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Consumers Overwhelmed with Conflicting Medical Info

Encore broadcast that originally aired March 18, 2009.

Audio

Aired 9/8/09

Consumers receive varying reports about what is healthy and what is not.

MAUREEN CAVANAUGH (Host): I'm Maureen Cavanaugh. You're listening to These Days on KPBS. News stories about health are sure-fire attention grabbers. Newspapers love to headline them, TV news programs love to promote them. They tell us that new research shows chocolate is good for us, or that coffee is bad for us, or that alcohol is good for us if we drink it sometimes and bad for us at other times. Then, like clockwork, we find out six months later that a newer study finds just the opposite. Something very like that happened recently when new medical research from Great Britain seems to have reversed the idea that red wine could have beneficial health effects. Now we hear a drink a day of any kind of alcohol can increase a woman's risk of cancer. Why does this keep happening and what are we to believe, especially about something as important as our health? To help us understand how to get beyond the hype and closer to the truth of what medical research is really telling us, I'd like to introduce my guest, Dr. Gary Firestein, chief of the Division of Rheumatology, Allergy & Immunology at UC San Diego School of Medicine, and Dean of Translational Medicine. And welcome to These Days, Dr. Firestein.

DR. GARY FIRESTEIN (Chief, Division of Rheumatology, Allergy & Immunology, UCSD School of Medicine): Thank you very much. I'm glad to be here.

CAVANAUGH: And we'd also like to hear what you think about all the contrasting medical information out there. You can call us with your question or comment. What medical study is confusing you? Our number is 1-888-895-5727. Well, Dr. Firestein, do you find that medical research in popular culture is helping people stay healthy or is it just making them give up?

DR. FIRESTEIN: Well, first of all, I think it's important to emphasize that there is tremendous chaos out there in terms of the amount of information that we're bombarded with every day in terms of our health. And it's not just the lay public that is confused by conflicting reports about whether or not coffee is good for you or bad for you or – or whether chocolate is good for you or – actually I haven't heard anywhere that anybody said that chocolate is bad for you, thankfully. So we can at least depend on that, I suspect.

CAVANAUGH: For the next six months.

DR. FIRESTEIN: Right. So it's not just the lay public that is confused by that but also the professionals that have to deal with the information on an ongoing basis and try again to separate the wheat from the chaff in terms of what is believable and what is not believable. It is a terribly daunting task. There are many reasons why we get such conflicting results from these large studies, and some of them are quite technical related to how statistics work and others are related to how studies are designed. And I'll give you an example. So if, for instance, I was able to show to you that people that drink alcohol are – a certain amount of alcohol are more susceptible to lung cancer, you could probably design a study that would show that but if one looked more closely in terms of the actual people that are enrolled in this questionnaire type study, what you might find is that people who drink alcohol also tend to smoke more cigarettes. And people that smoke cigarettes are more susceptible to lung cancer. And so what you then have is this causality or an association which doesn't apply causality so one might think from a study like that and you might see headlines that say 'alcohol associated with cancer,' but it turns out actually that it has nothing to do with the alcohol but other things that people are doing that are associated with that.

CAVANAUGH: That's Dr. Gary Firestein and he's chief of the Division of Rheumatology, Allergy & Immunology at UC San Diego School of Medicine, and Dean of Translational Medicine. I'd like to welcome a second guest now on the line, Dr. John Swartzberg, Director of the UC Berkeley-UC San Francisco Joint Medical Program and chair of the editorial board for the UC Berkeley Wellness Letter. Dr. Swartzberg, thanks for joining us.

DR. JOHN SWARTZBERG (Diretor, UC Berkeley-UC San Francisco Joint Medical Program): My pleasure. Thank you for asking me.

CAVANAUGH: And, also, I want to remind our audience we are asking for your calls. Tell us what you think about the medical studies. Which one is confusing you? Did you start taking vitamin E back in the nineties or do you think red wine can still benefit your health? Give us a call at 1-888-895-5727. And Dr. Swartzberg, I want to ask you, we heard from Dr. Firestein just a little bit about the process of scientific research, isn't it also not just the correlations that he was talking about, sort of switching the idea that A causes B when it's not actually that way, but the number of people involved in these studies and who they choose to participate.

DR. SWARTZBERG: Yes, I certainly would agree with Dr. Firestein's comments. In addition, the number of people in the study is critical. I can't tell you how many times we look at a study that says vitamin E prevents cancer and then you look and you see that there were 14 subjects who received vitamin E and 13 who received a placebo. And so you just can't make much sense out of these small studies, so that's another key thing that one has to look at.

