Archive for November, 2013

Placebo – what can it actually do?

November 18, 2013 1 comment

Placebo effect is one of the most bizarre and yet enlightening things discovered in medical research. It is one of the most widely studied psychological effects because of the need to eliminate it in medicine. However, the reason why general public should be aware of the extent of placebo effect is because many alternative medicine systems solely rely on the size of placebo they can exert on patients to proudly claim a therapeutic effect of their treatment. Homeopathy is a perfect example of this.

What is placebo?

For starters, placebo in medicine is an intervention that does nothing at all, except to convince you that it does something. Placebos can be pills, inhalers, injections, massages, ultrasound or heat application, fancy looking electronic devices, or even sham surgeries. They basically contain no active ingredient that treats anything, but it is described by the doctor in such a way to make the patient believe that it is legitimate medication which might lead them to report positive results.

Placebo effect is very important in medical research. When you want to test a new drug or a treatment, you need to make sure it works better than not just nothing, but better than a placebo. So, while testing the drug, a control group of subjects receive an identical procedure, but with a placebo instead of the new treatment. Making sure that neither the doctors nor the patients know which is the control group, we can understand the effectiveness of the new drug beyond a placebo.

Fun fact: Do you realize how strong placebo effect is? In clinical trials, placebo groups fare a lot better (up to 40%) than groups receiving no treatment. The fact is, when you think that you’re being treated, you’ll experience some relief.

However, in today’s clinical practice, researchers are not interested whether the new drug works better than nothing, they’re interested if it works better than the best treatment we currently have. This is a good yardstick while you’re trying to understand clinical trial reports.

Placebos don’t have any measurable improvement associated to them. They don’t offer any physical or therapeutic effect. Patients typically report a reduction of symptoms. It can help the way patient feels, but cannot treat the illness. Exceptions are in cases of nausea, insomnia, stress, etc., where there is an actual condition without any disease agent involved.

Clinical trials on placebo effect:

The bizarre thing about placebo is, not all placebos have the same effect. And we can compare one placebo with another. Some strange and interesting observations from meta-analyses of placebo groups in various clinical trials are:

  • Placebo effect thrives on value of ceremony: Four sugar pills work better than two, complicated dosage instructions are more effective than a simple “2 pills per day” instructions.
  • Cultural meaning plays a role in the way placebo effect works: Red sugar pills fare better than blue sugar pills as stimulants, and blue fares better than red as tranquilizers. Valium was more effective at treating anxiety in a green tablet, and more effective for depression when in yellow. Stimulant medication tends to come in red, orange and yellow tablets, and tranquilizers are generally blue, purple and green. In 1970, sedatives were found to be more effective in capsule form than a pill form, as capsules looked modern and more “sciencey”.
  • Method of administration influences placebo effect: Salt water injections (more dramatic intervention) were more effective than sugar pills. Elaborate sham treatment rituals were more effective than injections. Sham ultrasounds are beneficial as dental treatments, fake keyhole surgeries have helped ease knee pain, placebo surgeries have been shown to improve angina. Some studies have showed that sham treatments done with hi-tech looking machines and prefixed with word ‘LASER’ were effective.
  • Branding effects placebo as well: Pills with a recognized, well-known brand name and packaging are more effective than generic pills.
  • The way in which doctor gives the drug also has an effect: Overselling the sugar pill is more effective than underselling it. Sugar pills work better when they are given by someone in a white lab-coat than someone not wearing a lab-coat. Better results are obtained from placebos when the doctor spends more time with the patient explaining things.

Reasons behind placebo effect:

Belief is presumed to be the main reason behind placebo effect. It is strongest in self-reported symptoms like pain, and is non-existent in objective measurement of a condition like blood pressure. The placebo effect is related to the perceptions and expectations of the patient; if the substance is viewed as helpful, it can heal, but, if it is viewed as harmful, it can cause negative effects, which is known as the “nocebo effect”. Because the placebo effect is based upon expectations and conditioning, the effect disappears if the patient is told that their expectations are unrealistic, or that the placebo intervention is ineffective. A conditioned pain reduction can be totally removed when its existence is explained. So if you realize that your pills are placebo, they won’t work anymore. Social observation can induce a placebo effect such when a person sees another having reduced pain following what they believe is a pain reducing procedure.

