This page covers some of the medicinal uses of Scottish seaweeds, from our earliest records of remedies somewhere between medicine and folk magic, through to a number of the most recent biotechnology applications.

Early Medicine
The Victorians - 'Anti-Fat' and Tonic wine
Recent developments in 'The great Anti-Fat debate'
Other areas of current investigation

Early Medicine

‘Folk medicine’ in coastal Scotland has made extensive use of a variety of seaweed species. With advances in medicine today, the reasons behind the success of some these treatments are being elucidated, as we begin to understand more of the nutritional and biochemical properties of the marine algae. The following are some examples of uses of seaweed in early medicine:
 

An uncertain condition, known as 'falling of the uvula' in the Gaelic medical texts, was warded off with a charm made from a piece of red seaweed, taken from a pool at low tide.  The charm was given to the patient and the Holy Trinity was invoked. This condition may relate to either of two 'uvulas' found in the body: the one in the roof of the mouth (the soft palate) or the one in the bladder. The similarity in appearance between the uvulae and red seaweeds (both of them are scarlet and filmy in texture), combined with the use of an invocation, suggest that the plant's properties may have been identified by the ‘Doctrine of Signatures’, whereby the physical properties of a plant are used as indicators ofr its medicinal properties. This type of belief occurs throughout mediaeval European medicine, and is still found in traditional medicine systems across the world. [This is not one of the properties of seaweeds which is being investigated by medical researchers today !]

Preparations of seaweeds were used to 'draw' boils and suppurations. The seaweed was chopped and mixed with onion then laid on the boil, where it would begin to draw in the pus. It is likely that the water absorbing qualities of the seaweeds may be significant in this action.

The filmy texture of such species as Ulva lactuca, Monostroma grevillei, Enteromorpha intestinalis and the ubiquitous dulse (Palmaria palmata) allowed them to be used as cold compresses for nosebleeds, migraines, burns, sores and cuts.  As well as this, laying cold lamina ('leaf-blades') of these species on the abdomen after childbirth induced flushing of the afterbirth.

Seaweeds (Fucus canaliculatus and F. vesiculosus in particular) were thought to be effective in combating 'rheumatic in the knee'. The plants were boiled in water or heated on an iron griddle and then tied in place on the knee with a bandage.

The Victorians - ‘Anti-fat’ and Tonic wine

In 1880, the seminal work on medical botany - ‘Medicinal Plants’ by Bentley and Trimen - has this to say on the use of seaweeds as a slimming agent:

“ The chief interest  [in Fucus vesiculosus] relates ... to its reputed value as a remedy for obesity. From experiments of Dr. Godefroy on his own person....[who used] doses of 4½ grains [approx. 0.3g] taken thrice daily at the commencement of each meal, he lost about 5¼ lbs in weight; and that beyond its effect on the urine, which was rendered more abundant, more coloured, and more odorous than usual, he observed no physiological effect. Further trials are necessary before any definite conclusions can be arrived at on its action and its value as a remedy in obesity. It would appear that it is the essential constituent in the nostrum now so extensively advertised under the name of Anti-Fat.”

It is of interest to note that a recipe using similar ingredients, in the form of a Victorian ‘tonic wine’ was used “as a remedy in diseases of the hip and other bones and joints of children”:

• 16¾ gallons of distilled water
• 98 lbs of grapes
• 84lbs of white sugar
• 16¾ oz bitartrate of potash (acid of potassium tartrate)
• 23lbs 9 oz Fucus vesiculosus, dried

It is advised that people ‘DO NOT TRY THIS AT HOME’ - Victorian medical practices are notoriously spurious and are usually best left in the past !  

Recent developments in ‘the great Anti-fat debate’

In a correspondence between Prof. W. Wright Smith (of the Royal Botanic Garden Edinburgh) and J. Rutherford Hill (of The Pharmaceutical Society of Great Britain), from 1924, there is a further mention of the anti fat properties of seaweed:

“An extract of Fucus under the name of Fucusin has a has a reputation as a remedy for obesity. Fucusin is sometimes called the active principle but what its precise chemical constitution is I do not know. It is alleged that it stimulates the thyroid gland and in this way acts as what they call an antifat.”

Note that what was a trade name (Anti Fat) in 1880, became a general colloquial term by the 1920s.

The excerpts given above illustrate the attitude of much of the scientific community towards this property of Fucus throughout the past hundred and twenty years, i.e. that more studies must be done on the action of the extracts. In 1999, a new pill was put on the British alternative health market claiming to use this property of Fucus vesiculosus in combating ‘cellulite’. It was greeted with much the same scepticism in the medical and scientific professions as has been shown in the past. However, the product was much hyped by the media and welcomed by the general public- it should be fascinating to see what happens.........  

Other areas of current investigation

There are a considerable number of properties of seaweed species being investigated by modern researchers. As the race to find drugs to combat cancer, AIDS and drug resistant viral and bacterial strains heats up, research into plant-derived drugs is gaining pace and the seaweeds may provide some invaluable agents in the fight.

Squalene (C₃₀H₅₀), a product derived from Fucus vesiculosus, has been found (by Trunova and Grintal - 1977) to have anti-biotic action against Salmonella and other enteric bacteria. F. serratus and Laminaria digitata extracts have been found to have similar effects, possibly due to the presence of the same compound.  Other seaweed species have been shown to contain active anti-microbial and anti-helminth (worm) properties.

These same properties are useful in agriculture, as some studies have shown that plants grown on fertilisers containing seaweed extracts may be more disease resistant.

A recent study on Enteromorpha prolifera (a species found in Scottish waters) has shown the presence of a chemical compound called pheophytin in the seaweed's tissues. The research (conducted in Japan) showed that pheophytin has a significant anti-inflammatory action.

The fucoidins, a family of compounds derived from members of the genera Fucus, Ascophyllum, Laminaria and the species Pelvetia canaliculata, are thought to act as blood anti-coagulants, although they are currently only extracted on a small scale.
Another compound, Laminarin, may be put to a similar use, and the fucans, a group of chemicals first isolated from members of the Fucaceae, are a further possibility for use as anti-inflammatory agents.

These are just a fraction of the uses of seaweed in medicine, and there is little doubt that investigation will continue. Research is being conducted by many institutions and private companies and we are likely to see more and more applications of seaweed-derived drugs in the pharmacy and on the shelves of alternative health shops.

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