Seaweeds
The term ‘kelp’ is applied to a number of seaweed species. In many parts of the world seaweeds, often dried, are used directly in food as vegetables, and in salads and soups.They are sometimes sold in health food shops, supermarkets,and similar establishments. The greatest usage is in the Orient; e.g. in Japan some 50 species are utilized.
Phycocolloids (carbohydrates) such as agars, alginates, and carrageenans are extracted from seaweeds and used as thickeners and stabilizers in a vast array of foods,including canned commodities, confectionery, ice-cream,jellies, soups, and sauces.
Generally speaking, seaweeds contain protein (aminoacid profile similar to that of legumes), little fat, and some vitamins and minerals. Among the vitamins, B12has been recorded but, as in Spirulina, its biological activity is open to debate. Of the minerals present, the relatively high concentration (0.07–0.76% dry weight) of iodine is of interest.
Seaweeds in the diet provide fibre.Below is information on some of the utilized seaweeds:
● Laver (Porphyra umbilicalis): a red seaweed, found on the rocky shores of the UK and other temperate North Atlantic countries. Its product is ‘laver bread’, particularly popular in south Wales but also eaten elsewhere....
● Porphyra is popular in China, Korea, and Japan (where it is known as nori). The Japanese cultivate Porphyra by sinking bundles of bamboo canes, brushwood, or nets offshore, to which will become attached a crop of the seaweed.
● Dulse (Palmaria palmata syn. Rhodymenia palmata): a red seaweed, consumed in the
ways already described.
● Carrageen or Irish Moss (Chondrus crispus): a red seaweed collected commercially in Canada for carrageenan extraction. Small quantities are harvested in Ireland and
France, and utilized.
● Knotted wrack (Ascophyllum nodosum): a brown seaweed common in temperate Atlantic countries. It is harvested in Ireland, Scotland, and Norway for alginate extraction.
● Some other seaweed species utilized belong to Laminaria (in Japan known as kombu), Macrocystis, Nereocystis, Fucus, Gelidium (one source of agar), and Undaria (Jap.wakame).
Taking Laminaria (kelp) as an example of a seaweed, the nutrient analysis of fresh material is: water 81.6%; protein 1.7%; total fibre 1.33%; fat 0.6%; energy 43 kcal; 233 mg sodium; 168 mg calcium; 89 mg potassium; 2.9 mg iron; vitamin B10.15 mg; vitamin B2 0.47 mg; vitamin C 0.1 mg.
Spirulina, Chlorella, and kelp tablets are readily available. Kelp refers to a number of species, but usually to brown seaweeds. A considerable number of claims
for the therapeutic value of Spirulina and Chlorella have been made, particularly on the Internet; one claim concerns the presence of vitamin B12, normally found in animal tissues.
Similarly, kelp products have been used to treat a large array of complaints, including obesity, rheumatism, arthritis, indigestion, constipation, and other problems. These treatments have often been related to the high concentration of
iodine in seaweeds.The phycocolloids (gels) present have a bulking effect in laxative preparations, and a demulcent action.
E V I D E N C E
As stated earlier, the vitamin B12reported for Spirulina, Chlorella, and seaweeds is not considered biologically active. The value of iodine as regards therapeutic claims for seaweed should be treated cautiously. Iodine is required by
the thyroid gland to form the hormone thyroxine, which controls body metabolism. Deficiency leads to goitre, but in many countries this has been eliminated by fortification, such as by the use of iodized salt.
However, deficiency of iodine can occur and kelp could provide the necessary iodine, but professional advice is required because touch iodine (above 150 µg per day) can lead to hyperthy roidism (weight loss, sweating, fatigue, and other symptoms). Iodine in kelp has somehow been related to the use of the product as a slimming aid in dealing with obesity. There seems little scientific support for this claim.
Seaweeds may absorb and concentrate unacceptable heavy metals, such as cadmium and lead, from contaminated sea water. Ingestion of kelp has been associated with
the development of human acne.Considering all the evidence, careful thought should go
into the use of algal products. The therapeutic employment of kelp is not supported in Germany, and it should not be given during pregnancy and lactation.
