Return to Science

The Placebo Effect, Double-Blind Tests and Why Most “Alternative Medicine” is bunk

O765n any given day on Facebook, you are likely to see several graphics claiming incredible health benefits for some exotic plant, or claiming that some “alternative medicine” procedure can do everything that normal medicine can do but better. Very often these are accompanied by claims of people who tried them and testified to their efficacy. So how come medical professionals insist that they don’t work?<--break->

Centuries ago, medicine was practiced along mostly the same lines: a doctor would experiment with a herb or a root or a treatment, and ask the patient whether he/she felt better. If they said yes, it was retained. If they said no, it was discarded. It is during these times that we get leeches for everything, all sorts of plant parts - the more exotic the better - and so on. It was also a time when getting better was pretty much a hit and miss affair, as these early doctors stumbled around in the dark to find cures for illnesses that were decimating whole villages.

The placebo has been known for a very long time. An 1811 medical lexicon describes it as “any medicine adapted more to please than to benefit the patient”. It was in the late 18th century that one John Haygart started investigating the effects of a placebo. At the time there was a controversial but popular medical treatment called the “Jenkins tractors” - two pointed metal rods made of brass and steel, with which the inventor claimed to be able to “draw off the noxious electrical fluid that lay at the root of suffering”. Several medical centres had denounced them as quackery but others endorsed and used them. Haygart tested their efficacy by replacing them with a “dummy remedy” made of wooden replicas, and discovered that the patients were reporting the same results no matter which he used.

Haygart wrote that this showed “to a degree which has never been suspected, what powerful influence upon diseases is produced by mere imagination”. Today this phenomenon is called the placebo effect. If the patient is convinced that they have received a treatment that will make them better, they will report feeling better and in some cases they may actually get better, or do so faster.

Once this phenomenon became known, scientists and medical professionals turned to many other medical products and treatments of the time with a critical eye, and started trying to devise an objective way to determine whether they really were effective, or whether the patients were simply being convinced to feel better by the placebo effect.

The way to test this would be to have a group of volunteers and give half of them the treatment being tested (the “test group”), and the other half (the “control group”) a placebo - a “sugar pill” that does nothing physical to affect the illness. Of course, in order for the test to be effective the patient can’t know which they’re receiving. They’re told that they have a 50/50 chance of getting the medicine but can’t know in which group they end up. Also, since the body language of the medics might betray whether it’s the real deal or not, not even they can know. This test, in which neither patient nor medic know who is getting the real medicine and who is getting a placebo, is called the double-blind test.

Many medical treatments, some of which had been very popular and which had persisted for decades or even centuries, were suddenly revealed as doing nothing for the patients beyond setting their minds at rest. Nowadays, the double-blind test or placebo test is a standard part of the clinical trials before any new medical product is brought to the market.

It is precisely this test that most “alternative medicines” fail. They can have thousands of fans who swear by them, all saying that they felt better after the application of that treatment, but when the double-blind test is performed, the product fares exactly the same as coloured water. In a few cases there were even products that, when tested, were found to be causing harm rather than cure the patient.

Of course, when there’s a whole community and industry built on the foundation of a particular treatment, there’s a lot of resistance to these results. Some angrily attack the scientific method, or claim that this test somehow does not apply to their treatment. This can be clearly seen in homeopathy, which is a multi-million euro industry.

However this is where science differs from most other approaches. Everything is subject to testing, nothing can be taken for granted. Many assumptions turned out to be false. There are many cases where what was “common sense” turned out to be wrong. The double-blind test is applicable to almost all cases. Homeopathy was proved ineffective, despite its popularity, by simply switching the “homeopathic preparations” that were made by accredited homeopaths with ordinary drinking water, and in all cases the same percentage of patients reported feeling better. If it doesn’t make any difference whether they’re getting a homeopathic preparation or ordinary water, homeopathy does nothing, although the care and compassion of the homeopath can have a positive effect. There are some treatments where it’s not possible to precisely replicate the double-blind effect. For example, in acupuncture, the medic can’t pretend to be sticking needles into the patient since the patient can see and feel the needles. However, they do the next best thing - which is to compare the results of inserting needles into the correct locations by a professional acupuncturist, with sticking needles into random locations by someone with no knowledge of acupuncture, and again the results were found to be identical. Things get even more complicated when the treatment being tested is actual surgery, since you need volunteers willing to take part in tests where half of them will, essentially, have an incision made for nothing. Nevertheless even in these cases, the tests are done.

Although the double-blind test is useful in checking whether a treatment is effective or not, some medics are in a quandary over whether it’s ethical to intentionally give a patient a placebo when nothing else can be done. Since the placebo can not only make the patient feel better but actually help them get better, is it ethical to tell them a white lie in order to produce this effect? That’s a question that still divides ethicists and medical professionals.

What’s certain however is that, without these objective tests, it’s almost impossible to determine whether a medical treatment is effective or not. Anecdotal evidence simply doesn’t cut it, thanks in part to the placebo effect shown above. Evidence must be objective to be any use, and anecdotal evidence is by definition subjective.

Although one can’t dismiss offhand any treatment that falls under the broad definition of “alternative medicine”, there’s usually a good reason why it doesn’t fit in under conventional medicine, and one of the main reasons is that it failed this all-important test, and thus the treatment is doing nothing to help the patient.

There are a number of reasons why “alternative medicine” is so popular. One of them is that, unlike conventional medicine, they don’t need to go through a series of rigorous tests before they’re made available - they can be on the shelves quickly and easily and cheaply. Another is that they can make wild claims. Of course they have to be careful how to word these claims to avoid lawsuits. They don’t claim that “product X” will cure cancer. They might claim that it can be used on cancer, or may help cancer victims, or that cancer patients recommend it. It might sound the same but in a court that could make a big difference.

Some might wonder, why bother? If the treatment does nothing, then it is causing neither benefit nor harm. For instance, homeopathic preparations are nothing but water. What harm could a little water do? The harm primarily comes from using these treatments instead of conventional medicine that does work (not to mention wasting a lot of money on them). Probably the most famous death from homeopathy was Steve Jobs, who was suffering from a type of cancer that is quite treatable using conventional medicine, but against which homeopathy did nothing. Unfortunately he left it too late and by the time he turned to medicine it was too late. The death toll from alternative medicine is probably quite high, but difficult to determine since death certificates can’t say that drinking homeopathic water killed the person - it didn’t. It merely kept them from going for a treatment that does work, so ultimately the alternative medicine avoids the bad reputation of having caused any deaths directly.

Carl Sagan warned that "We’ve arranged a society on science and technology in which nobody understands anything about science and technology, and this combustible mixture of ignorance and power sooner or later is going to blow up in our faces." Although we can reasonably expect to have regulations to control clear scams, it is ultimately our own personal responsibility to be careful what choices we're making for ourselves.