CAVANAUGH: And also I read about research that found that a certain vitamin might do something to help people's health but then they found out that the people who were participating in the study regularly took all sorts of pills and they were probably more likely to be concerned about their health in general. And so it sort of tainted the results.

DR. SWARTZBERG: Right, it's a phenomenon that's very common and that is that the people who tend to take vitamins in general tend to take better care of their health in other ways, and so it's very hard to ferret out what the role of vitamins are compared to the other factors.

CAVANAUGH: Now, Dr. Firestein, why do the results change over time?

DR. FIRESTEIN: Well, it – assuming that humans – human physiology hasn't changed much over the last couple of thousand years, it's more likely related to the study design. And as was just pointed out, it depends on which population you study, how well you control for some confounding variables such as whether smokers are also drinking alcohol or drinking coffee or if someone is taking vitamins whether they're taking other supplements or whether they're exercising more. Though I suspect in many cases it's because of the design of the study and also how corrections are made for looking at multiple variables in the study. So, for instance, if you are looking at a large amount of data with thousands and thousands of data points, one would define, traditionally, what is called statistical significance by saying that you have a 95% chance of being correct. And if you are looking at thousands of data points, actually it's very easy to find a few things that will hit that 95% probability just by random chance. Now there are statistical ways of correcting for that and oftentimes those don't – those aren't correctly performed in some of the studies that have some more surprising results. So study design and proper use of statistics are the most, I think, among the most common reasons why we can get two studies that are supposedly looking at the same thing but can come up with exactly opposite results.

CAVANAUGH: Now, Gary, part of your title here is Dean of Translational Medicine, which means that you try – you attempt to translate what comes out of medical research into what doctors understand and what patients can understand. Can you guide us through perhaps one research study that perhaps sticks in your mind as to how you accomplished that translation?

DR. FIRESTEIN: Well, actually let me first just talk a little bit about translational medicine, which is – it's very nice to have that as one's specialty because everybody has a different definition, and it really has, actually, two different major components. One is the translation of fundamental scientific discoveries in the laboratory to new therapies oftentimes in either pharmaceutical industry or in academia. And then the second is probably what you're talking about here, which is translating those new discoveries into improvements in human health out in the community. And I think that there are a number of examples where well-controlled studies can have a major impact on how we view certain medicines or lifestyle choices. An example, probably one of the best examples, is related to estrogen. There were scores or perhaps even hundreds of studies looking in an uncontrolled fashion at how estrogens might have an impact on women's health, supplemental estrogens especially, after menopause. And, by and large, those studies all showed a marked improvement in health, very good benefit over the risk. But the NIH, the National Institutes of Health, had a very large study that really compared estrogen to placebo and, which is a sugar pill essentially, and when that study was done, actually the results were quite different from the uncontrolled studies that were done previously. And, ultimately, there was a massive communication effort to inform the public about how the risk-benefit ratio of estrogen might not be as favorable as everybody thought. Now, it turns out actually even that study has become somewhat controversial, that many of the issues that were raised were quite complex and estrogen, the risk-benefit ratio of estrogen is more complicated than even that study suggested several years ago.

CAVANAUGH: Why am I not surprised?

DR. FIRESTEIN: Well, of course.

CAVANAUGH: And Dr. Swartzberg, what kind of responsibility do you think the media has in the way the medical research is reported to the general public?

DR. SWARTZBERG: I think the media is – it's difficult for the media because most journalists are not trained in the kinds of work that Dr. Firestein and that we're doing here, that is what medical scientists are doing. And so they're having a difficult time translating it. And the other problem is that the people doing the research aren't really trained very well in general about how to communicate it. So that's the real dilemma that we have. And then if you couple that with the knowledge that what we're trying to do when we look at these research projects, we're trying to answer truths about nature and that's very difficult to do. But people want answers and so the best we can do is look at the data that we have and try to draw a reasonable conclusion for it. And, of course, what happens when you do that is that it leads to a contradictory study coming out two months later. It was about, oh, I guess ten years or so ago that antioxidants were really hot, vitamin E, vitamin C, beta carotene, and I remember that the Wellness Letter came out and said, well, you know, it seems reasonable to take these even though there's not real hard science that it's either safe or efficacious. And within a month, the studies came out with beta carotene in smokers showing that it increased the risk of cancer. So the public feels really whip-sawed. What's, I think, critical is that we have to put all of these studies into the context of the bulk of the literature and what's known and make sure that the public understands that we really don't know many of the truths about nature.

