The Benefits and Dangers of Vitamin Supplements for Cancer Patients

MD Anderson Cancer Center
Date: 2/14/11

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Lisa: Welcome to Cancer Newsline, a weekly podcast series from the University at Texas, M. D. Anderson Cancer Center. Cancer Newsline helps you stay current with the news on cancer research, diagnosis, treatment and prevention, providing latest information on reducing your family's cancer risk. I'm your host Lisa Garvin, today is our subject is supplement and cancer. We have two guests to talk about that topic today. Dr. Richard Lee, who is the Medical Director of the Integrative Medicine Center here at M. D. Anderson, and Laura Michaud who is manager of the clinical pharmacy services here at M. D. Anderson. Welcome to you both.

Laura: Thank you.

Lisa: I guess supplements can mean any and all things but how do you guys describe what supplements are? Laura?

Laura: I think there's a number of different kinds of products that can be grouped into that, that category. It includes things like vitamins, vitamin C, vitamin A, all those things you can buy over the counter, but it also includes a lot of other natural products, things like herbs, other natural products like soy. Things like Co Q 10, glucosamine. I mean you could go on and on with all the different types of supplements. But basically they're things you buy over the counter that aren't classified as drugs.

Lisa: It would seem to me that a lot of cancer patients are into the natural, you know, nutrients and everything, do you get a lot of patients who come in saying I'm taking this and this is helping my cancer? Or they believe that to be true? Dr. Lee?

Dr. Lee: Yes, supplement use is extremely popular and there have been several cities showing the prevalence rate sometimes being over 50% looking at different cancer patients. So it's a very hot topic right now in the field.

Lisa: Have you found that there are claims out there that people are saying that certain supplements like antioxidants give you a kind of anti-cancer benefit?

Dr. Lee: Uh, huh. These are very popular claims that we come across, that patients bring in either brochures or they heard on TV that these types of products can either prevent their cancer, treat their cancer, or somehow enhance the treatments that they're undergoing.

Lisa: What do you do with a cancer patient? I mean Laura you deal with you know pharmacy and drugs, when patients come in they are supposed to bring a drug list with them, are they not?

Laura: Yes, absolutely. And we highly encourage patients to not only bring the list but to actually bring the bottles, so with the actual medications in them, both prescription and non-prescription items. And that's really important for supplements. Because so many of these things are at multi, different ingredients. If you just have a brand name there might be five different kinds of that certain brand and it's really difficult to know what's in it just by the name. And that goes for prescription medications as well. It's really important to know dosages and whether it is a combination product or just a single agent product. So it's really important for us on the medical end to have a really accurate list of what the patient is actually taking.

Lisa: And I would think that, supplements are not regulated by the FDA so dosages and strengths can differ even amongst the same brand, correct?

Laura: Well there are some regulations. They aren't regulated like drugs so it's a much, much less regulation. There are some good manufacturing guidelines that the FDA puts out. There are also some other types of regulations that they regulate such as the claims that can be made about certain supplements, but the safety and efficacy claims are not proven and don't have to be proven. But for drugs they have to be proven before someone can market them to the public. So, there are some regulations but they are more like food is regulated, in terms of contamination, safety, those kinds of things.

Lisa: When we... go ahead Dr. Lee.

Dr. Lee: I just want to also add in addition to that looking at issues of quality regarding these types of products, and so, I think patients should understand that even though there are green tea type supplement that different companies will produce them differently, so you actually may be getting different compounds within them. And recently I had, we had a speaker coming in from the outside who looked at over 20 green tea type products. What he actually found was that 6 of them didn't even contain any kind of green tea compounds. And other large percentage of them didn't have the amount of green tea that they had on the label. So actually you know only a minority had what they actually had listed on the label.

Lisa: When we are dealing with cancer there have been some studies I understand that there are certain compounds that actually might have a negative impact on cancers. Can we talk about that, I think they were beta-carotene, B12 folate, and then certain anti-oxidants. Let's talk about the beta-carotene for instance.

Dr. Lee: Uh, huh. There have been some very large randomized trials that have looked at beta-carotene. One of the most well published studies looked at beta-carotene's ability to try to prevent lung cancer in those at high risk for lung cancer. So either smokers, current smokers or former smokers are those considered at high risk. What they actually found over the period of the trial is that those that actually receive the beta-carotene supplements versus those [inaudible] pill. Those who got beta-carotene actually had a higher risk of developing lung cancer than those on the placebo on. And that must have been shown in more than one study.

Lisa: What seems to be the issue with B12 folate? What have studies discovered?

Dr. Lee: There is a recent study published in JAMA looking at B12 folate supplementation on cancer risk. This is a study in Scandinavia where they provided B12 folate actually for cardiovascular reasons. And then they went back to look at cancer risk and they found that those who got B12 folate supplementation seem to have a higher risk of cancer development than those who did not.

Lisa: And anti-oxidants. I think that word has been thrown around, I mean obviously the word means like kind of anti-cancer. Anti-oxidants are free radicals. Um, but it seems like anti-oxidants might have cardio toxicity.

Laura: I think it's really important to find out that you have free radicals and reactive oxygen species, which is really what you're talking about with those things that scavenge those. Are not all bad and the fact that a lot of our chemotherapy agents rely on that as part of their mechanism to kill cancer cells so there is a potential to have a negative effect on what you're trying to do with our traditional therapies in terms of treating their cancer. And there also maybe additional risks in terms of just what the anti-oxidants do, but by themselves of in the body in terms of cardiovascular risk... I don't know if you want to speak to that, Dr. Lee.

