Wednesday, September 21, 2011

How Physicians Should Evaluate Dietary Supplements

I found this older article in a pile of stuff "to blog" about and gave it a quick look over. It seems like a nice refresher for those who are unaware of some of the history about hos the US got to where we are presently when it comes to the regulation of dietary supplements. The authors describe a number of limitations to this regulation strategy which leave supplements inherently flawed. For example, products are not tested and held to standards regarding active ingredients, but are instead usually "standardized" based on the amount of ingredients that are put into the mixer. As such you may have varying amounts of ingredients depending on (just to name a few):
  • cultivars vs. wild growth
  • misidentification of plants
  • stage of growth at harvest
  • environmental conditions during growth
  • methods of harvest and processing
  • misidentification of plant parts (leaf vs. berry)
  • environmental contaminants (heavy metals, microbes, insects)
  • improper storage
  • variations in temperature, moisture, or light
  • effects of solvents on active ingredients
  • binders and fillers in capsules affecting bioavailability
To answer the "What's the harm?" question, the authors briefly discuss ephedra and its aggressive marketing and misuse in the 90's which led to several reported deaths and who knows how many unreported injuries, hospitalizations, and fatalities. I was surprised, then, when the authors took a very soft conclusion on how they suggest clinicians address these issues with patients. They suggest that taking a history which includes supplement use is important, which I agree with. The authors do not, however, encourage the cessation of supplements, not even for those without evidence. Perhaps I misread the conclusions, but I would have thought that it would be generally good advice to avoid taking unproven remedies with no guarantees of safety and the potential for adulteration with unknown contaminants.

Curious, I looked further into the credentials of the senior author, Larry A. Walker PhD. He is on faculty at Ole Miss. He also serves as a member of the National Advisory Council for the NCCAM. His PubMed results are a little hard to weed through since "walker LA" is a relatively common name and many results go to research which appears outside his scope. His google search results were interesting. Of the first couple of dozen, many point to identical text in which Dr. Walker seems to be supportive of a mushroom-based product for immune support, and specifically a compound called "grifolan". So this is where I decided to indulge in a little trip down Alice's rabbit hole of the internet.

The text is quoting him could easily be taking some other reference out of context and I have no idea if he actually supports the product making the claims. So, I added "grifolan" to PubMed for "walker LA", but that does not yield any results. Searching for "grifolan" alone does generate 44 results, with several reviews of its benefits and, perhaps not surprisingly, no actual experiments involving actual humans. What is really amusing is to search google for "grifolan larry walker" which gets you dozens and dozens of websites all selling mushroom extracts and using the exact same quote: 
"Grifolan has been shown to activate macrophages, a type of cell consider the " heavy artillery": of the immune system, explains Larry A. Walker, Ph.D"
This amazing stuff seems to be good for diabetes, hepatitis, and is even sold at The echo chamber continues on as I found an Amazon reviewer who has three reviews of different herbal products, each of which reads like it is copied right of the back label of the bottle. Fascinating how out of the ether, internet traffic and content that is posted and reposted can eventually build into something appearing to be based in fact, despite a mere handful of actual scientific studies.

No comments:

Post a Comment