CAVANAUGH: You know, we are taking your calls about what medical studies are confusing you. The number is 1-888-895-5727. Let's go to David in El Cajon. Good morning, David. Hello, David, are you there?

DAVID (Caller, El Cajon): Yes, I'm here.

CAVANAUGH: And what is your concern?

DAVID: I – I'm – I just want to share with some humor an experience I had when the first artificial sweetener was banned and I was living in Massachusetts. And I was going in the grocery store and this woman came in with about ten cans of—those were the tin cans, by the way, before aluminum…

CAVANAUGH: Umm-hmm.

DAVID: …and started throwing them at the grocer, calling him a murderer because it had this sweetener in it. And I kind of chuckled because most of these reports then, when people – when scientists were still considered the god, the science, and all of truth, and that many of the studies now that are done, as some of your people have already said, are not really good science. They have to be repeated, they have to be actually structured so that they prove a point rather than someone's issue. And – But I'll never forget the – It was very amusing to me because, of course, about five or six years later, that artificial sweetener was found to be completely unaffect – you know, it didn't affect anybody, it just made stuff taste sweet without having sugar in it. I…

CAVANAUGH: David, do you use an artificial sweetener?

DAVID: No, I don't. I – I'm 68 years old and my family of 13 generations of Americans haven't had any cancer for the last 8 years and I never – 8 generations, rather, and I've never had the flu.

CAVANAUGH: Well, congratulations…

DAVID: I'm one of the normal…

CAVANAUGH: …for that. Thank you, David, for your call very much. We have to take a very short break. We will be back with our guests and our conversation about medical studies, what you can believe and why it's so difficult to believe. Our number is 1-888-895-5727. You're listening to These Days on KPBS.

# # #

CAVANAUGH: Welcome back. I'm Maureen Cavanaugh. You're listening to These Days on KPBS. And this morning we're trying to get beyond the hype and closer to the truth of what sometimes conflicting and contradictory medical research information is really telling us. I'd like to reintroduce my guests, Dr. Gary Firestein. He's chief of the Division of Rheumatology, Allergy and Immunology at UC San Diego School of Medicine, and Dean of Translational Medicine there, and Dr. John Swartzberg, director of the UC Berkeley-UC San Francisco Joint Medical Program and chair of the editorial board for the UC Berkeley Wellness Letter.

We are also taking your calls. If there are some medical research information that's confusing you, give us a call at 1-888-895-5727. And Dr. Swartzberg, I want to talk to you about – because you are on the editor – editorial board of the UC Berkeley Wellness Letter, and you were telling us about sometimes how you struggle over these conflicting studies. Tell us a little bit more about what our caller David was talking about when it comes to artificial sweeteners.

DR. SWARTZBERG: Yes, I think – I thought David made a really great point, and that is that there are a lot of people who have belief systems about, quote, chemicals and that they all must be bad with the shocking news for most people that everything we consume is, of course, a chemical. We're made of chemicals, and so one has to be really careful with just throwing out anything that's new because it's a, quote, chemical. What we do with a question like, for example, aspartame, one of the artificial sweeteners that I think David was probably talking about, is we'll try and look at the literature and try and make sense out of it. As Dr. Firestein was saying, we'll try to judge which of the papers were good, which of the papers really had a lot in limitations and whether we could use those, and then try to make a judgment based upon the information. The problem almost always is, is there's not enough good science to give us an absolute conclusion so one has to make a judgment based upon what's known. And that's called the editorial process.

CAVANAUGH: And do you think that sometimes perhaps the research comes out too soon?

DR. SWARTZBERG: Oh, I think that it's an amazing phenomenon to see the amount of literature today in medicine compared to just two decades ago. There's a – there are many, many more journals, many, many more articles, people's tenures based upon getting those articles cranked out, and so there's an awful lot of data to file through. People have attacked that issue though in a – in some creative and very good ways. The Cochran Foundation, for example, that critically looks at literature has been a wonderful resource for us.

CAVANAUGH: And Dr. Firestein, while – during the break, we were discussing what David was talking about with the artificial sweeteners and you made the point that, indeed, when they do laboratory studies on animals and they give the animals these huge doses, that sometimes that doesn't translate into what's going to affect human beings.

