At present, only one in four adults in Britain eats five a day and among teenagers, it is just one in ten. Pic: Debbie Yazbek

Gulping pints of maple syrup mixed with chilli peppers, having enemas, being sucked by leeches or getting wrapped in cling film until your body overheats...

All of these so called “detoxes” are undertaken every year by millions of women in the pursuit of good health and beauty.

The treatments promise to cure a range of vague ailments, such as tiredness, headaches, bloating, back pain and skin problems, by cleansing your body’s blood and organs of a welter of accumulated “toxic” chemicals.

Now a leading British expert has issued a festive warning for anyone hoping to purge themselves of so-called toxins after an indulgent Christmas break: detoxing simply does not work, says David Bender, a professor of nutritional biochemistry at University College London. At best, it is pointless - and at worst, highly dangerous.

The professor also points out, in this month’s edition of the British Society of Biology’s journal, The Biologist, that we have an excellent system for getting rid of potentially harmful substances - it is called the human body.

However, Professor Bender’s wise warning is in danger of being drowned by the clamour of commercial propaganda.

Over the past decade, detoxing has grown from an obscure alternative quirk into a multi-million-pound industry promoted by celebrities such Beyonce Knowles, Angelina Jolie and Demi Moore.

Even Prince Charles has joined in, by marketing a Duchy Originals herbal “detox tincture” featuring globe artichoke and dandelion.

But there is no doubt that detoxing can be dangerous as well as expensively pointless.

Last August, one woman died at a detox spa and another was rushed to hospital in Canada after they had spent hours wrapped in mud and plastic intended to draw “poisons” from their skin.

Medical officials in Quebec said their tests showed that the dead woman, Chantal Lavigne, 35, had suffered heat stroke and asphyxiation.

In terms of human biology, the idea of detoxing is absurd. But the health and beauty industry is notoriously reluctant to let science get in the way of a money-spinner.

The basic fallacy, says Professor Bender, is that “large amounts of toxic waste accumulate in our bodies and must be eliminated by some kind of dietary regime”.

In fact, “the human body processes and removes toxins very efficiently”.

This waste disposal system has evolved over millions of years and works throughout the day and night to remove unwanted substances.

The gut prevents bacteria and many toxins from entering the body. And our organs are constantly creating highly complex chemical reactions throughout our bodies that turn food and drink into hormones, energy and even medicines, says Professor Bender.

Our metabolisms are also highly efficient at dissolving unwanted substances harmlessly into our urine and bile - a process that biologists call “conjugation” - so we can void them when we visit the bathroom. Thus the idea of “bad” chemicals simply sitting around in our bodies waiting to be removed by expensive detox regimen is nonsensical, says Professor Bender.

The scientific community stands fully behind the professor’s conclusions. The campaigning group Sense About Science has investigated 15 detox products, ranging from foot patches to “detox” hair straighteners, and asked the manufacturers for evidence to justify their claims.

“No one we contacted was able to provide any evidence for their claims or to give a comprehensive definition of what they meant by detox,” says Sense About Science.

There is heavyweight support from other quarters, too. Professor Edzard Ernst, the recently retired professor of complementary medicine at the University of Exeter, has argued that if detoxing really did work, it would be simple to prove its effectiveness:

“All you would need to do is to take a few blood samples from volunteers and test whether this or that toxin is eliminated from the body faster than normal,” he says.

“But there are no studies that demonstrate this effectiveness. The reason is simple: these products have no real effects.”

Nevertheless, the detox industry continues to go from strength to strength. According to market analysts Mintel, detox products were second only to cold and flu remedies for the number of healthcare product launches last year.

The detox industry isn’t adverse to employing a dirty trick or too, either.

Professor Bender explains how the water in the footwell of “detoxing” foot spas doesn’t turn brown because they have drawn nasty coloured toxins out of the body. All you are witnessing is the salts in the footbath reacting with the electrodes in the machine.

If you don’t put your feet in the water, it will still turn brown after 30 minutes.

Such foot-spa kidology is not simply harmless, says Professor Bender.

“Far from removing toxins in the body, the process of electrolysing sodium chloride creates substances that are actively hazardous to human health - explosive hydrogen gas and poisonous chlorine gas.”

And as for the many detox diet regimes that are promoted by bestselling books - yes, you may find yourself visiting the toilet a good deal more. But that is not because you are purging yourself of stubborn waste chemicals. It is the natural result of gorging on high-fibre fruit and drinking lots of liquids, the typical fare of detox diets, which make everything in your bowel far looser.

At the other end of the biological scale are the “spiritual benefits” - most often experienced in the shape of light-headedness. “To the mystic, this might signal divine revelation. And to the proponent of detox, it signals the release of toxins ready to be eliminated,” says Professor Bender.

But to the scientist, it simply reflects the normal response to a drop in blood sugar that these regimes can cause. And light-headedness may be the least of your problems.

The experts at Sense About Science warn that many detox tonics can contain stomach irritants - including herbs such as St John’s Wort - to make you visit the bathroom more often.

These can interfere with the way that medicines can work. In particular, they may lower the effectiveness of the contraceptive Pill. Thus, women embarking on weight-loss detoxing regimes may discover another unwanted side-effect: pregnancy.

Far from ridding your body of unwanted elements, you may get a lot more than you bargained for. - Daily Mail