A letter in the T&A last week (Herbal remedies can be very effective, March 1) took me to task about a recent article in which I doubted the effectiveness of alternative health therapies.

I'm sorry Mr Bailey is so angry, but I do not withdraw my article. My position is clear: people have forgotten the huge steps forward in health in the 20th century that were directly the result of evidence-based medicine. By that I mean medicines that have been developed through knowledge of biochemistry, physiology, pharmacology, microbiology, pathology, genetics and much, much more.

That is why we have eradicated all the childhood illnesses that killed tens of thousands of British children a year. That is why we now save 80 per cent of our leukaemic children, and don't have to remove stomachs for ulcers any more, and can cure many cancers that only a generation ago were fatal.

I could go on and on. The proof is in the fact that a baby from a working-class family born in 1900 could expect to live only to 40, and that one born now can expect to live until 90.

My criticism of the alternative or complementary therapists is that their treatments are not based on knowledge of the human organism. The acupuncture 'meridians' do not exist in reality. Homoeopathy is based on the two principles set out empirically by Dr Hahnemann in the 1750s, and hasn't shifted in any real detail since then. And although he quotes trials that prove they work there are far more that show they are no better than placebo or a good physician effect.

The fact is that the world had all these alternative and complementary techniques for hundreds and even thousands of years, but they did not cure the diseases that we can now cure because of scientific advances in the last 40 years.

This is why I'm so concerned that so many women's magazines are now pushing forward such treatments, while at the same time criticising modern medicine. They have forgotten what the struggle to live healthily was like just a short time ago, when all we had were these non-scientific alternative systems.

Of course it is comforting to have a massage, or to have acupuncture or homoeopathy or herbal remedies from practitioners who are good at communication. We have known about placebo and physician effects (how people feel better when they are given good attention) for centuries. They have their place.

But we should be aware that they are not a replacement of modern medicines when people are ill. Would you go for acupuncture or a herbal medicine if you had a heart attack? Or a relative was having a stroke? Those are the key questions.

As for St John's wort, I have been studying its effects for some years, since a pharmaceutical company asked me, as an independent specialist in pharmaceutical medicine, to look into it. So I am qualified to comment. It does have powerful effects, because it contains several active ingredients that change the levels of brain neurotransmitters - the substances that alter moods. The problem is that different preparations of St John's wort have different strengths and perhaps even different active substances in them, so that the effect is not completely controllable.

Just as important, people who add St John's wort to their other medicines, like warfarin after a heart attack, or other drugs that control their heart rhythm, may suddenly find that their medicines either do not work or work too well. That is because the active ingredients in St John's wort alter the way the body deals with them.

This can be dangerous - which is why the Irish government, for example, is making it a prescription-only drug.

The whole point of my article was to fight back on behalf of modern medicine against people who want to turn back the clock to the middle ages. If you wish to be comforted by a little massage, and by the close attention given by alternative and complementary practitioners, then that is fine. I'm not against them. You will surely feel a lot better. And you can go back, time and again to have this comfort and reassurance.

But don't be deceived that it will cure disease. For that you need modern medical methods - practised by doctors who follow the discipline of evidence-based medicine."

Converted for the new archive on 30 June 2000. Some images and formatting may have been lost in the conversion.