DR. FIRESTEIN: That's absolutely correct. Some of these toxicology type studies in animals or in animal models are essential to assess safety before something can be judged usable in humans. But they need to be interpreted with some caution because physiology in dogs and mice and rats can oftentimes be very different from what appears in humans. A good example of this would be chocolate. Chocolate is, in reasonably large amounts, is actually quite toxic to dogs. And if we use that as the judge for what would be safe to go into humans or not, we would live in a world without chocolate and I – it's hard to think of a greater tragedy than that.

CAVANAUGH: Yes.

DR. FIRESTEIN: So it's just important to understand them in the context. The other thing is that typically these studies use very large amounts of a particular chemical or compound and then you try to extrapolate to what would happen if a smaller dose were used in a much larger group of people. And there are lots of issues with trying to extrapolate like that.

CAVANAUGH: We're taking your calls on the subject of medical research. Our number here is 1-888-895-5727. And Arlene in Mission Hills is on the line. Hi, Arlene.

ARLENE (Caller, Mission Hills): Yes, thank you for taking my call. I have been dealing with blood pressure problems for years and I'm concerned about the side effects of medication that make you – I realize that hypertension is a silent killer but when the side effects of medication make you feel so bad that you don't even want to get out of bed in the morning, you're so fatigued and depressed, I have a problem with that.

CAVANAUGH: Uh-huh.

ARLENE: And I'm just losing faith in not only the medications but my doctor as well. And in the process of trying to find a new doctor, I – I'm finding, well, this doctor isn't taking new patients, that doctor can't see anybody until July, and the other one, you know, is just graduated from medical school. And the problem that I see with all of these studies and information is that they don't take into account individuals. They keep moving the goalposts on blood pressure and cholesterol and I'm 72 years old and I know I'm getting older, I can feel that, but I'm just completely frustrated.

CAVANAUGH: Well, thank you for that, Arlene. Thank you for sharing that with us. I wondered, as Arlene was talking, Dr. Swartzberg, I got – I was reminded of the fact that we've had these recalls of medicines. Vioxx, right, and that have been tested, that have gone through research and yet when they get out in the public and people like Arlene start to take them, they manifest these terrible side effects. What about that kind of research?

DR. SWARTZBERG: Well, the problem with that kind of research there is manifold. One is that although there's a lot of pre-marketing research done, one has to be sure that scientists have all of that data that the pharmaceutical companies utilized to reach the conclusions. With the example you gave of Vioxx, it wasn’t until a considerable amount of time after that drug was released that the scientific community was able to have access to that data and really had a very different interpretation than the company had. So that's one big problem. Another is that no matter how large the pre-marketing trials are, they're not going to be nearly as large as the drug that's being used in the general population once it's been released. So you've got a much large denominator now, and other things may be discovered after drugs have been released. I think Arlene brings up a very good point that there's no free lunch, that drugs do have side effects. The good thing about hypertension is that there are a plethora of drugs and if one doesn't work or if one works but causes side effects, then there probably is another family of drugs that would work for her, and it's often trial and error. On the other hand, hypertension's a good example of a disease where we know that treating it does reduce the consequences of, for example a heart attack or stroke, which are devastating. So we know treating it helps. Finally, she brings up another, what I thought was a excellent point, and that is that she's a 72 year old woman. How many studies have been done with 10,000 72-year-old women of her background and looked at that with blood pressure medications? And the answer is, of course, none. We try to generalize – or we generalize from specific studies to large swaths of the population and that's a limitation. I think, in time, as our science gets better and our ability to look at individuals more carefully, we're going to have much better answers.

CAVANAUGH: We have another caller on the line on this point. Edeet (sp) in San Diego. Hi, Edeet.

EDEET (Caller, San Diego): Hi. Thank you for taking my call.

CAVANAUGH: You're welcome.

EDEET: I'm actually a physician assistant and what's frustrating I think from my point of view is that a lot of these studies, because of financial reasons, are driven by pharmaceutical companies whose – who we can say, at the least, have some conflict of interest in terms of the outcome of the studies. And I think there's a lot of health related issues that are not addressed and so it's just easier if people just take the drug and the drug companies are marketing them and, you know, bottom line, if you sit down with your patient and if you help them lose weight and quit smoking and get better diets that a lot of these problems, you don't have to throw a pill at. But it's, you know, research is driven by pharmaceutical companies a lot of times and there's not a lot of research on how vitamin B affects, you know, memory or so on and so forth.

CAVANAUGH: Thank you for that call. Dr. Firestein, the idea of a pharmaceutical company doing its own research and then releasing a drug with FDA approval and then the larger scientific community actually finally starts to get a look at it. Does that happen a lot?

