Can drinking milk potentially increase your risk of breast cancer? Join us as we explore the controversial link between bovine leukemia virus (BLV) in milk and breast cancer risk. Sparked by a patient’s concern and a meta-analysis review, this episode emphasizes the importance of asking detailed questions in understanding scientific research.
We critically examine a meta-analysis on BLV and breast cancer, uncovering significant methodological flaws, from lack of pre-registration to biased selection criteria. Our discussion highlights the need for intellectual honesty and rigorous scrutiny in healthcare research.
We also question the credibility of the systematic review, pointing out the drastic reduction of eligible studies and the peer review process's legitimacy. By discussing the 2.57 odds ratio of BLV's association with breast cancer and the difference between correlation and causation, we aim to provide a comprehensive understanding of the challenges in interpreting scientific research. Tune in to gain insights into the complexities of medical studies and the importance of critical appraisal in healthcare.
Learn more and become a member at www.DrJournalClub.com
Check out our complete offerings of NANCEAC-approved Continuing Education Courses.
Can drinking milk potentially increase your risk of breast cancer? Join us as we explore the controversial link between bovine leukemia virus (BLV) in milk and breast cancer risk. Sparked by a patient’s concern and a meta-analysis review, this episode emphasizes the importance of asking detailed questions in understanding scientific research.
We critically examine a meta-analysis on BLV and breast cancer, uncovering significant methodological flaws, from lack of pre-registration to biased selection criteria. Our discussion highlights the need for intellectual honesty and rigorous scrutiny in healthcare research.
We also question the credibility of the systematic review, pointing out the drastic reduction of eligible studies and the peer review process's legitimacy. By discussing the 2.57 odds ratio of BLV's association with breast cancer and the difference between correlation and causation, we aim to provide a comprehensive understanding of the challenges in interpreting scientific research. Tune in to gain insights into the complexities of medical studies and the importance of critical appraisal in healthcare.
Learn more and become a member at www.DrJournalClub.com
Check out our complete offerings of NANCEAC-approved Continuing Education Courses.
Welcome to the Dr Journal Club podcast, the show that goes under the hood of evidence-based integrative medicine. We review recent research articles, interview evidence-based medicine thought leaders and discuss the challenges and opportunities of integrating evidence-based and integrative medicine. Continue your learning after the show at www. d rjournalclub. com.
Dr. Joshua Goldenberg:Please bear in mind that this is for educational and entertainment purposes o nly. Talk to your doctor before making any medical decisions, changes, etc. Everything we're talking about that's to teach you guys stuff and have fun. We are not your doctors. Also, we would love to answer your specific questions on drjournalclub. com. You can post questions and comments for specific videos, but go ahead and email us directly at josh at drjournalclub. com. That's josh at drjournalclub. com. Send us your listener questions and we will discuss it on our pod.
Dr. Joshua Goldenberg:Hello, this is Dr Joshua Goldenberg and Dr Adam Sadowski and we are here for take 17 of today's episode, where we are desperately trying to beat technology and the technology gremlins which is a thing and actually record this stinking podcast. So, as I was saying before, Adam, this article that we're talking about today was brought to my attention by a patient of mine who said hey, josh, would you mind reviewing this meta analysis? And I just had this like amazing moment, like I don't think a patient has ever asked me to review a meta-analysis. You just warmed my heart and then I proceeded to completely forget about it. She like very kindly reminded me when I saw her the other day. So, um, this is my attempt to make amends and actually review the article. She had questions about uh, bovine, what is it bovine something virus? What is it bovine? Bovine, what is it Bovine something virus? What is it Bovine?
Dr. Adam Sadowski:Bovine leukemia virus.
Dr. Joshua Goldenberg:Leukemia virus.
Dr. Adam Sadowski:And before we get into the episode, if listeners, if you do send us stuff, do a one over and kind of like, ask us what the question is that you're looking for. Don't just say is this a good paper, like is this good? Because that's a relative term and we're not giving any medical advice on this podcast either. So if you have a paper, do like who was it that sent in a paper and had like six pinpoint questions to ask about it.
Dr. Joshua Goldenberg:Was it Mark Mark Davis?
