by PAT HAGAN, Daily Mail

Last updated at 14:36 04 October 2005

The juice of the marshmallow plant could be the latest treatment for dry coughs and sore throats.

The shrub, which gave its name to the popular soft sweet, has been valued for hundreds of years for its healing properties.

Now the active chemicals in the plant's leaves and roots have been extracted and put into capsules that can be taken at the first sign of problems.

It's thought the plant works on coughs by encouraging the loosening of mucus and catarrh from the lungs. In the throat, it works by coating tissue and protecting it against any infection.

'More effective than cough mixtures'

One clinical trial in the early Nineties showed it was more effective than two out of three commonly used cough mixtures.

For centuries, physicians have extracted the juice from marshmallow plants, which grow in damp, marshy conditions across Europe and western Asia.

The shrub's key ingredient is a substance called mucilage, a viscous, gel-like liquid that soothes and protects inflamed mucus membranes and other tissues.

Mucilage is made up of proteins and sugar, and serves to stem the loss of water from the plant so that it can germinate and store food.

In the 19th century, doctors treating children with sore throats cooked mucilage with egg whites and sugar and whipped the mixture into a foamy meringue that eased their symptoms.

These soft treats gave rise to the marshmallows still enjoyed by thousands of people today, although use of the plant extract was stopped years ago.

Cooled marshmallow root tea is a popular remedy for inflamed skin or mouth irritations. And the shrub has been used to treat heartburn, irritable bowel syndrome and constipation.

Remedy clears up air hostesses cough

Air hostess Emma Cook, from Worthing in Sussex, found the marshmallow remedy on a work trip to New York.

After seven years in the airline business, the 29-year-old mother-of-two has become used to suffering persistent coughs and sore throats brought on by the dry atmosphere of an aircraft cabin.

"I get coughs and sore throats all the time - at least once every other month," she says.

"And every now and then, it would turn into something really nasty.

"I have been searching for ages for something that will make it feel better. The air on planes is so dry, and because I do longhaul flights to Hong Kong, the Caribbean or Australia, I can be in the air for 12 to 15 hours.

"Working in first class, I have to look and feel good the whole time. I can't be seen to be coughing and spluttering all over the passengers."

During one trip to New York, Emma felt so ill she headed straight for her hotel as soon as she landed. On the way, she stopped at a health store and was told to try marshmallow capsules.

She took two capsules three times a day, and within 48 hours was on the road to recovery.

"All through the flight home, I felt so much better," she says. "Now I swear by it and keep telling my colleagues who are affected to try it."

Two capsules taken three times a day are normally sufficient to ward off most throat and cough problems. The capsules can also be opened up and the liquid added to hot water to make a marshmallow tea.

Juice can interfere with diabetes treatment

Although marshmallow juice is harmless, some studies suggest it can slow the rate at which the body absorbs other drugs. Animal studies suggest it can lower blood sugar levels, which could interfere with treatments for diabetes.

Ed Berger, lecturer at the College of Naturopathic Medicine in West Sussex, says mucilage is most commonly used to ease stomach irritation.

"It sticks to the mucus membranes of the stomach and treats any inflammation," he says.

"But it's very good for dry coughs, especially the kind you'd get from being in an aircraft.

"Marshmallow encourages the loosening of mucus and catarrh from the lungs.

"In the throat, it works by coating tissue and protecting it against any infection. The reason why cough medicines tend to be thick and sticky is so that they linger longer in the throat.

"The longer it takes to go down, the greater the effect on the lungs. It's basically the same with marshmallow."

Berger recommends swallowing capsules whole for stomach problems, but cracking them open and drinking the liquid on its own or added to tea for sore throats and coughs.

But he stressed serious chest infections should still be treated by a GP, perhaps with marshmallow as a support.

Marshmallow capsules are available from Holland & Barrett stores, £9.99 for 100.