Wort warning

Ben Goldacre
Thursday May 20, 2004
The Guardian

Talk about bad science here

· People often ask why I get so grumpy about the lack of intellectual rigour in alternative medicine. “What’s so bad,” they say, “about people believing whatever they want, if it makes them feel better?” What’s so bad is that sometimes, when people mix and match ideas, and believe that “natural” means “safe”, they can concoct some pretty dangerous suggestions.

Over to Richard Brook, chief executive of mental health charity Mind. “Prozac or cognitive behavioural therapy?” the Independent asked him last week. “CBT every time,” he replied, and fair enough. “I’m a strong supporter of non-medicated approaches, which also include exercise, improving social contacts, diet” he said. Excellent advice so far. “And possibly homeopathic remedies such as St John’s Wort.”

Now, homeopathic remedies are pretty close to pure water, and that’s not going to do you any good or any harm. But St John’s Wort contains a drug that is very similar to Prozac, which can interact dangerously with many antidepressants and numerous other medications. And unfortunately, as they say, not a lot of people know that. Researchers at King’s College London questioned 929 people, visiting four pharmacies in London, and found that when they asked people which medicines they were taking, 41% did not mention herbal remedies, because they did not think of them as medicines. Seven per cent were taking potentially dangerous combinations of herbal remedies and prescription medicines, and the most common was taking St John’s Wort at the same time as SSRIs, the class of antidepressants that includes Prozac. What’s more, taking St John’s Wort with the oral contraceptive pill can cause side effects and stop the pill working. Even pharmacists can believe the hype. In 21 visits to buy St John’s Wort, five Which? researchers were given unsatisfactory advice, twice they didn’t need to see a pharmacist, and one pharmacist said it was “fine to take with the pill”.

· About a quarter of prescription drugs are derived from plant sources and just because something comes from a plant doesn’t mean it’s safe. Aspirin comes from willow bark, but it will still make your haemorrhoids bleed. Diamorphine was made from opium poppy extract, in the same lab as aspirin, by the same bloke, two weeks later, using the same process (acetylation), 107 years ago this summer, since you ask. Diamorphine is also known as heroin, and although it’s undoubtedly effective, it has a few side effects that might worry you.

This slightly odd letter was printed the following week.