Urine: The body's own health drink?

And last year, yachtsmen Mark Smith and Steven Freeman spent 11 days stranded in the South China Sea after their boat capsized and put their survival down to urine.

But apart from possibly helping to keep one alive in extreme circumstances, is drinking urine really good for your health?

Auto-urine therapy, or urotherapy as it is sometimes known, dates back to several ancient cultures and even, arguably, the Bible. Egyptian medical texts and Chinese and Indian documents mention the benefits of drinking one's urine, while the Aztecs used it to disinfect wounds.

Contrary to popular perception, urine is not a by-product of the body's waste disposal system but of blood filtration. Nutrient-filled blood passes through the liver, where toxins are removed and excreted as solid waste. The purified blood then goes through another filtering process via the kidneys, where components for which the body has no immediate use are collected in a sterile, watery solution. For that reason, it is highly sterile, consisting of 95 per cent water and five per cent nutrients, including vitamins, minerals, proteins, antibodies and other beneficial ingredients.

Advocates of auto-urine therapy believe that this combination can help cure everything from the common cold to cancer, boosting energy levels and sexual performance along the way. While the practice has always been popular in China, India and South-east Asia, a small but growing band of Western fans are also downing a daily dose. Books with titles such as The Golden Fountain all extol the virtues of urine.

One of the prime movers in the movement, Martha Christy (author of Your Own Perfect Medicine) says that the first toilet visit of the day is the most beneficial. She recommends a regime beginning with five drops of "fresh morning urine" under the tongue before gradually increasing the dosage to as much as a cupful, morning and night. Urine can also be used as eye and ear drops, for gargling with or in the bath.

Ms Christy, who claims that drinking urine cured her of a host of medical problems, says that doctors have deliberately not highlighted the benefits of auto-urine therapy because there are no profits in it for them.

But there is little firm proof for the claims made about the therapy and medical experts have remained unconvinced. Dr Michael Stroud, an expert in nutrition at Southampton University and who has been in many extreme situations during his record-breaking expeditions with explorer Sir Ranulph Fiennes, says that people who believe that their urine can cure them of Aids and improve their complexions are "daft as brushes".

Sceptics have even poured cold water on the theory that it can save lives on the high seas or frozen mountain tops. They say that the concentration of nutrients such as sodium will take more water to get rid of than is present in urine - meaning it will dehydrate you rather than helping to keep you hydrated.

Helen Andrews, of the British Dietetic Association, said: "There are no health benefits to drinking your own urine, and in fact I think it could be quite detrimental. Each time you put it back it will come out again even more concentrated and that is not good for health as it could damage the gut. If you are stranded, your body will try to conserve as much water as it can. Drinking your urine would be like drinking seawater."

Perhaps the last word should be left to that embracer of all things alternative, Jennifer Saunders' character Eddy in the sitcom Absolutely Fabulous. "It's urine therapy darling; it's not to be sniffed at."

* Urine is 95 per cent water, but it also contains small quantities of nutrients including calcium, folic acid, iron, magnesium and zinc.

* The actress Sarah Miles is an aficionado of drinking her own urine, while the author JD Salinger was also a fan.

* Self-urine therapy dates back 5,000 years to ancient India, where it was known as "shivambu shastra" and seen as a way of rejuvenating body and soul.

* Male porcupines use their urine to soften the female's quills before mating, while vultures urinate on their legs to cool themselves.

* Advocates claim it has antibacterial, antifungal, antiviral and anticancer properties.

* Research in the 1990s claimed that drinking urine could cure jet lag.

* It is highly sterile. The Aztecs used it to prevent wounds becoming infected.

* The practice is particularly popular in China, where millions of people drink a daily dose of their own urine.

* In Cameroon, people were banned from drinking their own urine in 2003 amid health concerns. They were warned that transgressors would be prosecuted.

* Some fans believe the Bible recommends urine therapy. A verse in Proverbs advises: "Drink waters from thy own cistern, flowing water from thy own well.
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