Humility among scientists

Yesterday, Revere (Effect Measure) threw down the gauntlet challenging those critical of alternative medicine to examine work done at the University of Nebraska Medical Center in 2000 on the medicinal properties of chicken soup.

The news release cites work that a chicken/vegetable soup, but not simple chicken broth, inhibits in vitro neutrophil migration, or chemotaxis. Inhibiting the migration of this class of white blood cells might reduce the nasopharyngeal symptoms of the common cold, thereby providing some evidence that grandma's chicken soup might very well help one feel better during cold and flu season.

Since these were in vitro or Petri dish experiments, my first question was whether the bioactive components of the soup get into the blood or mucosal tissue at the concentrations required to have such effects against isolated neutrophils. However, the bioactive component(s) were not identified in this work. Revere asks whether this study might be enough to move chicken soup out of the category of alternative medicine into something more believable.

In a larger sense, what Revere seems to have intended by this post was to ask whether we scientists have the humility to recognize that we may not always apply the same rules for scientific rigor to our own respective fields that we expect from examinations of the more conceptually implausible forms of alternative medicine.

Perhaps even more broadly, he asks us to examine our own biases in the science/pseudoscience demarcation. This broader discussion is better handled by the resident science philosophers, such as has been done by Prof Janet Stemwedel at Adventures in Ethics and Science:

Revere stirs the pot (of chicken soup) to ask why alternative therapies are presumptively regarded as pseudo-science. The reflexive response of the quackbusters has been that alternative therapies fall on the wrong side of some bright line that divides what is scientific from what is not -- the line of demarcation that (scientists seem to assume) Karl Popper pointed out years ago, and that keeps the borders of science secure.

My professional time is spent studying the scientific aspects of herbal medicine, an area that is often placed over that line of alternative medicine or "woo" even by some of my colleagues. But upon closer examination, it is quite easy for me to equivocally discuss alternative and conventional medicine because 25% of prescription drugs can trace their origins to natural sources, including plants, bacteria, fungi, marine creatures, etc. In fact, some of our greatest advances in antibiotics, cancer, and pain therapeutics have been the direct result of natural products.

Where I make a distinction in my field is the difference between saying an herb works, say, as a hypolipidemic because it is "God-given" or inherently safe because it is natural vs. the same herb being represented as a source of one or more chemicals that acts as an enzyme inhibitor in pathways that control cholesterol or triglyceride metabolism. The former is a belief that does not provide a chance for testing a hypothesis; the latter, on the other hand, is amenable to investigation.

The basis for generating a hypothesis to test whether an alternative remedy has biological efficacy must have some scientific basis that is sound. I've heard herbalists tell me that "whole herbs" are superior to purified compounds because of synergy among components or because one herbal component blocks a side effect of an active component. These are both reasonable scenarios, but there is a great paucity of evidence in the literature to support such suppositions. (One good example of true synergy in a medicinal herb can be found in this PDF of a PNAS article from Frank Stermitz's group.)

However, if an herbalist tells me that a whole herb works better than a pure compounds because the herb is "energized" or contains a "life force" that is extracted away by laboratory purification, I call bullshit unless there is a method to quantify these forces and demonstrate their causality with biological activity.

Back to Revere's original query, I try to write with a degree of humility that we may not know all there is about modalities espoused by alternative practitioners - I would not put chicken soup in this camp because its purported mechanism of action is conceivable. But, again, I believe Revere is concerned more broadly about scientific humility (as evidenced by another recent post on the preconceptions at the time on the origin of 19th century cholera epidemics of Victorian London).

Back to my area of the discussion and where I draw the line: I am most critical of some aspects of alternative medicine not because of whether they should be tested or not. Rather, I am critical of those who intentionally deceive patients and consumers with unproven therapies for their financial gain, personal fame, or both. I know a great many people whose income depends on the continued separation of alternative medicine from conventional medicine (kind of how the tag "alternative music" used to mean something). These people do not care for their modalities to be proven under conventional clinical trials because to do so would mean alienating themselves from their clients who wish to say they are doing something their doctors don't know about/don't believe in.

Hence, there should be no alternative medicine. There is medicine that has been proven, medicine that has not been proven, and modalities that are pure quackery meant only to enhance the revenue of the practitioners.