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Meet Some Medicine Hunters: |
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Urologist, Kingston General Hospital, Kingston, Ontario
What diseases are the focus of your research with medicinal plants? First, a little background. Prostate is associated with three major diseases in men. One is prostate cancer; another is benign prostatic hyperplasia, or enlargement of the prostate in men as they grow older; and prostatitis, which is inflammation of the prostate gland. Herbal treatments and supplements are being explored for prevention and treatment of prostate cancer, prevention and treatment of benign prostatic hyperplasia, and treatment of chronic prostatitis. I'm particularly interested in, and we are studying, herbal treatments for benign prostatic hyperplasia and prostatitis. We are very interested peripherally in the use of these compounds for the prevention of prostate cancer. What herbal remedies show promise for treating the different kinds of prostate problems?
One of them is an extract from the berry of Serenoa repens, the saw palmetto. Saw palmetto grows wild and it's now cultivated in the southeastern United States for this purpose. The other compound we believe has some proven efficacy is extracted from the inner bark of Pygeum africanum, an African tree. We believe these two compounds are probably the ones most worth studying for this particular type of prostate health. As far as prostatitis is concerned, we are investigating three potentially important compounds. One of them, quercetin, is a natural bioflavinoid found in grape seed. The second compound is a bee pollen extract from rye grass that is processed by the bee; we're looking at the pollen extract. The third compound we're using, again, is saw palmetto, or Serenoa repens, and we're looking at its effect in prostatic inflammation. There are four compounds that may help prevent prostate cancer. One of them is vitamin E, which is not an herbal compound. Another is a mineral, selenium, that is found in food and soil. Again, it's not a herbal remedy. And then there are soy products, and lycopenes, another product from tomatoes and other vegetables and fruits. Lycopenes are released in cooked tomato products. Those are the compounds we're looking at for prostate cancer, or others are looking at and we have an interest in. How do you conduct your studies? The study we'll be starting [in early 2005] will be looking at saw palmetto and Pygeum africanum in 3,000 to 4,000 men, over six to seven years, to see whether or not compared to a placebo - a pill that looks identical to these compounds but which contains no medicinal ingredients - they actually promote prostate health. In other words, do they improve symptoms, or prevent the development of prostate enlargement, prevent the development of prostate-related symptoms, or perhaps even prevent prostate cancer (though this last one is not one of our primary goals)? What challenges do you and other plant-medicine researchers face? One of the problems with these herbal treatments is that they have not been subjected to rigorous and validated scientific study, so most of the evidence we have that they work is based on anecdotal case reports or investigators telling us that they work. One of the major problems we've run into with these compounds is the lack of standardization. It's taken us many, many months to find compounds that are standardized and stable and that we know will be standardized and equivalent from batch to batch. We've also had to do stability studies, because many of these compounds don't remain stable in the form that we buy them. We've been upset to find that many of the compounds that we can buy do not contain the active ingredient in the dose or the stability that is suggested by the label. And there's significant batch-to-batch variation. So we've had to go back to suppliers and start all over again, and we're making our own supply of Pygeum africanum and Serenoa repens for use in our study. Do you grow the plants you're investigating?
We've just completed the stability studies and have finally found out we can keep the compound in capsule form for at least six months. Unfortunately, that's not the case in many of the products we buy over the counter. Where will your work fit into Canada's new regulatory framework for herbal and natural medicines? Ours will be one of the first large multi-centre clinical trials using sound scientific methods to determine the benefits of these herbal remedies on prostate health. So in some respects, it will be the template for other studies in the future that look at these types of herbal compounds and human disease states. How did you become involved in this clinical trial? One of the problems is that these types of studies require millions of dollars. The companies producing the therapies cannot afford these types of studies, collectively or individually, so they have to be done by governments. Up to now, the Canadian government has not funded the large-scale studies required. The American government, through an act of Congress, is mandated, through their National Institutes of Health, to look at these complementary and alternative approaches to human health. I'm part of the National Institutes of Health Steering Committee for the use of these herbal treatments in prostate disease, so because of our interest here in these complementary medical therapies we've been able to get involved in the United States National Institutes of Health studies. Canadian patients are going to be able to take advantage of this association.
