Seaweed – Kill or cure?

Seaweed may not be too appetising when it is dried out and ponging on the beach, but Bladderwrack, kelp, and sea palm could hold the key to improving the British diet. Extracts from different types of brown seaweed, known as alginate, are the ideal way to add fibre to junk food favourites such as burgers, pies and cakes. The natural gelling agent, which helps to bind water molecules, is already used in some foods and pet food chunks. Professor Jeff Peason, who lead the research team at Newcastle University looking into this extract, explains: “We’re just not eating enough fibre, yet we need this to keep us healthy. Adding the seaweed extract could quadruple the amount of fibre in white bread.”

Does it work?

Alginate, a structural polysaccharide, is undoubtedly a form of fibre. Studies have proved that fibre is essential for good digestive health, and for warding off diseases such as bowel cancer. The Newcastle study also found that alginate strengthens the mucus lining the gut wall, can inhibit digestion and can slow the uptake of nutrients in the body.

However, not everyone is convinced that alginate will be effective in the human digestive system. “Its is a highly processed white powder with dubious nutritional value,” says Professor Mike Lean, professor of nutrition at Glasgow Royal Infirmary. “It may technically resemble dietary fibre, but that does not mean that alginate will have the same benefits of eating fibre-rich foods such as beans and whole meal bread.”

What other health benefits does seaweed have?

Seaweed, or sea vegetables, are rich in minerals. “For example, they contain between seven and 14 times as much calcium as milk, depending on the type of seaweed,” explains dietician Nigel Denby. Seaweed also contains essential fatty acids, including nucleic acids like RNA and DNA.

Can pregnant women eat seaweed?

Women in Asia eat seaweed when they are pregnant and seem to suffer no ill effects. “Seaweed contains folic acid and other vitamins of the B complex,” says Nigel Denby. This vitamin is known to protect the developing baby in the womb from certain neural cord defects.

Is seaweed fattening?

Although 20-40 per cent of seaweed is protein, only around 20 per cent of the plant is made up of carbohydrate. Seaweed contains no fat and around one third of the plant is minerals, including potassium, magnesium and iron.

Is there a down side?

Well yes if you like a type of seaweed called hijiki. Last year, the Food Standards Agency advised people not to eat this distinctive black shredded seaweed sold in Japanese and Chinese restaurants and supermarkets. Apparently, it contains high levels of inorganic arsenic, which can increase the risk of developing certain types of cancer.