In conclusion, understanding the power of placebo effect is very important to understand if a claimed alternative therapy is effective or not. A well packaged and marketed quack treatment can, under the right conditions, produce a subjective improvement in the patient’s symptoms, but doesn’t treat the underlying illness. Also, the new treatment should only be considered if it works better than not just placebo, but with the best treatment available.

References and further reading:

Ben Goldacre (2008). Bad Science. United Kingdom: Harper Perennial. p63-84.

Daniel E. Moerman, Wayne B. Jonas; Deconstructing the Placebo Effect and Finding the Meaning Response. Annals of Internal Medicine. 2002 Mar;136(6):471-476.

Barry Blackwell, SaulS. Bloomfield, C.Ralph Buncher. “Demonstration to medical students of placebo responses and non-drug factors.” The Lancet 299.7763 (1972): 1279-1282

Johnson, Alan G. “Surgery as a placebo.” The Lancet 344.8930 (1994): 1140-1142.

Dunning, B. “The Placebo Effect.” Skeptoid Podcast. Skeptoid Media, Inc., 28 Apr 2009. Web. 17 Nov 2013. <;


Homeopathy – Partial Nonsense or Complete Nonsense?

November 11, 2013 1 comment

Homeopathy is one of the most popular alternative medicines around us. In India, almost everyone knows someone who has been taking homeopathic remedies for a long time for various ailments, and there is always someone who would suggest to us to try it citing a variety of reasons, like absence of side effects, holistic approach towards healing, non-toxicity and so on. Today, we examine the history of homeopathy, how homeopathic remedies are made, and how homeopathy has fared in clinical trials conducted across the world.

History and context

Samuel Hahnemann, a German physician invented homeopathy in late 1700s, when conventional medicine practice was based on the notion that human body is made of four fluids or “humors”: Black bile, yellow bile, phlegm and blood. When these humors are in balance, a proper temperament and health is maintained, and any disease should aim at balancing them, by means of bloodletting, purging, leeching, etc., by removing any excess of these four fluids that spoil this balance. Note that people weren’t aware that microbes cause diseases and microbiology wasn’t born back then. Hahnemann observed that these practices caused more harm and pain than relief, and so sought out to develop a better way of balancing these humors. He postulated something called “Law of Similars”, according to which like cures like. In other words, something which induces the symptoms of a disease, when given in small quantities, gives the diseased body a “kick-start” to balance the four humors by itself.

Now the problem is that these symptom-inducing substances or “remedies” should be given in such miniscule quantities so that they won’t be toxic to the body. So, Hahnemann developed a system of massively diluting them with water and claimed that greater dilutions have greater balancing effect on the body humors. He called this the Law of Infinitesimals. He published his theory in the early 1800s, and homeopathy was born.


Homeopathic remedies are diluted with either alcohol of distilled water in a process called “potentization”. Hahnemann created the “C scale”, which dilutes a substance by a factor of 100 at each stage. The C scale was favored by Hahnemann for most of his life. A 2C dilution requires a substance to be diluted to one part in 100 parts of water/alcohol, and then some of that diluted solution diluted by a further factor of 100. This works out to one part of the original substance in 10,000 parts of the solution. A 6C dilution repeats this process six times, ending up with the original substance diluted by a factor of 100^6 (one part in one trillion or 1/1,000,000,000,000). Higher dilutions follow the same pattern. The typical remedies a homeopath prescribes today are of 100C, 200C potency.

Critical analysis of homeopathy

One thing that immediately attracts any critical thinker to homeopathy is its massive dilution system. Back in Hahnemann’s time, it was reasonable to assume that remedies can be divided indefinitely and the idea of atom as the smallest unit of division wasn’t known. Now let’s take 30C potency, which is 1 part in 10^60.

Fun fact: Do you realize how big 10^60 is? The number of atoms in our galaxy is about 10^60.

