From: http://www.csus.edu/indiv/m/mccormickm/ ... ticles.htm
Human Psychology, Evidence, and Alternative Medicine
Alternative, fringe medical therapies are huge business. In a given year, Americans will spend as much as $50 million on complementary and alternative medical therapies. These include medications like echinacea, ginseng, glucosomine, and medical treatments like prayer groups, meditations, massage, yoga, chiropractic, and acupuncture. That's more money than Americans will spend in a given year on regular medical therapies and medications. Given that we are all spending so much money on them it is important to consider the sorts of evidence we have to support or reject the claims concerning their efficacy. Do these treatments work, and do we have good reasons for thinking that they do? Evidently, people believe that they do work, or they wouldn't be spending so much money on them. But what exactly is the typical person's reasons for buying into one of these alternatives?
When someone says something like, "Echinacea works, I took some last week when I felt a cold coming on and I felt better immediately," what sort of argument are they making? Typically, someone they trust told them that the supplement works. Your mother or your cousin, or a friend said, "you should try echinacea, it cures colds." So looking for relief, you gave it a try. Then you felt better. Or maybe you didn't. So you gave it some more time, maybe you took a few more pills, and then you started to feel better. So for the typical person, their evidence for the claim, "Echinacea works," is 1) people I trust said that it works, 2) the label says that it works, and the label can't outright lie about something like that, and 3) I took it and then I felt better.
Let's consider the last category of evidence. Here's the vital question to ask about a case like this where we think that X is true and we have some experience that seems to be consistent with X: Have I considered the class of evidence that could possibly disprove X? Did I consider what would have happened to my cold if I hadn't taken the echinacea? If my cold would have gotten better anyway, at the same rate, with or without the medication, then we should conclude that the medication doesn't work. But how would I know whether it would have gotten better without the drug? I can't know for sure about a particular cold of mine. What we can do is look at a larger data set. And that is what clinical trials do. A clinical trial of a drug will look at the regular course of a disease in a control group. And they will consider the impact of the placebo effect on test subjects. And they will compare those two results with the course of the disease among test subject who took echinacea. If on the whole the echinacea group got better faster, or had less severe colds than the control group and the placebo group, then we could have evidence that echinacea actually works to reduce the length or severity of colds. But when I reason from my own case of one or two colds that I had and then I got better after taking echinacea, I do not have the sort of evidence I need to figure out whether or not echinacea works. My feeling better is consistent both with its working and with its not working from my perspective. It might be that it was the full night's rest that I got that made me feel better. It might be the placebo effect making me feel better. It might be that I would have felt better anyway, even if I hadn't taken the drug. Or it might be that the drug actually did work and made me feel better. But unless I can control for those other factors and compare to a data set where no drug was taken, my evidence is incomplete. My own experience and a few stories from friends and family just aren't enough to establish one way or another whether one of these therapies works. But since we think that this weaker body of evidence is sufficient to prove the claim, we spend our money--millions of dollars--on the drugs, making the manufacturers rich on the basis of fallacious reasoning.
For the most part, the claims made by manufacturers about the effectiveness of alternative medications such as echinacea have not been tested. Typically, there are no careful, double-blind, randomized clinical trials to support the therapeutic claims associated with these medications. The FDA has a number of regulations that manufacturers have managed to cleverly circumvent. Any specific claims that a manufacturer wants to make about a supplement's improving a person's health have to be reviewed and approved by the FDA. So before calcium companies could claim that calcium lowers the risk of osteoporosis, for example, the FDA had to review the scientific evidence concerning the claim and determine that the claim had been proven in clinical trials. There is a huge market for dietary supplements, so when clinical studies do not support the disease claims, what can the manufacturer legally put on the label? What they have discovered is that more general claims that do not name any specific disease are not prohibited by the FDA regulations. The clinical studies of the effects on echinacea, for instance, have not found any significant effects on the length or intensity of colds beyond the placebo effect. So rather than put, "reduces the length and severity of colds!!" on the label, which would be prohibited, manufacturers will make claims like, "Helps your body's immune system to keep you active," or "Boosts your immune system," or even vaguer, "Helps your immune system." These claims, manufacturers have discovered, are not prohibited by FDA regulations and will be tolerated, at least for the time being. So the unwary consumer hears what friends and family had said about echinacea, reads the label, and spends the money to try some.