DR. FIRESTEIN: Well, it's a little bit more complicated than that in terms of drug development. For a drug to be approved, generally it goes through three main phases of testing. Phase one is really for safety and tolerability, and those tend to be fairly small. And then phase two is generally looking for the first signs of efficacy. Those are somewhat larger studies. And then the very large, what are called phase three studies are the ones that really test for efficacy in large, typically placebo controlled, studies. And there has been a problem in the past related to release of information and it's understandable from the perspective of the pharmaceutical company why they want to keep their data in house. But there's a growing trend towards now providing data warehouses that can hold this information and allowing other researchers access to them – to it in order to really assess what the true benefits and risks and toxicities might be.

CAVANAUGH: That's Dr. Gary Firestein. And my guest on the phone is Dr. John Swartzberg. And we are talking about the efficacy of medical research and what you can believe and what sometimes is difficult to believe. And we are taking your calls at 1-888-895-5727. I want to ask the two of you doctors about some of the biggest medical studies – results that you think cause a great deal of confusion. Now, Dr. Firestein, you mentioned the estrogen study. Do you have another one that you could point to?

DR. FIRESTEIN: Well, you know, I mean, just in the last couple of weeks there was a report out of England related to folic acid supplementation increasing the risk of prostate cancer. And I think that's one where, again, it's uncertain having – you know, whether or not this is a true risk or whether, again, it's one of the random – it's due to random chance just from looking at large numbers of variables. But, I mean, I think you pointed out some of the key ones and those were related to coffee, vitamin supplementation, especially antioxidants, and alcohol, are probably the three areas where there has been as much whiplash as people go – get moved back and forth as to whether something is good or bad for you. And I think it really requires a fairly healthy degree of skepticism when looking at all of these studies at this point.

CAVANAUGH: And what is the latest word on coffee, as you understand it?

DR. FIRESTEIN: Well, it's a loaded question. All things in moderation, I think is probably the safest bet on that. And I suspect that coffee in moderation is probably safe and also helps make that morning drive in from – into work a little bit safer as well.

CAVANAUGH: And, Dr. Swartzberg, is that how you understand the coffee studies?

DR. SWARTZBERG: You know, coffee's interesting because it's probably been studied for more years and more thoroughly than most other things we consume. And the bulk of the data with coffee suggests that it's safe, just as Dr. Firestein said. There's some data that's so-so, that suggests perhaps you have a lower chance for gallstones, a lower possibility of type II diabetes, but these studies are – they're not sufficient to really draw absolute conclusions from. But I think generally speaking, yes, coffee's safe. And I sure hope so because I do need it to get into work in the morning.

CAVANAUGH: Well, you…

DR. SWARTZBERG: I…

CAVANAUGH: I was just going to mention the point that in so much of the information on these studies, even if it's good news about a particular substance, coffee or red wine, there's always the proviso 'but if you don't drink it, don't start.'

DR. SWARTZBERG: Well, yeah.

CAVANAUGH: Which kind of sort of like puts everything on its head.

DR. SWARTZBERG: Well, we really struggle. I think the question of alcohol is an area that we've really struggled with at the Wellness Letter editorial board, and that is that has already been mentioned, there are some apparent salutary affects from consuming modest amounts of alcohol. The problem is that there's also the danger for at least a small percentage of the population, sometimes not that small, of a problem of alcohol dependency and sometimes addiction. And so we go back and forth about saying, should you tell an entire population that it's important to drink and then have people develop alcoholism? Well, of course not. On the other hand, if there is some value to this, how do you tell people to try it? We really struggle with how to communicate that information.

CAVANAUGH: Let me go to the phones because we have a lot of people who want to join the conversation. Larry is in La Jolla. And good morning, Larry.

LARRY (Caller, La Jolla): Hey, good morning. My question is aspirin. I've heard it's good for you, bad for you. My doctor said I don't need to take it. And I heard the other day on the news if you don't take it, you could die. So it's very confusing.

CAVANAUGH: I heard that just yesterday, Larry. So which doctor would like to take that?

DR. SWARTZBERG: I'll be happy to start.

DR. FIRESTEIN: And…

CAVANAUGH: Okay. Dr. Swartzberg.

