"As a physician who has studied herbs for the past 50 years, I always seem to reach the same brick wall. When I hear that something is "nourishing to the liver," "hepatoprotective," or the same types of terms applied to the kidney, usually the person praising these qualities of the herbs are not citing actual scientific studies. I highly value clinical experience or I wouldn't be taking this course! However, general statements like these are not sufficient for me. You seem to have done a lot of research on the chemical properties of herbs. How can I overcome my resistance to reputed generalities? I haven't read David's book on adaptogens yet. Will that help me? Will the specific "hepatoprotective" evidence become evident to me as we study individual herbs? Thanks!

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4209543/ This looks like a decent review study in what is described as a peer-reviewed journal. It appears that what I'll need to do is carefully evaluate each herb that I decide to use as they come up. I'm retired so don't have an active practice right now, so I have the luxury of trying to get the big picture before I focus on detailed studies. I'm a highly intuitive practitioner who trained in allopathic medicine at a time when thinking "outside the box" was quite suspect.I'll try to deal with my skepticism as it arises. By the way, I was looking through my herb reference library and found Pharmacognosy and Pharmacobiotechnology by James Robbers, Marilyn Speedie, and Varro Tyler from 1996. I'm not sure if you're familiar with the book but it looks good, so I'll do some supplemental reading there about phytochemistry.

Rich said: Thank you so much for the comment/question. One thing to keep in mind for these classes that I am teaching is that they are not clinical classes - I am going through a fair amount of material i both the botany and the phytochemistry sections, and though I know there is understandably a lot of interest in digressing into clinical applications, that is something you will get plenty of with David and can't be a focus for me in these few weeks I am with all of you. I do think David's books are good choices for you. I also have found Rudolf Weiss and Donald Yance to be authors helpful for MDs or people with a background in mainstream medicine. You should also get your hands on AHPA's Botanical Safety Handbook and Herb, Nutrient, and Drug Interactions, by Stargrove et al., though both are specifically safety-oriented. Thank you for the link to the article. I have not had a chance to read it yet but will check it out. This article aside, one thing to understand is the deep bias against herbal medicine in the U.S., making a lot of the published research suspect. The peer review process does nothing to protect against this if the "peers" included are not herbal experts but rather, mainstream medical research experts with their own biases - or even when outright bias is lacking - their own ignorance of herbal medicine, all of which often leads to conclusions that are off the mark or misleading. If you are looking for published research, I recommend going outside the U.S., which is fairly backward in this area (with exceptions). The Lancet for instance is vastly superior to both NEJM and JAMA for herbal studies, but other countries are getting it better still. It doesn't have to be this way - over twenty years ago (late 90s) JAMA published an entire volume on herbal medicine, and it was fairly good - a combination of positive and negative results, things to quibble about, but fair-minded and very helpful. For ex., one study showing positive results for ginkgo slowing the progression of Alzheimers-related dementia. Another showing clear safety and efficacy for use of saw palmetto for BPH. It made me very hopeful that the medical establishment was turning a corner. Since then what has JAMA contributed in a fair way to this area of research and knowledge? Basically, nothing. What has been published has been often very problematic. One place where you can see that anti-herb bias very clearly with a thin veneer of objectivity is the NIH's National Center for Complementary and Alternative Health. Their conclusions and public statements are almost always negative - i.e. advising against use - even when their linked citations say otherwise. I teach a class for my own students on reading published research and how to approach it skeptically - something I am sure with your expertise you would not need - but I fill the class with specific examples of this kind of bias, which I don't have time to list here, as well as counter-examples when the herbal industry / community has exhibited its own kind of bias. That is also a problem! There is a lot of pseudo-science cited or fine but extremely limited findings cited by herbalists as if it were definitive - such as in vitro research, which we know statistically is likely to not even be a true replicable finding with clinical relevance. Weiss (whose text is the standard in Germany for herbal med students) wrote that "empirical data are data". What he meant by that is that the accumulated knowledge of practitioners over centuries and millennia is actually quite reliable data, and it is not "scientific" to ignore that data. Today much of what is called science is really just one specific subset of science, and unsurprisingly the model that best supports the commercial aspects of medicine - patenting and proprietary ownership in particular. I consider myself a healthy skeptic but there is a difference between being a skeptic, and a pretense of objectivity that refuses to recognize empirical data collected over millennia. So that will most likely be a challenge for you, but I would encourage you to consider all of that. Good quality, unbiased science is a crucial source of information about herbs and we need more of it - though there is sometimes more out there than people realize if they do not conduct a literature review or search. Either way we clearly need more. That said, because of inevitable biases as well as limited funding, and the inherent limitations in research models including RCTs, science as a whole is less reliable than solid tradition for the use of herbs. But actually I agree with Weiss that there is actually no difference between the two - strong, solid traditional data is science. so that is all a choice you will have to make and figure out for your own path - I will say that if you limit yourself in the way you're describing you will be helping people far less with herbal medicines than you otherwise could be. And btw I do not consider Varro Tyler to be a good source. He was far too conservative in my opinion in the same way the NIH is today. But you can see how you feel about it. All of this is intended as food for thought for you, nothing more, and I hope you receive it in that constructive light Chew thoroughly! (ha)

Thanks so much for your thoughtful reply! I especially appreciate your thoughts on the NIH's National Center for Complementary and Health and Varro Tyler. My husband (also a physician) and I are both well aware of the influence the pharmaceutical industry has on the outcome and bias of studies. Also, I am very clinically oriented and totally respect the years and indeed thousands of years of clinical experience available to us about the importance of herbal medicine in healing. I look forward to learning more of what David has to teach in this regard. I don't seem to have a frame of reference for terms like "hepatoprotective" and herbs that are "nourishing" to particular organ systems. I'll see if David's book on adaptogens has any answers to this mystery for me, but wanted to touch base with your thoughts on the subject before your unit was complete. It's obvious that you value the science of healing and I've enjoyed your summary of a lot of info I last addressed many years ago in broad strokes.