The term ‘kelp’ is applied to a number of seaweed species. In many parts of the world seaweeds, often dried, are used directly in food as vegetables, and in salads and soups.They are sometimes sold in health food shops, supermarkets,and similar establishments. The greatest usage is in the Orient; e.g. in Japan some 50 species are utilized.
Phycocolloids (carbohydrates) such as agars, alginates, and carrageenans are extracted from seaweeds and used as thickeners and stabilizers in a vast array of foods,including canned commodities, confectionery, ice-cream,jellies, soups, and sauces.
Generally speaking, seaweeds contain protein (aminoacid profile similar to that of legumes), little fat, and some vitamins and minerals. Among the vitamins, B12has been recorded but, as in Spirulina, its biological activity is open to debate. Of the minerals present, the relatively high concentration (0.07–0.76% dry weight) of iodine is of interest.Seaweeds in the diet provide fibre.Below is information on some of the utilized seaweeds:
● Laver (Porphyra umbilicalis): a red seaweed, found on the rocky shores of the UK and other temperate North Atlantic countries. Its product is ‘laver bread’, particularly popular in south Wales but also eaten elsewhere....
● Porphyra is popular in China, Korea, and Japan (where it is known as nori). The Japanese cultivate Porphyra by sinking bundles of bamboo canes, brushwood, or nets offshore, to which will become attached a crop of the seaweed.
● Dulse (Palmaria palmata syn. Rhodymenia palmata): a red seaweed, consumed in the
ways already described.
● Carrageen or Irish Moss (Chondrus crispus): a red seaweed collected commercially in Canada for carrageenan extraction. Small quantities are harvested in Ireland and
France, and utilized.
● Knotted wrack (Ascophyllum nodosum): a brown seaweed common in temperate Atlantic countries. It is harvested in Ireland, Scotland, and Norway for alginate extraction.
● Some other seaweed species utilized belong to Laminaria (in Japan known as kombu), Macrocystis, Nereocystis, Fucus, Gelidium (one source of agar), and Undaria (Jap.wakame).
Taking Laminaria (kelp) as an example of a seaweed, the nutrient analysis of fresh material is: water 81.6%; protein 1.7%; total fibre 1.33%; fat 0.6%; energy 43 kcal; 233 mg sodium; 168 mg calcium; 89 mg potassium; 2.9 mg iron; vitamin B10.15 mg; vitamin B2 0.47 mg; vitamin C 0.1 mg.Spirulina, Chlorella, and kelp tablets are readily available. Kelp refers to a number of species, but usually to brown seaweeds. A considerable number of claims
for the therapeutic value of Spirulina and Chlorella have been made, particularly on the Internet; one claim concerns the presence of vitamin B12, normally found in animal tissues.
Similarly, kelp products have been used to treat a large array of complaints, including obesity, rheumatism, arthritis, indigestion, constipation, and other problems. These treatments have often been related to the high concentration of
iodine in seaweeds.The phycocolloids (gels) present have a bulking effect in laxative preparations, and a demulcent action.
E V I D E N C E
As stated earlier, the vitamin B12reported for Spirulina, Chlorella, and seaweeds is not considered biologically active. The value of iodine as regards therapeutic claims for seaweed should be treated cautiously. Iodine is required by
the thyroid gland to form the hormone thyroxine, which controls body metabolism. Deficiency leads to goitre, but in many countries this has been eliminated by fortification, such as by the use of iodized salt.
However, deficiency of iodine can occur and kelp could provide the necessary iodine, but professional advice is required because touch iodine (above 150 µg per day) can lead to hyperthy roidism (weight loss, sweating, fatigue, and other symptoms). Iodine in kelp has somehow been related to the use of the product as a slimming aid in dealing with obesity. There seems little scientific support for this claim.Seaweeds may absorb and concentrate unacceptable heavy metals, such as cadmium and lead, from contaminated sea water. Ingestion of kelp has been associated with
the development of human acne.Considering all the evidence, careful thought should go
into the use of algal products. The therapeutic employment of kelp is not supported in Germany, and it should not be given during pregnancy and lactation.
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