DR. SWARTZBERG: Well, we've been whipsawed in this as well, Larry. The best data that was available until very recently, like about a week ago or less, was that there's not good information that if you've never had a heart attack that taking aspirin is going to be better for you than not taking it. As a matter of fact, it might have been a little more – might be a little bit more risky if you've never had a heart attack in terms of a less common type of stroke called a hemorrhagic stroke. And then in the Annals of Internal Medicine this week, it came out the report from a branch of the – a group that advices the CDC saying that in males even if they've never had a heart attack, that taking a very small dose, it's 81 milligrams a day of aspirin, probably is beneficial to prevent a heart attack but it won't affect the chances of a stroke. And in females, it probably doesn't prevent a heart attack but may prevent a stroke. So I think our feet are fairly planted in the air in terms of what's called primary prevention, that is if you've never had a heart attack, should you take aspirin? On the other hand, if you have had a heart attack, clearly you should check with your physician but the data is really very good that using small doses of aspirin will be helpful in preventing a second heart attack.

DR. FIRESTEIN: Yeah, and just to add onto that, it's also important to recognize that a drug such as aspirin, even though they're over the counter, can carry some significant risk and the one that we see the most commonly in our arthritis clinic, of course, is related to gastric ulcers and duodenal ulcers that can sometimes perforate or cause bleeding. And aspirin, like all of the other nonsteroidal anti-inflammatory drugs like ibuprofen and so on, can potentially have side effects. And in an Institute of Medicine study contributed significantly to tens of thousands of adverse events over a period of years. So it's important to recognize that aspirin, even though it's sitting on the counter at the drug store and you can buy it without a prescription, does have potential for some toxicity and risk.

CAVANAUGH: That's Dr. Gary Firestein, and my other guest on the line is Dr. John Swartzberg. We are going to take a short break right now. When we return, we will continue our discussion about sometimes confusing medical research and what you should believe and perhaps what you should not believe. And we'll continue to take your calls at 1-888-895-5727. We'll be back in a moment.

# # #

CAVANAUGH: I'm Maureen Cavanaugh. You're listening to These Days on KPBS. My guests are Dr. Gary Firestein and Dr. John Swartzberg. And we are taking your calls on what medical studies are confusing you and any information that you'd like to have, the latest information we have about what's good for you and what isn't. 1-888-895-5727. Right now, I'd like to go to Zoe in Lakeside. Good morning, Zoe.

ZOE (Caller, Lakeside): Good morning. Thanks for taking my call.

CAVANAUGH: You're welcome.

ZOE: I'm asking about, excuse me, the research on medical marijuana and will the research ever trump the legal laws concerning, and – and I know it'd be going into legal ramifications but what is the national consensus? Are there states that do allow it – or, anyway, that's basically the premise.

CAVANAUGH: Thank you, Zoe. I don't know if we can go too heavily into the politics of medical marijuana but Dr. Swartzberg, what's the status of the – using marijuana to help reverse the side effects of some diseases?

DR. SWARTZBERG: I think the data is pretty good that marijuana in some people can really be helpful with the nausea associated with cancer chemotherapy and sometimes with the vomiting attendant with that. Whether it's better than the available medications is not clear because, to my knowledge, there haven't been any blinded control trials looking at those medications versus marijuana for those – for that population. That's the extent of my knowledge about that question.

DR. FIRESTEIN: So it's actually quite difficult to do a blinded study with smoking because you would have to have placebo marijuana cigarettes and then actual marijuana cigarettes and then compare them and it would be very difficult to have somebody know – be fooled about whether or not the, you know, the smell and the effects were the same, or so I've been told.

CAVANAUGH: Oh, that's very interesting. And also, I would imagine that since a fundamental idea is that smoking in and of itself is bad for you, it would be hard to conduct a study with volunteers on an ethical basis that way, wouldn't it?

DR. FIRESTEIN: Well, my suspicion is that there would be no shortage of volunteers for that type of a study but – And there is probably little doubt that inhaling a concentrated smoke of any type is not great for lung function but when compared – when comparing it to the danger, say, of cigarette smoking, it probably is considerably less because for most individuals that might use it, there would be many fewer cigarettes consumed over a period of a day and also the chemical composition of smoke from a cigarette is probably – contains probably considerably more toxic elements, including tar and nicotine and selenium and many other chemicals.

CAVANAUGH: I understand. Let me take another call. Dan in Kearny Mesa. Good morning, Dan.

DAN (Caller, Kearny Mesa): Yes, hi. Thanks for taking my call.

CAVANAUGH: You're welcome.

DAN: Yes, I'd like to ask about sort of the current state of medical science when it comes to, you know, the issue of whether it's better to consume a plant-based diet or a meat-based diet. I'm a, you know, I should say as well that, you know, I'm aware of a lot of correlational studies but again it sort of brings up the issue that we talked about earlier, which is, you know, maybe people who eat plant-based diets are just, you know, engaging in other activities that tend to be healthy. So I guess my question kind of boils down to whether or not there's good causal evidence to indicate, you know, it's better to consume the majority of ones calories in plant food.