Dr. Adam Sadowski:No, it wasn't. It wasn't Mark Davis, it was, oh my gosh, dr Yarnell. When Dr Yarnell did that, that was helpful because we knew sort of like what we, what the intent of the paper was, outside of our own interest. So if you send us a paper, read it and give us your input and give us a question. If you don't know what you're reading, go Dr. Journal Club.
Dr. Joshua Goldenberg:So let me give some background, because in this case the patient gave me lots of background information. So, basically, I think she had heard about this bovine leukemia virus in the supply of milk and that I think there were a couple European countries I think she was saying that had like gotten control of the virus in the bovine population because there was this supposed connection with breast cancer and so she was concerned. She wasn't sure if she would should continue to drink milk or not, or if it would be I think she was traveling and if it would be okay to have the milk in these countries. So that was the question. So very targeted question have the milk in these countries? So that was the question, so very targeted question. And then what I was excited about is you know, someone you know, coming up with an actual meta-analysis and knowing what that was and be like, hey, what do you think? So let's jump into it. So let's see here, all right. So, oh, of course, because this is how this day is going, my PDF player is off.
Dr. Adam Sadowski:Well, that's okay, I've got it.
Dr. Joshua Goldenberg:Oh, you got it. Okay, great, why don't you set us? You want to set us up with some background in methods and then we can do like a critical eval and take home Keep it a little short today, Sure sure, sure, sure.
Dr. Adam Sadowski:So basically, what this study is looking at is trying to look at some sort of association between this virus known as bovine leukemia virus, which I had never heard of.
Dr. Joshua Goldenberg:Me neither.
Dr. Adam Sadowski:And the risk of breast cancer.
Dr. Joshua Goldenberg:Oh, sorry, sorry, that reminds me, this is what it was. She had asked me about this and I said I have no idea. So what does she do? Because she's amazing, she comes back with a freaking meta analysis and asked me to then opine, that's so awesome, right? So anyway, yeah, go ahead. So now I'm remembering.
Dr. Adam Sadowski:Now it's all coming back, go ahead, yeah, yeah, yeah. And so this was a systematic review and meta-analysis of case control studies. And so, for those who don't know what a case control study is is you're taking cases and controls. So there's the there.
Dr. Joshua Goldenberg:So in this case, with breast cancer and without breast cancer.
Dr. Adam Sadowski:Yes, and so in a case control study, you have cases and you have controls. The controls are individuals who would not have some sort of exposure or, excuse me, some sort of outcome of interest. And these are, and you're comparing them to cases, and they're called cases because they already have the outcome of interest that you're interested in. So in this case, the case would be breast cancer and they're taking people who have breast cancer already diagnosed and comparing them to a group of controls who, in theory, outside of the breast cancer diagnosis, are very similar in their demographic makeup, if you will, relative to the individuals with breast cancer. So you're trying your best to say, hey, we have these two groups of individuals. You're trying your best to say, hey, we have these two groups of individuals where the only difference is that one has breast cancer and one doesn't.
Dr. Adam Sadowski:Now, in reality, that's not. That's not the case, because these are, these are, you know, sort of low, low level observational studies. So you know that there are going to be a lot of differences, going to be a lot of differences, and that's why we like randomization is because if you're randomizing participants to two different groups, there's basically a nice evenness, if you will, between the two groups. If there's any sort of differences, so those differences get accounted for, whereas with this they don't.
Dr. Joshua Goldenberg:Right and so, and there's some cases where I mean can't randomize to get breast cancer.
Dr. Adam Sadowski:So it's like like it's usually these harm studies like this where you're looking at these case control studies because obviously you can't randomize to that same with like smoking sensation, stuff like that or you have a very rare outcome where, yeah, you would have to recruit millions of people just to get one outcome, or you would have to get several thousand people and watch them, for you know 30 years before you get one outcome, or you would have to get several thousand people and watch them for you know, 30 years before you get one event.
Dr. Adam Sadowski:And so it's just from a practical standpoint doesn't make sense to do that. So this is if you already have the cases, you can kind of compare them to the control, so it's kind of the next next best option. And then you look backwards in time and kind of look, for you know, were they exposed to something or not? And then, if they were, is there an association between that exposure and the outcome? So in this instance we have our cases which are individuals with breast cancer, and then we have our control people without breast cancer and we're looking back in time to see if people who are exposed to the bovine leukemia virus had a greater odds or greater likelihood of developing the outcome of interest. So in this case, breast cancer.
