In the 1950s, cardiologist Leonard Cobb wanted to study the effectiveness of mammary arterial ligation (tying two arteries to increase blood flow to the heart), a procedure then commonly used to treat chest pain. Cobb performed the surgery for some patients; for others he just made a cut in the chest and bandaged them up again, though patients believed they had had the surgery.

The two groups healed at the same rate, and 90% of both groups said the procedure helped them.

This is the placebo effect: if you expect a drug, or surgery, or therapy to make you feel better, it probably will. The placebo effect is not imaginary: the improvements people feel are very real, though the effects are due to the power of the mind rather than the therapeutic effects of the treatment.

Today, it is routine practice in clinical trials to test how well any treatment works compared to a placebo. Complementary and alternative medicine (CAM) fails in this. Much of their ‘effectiveness’ is due to the placebo effect. That is why scientifically-trained doctors, who look to clinical trials for proof of effectiveness, routinely dismiss alternative medicines, even though people swear it works.

But, as Cobb’s experiment showed, even conventional medicine often works due to the placebo effect. CAM practitioners can also claim you should not mind how it works so long as it does.

But this does not really satisfy: if you know what you are receiving is a placebo, it will not work for you. And some medical treatments are really much more effective than placebos. Till we find a scientific cure for everything, quacks (and doctors) will continue to use placebos and get results too.

But most quacks will get less results than most doctors. Don’t you hate the uncertainty? But that is how science works. And the placebo effect still cannot cure AIDS or set a broken bone.

Susan Vinodh Pandian

Some more on placebos:

1. The power of the placebo

2. Is homeopathy better than a placebo?

3. Thrill-seekers are more sensitive to the placebo effect

4. Acupuncture fertility treatment is no better than a placebo