CAVANAUGH: Thank you for that call, Dan. And I'd – If you'd like to express your opinion about Dan's question specifically, please do but, boy, that brings up the topic of diets and all the research into so many kinds of diets. Dr. Swartzberg, what do you have to say about that?

DR. SWARTZBERG: Yes, Dan brings up a really good point. Diets are probably arguably one of the most difficult areas for scientific study. Most of them are – most of the studies we have are designed as what are called observational studies. Sometimes they're what are called cohort studies, which are a little bit better but still they have the limitation that they usually require recall in terms of what you've eaten and, frankly, most people have difficulty recalling what they ate the night before much less the week before and so on. So it's very difficult to know – it's very difficult to judge a lot of these studies. And then that's compounded with the fact that to see the benefit of a particular diet, one may have to be on that diet for many, many years and there are no studies, to my knowledge, that have looked at consistent diets in a prospective fashion over many years. So we have to make some judgments. The judgments that I think is – are reasonable to make about diet is that, in general, what's found in plants tends to be healthful for people. We know that the high fiber, the carotenoids are healthful, just to name a couple of things. We also know that people who are on a – mainly a plant-based diet tend to have lower cholesterol levels, and LDL cholesterol, the, quote, bad cholesterol. These things – there's pretty good evidence for that, so plant-based diets in general are probably very healthful. The next question that sometimes follows is, well should this be taken to extreme and should you only eat a plant-based diet at the exclusion of anything else? And there's really good no data (sic) to support that.

CAVANAUGH: And what about the craze over super foods that's going on right now? You know, blueberries and the like, these foods that are supposed to be so completely marvelous for you that you perhaps should just eat them in vast quantities.

DR. SWARTZBERG: That's a good example of what Dr. Firestein was talking about earlier and that is that companies that have a vested interest in promoting their products will look at animal studies or chemical studies and show that the particular product that they're selling has chemicals that in some other study were shown to be beneficial for human beings and they call it a super food. I think the public needs to be well aware that a lot of these foods that are being sold are, I'm sure, very healthy but they're no more healthy than the other foods that are available and why pay an incredibly premium price for those things? I think this is a phenomenon of marketing and nothing more.

DR. FIRESTEIN: The other thing to keep in mind is that health is not just determined by diet and behavior but also genetics. And I know that it is always fashionable to blame ones parents for everything but it is true that a good portion of our future for an individual is genetically determined. Now this is oftentimes, you know, exemplified in diseases such as high blood pressure or rheumatoid arthritis and so on. But even from a large population perspective, the genes that are prevalent in a particular society can play a key role in susceptibility to heart disease, strokes, arthritis, lung disease, and so on. Now this is not something that we can change, obviously, but it will have an impact in terms of drug development and recommendations in terms of diet and behaviors in the future. If we can understand what someone's genes are and what their risks are for a particular disease then we can personalize medicine in a way that is more appropriate to them specifically as opposed to a general population of people that are completely unrelated to them.

CAVANAUGH: And I don't want to leave this topic of diet before we talk about the report about how much water the human body needs to consume and whether that eight 8-ounce glass of water per day that we've been hearing about for years is – has any validity. There was a report—a devastating report—that came out, I think, in the middle of last year about the fact that we don't need eight 8-ounce glasses of water each day and that it doesn't facilitate anybody's diet. Dr. Swartzberg, what are we to think?

DR. SWARTZBERG: Well, that's a great example of what's called medical and public lore. About a year or so ago, we looked at where that came from and tracing it all the way back, we found in the early part of the 20th century there was a physician who suggested, and it was picked up in a newspaper, that it's probably a good idea to drink eight glasses of water a day. And from that one suggestion by one doctor that got picked up by the newspaper, it became the standard advice that everybody thought that they should do, and that if they weren't drinking eight glasses of water a day, they were really harming their kidneys or at least harming their general health. Absolutely no signs to support that at all.

CAVANAUGH: And no effect on a person who wants to lose weight either, Dr. Firestein?

DR. FIRESTEIN: Not that I'm aware of.

CAVANAUGH: Okay.

DR. FIRESTEIN: But I think – I think like, you know, people should drink water appropriately when they're thirsty. I think that makes the most sense.

CAVANAUGH: Again, with this practical advice.

