The pros and cons of fasting for health purposes

Feb 27, 2012, 3:06 GMT

Berlin - Some of us eat too much, too quickly and too much, while others do not have a balanced diet, drink too little or take in too much fat, salt or sugar. Virtually all of us have a few problems in our eating habits.

Lent is often the time of year, with spring looming, for thinking about eating habits and lifestyle - and for some of us to think of changing ingrained habits through a prolonged fast.

A standard-reducing diet normally involves the subject abstaining from solid food for a fixed period, drinking only mineral water, herbal teas, juices and vegetable broth. There is a wide range of such fasts.

Doing without solids during a fast is usually accompanied by abstinence from alcohol, coffee and tobacco. 'The body is given a temporary respite in this way,' says Andreas Buchinger, a member of a German medical association promoting fasting for health reasons.

The body is able to expel waste and rejuvenate, he says. A wide range of support measures can be undertaken to promote the expulsion of toxins and enhance the purifying effects, among them using oils to promote expulsion through the skin and a liver compress to stimulate this purifying organ.

'Clearing out the bowels is probably the most important part. Purgative salts are used at the start of the fast, and enemas repeated every two days at least, to dissolve harmful deposits in the body,' says Christa Kling, an expert in fasting.

However, the association of German internists recently warned about using enemas for 'detoxing,' pointing to a new study conducted in the United States which found there was no clear evidence that the various enema systems on the market for wellness purposes were effective and that they could have harmful side-effects, the mildest of which were nausea, vomiting and diarrhoea.

The advocates of 'the big clean-out,' however, point to numerous positive effects, ranging from boosting the immune system and self-healing capacity to the prevention of illnesses like type 2 diabetes.

Kling says that fasting also helps to lose weight, as weight loss during a fast is around 500 grams a day and fasting often encourages a long-term change in behaviour.

'A precondition for this is to avoid falling back into the old habits,' dietician Silke Restemeyer says. 'Anyone wanting to lose weight in the long term has to change the way they eat and must also take proper exercise.'

In her view, a controlled fast only makes sense if the person undergoing it learns something about healthy eating and lifestyle.

Restemeyer is strongly against intensive fasting. 'If you drink only water for days at a time, you lose protein, and the uric acid level in the blood rises. People with raised purine levels should not fast as it increases the likelihood of an attack of gout.'

Other undesirable side-effects are disrupted cardiac rhythm resulting from a lack of energy or kidney problems caused by loss of electrolytes. 'Even if the subject is in robust health, the period of fasting should not exceed five days,' Restemeyer says.

She strongly advises people going on a fast for the first time to seek medical advice, and says anyone with health problems should avoid fasting altogether.

Devotees of the practice insist that fasting can alleviate or even cure a wide range of ailments. Buchinger says it can have long-lasting beneficial effects on patients with high blood pressure and work against insulin resistance and thus alleviate diabetes.

But he advises that those with health problems fast only under medical supervision to avoid risks of complications and because certain conditions might require vitamin or mineral supplements. They should also undergo medical checks before starting to fast and be carefully monitored over the fast's duration.

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