In 1807, they knew more about mathematics and chemistry than they did about medicine, and it was known that there is a maximum dilution possible in chemistry. Some decades later it was learned that this proportion is related to Avogadro’s constant, about 6×10^23. Beyond this limit, where many of homepathic dilutions lay, they are in fact no longer dilutions but are chemically considered to be pure water. So Hahnemann designed a workaround. He thought that if a solution was agitated enough, the water would retain a spiritual imprint of the original substance, and could then be diluted without limit. Homeopathy calls this “Water Memory”. The water is often added to sugar pills for remedies designed to be taken in a pill form. So when you buy homeopathic pills sold today, you’re actually buying sugar, water, or alcohol that “remembers” some described substance. The substance itself no longer remains, except for a few millionth-part molecules in the lowest dilutions.

So effectively, homeopathic pills are nothing but sugar pills soaked in water or alcohol.

Secondly, homeopathy is based on the idea of four humors and their balance in maintaining health, which we understand is nonsense. Once we discovered that diseases are caused by microbes, it changed our understanding of human health. Scientific medicine has improved by leaps and bounds from 18th century into various disciplines like internal medicine, oncology, neurology, cardiology, psychiatry, pathology, surgery, infectious disease, hematology, geriatrics, gastroenterology, ophthalmology, radiology, orthopedics, nephrology, urology, pharmacology, emergency medicine and critical care. Conveniently dismissing this whole evidence-based medicine with an insulting tag of allopathy is grossly misleading and dangerous when publicly advocated.

Clinical trials

In pharmacology, you can prescribe any drug provided it works in clinical trials, has better potency and lesser side effects compared to the current medication available. However, the efficacy of homeopathy has been in dispute since its inception. Homeopathy has been subjected to numerous trials over half a century, perhaps the highest money spent to research a quack healing practice. Meta-analyses of studies on homeopathic remedies showed no significant effect than a placebo. This meta-analysis of 107 trials published in British Medical Journal in 1991, and this landmark meta-analysis of 110 homeopathic trials comparing with 110 conventional trials published in The Lancet medical journal in 2005 are a couple of examples of the immense literature out there debunking homeopathy.

Apart from these, the American illusionist and scientific skeptic James Randi has offered $1million to anyone able to prove, under observed conditions in a laboratory, that homeopathic remedies can really cure people. To date, no-one has passed the preliminary tests. And the UK society of homeopaths has stated: “It has been established beyond doubt that the randomized controlled trial is not a fitting research tool with which to test homeopathy”. In other words, homeopathy has given itself a Get Out of Jail Free card. So, if you conduct a trial and failed to observe that homeopathy worked better than placebo, your failure is simply because homeopathy shouldn’t be tested!

Now one rule of thumb of critical thinking is that, if anything claims that its effect cannot be detected through testing and is immune to scientific scrutiny, you should always be skeptical about it; Always, until demonstrated with a statistical significance.

In summary, homeopathy is a complete quack healing practice, with no better effects than placebo. It has no active ingredients and is pure sugar pills, water and alcohol, and its efficacy is disproved by numerous trials and meta-analyses. Since it has no effects (and side-effects), it is harmless to use for ailments like occasional headache, benign skin tumors, viral sinusitis and so on from which our body heals without external assistance. However, be cautious if someone recommends homeopathy to your family, friends or yourself for serious illness.

References and further reading:

Ben Goldacre (2008). Bad Science. United Kingdom: Harper Perennial. p28-60.

Kleijnen J, Knipschild P. “Clinical trials of homoeopathy.” British Medical Journal. 9 Feb. 1991, 302(6772): 316-23. <;

NCAHF. “NCAHF Position Paper on Homeopathy.” National Council Against Health Fraud. The National Council Against Health Fraud, Inc., 1 Feb. 1994. Web. 22 Mar. 2007. <;

Shang, A., Huwiler-Müntener, K., Nartley, L. “Are the clinical effects of homoeopathy placebo effects? Comparative study of placebo-controlled trials of homoeopathy and allopathy.” The Lancet. 27 Aug. 2005, Volume 366, Issue 9487: 726-732. <;

Dunning, B. “Homeopathy: Pure Water or Pure Nonsense?” Skeptoid Podcast. Skeptoid Media, Inc., 22 Mar 2007. Web. 10 Nov 2013. <;

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