The natural alternative

Professor Edzard Ernst, Professor of Complimentary Medicine, University of Exeter, also urges caution when taking herbal supplements. 'The problem with these supplements is that anything that has the potential to do good also has the potential to harm.'

In certain cases, supplements can be invaluable. Current advice from the Department of Health (DoH) is that women planning a pregnancy should take 400mg of folic acid every day, up until the 12th week of pregnancy, to help prevent neural tube defects, or spina bifida, in an unborn baby. To get the equivalent from your diet, you would have to eat six servings of broccoli every day.

The DoH says that dietary supplements should only be taken after medical advice has been sought. This is because of the risk of overdosing on supplements that are widely available, taking the wrong ones or even the wrong combination of them, as the side effects can be devastating.

For example, St. John's Wort can interfere with the effectiveness of anti-depressants and the contraceptive pill; Evening Primrose can provoke epileptic attacks in susceptible patients; and Echinacea may contribute to a range of allergic reactions. Other supplements containing iron, manganese, silver and gold (which can be found in certain Chinese preparations) can lead to chronic renal failure (a malfunctioning of the kidneys.)

It is also not advisable to use herbal remedies if you are undergoing surgery, since they may cause unforeseen complications during the operation. (Ginkgo biloba, which has been linked to excess bleeding, is an example of this.)

Professor Ernst adds 'there is a certain section of the community that are more vulnerable to side effects of herbal and vitamin supplements, such as pregnant women, and there is an awful lot of nonsense being handed out to them by health food shops and herbalists.'