Dr. Joshua Goldenberg:Well, so opposite in this case, right? So it's like of those with breast cancer. Do they have an increased odds of testing positive on this virus test, right.
Dr. Adam Sadowski:Okay, and so, to kind of set this all up, they basically said that you know, breast cancer is very common. I think our listeners are aware of that. I don't think there's anything you know from that that we really have to talk on, to talk on. However, with regards to the bovine leukemia virus, basically it belongs to a family of virus known as retroviridae, so they're retroviruses, and then there's different classes within that and then the main host where we would find them is in cattle, but they can be in other animals as well. And I thought it was funny that they said that the prevalence of the virus infection is high in cattle and varies anywhere from 39 to 100%.
Dr. Joshua Goldenberg:That was mind-blowing yeah.
Dr. Adam Sadowski:Yeah, so basically half or all cattle have this virus.
Dr. Joshua Goldenberg:Yeah.
Dr. Adam Sadowski:And it can easily transmit through infected blood and milk. However, it causes disease in less than 5% of infected cattle. So I mean, if you kind of think about it, it's kind of like H pylori in humans, where all humans basically have H pylori. The issue is when it causes disease disease?
Dr. Joshua Goldenberg:yeah, and then did you get a sense of like is it only infectious to humans if the cattle is actively showing disease, or or if they have it right? Um, I don't, that wasn't clear to me because it's like oh my gosh, like I like a half to all of beef have it, or dairy have it, and I don't know how that's just not being passed all the time. But but I guess if you're saying only 5% are infected or show disease, rather I suppose that's when you would be more likely to spread the disease. But it seemed like they weren't really clear on how infection to humans happened.
Dr. Adam Sadowski:Well, they also said that the mechanism of transmission to humans is not known, with the exception that raw milk consumption can transmit the virus from cattle to human population.
Dr. Joshua Goldenberg:Right, so you got to watch the raw milk. Did I ever tell you my raw milk story Super fast? So, okay, really really quick.
Dr. Adam Sadowski:On the topic of tangents.
Dr. Joshua Goldenberg:Yeah, no, I know, I know, Hold on. You got to let me have this one because as I was reading it I remembered it and I hadn't remembered it since, like I don't know, over a decade ago. Anyway, long story short, in my wandering years I was backpacking through Central America and I was living in Guatemala for like a while and I was living with a Guatemala Teca family and the mother was sort of like the surrogate mother while I was there and it was, like you know, didn't really speak much English and it was super fun. Anyway, she was really into far out there natural things. She was doing like these, like naturally, essentially naturopathic stuff, but out in like the mountains of Guatemala, and one morning she's like Josh, I have to take you, I have to show you something.
Dr. Joshua Goldenberg:So we hiked all the way up into the mountains outside of town. We were in a town called Sheila and we go up and we just stop at this like random farm, just whips out a. Um, we're on a hike and it's like she's thirsty. So she whips out her cup, walks, knocks on the on the farmer's door, he comes out, he grabs the cup and he sits down in front of the cow and just starts milking it directly into the cup and she's just down the hatch and off we go and we're on our we're on the rest of our hike to some like amazing, like sweat lodge up in the mountains or something.
Dr. Joshua Goldenberg:Anyway, that was. That's my raw milk story.
Dr. Adam Sadowski:My raw milk story is that, uh, the farm that my dad grew up on, uh, is still. They still own it and it's just one of his brother brothers operates it and when I went to go visit we just, you know, we put milk in a bucket and we just had it from there and then, like the next day, if you wanted milk or something like you, just open the fridge and so cool it was just literally farm fresh milk, but yeah, not pasteurized or anything.
Dr. Joshua Goldenberg:That is so cool. Yeah, well, as far as we know, you don't have bovine leukemia virus, although I guess we don't know for sure, it's always a possibility. Anyway, I love those stories. Okay, so what we're talking about? Oh yeah, tangents. All right, so back we go to talk about the study and all right. So I think that's enough for mechanism. They were pretty. The authors themselves were pretty light on details of how this could work, except that basically saying, yeah, cancers sometimes are associated with viruses. We've got multiple examples of that. There's evidence that breast cancer maybe 10, 20% of it may be associated with different viruses. What about this one? There's been multiple studies. Let's meta-analyze it. That was sort of like the setup as far as I could tell. Anything else you want to add for the setup?