Dr. Lee: Yes, just following up on your comments. In this study looking at beta-carotene, they not only found there is a higher risk of lung cancer formation but they also found that they had a higher mortality rate and that seemed to be due to increased cardiovascular events like heart attacks. In addition like you mentioned, there is a study where they looked at anti-oxidants during radiation therapy for head and neck cancer patients, and what they found was that it did seem to help reduce side effects. But long terms there seemed to be a higher recurrence rate of their cancer as well as a lower survival rate in those patients who received anti-oxidant therapy. The concern there being that the anti-oxidants may have interfered with the radiation treatment effectiveness.

Lisa: So how do we deal with cancer patients who want to take supplements? Is there any standard recommendation for cancer patients who obviously have nutrition issues, a lot of them? What do you tell them?

Laura: I think the major thing is, is that you keep an open conversations with the patients. I think that many of these people are just trying to do the best for themselves and to make sure they live as long as they possibly can, despite their cancer diagnosis. I think one of the biggest resources we have here is our dietary consults through our nutritionists and trying to get your nutrition through actual food is probably the best thing that a patient can do for themselves. And all of those things that you hear about all the time, diet and exercise are just healthy choices all the way around. And we have wonderful dieticians who can help you in terms of what kinds of things you can do to your diet to make sure you have the balance throughout your entire day and they have fancy software and stuff that could even help you in terms of tracking what you're eating and how you're eating those kinds of things. How you prepare your food. I think that's the best thing that patients can do. On the other note is if people really feel the desire to take supplements in addition, I think it's really important that they tell us what they're taking. So that we can evaluate it and really talk with them about the risks and potential benefits and try to approach it from a scientific perspective and not harm them in the course of them trying to do everything that they can. [Inaudible]

Dr. Lee: I second your comments there about really trying to have an open conversation. Thinking about whole foods and using the dietary consultation service that we have here for patients to really get an assessment. I think the way I approach supplements is really looking at them like medicines. Anytime you take a whole food product and you process it into a pill, or powder, or liquid, then it really becomes more like a medicine. The common question I get all the time is talking maybe about Vitamin D which is another hot topic right now. And so patients will say, well how much vitamin D do I need? And what I'll say is, well have you had your vitamin D level checked. First let's see what your level is, because if it's normal you may not need anything. But if you're deficient then we need to supplement you and if you have high normal levels well maybe you need to back down on the vitamin D supplement you are on. So really thinking about an assessment, either through blood test or with a dietician, to see what your whole food nutrition is like and then proceeding from there I think is a good way to start.

Lisa: We had discussed earlier that you know if they wanted to take a vitamin like a multi-vitamin, a standard multi-vitamin would take care of most of their recommended daily allowances. Is that correct?

Laura: Absolutely. And I think too, you know, for example post menopausal women you know calcium is very important and vitamin D would be important in terms of making sure you absorb the calcium in those supplements, but I think as Americans we don't do very well at getting certain things in our diet and I think that's where the dieticians can really help you make better choices with what you're doing with whole foods and then if you really need assistance taking a good general multi-vitamin I think is a good thing to do. Being careful that a lot of the vitamins that are out there have mega doses in them and you really need to be careful about the amounts of things and how they add up. You know if you're taking multiple supplements that all have vitamin D in it for example, you have to take into account that you're not only getting all that vitamin D but you're also getting vitamin D from your diet. So you have to kind of include everything that you're doing.

Lisa: Well it seems like there is in certain populations a more is better mentally when it comes to supplements, do you see a lot of that amongst our patients here?

Dr. Lee: Yes, they read an article and it says, oh, this is important and it is, but too much of a good thing can actually be dangerous and I think these studies looking at beta-carotene supplementation, vitamin A, vitamin E, B12 folate are showing that once you get to really high dosage you might run into other harmful side effects related to them.

Lisa: So in closing Dr. Lee what would be your take home message to people who are considering supplements? Not only for as a cancer patient but just for overall health.

Dr. Lee: I think supplementation can be an important part, especially for those who have diagnosed deficiencies. But really patients as a whole should be really thinking about food and nutrition as a best source of vitamins and minerals rather than trying to achieve that through pills, or powders, or liquids.

Lisa: And Laura you say there are good online resources where people can check into the efficacy and safely of herbal or natural supplements.

Laura: Absolutely. Some of which are free. Obviously our website has a very good page, several pages that are available to patients and they can look up supplements and things, but most importantly is talk to your healthcare providers about what you are thinking about doing about, your rationale, and really keep that conversation open so that everybody is aware of what you're doing and can help you to assess kind of the benefits and potential harms. That's the best advice I would have.

Lisa: And it sounds like on top of that a drug journal would be a very good idea.

Laura: Yeah absolutely. Keep a list or at least bring a bag with you when you come to your visits.

Lisa: Thank you both. Very interesting topic today. Thank you both for being with us.

Dr. Lee: Thank you.

Laura: You're welcome.

Lisa: If you have questions about anything you've heard today on Cancer Newsline contact askmdanderson at 1-877-MDA-6789 or online at www.mdanderson.org/ask. Thank you for listening to this episode of Cancer Newsline. Tune in next week for the next podcast in our series.

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