Seaweed is a sustainable and nutritious food that is increasingly finding its way into recipes and health products. According to a recent Mintel report, the use of seaweed flavours in new food and drink products across Europe increased by 147% between 2011 and 2015.

Globally, the highest number of launches were, not surprisingly, from the Asia Pacific region, but Europe launched 7% of new seaweed-flavoured foods world-wide, almost twice the percentage for North or Latin America.

Seaweed is a bit of an acquired taste. For many people, nori-wrapped sushi is just about fine, but wakame or kombu flavoured crisps are a culinary step too far. If you can bring yourself to eat more seaweed, however, it offers a wealth of health benefits.

The health benefits of seaweed

Marine algae and weeds are a rich source of vitamins and minerals, especially potassium and iodine. A study involving French males showed that seaweed has a high bioavailability, with almost all (90% to 100%) of the iodine present in seaweed (Gracilaria and Laminaria species) absorbed for use in the body. Another study showed that even low intakes of seaweed could improve the iodine status of iodine-deficient women within just two weeks of daily consumption.

The protein-content of Dulse varies from 9% to 25% depending on the season and manufacturers are now using seaweed protein to improve the nutritional value of a variety of processed foods, including sausages, cheese and pizza bases.

Soluble fibres found in seaweed (alginates) help to reduce hunger and appetite, and slow the absorption of dietary fat, cholesterol and sugars. One study showed that the consumption of seaweed alginate-enriched bread at breakfast led to a significant reduction (16.4%) in energy intake at another meal, four hours later. As well as aiding weight loss, alginates can also improve glucose and cholesterol balance.

Some species of seaweed (eg Palmaria palmata) also contain peptides that have a blood pressure lowering effect by blocking the action of angiotensin converting enzyme (ACE). This action is similar to that of ACE-inhibitor drugs. Researchers are now also adding these peptides to bread to see if they can develop a functional food for the one in three adults with hypertension.

Seaweed is a source of unique antioxidants

Recent research shows that phlorotannins – a type of polyphenol antioxidant only found in brown seaweed – are metabolised by bacteria in the large intestines, from where they are absorbed into the circulation to have an anti-inflammatory action.

When 24 healthy volunteers took capsules containing polyphenols extracted from a Scottish brown seaweed, known as knotted or egg wrack (Ascophyllum nodosum), their blood and urine was analysed over the following 24 hours. As their circulating level of seaweed-derived antioxidants increased, so did those of a powerful anti-inflammatory cytokine (cell signalling molecule) called interleukin-8. More research is now underway to evaluate the medicinal value of this and other strains of seaweed.

Check labels for salt

Some seaweed products are quite salty, although natural sea salt also contains potassium which flushes excess sodium from the body via the kidneys to help regulate blood pressure. According to Mintel, 36% of UK consumers who use herbs, spices or seasonings agree that dried, ground seaweed could be a good alternative for flavouring meals.

Where labels are provided check that they aren’t providing excessive amounts of salt. A good rule of thumb is that, per 100g of ready-to-eat food (or per serving if a serving is less than 100g):
0.5g sodium (1.25g salt/sodium chloride) or more is a lot of sodium/salt
0.1g sodium (0.25g salt/sodium chloride) or less is a little sodium/salt

Seaweed In The Kitchen

If you fancy cooking your own seaweed-flavoured dishes, I recommend Seaweed In The Kitchen by Fiona Bird. The book includes a wealth of information on edible seaweeds and how to harvest them, plus recipes such as Mermaid Biscuits (shown on the cover), Dulse Soup, Marsh Samphire with Sea Lettuce Custard, Sea Astor Pesto, Sea Spaghetti and Scallop Omelette, La-Sea-Agne and Chocolate Laver Bites to name but a few. Seaweed In the Kitchen is available from Amazon.co.uk and Amazon.com.

Image credits: leechentou/pixabay; meditations/pixabay; book cover/Prospect Books