DR. SWARTZBERG: Yeah, there are caveats to that. Elderly people, often their thirst mechanisms don't work as well and they have to pay a little more attention but in general I totally agree with that.

CAVANAUGH: Let's go to the phones and talk with Steve in north county. Good morning, Steve.

STEVE (Caller, North County): Yes, good morning. Just a quick question. With children in the K-thru-6 range being prescribed the Ritalin class medicines or other effective medicines for the treatment of ADHD. What are the long term implications? Or can you comment on the implications of children being prescribed medicine at that age?

CAVANAUGH: What do the studies tell us, Dr. Swartzberg?

DR. SWARTZBERG: I don't have sufficient expertise for that specific question. Generally speaking, one is much more conscious of what we're putting into children for obvious reasons. They've got many, many more decades of life than older adults and so there's a much greater tendency to be very, very careful. In spite of that, there's been an awful lot in the press lately about some perhaps conflicts of interest in terms of the advice that parents are getting. But I don't have a sufficient expertise to comment on that.

DR. FIRESTEIN: The other, I think, key point that this brings out is the differences between how children and adults can respond to particular medicines because Ritalin is generally considered a stimulant and if an adult takes it it tends to be activating whereas in children it tends to have the opposite effect and help in terms of calming them down and also improving focus. Now that might be beneficial for controlling behaviors in the classroom but we really don't know enough about what the long term effects are 10, 20, 30, 40 years down the line in terms of how this will affect brain function, longevity or any other co-morbidities.

CAVANAUGH: Well, as we come to – as we're coming to an end of our hour-long discussion on medical studies and how to believe them and what to look for and what – where the truth lies, I wonder, Dr. Firestein, if – when a person – when the next study comes out and says this is good for you or that's bad for you, what is it that people should listen for? What kind of information do they need to have in order to put that information in its proper context?

DR. FIRESTEIN: Well, I think, as I commented earlier, a healthy degree of skepticism is required for all of these studies. And I actually think, you know, based on the, you know, what comes through the lay press, it's extremely difficult for a health consumer to make any judgments whatsoever on the validity or whether the results are applicable to themselves. So I really suggest a very strong filter and wait for some commentary from experts with newsletters and websites, such as Dr. Swartzberg's, and also others that are available from major academic institutions to try to, again, put some of these critical questions into context.

CAVANAUGH: And also, does it make any sense to maybe check it out on the internet? Is there any better information on the internet about these studies?

DR. FIRESTEIN: Well, everybody knows that everything on the internet is true. So – So I…

CAVANAUGH: Yes.

DR. FIRESTEIN: …I would be very careful about that. I think that there are some websites such, you know, that are reputable and enlist experts to provide commentary such as Mayo and at Berkeley and at Hopkins, and I think those would be the sorts of websites I would go to. Others are much more suspect.

CAVANAUGH: And, Dr. Swartzberg, when you are reviewing information for the UC Berkeley Wellness Letter, what is it that you look for? And would that help a lay person in trying to understand these medical research results?

DR. SWARTZBERG: Well, we're looking at the – we try to look at the entire corpus of the literature which, I think, is beyond the interest or scope of the lay person so that's not a great option. But as Dr. Firestein was saying, there are safe, good places that people can go to get information. I think one thing that the lay person should do is to ask the question, who benefits from my doing this particular procedure or my buying this particular product? And I don't think I'd get my information from people who are going to benefit from my spending money on the product or doing this particular procedure, that's one thing. Another – Some other sites besides – I would go to university sites as Dr. Firestein was saying. In general they tend not to have – again, not to have a bias. Another good site that we use all the time is at the National Institute of Health and I think that, although it may sound intimidating, there's some very good data available there, and the Centers for Disease Control.

CAVANAUGH: Okay, then, we'll have to leave it there. I want to thank you both for a very good discussion on this topic. Dr. Gary Firestein, chief of the Division of Rheumatology, Allergy & Immunology at UC San Diego School of Medicine, and dean of Translational Medicine. Dr. Firestein, thank you for coming in.

DR. FIRESTEIN: Thank you for having me.

CAVANAUGH: And Dr. John Swartzberg , director of the UC Berkeley-UC San Francisco Joint Medical Program and chair of the editorial board for the UC Berkeley Wellness Letter, thanks for participating.

DR. SWARTZBERG: My pleasure. Thank you.

CAVANAUGH: You can find links to our guests and what they do at our website, KPBS.org/TheseDays. These Days will return in just a few minutes.

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