15 January 2007
Black Cohosh? Oh My Gosh!
by Serena Mackesy
Derren Brown's adorable new book, Tricks of the Mind, which made my Christmas a good deal more fun than I'd been expecting, tells a delightful story illustrating the difference between the scientific brain and that of the believer. Once upon a time, a group of scientists set out to investigate that fundamental of chiropractic diagnosis, kinesiology. Kinesiology is based on the belief that contact with allergens/substances to which the body is sensitive will produce dramatic weakening in the body. Apply a drop of an allergen while pressing down on someone's arm and the subject will suddenly be unable to resist the pressure.
OK, said the scientists, let's test this. Such a simple diagnostic test, if reliable, would, after all, save everyone a lot of time and money if adopted into health systems worldwide. So, with the full cooperation of a group of chiropractors, they devised a set of double-blind trials. First, they tested reactions to the "good" sugar fructose and the "bad" sugar, glucose. Almost all the test subjects reacted exactly as the chiropractors, who were conducting the tests, had predicted. After lunch they did it again, only this time it was a double-blind trial, in which neither the scientists nor chiropractors knew what was in the test-tubes.
The results? Surprise, surprise, there was no difference between the subjects' reactions to glucose or fructose. When the results were read out, the head chiropractor turned to the psychologist Ray Hyman and said "you see? That's why we don't do double-blind testing any more. It never works!" And he wasn't kidding. Belief systems, you see, are so powerful that, even when faced with insurmountable evidence proving them ill-founded, the believer will simply edit out the inconvenient truths and continue to believe.
So, what are you supposed to believe when it comes to alternative medicine? Well, a popular saying among the skeptics goes thus: if an alternative medicine is exhaustively tested and found to do what it claims to do, then it stops being "alternative medicine" and becomes just "medicine". Scientists really aren't that interested in denying the world medicines that work, after all. The vast majority of them, even if they are being paid by Pfizer, are still interested in improving both our health and medicine's body of knowledge. So, the best thing to do is accept that, if they've tested it and tested it and never come up with any proof beyond the percentile likelihood of change associated with the placebo effect that it works, then it probably doesn't.
The latest herbal medicine to be subjected to double-blind trial (where nobody apart from the computer knows who's getting what) is black cohosh, one of the most popular alternative remedies for menopausal symptoms among those who, perfectly reasonably, feel nervous about the effects of synthetic hormone therapies. Over a 12-month period, 351 perimenopausal, menopausal and post-menopausal women aged 45-55 were given regular doses of one of the following: black cohosh; a multibotanical supplement (including black cohosh, alfalfa, boron, chaste tree, dong quai, false unicorn, licorice, oats, pomegranate and Siberian ginseng); a multibotanical supplement plus diet counseling to increase consumption of foods containing soy; menopausal hormone therapy (consisting of estrogen with or without a progestin); a placebo (containing no drug or supplement).
They reported back regularly over the 12 months. At the end of the year, a difference of 0.6 flushes a day was found between those taking the herbal supplements and those in the placebo group. Those on the hormone therapy, meanwhile, had 4.06 fewer flushes a day. The conclusion? Sorry, girls, but the herbal remedies barely work. Any perceptible difference is, I'm afraid, down to the placebo effect. Until someone finds one that does work - and there may well be something out there - you're stuck with a choice of taking the hormones, or fanning yourself with a magazine at every available opportunity.
A popular saying among alternative medicine aficionados is "science doesn't know everything." Well, no. They're right there. But actually, science has never claimed to know everything. There was a time when science believed itself to be closer to knowing everything than it does now, but scientists have never claimed to know everything. But there's a big difference between not knowing everything and throwing your hand up in the air and agreeing with absolutely any idea just because someone else says it's true.