Dr. Adam Sadowski:No, that's it Okay, far as I could tell. Anything else you want to add for the setup? No, that's it Okay. Should we jump into methods and critique thereof? Yeah, so basically what they did is they followed the PRISMA reporting guidelines, which in all honesty, doesn't really mean much. And then what they did was all case control studies that investigated the virus infection and breast cancers were collected from several databases, and then that's kind of like how they picked studies, eligibility criteria, looked at case control and prevalence studies in English between 1995 to January of 2020. And then detection of the virus was through random assays and then they were excluded if they were published in languages other than English. Studies other than breast cancer or other viruses that were not bovine leukemia virus infection in any sort of male participants, and they also did not include other systematic reviews or meta-analyses, which I thought was kind of an issue, because there are ways where you can kind of use that data.
Dr. Joshua Goldenberg:They said. They seemed to suggest no one had done it before. I don't know, maybe I misread that, but that's fine, Then then.
Dr. Adam Sadowski:okay, then I'll give them a pass.
Dr. Joshua Goldenberg:But how would they know that? If yes, how would they know that if? Uh, I guess how would they know that if they hadn't done a search? So, to your point, just trust us, just just yeah. Well, I think that just trust us is kind of throughout. So there's no registration that I can see.
Dr. Adam Sadowski:Did you catch a registration? No, I didn't see one yeah, so they didn't register.
Dr. Joshua Goldenberg:So if we think about like, okay, so, so that's basically the method, just like you said, so if we quickly go through the seven deadly sins, so remember the seven deadly sins for systematic reviews, so we've got. Did they register Ideally a priori? No, did they do. Was their search quality decent? Did they explain?
Dr. Adam Sadowski:They didn't expand upon that.
Dr. Joshua Goldenberg:Yeah, well, let's go through all these. Did they give rationale for their exclusion? Did they do a risk of bias assessment? Did they do adequate meta-analytic methods? Did they see how the risk of bias impacted their meta-analytic result? And was there publication bias? So these are the seven deadly sins. These are the critical domains of AMSTAR II. If you have any one of these, be off. Your entire systematic review is considered critically flawed and you cannot rely on it at all.
Dr. Joshua Goldenberg:Look, the thing is we don't do this for money. This is pro bono and, quite honestly, the mothership kind of ekes it out every month or so, right? So we do this because we care about this, we think it's important, we think that integrating evidence-based medicine and integrative medicine is essential and there just aren't other resources out there. The moment we find something that does it better, we'll probably drop it. We're busy folks, but right now this is what's out there. Unfortunately, that's it, and so we're going to keep on fighting that good fight and if you believe in that, if you believe in intellectual honesty in the profession and integrative medicine and being an integrative provider and bringing that into the integrative space, please help us, and you can help us by becoming a member on Dr Journal Club. If you're in need of continuing education credits, take our NANSEAC approved courses. We have ethics courses, pharmacy courses, general courses. Interact with us on social media, listen to the podcast, rate our podcast, tell your friends. These are all ways that you can sort of help support the cause. Help support the cause, so let's go through here.
Dr. Joshua Goldenberg:So first, deadly sin registration. We both saw no evidence of registration, so we don't know if they came up with their methods after the fact. And that's of course, a problem when you're looking at outcomes and you basically say, well, you're just reporting the stuff that looks sexy, especially when there are some interesting calls about their methodologies, which I think there there were some. So that's number one. So already we've got one deadly flaw search quality. What do you think about the search quality? They didn't really go into it. Yeah, they didn't. That's a problem. Yeah, so there's no, there should be a in an abstract or something, at the very least the pubmed search strategy. There was not. They gave a couple, a handful of like mesh terms that they basically riffed on, but that's about it. Um, also, they said very strange things. I don't know if you caught this. They said that they independently did the search, which makes zero sense.
Dr. Adam Sadowski:You don't independently do the search, you independently screen the search it may be a translation issue, because this was, I think, based in Iran. Yes, yes, and so they may have you know. It may just kind of be like loosely translated incorrectly.
