Many detox plans promise dramatic results, but do they work? Peta Bee separates the truth from the fiction

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It’s hard not to be lured by the promises of a detox plan, particularly one that is lauded by a dewy and super-slender celebrity. When beach holidays beckon and the unveiling of our puffy, pasty flesh becomes a looming reality, our appetite for them peaks. Certainly I’ve been tempted myself. Who could resist the lure of the Master Cleanse diet that allegedly helped Beyoncé to shed 20 pounds in ten days, even though it entails drinking up to 12 glasses a day of a maple syrup, lemon juice, water and cayenne pepper. Or the past celebrity favourites, the BluePrint juice plan at £45 for the 6-bottle a day cleanse and the 21-day Clean detox programme created by Gwyneth Paltrow's diet guru, Dr Alejandro Junger, which prescribes 'liquid meals' for breakfast and dinner and a light lunch along with supplements that come in a kit for around £230. If it’s good enough for the detox queen herself, then surely it will undo the toxic overload we inflict on ourselves every day?

Nothing, of course, is ever that straightforward. The detox theory is that too much of the wrong sorts of food, a polluted environment and unhealthy habits such as drinking and smoking contribute to a build-up of poisonous substances in the body, which eventually buckles under the strain. The signs of this toxic strain include headaches, body aches, chronic fatigue, allergies, chronic digestive problems, muscle aches, autism, schizophrenia, even drug reactions. Among the substances commonly considered poisonous include caffeine, alcohol, drugs, cigarette smoke, exhaust fumes, high protein diets, organophosphate fertilisers, paint fumes, saturated fat, steroid hormones - the list goes on. But by temporarily sticking only to foods that are considered pure and unadulterated, and by avoiding anything that might strain the internal organs, you will purge yourself of poisons, reverse the damage wreaked on your health and lose a few pounds in the process, claim detox advocates.

Cleanses vary in length and precise prescription, but their basic content is pretty similar. Typically, they prescribe drinking two litres or more of fluid a day along with a variety of dandelion coffee and herb teas, half a pint of fruit or vegetable juice — green vegetables, carrot or apple are favourites because of their “digestive-boosting” properties — and some raw fruit and vegetables considered beneficial for detoxification purposes, such as fresh apricots, citrus fruits and mango or peppers, watercress and bean sprouts. Without exception, meat, fish, dairy and processed foods are definite detox no-nos. Alcohol and caffeine are also out. As is salt. And sugar. Some take the list of banned substances to greater extremes. In plans he’s devised with Paltrow, Junger asks for gluten, shellfish, all soy products, nightshades (potatoes, tomatoes, peppers and aubergine), condiments and anything remotely fizzy to be eliminated too.

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The popular perception is that dietary cleanse will probably do some good, and it can’t do us any harm. What’s concerning is that there's very little scientific evidence to back up the claims made for detox diets. Many experts believe that detoxing is at best a waste of time, effort and money, and at worst it can be dangerous.

“There is this fixation with the notion that we can detoxify the body through what we eat and drink, but the whole idea has no scientific basis and anything that promises to help you to detox is a rip-off,” says Catherine Collins, dietician at St George’s Hospital in London. “Sticking to a detox regimen for a day or two won’t be harmful for most people, although neither will it have any affect on their long-term health.”

Scrutinise the concept of detoxing and you begin to realise the science behind it is decidedly iffy. A review of popular detox plans at the University of Southern California a few years ago found none lived up to the claims that it would purge environmental toxins over and above what the body itself was capable of doing anyway. Chemists at the school of pharmacy said suggesting the digestive system needs a break is ludicrous. When detox plans promote longer periods of severe dietary restriction, which many do, they can cause serious problems. In the years I’ve spent writing about the trend, I’ve heard alarming stories about the side potential effects. One doctor told me about a 23-year-old man who was rushed to a London hospital after slipping into a coma following attempts to adhere to a strict 2-week detox regime which consisted almost exclusively of fruit, vegetables, fruit juice and water. His serum sodium levels had plummeted to a dangerous level, causing his brain to swell. His was an extreme case but dieticians report seeing people with side effects ranging from bowel problems to chronic dehydration as a result of their over-zealous attempts to detox.

Even the idea that some foods are toxic and others are not is inaccurate. Ironically, broccoli and cabbage, onions and other vegetables, even organic, are high in naturally-occurring toxins, while meat and fish are relatively low. Brown rice - a detox favourite - contains phytic acid that inhibits the absorption of some vitamins and minerals, and legumes are poisonous unless properly cooked. The list goes on. “It is true that there is a vast array of substances in lots of foods which would be toxic if they were allowed to accumulate in the body,” says dietitican Louise Sutton of Leeds Metropolitan University. “But we are equipped with a digestive system and liver that enables us to break down and excrete them.”

Despite the negative stories, I remain a passing fan of the concept. If the physiology behind it is questionable, the psychology is not. There is a sense of calm that prevails whenever I try it, that perhaps can be linked to the centuries-old fasts and cleanses practiced for religious reasons with the idea that, at certain times, it is beneficial to concentrate more on keeping faith and less on the concerns of everyday life such as eating and drinking. Even the most skeptical experts concede that 24-48 hours of cutting out processed foods in favour of juices, vegetables and wholesome fare won’t be harmful. Keep it short seems to be the overriding rule. Very often, says Dr Schenker, a brief cleanse gives people the psychological spur they need to change their eating habits for the better. If you have tried a detox plan then the likelihood is that you will agree. I’ve emerged feeling virtuous, internally scrubbed and lighter. What better boost for braving it in a bikini?