Article: Thelma Agnew from SHAPE
Image: Fairlady

In Detox Yourself, Jane Scrivner explains the process as spring-cleaning yourself". The Scrivner programme requires more than dietary changes – dry-skin brushing, self-massage and visualising positive images are also involved. But, as with most detoxes, the core message is to cut out so-called toxic foods and substances (such as alcohol and, er, bananas) and replace them with so-called detoxifying foods (brown rice is often key).

The aim is to give your body a break from handling its usual load, allowing it to work on what Scrivner calls the "build-up of excess waste and toxins accumulated over the years". Some detox programmes are little more than fad diets or fasts – on one, for instance, you eat nothing but apples for two days.

Q. What is a toxin, anyway?
A. The scientific definition is that a toxin is a poison of natural origin that causes structural damage or disturbs the workings of your body. It's a complex area – just about anything in a high enough dose can be poisonous – but, say the specialists, foods are not generally eaten in sufficient quantities to qualify as toxic.

According to the detox school of thought, toxins are foods and pollutants that are difficult to digest or eliminate, and are blamed for creating an imbalance in your body. Many detox programmes hark back to a time when diets and lifestyles were simpler and purer.

As Scrivner says, "the detox diet is a way of eating healthily like we used to – when there was no grabbing take-away meals, and drinking coffee at every meeting." Nutrition scientist Sara Stanner argues that in the literal sense, there's no such thing as a detox diet. "People worry about processed foods because of pesticides," she says, "but levels are regulated, so they shouldn't cause a problem. We can't say, 'If you cut out these foods your liver will function much better."

On the other hand, there's no harm in eating nothing but whole foods and cutting out caffeine and sugary foods for a few days. (Be aware that if you're used to drinking lots of coffee or cola, stopping suddenly can leave you feeling temporarily worse.) Eating more fruit and vegetables will boost your vitamin and mineral intake, while drinking extra water will bring benefits such as increased energy. Stanner points out that it's always good to eat a wider variety of foods.

Q. Is it true that exercise produces toxins?
A. There's a theory that high-intensity exercise can have a toxic effect on the body by increasing the production of free radicals and lactic acid. Free-radical production does appear to increase when your body consumes more oxygen during exercise. But all the evidence suggests that a well-nourished person's antioxidant defence system is more than able to cope.

Lactic acid – a byproduct of high-intensity exercise – is also innocent. At very high concentrations, lactic acid interferes with the contraction of your muscles, which in the short term will cause pain and stop you from exercising. But lactic acid is used as an energy source by cells in the body, and is also readily converted into glucose.

Contrary to popular opinion, it's not responsible for delayed onset of muscle soreness, which is usually caused by doing an exceptionally vigorous workout or more exercise than you're used to. This results in microscopic damage in the muscle cells, which in turn leads to an inflammatory process which causes swelling and pain in the muscles.

Q. Does detoxing work?
A. There's a mountain of anecdotal evidence in its favour, but scientific proof is rare. Like most orthodox doctors, Professor Ian Gilmore of the Royal College Of Physicians, who is a gastroenterologist and liver specialist, is sceptical. "I think, on the whole, it's fairly dubious," he says.

"The only detoxification I recognise is the one undertaken by alcoholics when they withdraw from alcohol." Cutting out alcohol is a less controversial requirement of detoxing but, says Gilmore, "There's no evidence that people drinking in moderation (that's a maximum of one or two drinks a day) gain any benefits from cutting out alcohol."

It could be argued that good detox regimes are simply healthy diets and lifestyles repackaged to appeal to people who often lose the struggle to be good every day, or who want to kick-start themselves into better eating habits. The detox glow has nothing to do with freedom from toxins – it's how people feel when they look after themselves.

Know a good detox? Share your detox stories below.