Wu is the very widespread east Asian system of shamanistic healing, which involves shaking bells and chanting and burning slips of paper and what not. Usually spelled woo, it has been adopted by defenders of rational, scientific medicine as a generic label for the mystic arts promoted in late night infomercials and the Huffington Post. Probably the most popular form of woo around is homeopathy. I won't bore you, or reinvent the wheel, by describing and debunking this utterly ridiculous belief system, but check out the thorough historical treatment at the Skeptic's Dictionary.
I recently got into an e-mail pissing match with a proponent of homeopathy and it has provoked me once again to contemplate the allure of the irrational. After I avowed that there is no such thing as "legitimate homeopathy," her first response was to insinuate that I denounce homeopathy because I have some sort of financial stake in my opinion. You can imagine what happened when she pushed that button. At that point further conversation was undoubtedly useless, but let me carry on here.
It is well known that the first recourse of the wumeisters is to claim that medical science is all a conspiracy by Big Pharma to defraud us, that "They" don't want you to know about the miracle cure because it would hurt "Their" profits, and that the critics of wu are all shills for Big Pharma who are lining their pockets with consulting fees, kickbacks, and stock dividends.* Unfortunately, they can't claim this about their bete noir, Dr. Stephen Barrett, who is a retired psychiatrist, so they just accuse him of having a closed mind and continually sue him. When I pointed out to my correspondent that Barrett has never been successfully sued for libel or defamation -- or anything else -- she responded that he has too lost a lawsuit. Well, yeah, except he was the plaintiff. Here's the truth about this case, from Barrett:
In November 2000, Attorney Grell, Dr. Polevoy and I filed suit in Oakland, California against Hulda Clark, the Bolens, JuriMed, David Amrein, the Dr. Clark Association, Ilena Rosenthal, and others who have spread or conspired to spread the defamatory messages . New Century Press was subsequently added as a defendant. In July 2001, the judge ruled that defendant Rosenthal, who had republished messages from Bolen to several news groups, was shielded from liability by the Internet Decency Act, which the judge believed was intended to protect anyone posting messages to newsgroups. The judge also ordered us to pay $33,000 in attorney's fees. We believe this ruling was incorrect and extremely unfair. In March 2002, we filed an appeal which noted that the judge's ruling, if upheld, would abolish all protection against Internet libel because a "clever libeler" could easily escape liability by having an anonymous or remote "Internet user" publish libelous statements that any other Internet user" would be free to republish . We also appealed the judge's order for attorney's fees. In October 2003, the appeals court agreed with our view of the Internet Decency Act and ruled that Rosenthal could be sued for posting a defamatory message about Dr. Polevoy. However, the California Supreme Court reversed the Appeals Court, so Rosenthal was dismissed as a defendant. The other defendants remained, but in 2009, the local judge concluded that we had not pursued the case quickly enough and dismissed it.
Hardly evidence against Barrett's integrity, but this is the sort of tendentious, facts-be-damned argumentation style that the wumeisters generally adopt.
A scientist named Edward Calabrese is interested in the phenomenon of hormesis, which is a label for a perfectly well-known phenomenon. Essentially, the biological response to low doses of some substances can be dissimilar to the response to higher doses, in other words the response to more is not just more of the same. Obviously, low doses of any medication may be beneficial whereas doses that are too high are toxic, but this idea goes a little bit further. A mild irritant can recruit a reparative response, such as inflammation, which may also repair some pre-existing lesion or disease process. Peppermint oil, for example, is a mild irritant which may actually be helpful in some gastrointestinal and other conditions.
However, this has nothing to do with homeopathy. Homeopathic remedies are water; they are biologically inactive except for the prevention and treatment of dehydration. Nor is it in any way a promising organizing principle for a broad program of research. There might be a useful remedy or two based on the idea. However, there is no single, secret key to all disease and healing. Organisms are extremely complicated; they are systems of systems, with all sorts of feedback systems to maintain homeostasis and competing positive feedback systems to respond to challenges; beset by pathogens; and disturbed by sub-optimal inputs such as malnutrition and environmental toxins.
Accordingly, medicine is eclectic. There isn't any single principle, or even just a few principles, on which scientific medicine is based. Rather, biomedical scientists try to understand each situation as it is, and evaluate treatments based on their specific merits and risks. Antibiotics kill pathogens; antivirals restrict viral replication; antihypertensives target various signaling systems; insulin replaces a hormone the body fails to produce; surgery repairs physical lesions; some treatments, such as analgesics, are largely palliative; etc.
Some people apparently find it tempting to believe that a single magic principle will banish all disease and suffering but it just doesn't work that way. Homeopathy grows out of a sort of mantra: Like Cures Like. Well, generally, it doesn't. Just believing in a slogan doesn't constitute evidence. There is plenty of evidence regarding homeopathy and it all points, inescapably, to a single conclusion: homeopathy is useless.
There isn't any evil conspiracy against homeopathy, and we don't denounce homeopathy because we have closed minds. Homeopathy is nonsensical. And no, it isn't harmless. When people's belief in nonsense causes them to refuse potentially beneficial therapies, they can be seriously harmed, or die. Now, that's an evil conspiracy.
*For the record, I am a medical sociologist, who earns a modest academic salary mostly based on funding from the National Institutes of Health to study physician-patient communication. NIMH does not know, or care, what I think about homeopathy, nor does my employer.