Where will the test patients be? They're going to be North American patients. This is start of many studies. For instance, in one particular study that's using saw palmetto and Pygeum to look at prostate health and enlargement, we will be enrolling over 3,000 patients in North America. About 400 of those will come from the Southeastern Ontario area. We'll be the only Canadian site studying this particular medication. There are 10 other sites in the United States. How do you choose the patients? Through advertising, family physicians, and other urology practices. We're looking for men over 50 who have some mild to moderate prostate voiding problems, who don't require surgery or active medical therapy, who are interested in prostate health and these type of nutraceuticals or botanicals, and who are interested in helping us discover the long-term effect of these medications. To find these men we'll be advertising by radio, TV, and newspaper. Once we find them, the volunteers will be randomized to either nutraceuticals (or botanicals) or placebos, and they'll continue on them for many, many years. We'll monitor them closely for the development of symptoms, for prostate enlargement, and for the development of prostate cancer. Over time, we'll see if we can prevent prostate disease and help these men. Is it easy to find volunteers for a clinical trial? Finding interested volunteers will be our major challenge. We feel that there are many men out there who are interested in knowing whether or not these plant and herbal therapies really have any benefit. Many of them realize that the evidence is not there yet, and they may want to participate in one or more of our trials.
Have you been doing clinical trials throughout your urology career? I have a clinical practice at Kingston General Hospital at Queen's University, but I've been very interested in clinical trials and prostate disease - primarily benign prostatic hyperplasia and prostatitis and, to a lesser extent, prostate cancer. But until now, all the trials I've done have been with pharmaceuticals and traditional treatment methods. Over time, you start to realize that there is a limitation to what the pharmaceutical industry can do, and that a cure is not always obtainable in these conditions and that it would be nice to just prevent the condition in the first place, or to have a safer, and moderately effective, treatment that would promote long-term prostate health and help the symptoms. Now, many of my patients believe they have found that sort of thing by taking herbal treatments. Unfortunately, as a traditional scientist, I'd like to see proof of efficacy and of long-term safety, which we don't have. Only by these standard methods of research and enquiry can we determine the true efficacy and safety of these compounds. If they are truly efficacious, it's these types of studies that will truly convince the medical community. Is the medical community skeptical or open-minded about these treatments? They're skeptical, but open-minded. In fact, that's a sign of a good scientist. It's the way we progress in science. We remain skeptical, but open-minded so that we're willing to change our mind based on real evidence. I think that's what our role in this is. Traditional clinical scientists like myself, using the clinical skills that we've developed in assessing pharmaceuticals, use those same skills to assess the herbal treatments and botanicals. What do the patients expect when they use herbal remedies? We have to make sure we don't make an unrealistic bar for these herbals to jump over, because studies show that men with prostate disease are willing to accept a lesser result with herbals for a perception of increased safety. And men are willing to consider taking herbal treatments, even if they're not helping the symptoms, as long as they're convinced that these herbal treatments will prevent progression of the disease over time - in other words, keep them where they are right now and not let them get any worse. So these are the type of scientific programs we're looking at - not necessarily curing the disease, but rather preventing progression or preventing it in the first place. Do you prescribe herbal remedies in your clinical practice? The interesting thing is that in Canada, there are no regulations. There is no prescription for these [compounds], and anybody can pick them up anyplace. This is a major problem. Based on evidence, I cannot ethically prescribe or suggest the use of a botanical or herbal treatment because the evidence [that they work] is not there. But if a patient is interested, I will then work with the patient and make suggestions based on the best available evidence of which ones they should be on. The problem I have is that there are literally thousands of these botanicals available on the Canadian market either via the health food store, the pharmacy or the Internet. Many of these compounds are not legitimate. They do not contain what they say they contain, or the product is not durable and stable. So it's sometimes "buyer beware." I do suggest to my patients that they obtain their supply from a reputable source and investigate the source. We've done that as well, and many times have come up with a product lacking in many of the attributes we'd like to see in a good product. But there are some very good companies in Canada and North America who produce herbal preparations that do contain what they're supposed to contain, and if they do what they're supposed to do, then they'll be very helpful to the patient. But until the evidence is actually there, it's really unethical for a physician to suggest taking something just based on anecdotal information and case reports. Another problem is that the biggest proponents of the use of herbal treatments are the companies that produce them. There is a major conflict of interest there. And they are marketed very well. In fact, the amount of money spent in Canada on herbal treatments rivals that of the regular pharmaceuticals. It's amazing - millions and millions of dollars. I have patients who are quite willing to spend $ 50 to $ 100 a month on herbal treatments who would not even consider spending $ 30 a month on a regularly prescribed medication. The reason, of course, is very good marketing, but also the perception that herbal treatments are better for you, that they're safer and more natural. That could be the case, but it would be nice to prove it, wouldn't it? |
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