Sunday, August 16, 2009

Mushroom extracts for cancer?

A recent question from a client about mushroom extracts for "immune modulation" in cancer patients led me to look into the evidence for these supplements. While the idea that mushrooms could contain medically effective compounds is reasonable, (there are many active chemical compounds, including some very toxic compounds) the evidence for their use is still weak. There have been traditional uses of mushrooms in cancer treatment for centuries or longer, and preliminary testing of mushrooms and compounds in mushrooms since at least the late 1970's. As is the case with many things which fall under the DSHEA as nutritional supplements, mushroom extracts are not required to be tested for efficacy or safety before being sold.

This website is the one my client was asking about. They claim that their two supplements, K9 Immunity and K9 Transfer Factor will help to modulate the immune system which will help to prevent cancer and also help the immune system to recognize the cancer and eliminate it if it is already present. They really have no data to support these claims, and so resort to vague, nonspecific claims of "immune modulation", "detoxification" and "support". One of the videos they have produced looks like a news feature, but is really the president of the company promoting the products. He is careful in that video to avoid specific claims, and says repeatedly that pet owners should pursue appropriate treatment, but their supplements can "improve quality of life". All of the testimonials indicate that the dogs that have done well received appropriate treatment for their cancer including surgery, radiation and/or chemotherapy.
There is never any evidence presented that using the supplements changed the outcome or course of therapy for any of these pets. A paper presented on the website as evidence of effectiveness is basically a series of uncontrolled, unblinded case reports with no controls for
comparison of outcomes, and does not really address the main claims of "immune modulation"
made by the site. Some of the dogs in the report died of their disease, some needed adjustments to their treatment due to side effects, (including immune suppression) and others had progression of their disease. Their definition of cancer as a failure of the immune system to recognize aberrant cells is very simplistic, and does not account for the complexities of cancer biology.

The website seems to be named to attract people searching for information about canine cancer, and has a discussion forum and pages giving basic information about four of the most common types of cancer in dogs, but every page and nearly every paragraph leads to a link or button to order their products. As with many unproven and untested products, the people who seem to be providing such sympathetic and valuable information are really just pushing their specific products. The cost of their two supplements would be between $240 and $300 per month for a giant breed dog (120lbs). That seems like a lot to spend for an unproven and probably ineffective treatment. If they are going to support research, they could at least do a randomized, controlled trail rather than a poorly done case series.

Wednesday, August 5, 2009

Supplements; the sales call.

Yesterday the sales rep from our major supplier of veterinary supplies and drugs stopped by with a rep from a supplement company in tow. Since it was a hot day, and no one in Flagstaff has air conditioning, we decided to sit at the table out back under an awning (this will be important later). The supplement rep (SR for the rest of this post) was very nice, and is a sales rep, not a veterinarian or scientist-she was just doing her job. I did find the methods and claims she used interesting however. Because of DSHEA, supplement makers are not required to test their products for safety or efficacy and also cannot make specific claims to diagnose or treat disease.

The first type of supplement the SR talked about was a joint support supplement containing mostly Glucosamine and MSM. The company has scientific evidence to support their claims for this product. After the sales reps left, I had time to examine these claims more closely. Two of the studies they cite are in vitro studies, shich are fine, but say noting about actual clinical effectiveness, and the third looks better as it involves a randomized, blinded study that used force plate analysis and evaluation of inflamatory factors in the synovial fluid. The problem with this study is that only a summary written by the company is available, the actual paper has not been published, so there is no way to evaluate the methods and data they used.

Next came liver support supplements. My baloney detectors were activated when the SR said that it was "completely natural, and safe, with absolutely no side effects." Apparently it can also help to "detoxify" the liver. the references for the flier on this product have a lot of studies of the pathophysiology of various liver diseases, mostly in humans, and very little or nothing on the acutal clinical effectiveness of most of the ingredients.

Most of the information provided on this company's products was written by Susan Wynn, DVM, who the sales rep said was from the University of Georgia's College of Veterinary Medicine. Actually, Dr. Wynn is the past president of The American Holistic Veterinary Medical Association, and is an adjunct (generally nonsalaried and paid per class or lecture given) professor at Georgia. She is probably paid much better by this supplement company than she is for whatever talks or classes she gives at the veterinary school. She does not have any scientific publications that I could find (there is one case report of treatment of gastrointestinal problems with herbs) and she is the author of a book on veterinary herbal medicine. No controlled trials, but lots of dicussion of the "energetics" of different herbs-yet another type of energy medicine that I was not previously aware of.

Finally, at the end of the visit, the SR said something that I was hard pressed not to laugh at.
She looked around at the backyard, which I have spent the last 10 years making as pleasant as possible (rebuilding the patio, installing a pond and vegetable garden, planting trees, etc) and said; "you have really good feng-shuei here". Feng-shuei was one thing I never considered while improving the backyard. That comment mae me think that maybe the SR was not just doing her job as trained by the company, and maybe was more of a true believer than I thought.

Apparently this sales pitch works on many veterianrians, natualistic fallacies, vague references to toxins and all. It did not inspire me to start selling any of these supplements however.