of minerals & trace elements, many times greater than is found in land-grown vegetables. They offer a large amount of digestible vegetable protein (up to 70%) and are an important source of calcium, iron, enzymes and anti-oxidants. They are a top source of chlorophyll, iron, fiber and Vitamin A, B & C.
The broad health benefits of green seaweeds includes:
- improving digestion
- reducing sugar absorption
- balancing blood PH,
- boosting immunity – antiviral against influenza,
- soothing (use on burns, cuts & sores as a compress or poultice)
- toning, hydrating and & nourishing for the skin and
- clearing of intestinal worms.
Disclaimer: This material is provided for educational purposes only and IS NOT intended as a substitute for professional medical advice, diagnosis, or treatment. This information is generic and should be verified by a qualified health practitioner for specific & individual needs & requirements.