As many of you, gentle readers, no doubt know, many rank idiocies emanating from the world of pseudoscience irritate me to no end. But very few of them come close to the R-A-G-E (Hulk SMASH!) that ebulliates in me when I hear ‘toxin’, that standard catchphrase from all manners of peddlers of pseudoscience.

Twitter convo; toxin and papaya!

A chance encounter on Twitter brought me in contact with this cosmetic dermatologist, whose name and twitter handle I have redacted for privacy reasons. Suffice it to say that this person, with a basic medical degree and post-graduate specialization in cosmetic dermatology, has a pretty well-established clientèle, who consults with her presumably for skin and related issues. Which is all very fine.

The sentence fragment “Flushes toxins” – from particularly one who is supposed to be a medical professional – raised a red flag, but wishing to give this person the benefit of doubt, I wrote back asking which toxins and how. In reply, I was told about papain and its presumed benefits. Once again, I asked for some evidence for the sweeping statements in favor of papain, a proteolytic (‘protein breaking’) enzyme that is used for tenderizing meat. In reply, … tumbleweed …!

Oy vey, the toxins! I could go on and on, but I’d defer to physician and Science Based Medicine blogger extraordinaire, David Gorski, to hold forth on ‘toxins’:

How many times have I read or heard from believers in “alternative” medicine that some disease or other is caused by “toxins”? I honestly can’t remember, but in alt-world, no matter what the disease or condition under discussion is, there’s a good chance that sooner or later it will be linked to “toxins.”

…why this fascination with “detoxification” in alternative medicine? Why do so many of its treatments, be they dietary, chelation therapy, purges, colon cleanses, or whatever, claim to eliminate “toxins”? Why is it that, if you Google “alternative medicine” and “detoxification,” you find so many references, some of which claim external toxins need to be eliminated, some of which claim that internal toxins need to be purged…?

What are these ‘toxins’ anyway?

In science, the formal definition of a “toxin” is actually quite narrow. Basically, a toxin is a poisonous substance produced by living cells or organisms. Man-made substances that are poisonous are not considered, strictly speaking, “toxins” by this definition. Rather, they are called toxicants. In marked contrast, alt-med practitioners do not distinguish between “toxin” and “toxicant,” lumping them all together as “toxins,” be they the products of autointoxication, heavy metals, pesticides, or industrial chemicals.

… perhaps the most important differences in how science views toxins versus how alt-med views toxins is in demonstrating an understanding of (1) identity and (2) how the dose makes the poison. When toxicologists speak of toxins or toxicants, they tend to be very specific about the identity of the toxin or toxicant… to identify the specific compound or chemical that is causing illness, regardless of its source… In marked contrast, alt-med aficionados are almost intentionally vague when discussing toxins. To them, it seems, toxins are either all-purpose nasty substances without specific identities or substances whose toxicity appears not to depend upon dose.

… in real medicine “detoxification” means removing a real and specific toxin or toxicant (or set of toxins and/or toxicants). In the case of real heavy metal poisoning, chelation therapy is real detoxification. Similarly, using lactulose to decrease the production absorption of ammonia by the gut is an example of detoxification. In contrast, alt-med “detoxification” is far more akin to the exorcism of evil spirits, the removal of evil humors, or the driving away of miasmas.

In his customary style, David cuts to the heart of the matter, and schools the alt-med aficionados in normal human physiology (and it’s worth emphasizing).

the body has very finely tuned and efficient mechanisms for disposing of waste material or recycling it into other molecules that the body needs, such as proteins, nucleic acids, and lipids. The liver is incredibly adept at getting rid of various waste products, as are the colon, lung, and kidneys. Except when these organs fail, help is rarely necessary; the body can “detoxify” itself just fine, thank you very much…

Do read the whole of his blog-post. It’s a fascinating read.

I am sure I have absolutely no quarrel with papaya (or papaw or pawpaw), the tropical fruit, either. Although I have no means currently to verify many claims made in regards to the benefits of this fruit, I am willing to allow some general points true for most, if not all, tropical fruits, as mentioned in that venerable font of knowledge, Wikipedia, on Papaya:

Papaya fruit is a rich source of nutrients such as provitamin A carotenoids, vitamin C, B vitamins, lycopene, dietary minerals and dietary fibre. Papaya skin, pulp and seeds also contain a variety of phytochemicals, including natural phenols… Papayas have a relatively high amount of pectin… Both green papaya fruit and the tree’s latex are rich in papain

Interestingly, from the sparse references following the Wikipedia entry, two different groups from Nigeria have looked at properties of aqueous crude extracts of papaya seeds: One found that at a high dose (800mg/kg body weight), the papaya seed extract could act as an abortifacient in Sprague-Dowley rats. The other demonstrated some nephro-protective (‘protection of kidney’) effect in male Wistar rats with experimentally induced kidney injury, but concluded that the observed effect could be mediated by any of the phytocomponents present in the crude aqueous extract via either antioxidant and/or free radical scavenging mechanism(s). One Ethiopian group found that at fairly high concentrations, the papaya seed aqueous extract could inhibit the growth of certain bacteria in vitro. One Indian group has been studying the contraceptive effects of a chloroform extract of papaya seeds, which induced long-term reversible azoospermia (reduction in sperm count) in male langur monkeys, and in Sprague–Dawley rats; they have apparently identified in 2005 two chemical fractions of the papaya seed chloroform extract with similar contraceptive properties, although there is no word yet on actual chemical structure and properties of either.

And not just seeds, a Japanese group demonstrated recently that aqueous extract of papaya could inhibit the growth of various tumor cell lines, and modulate the release of various chemical messengers from human leukocytes activating their ability to kill leukemic cells in vitro. The group further identified the active small-molecule components of extract responsible for these actions.

Pharmacognosy (study of medicinal substances obtained from plants or other natural sources) and ethnopharmacology (study of the use of various natural substances by ethnic groups for medicinal purposes) are valid research areas with a lot of untapped potential. However, while the identification of the source of possible medicinal substances of natural origin may well depend on tales, parables, anecdotes and folklore, the only way such substances can get entry into the realm of medicine is via empirical evidence. The laboratory and pre-clinical tests are done to ensure that the ideas of the efficacy, as well as safety, of these substances are valid in a repeatedly demonstrable way. The chemical structure-function studies are required so that the nature of the substance is understood, and if possible, mimicked in a synthetic manner. This is the exact way in which the study of indigenous remedies has given us quite a few useful pharmacoactive agents (for example, atropine, ephedrine, D-tubocurarine, digoxin, reserpine, morphine, taxol, physostigmine, quinidine, emetine, and most recently, artemisinin) for therapy and/or for study.

That scientific empiricism is essential for the progress of knowledge. And with all the talk of ‘flushing toxins’, this is exactly what the gormless purveyors of pseudoscience don’t understand.

And now for those who didn’t understand the last panel of the image, it’s the photo of rolling tumbleweed, watching which endlessly roll by is a fine and time-honored way of passing idle time. I am still waiting to hear from this person about my question. I am glad I took the screenshots, though – because the tweets themselves appear to have been deleted(!). Heh.