Terra Sigillata

Misconceptions on herbs and cancer

Curcumin has been much in the news as of late as considerable cell culture data has been suggestive of the compound’s utility in cancer prevention and cancer treatment. The impetus for me speaking on this has been the recent report by my ScienceBlogs.com colleague, Razib, at Gene Expression.

Unfortunately, the story of curcumin has been clouded by overly aggressive attempts by marketers to manipulate in vitro, or Petri dish, cell culture studies with human consumption. Some very outstanding scientists have been working on the anticancer effects of this herb, but it seems that their efforts and results have been overexaggerated and misrepresented.

Briefly, we have known that many natural compounds used at high concentrations, including curcumin, can arrest or kill human cancer cells growing on a plastic dish in the laboratory.

The bigger question in using these remedies for humans with cancer has been whether the concentrations used in cell culture can be acheived in the bloodstream of patients. Most naturally-occuring compounds must be concentrated hundreds or thousands-fold from their natural source, and then be given at doses that would choke a horse.

With curcumin, the very attractive in vitro anticancer data on the compound is offset by the fact that curcumin is poorly bioavailable. What that means is that one takes a certain amount of curcumin by mouth, very little is absorbed into the bloodstream. The question, with curcumin and any other drug, is whether concentrations that kill cancer cells in culture can be achieved in human cells.

Sadly, this is not possible with curcumin, at least at doses of one or more grams per day.

Any recommendations for its use in humans should not be taken seriously until prospective studies of its anticancer action are performed in human subjects.

Comments

  1. #1 John
    September 21, 2006

    Hi–
    I saw a link to your post on an internet support board for lymphoma. I get a newsletter with ideas for helping my lymphoma and one of the recommendations is to take curcumin as follows. You mention problems with absorbtion— do you think the method mentioned would help????? Here is a quote from the newsletter

    Thank you for your help. John

    It’s good to hear that many people are enjoying the new (therapeutic)
    breakfast described in item #6 in the August 2006 newsletter. I even
    hear the word “delicious” …on occasion (haha). It is the
    “centerpiece/foundation” for most of the dietary natural strategies
    chosen from scientific articles on MedLine, with the potential to
    influence cell signaling pathways governing lymphoma progression…all
    that…while keeping you healthy and strong too!
    Some questions have arisen and there are some additional points that
    can be made.
    Re the turmeric/curcumin, there is no further need to combine it
    with bioperine to help with absorption. Curcumin is absorbed in fat,
    not water. Opening the capsules and stirring the powder into the
    cottage cheese and yogurt will ensure absorption at that point in the
    “process” and then, equally important, being a fat, it will be absorbed
    from the intestine into the lymphatic system; exactly where we want
    it….not into the bloodstream and then to the liver to be filtered out
    before it ever does any good.
    It is also believed that you can reduce the curcumin from the old 4500
    mg./day to about 2000 mg./day and take it this way *everyday* in
    between treatments. There is some indication that curcumin blocks the
    effectiveness of the chemo drug cyclophosphamide (the “C” in CVP and
    CHOP), so it should be stopped if taking either of these chemos. In
    fact, I generally recommend the entire group of natural *dietary*
    strategies be stopped while on chemo of any kind.
    Those who experience instability, that is some growth in their nodes,
    may want to increase the curcumin dosage to perhaps 4000 mg./day.
    This will still be well within the safe range, which in humans has been
    shown to be upwards of 12 grams/day.

  2. #2 Mara
    September 21, 2006

    Just wondering if you could post some comments on glucosamine for “troubled” joints?

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