Here's another phenomena that plays into our beliefs that these drugs work. When you feel sick, you go ahead and take the medication. If you feel better shortly thereafter, you credit that improvement to the drug. After all, that’s what you were expecting and hoping for, and a friend said you would feel better, and the label says that it works. So even if you would have gotten better around that time anyway, you give the credit for that improvement to the drug. And at what point are you most likely to take something for your cold? When you have had it for several days, and when it has progressed to what feels like its worst state. So given the normal trajectory of a cold, you had hit the worst of it and your immune system was catching up and getting ready to conquer it anyway. But since you just took the pills, you chalk the improvement up to them.
Now what happens if you take the pills and you don't feel better right away? If you have the expectation that the pills should work, then a couple of different things go through your mind: "Maybe I should wait a while longer to give it some time to kick in." or "Maybe I didn't take enough--it will start to work once I take some more." So now you wait, or maybe you take some more 4 hours later. Then when you feel better shortly thereafter, you conclude that the drug was working, it just took a little longer than expected. Or "the drug was working, I just needed to get more of it into my system." So now, once again, you conclude that the drug must be what made you feel better. So no matter what the outcome after we take a medication that we think is going to work, we conclude that the drug works. We just weren't considering the category of evidence that might have disproven the claim. As a result, people have enthusiastic and entrenched convictions about the effectiveness of these treatments. And given that all the evidence that they considered seems to support the belief, those convictions seem warranted. But once we take a broader view of the phenomena, we realize that our data was skewed, we had strong expectations, and we didn't consider a whole category of evidence that is essential for supporting the belief.
What do the scientific studies say about some of these treatments? Echinacea use has no significant effect on the length or severity of colds. Zinc lozenges do reduce the length and severity of colds. Testing has not supported the claim that Airborne, a vitamin mixture, cures or prevents colds.
Besides possibly wasting one's money, what is the harm in trying or believing in alternative medical treatments? Someone might argue that if nothing else, one derives the placebo effect from a medication that has no other effect. And that is worth something, especially if it makes my cold feel better.
But there are several other more serious harms that could result from untested medical therapies. First, these remedies are not cheap. You're not just wasting a little money when a treatment doesn't actually work, you may have had to spend $50, or $100 or more on it. In a recent case in Sacramento, a woman with chronic pain had paid over $3,000 for a questionable "pain reduction" machine. Thieves stole the machine from her office. People in the community offered their support after her story was on the news and bought her another one. What was portrayed as an example of human charity and compassion at work on the news was actually a $6,000 waste of money. Second, many of these diet supplements and alternative treatments have not been thoroughly tested by the FDA or clinicians for safety. We do not know the long term effects of the drugs, we do not fully understand their side effects, we do not have reliable data about safe or effective dosages, we do not know how they may interact with other drugs, we don't know what's really in the pills because they are not as closely regulated, and people often do not tell their doctors that they are taking them. The manufacturers have proven themselves to be unscrupulous, and the FDA is not able to do careful monitoring of contents. So you are taking significant risks with your own health and safety. And you may be endangering others. Health food stores often sell a variety of herbal remedies that they recommend to pregnant women for morning sickness, pregnancy discomforts, cramps, or sleeplessness. There are even herbal remedies that are suggested by advocates for the overdue mother-to-be to induce or accelerate labor. The danger is that we do not have good information about the possible effects of such drugs on a fetus, and the development of the fetus, especially during the first trimester, is extremely sensitive and vulnerable. So taking alternative medical therapies is not as cheap or harmless as one might think.