Dr. Joshua Goldenberg:I think we give them that one. I think you're probably right about that, because it would just be so bizarre to do that. That. I think you're probably right. Okay, so we'll give them a pass on that. But they don't really report their search really at all. I don't like that. They only included studies in English. I don't think that makes any sense. Why would you do that? And I think you might be opening yourself up for bias. So I would say concerns, critical concerns. I don't know, probably, if you wanted to be strict about it, but I didn't like the search very much. Next, one exclusion rationale Did you see anywhere a list of studies they excluded on a study level that explained why for each study? Nope, nope, I didn't see it. Either they did aggregate stuff, like we excluded eight for you know they didn't have this or they didn't have that, but there is no individual study level where you could go and say so. We got another critical flaw there. Did they do risk of bias assessment on the primary studies?
Dr. Adam Sadowski:Kind of.
Dr. Joshua Goldenberg:They did, yeah, they did. Was it Newcastle, Ottawa? I think they used.
Dr. Adam Sadowski:Well, so that's not necessarily. Well, actually, yeah, that is a risk of bias tool, because they had it as quality assessment and so those two are different. I view quality assessment as something like a grade, whereas this really should be a bias assessment which can then influence the quality.
Dr. Joshua Goldenberg:Yeah, and like you said earlier, language matters. I 100% agree with you. I think, unfortunately, people are loosey-goosey with this language and you see that a lot they talk about study quality when really what they mean is risk of bias, to your point. Maybe it's a translation thing too. But yeah, so they did do a risk of bias assessment. They only included studies that scored high, like that did well on the risk of bias assessment, which I thought was interesting. It was like sort of a strict interpretation. They had a threshold cutoff and they said we only are basically looking at the studies above this. It threw me a bit, because calls like that it's like why and when did you decide to do that, and I would be much more comfortable.
Dr. Adam Sadowski:And why that score? It seems arbitrary.
Dr. Joshua Goldenberg:And why that score? Yeah, is that standard? Is that considered a standard high level? And again, like if we had a a priori registration, we'd say, oh yeah, this is what they plan to do. They were worried about risk of bias studies, but we just have to, kind of like you said, take their word for it now. So I give them a pass on the risk of bias assessment, but I'm a little questioning about their inclusion.
Dr. Adam Sadowski:What I would have done, too, was I would have included all of them and then, if you wanted to do like a sensitivity analysis, say, okay, we're only going to include studies with a score of, let's say, four or higher. Yes, and we're saying four or higher because and then have evidence saying why, why that number, as opposed to just an arbitrary number, saying, oh, this, this sounds like it's a higher quality.
Dr. Joshua Goldenberg:Yeah, that's the right way to do it, in my opinion. You, you have all the evidence and then, exactly, you view risk of bias as a sensitivity approach. So I agree with you on that one. I have seen other people do this. I agree with you though. But yeah, and then I think they meta-analyzed appropriately. I didn't see any technical problems there. The risk of bias impact on their overall estimate is kind of moot, because they only looked at low risk of bias studies and then publication bias. They did visual inspection and statistical analyses, which is appropriate, but the rule of thumb for publication bias is you don't do those if you've got under 10 studies, and they only meta-analyze nine. So it's underpowered. So for them to say we didn't see any evidence of publication bias, I mean it doesn't really mean anything. It's an underpowered test at that point.
Dr. Adam Sadowski:No one's going to see evidence of publication bias. So I don't know, I don't know a methodologist on their team, yeah, and just kind of used sort of like very rudimentary methods to this.
Dr. Joshua Goldenberg:Yeah, I agree. So I think my take home is they've got three, three and a half critical flaws. This is a critically flawed systematic review. We'll talk about the results in a second, but pretty much I don't trust the results before we even kind of talk about them. Is my take home on that one? Anything else on methods you want to add?
Dr. Adam Sadowski:No, that's it.
Dr. Joshua Goldenberg:OK, cool, and I think you had the same impression, sort of talking in the green room there as well. Ok, so let's talk about results. So both of us are skeptical about what the results will be, but we'll. Oh, they also had like crazy heterogeneity 80, not crazy, but very high, 85 percent 85 percent yeah, yeah, super heterogeneous. Um, they tried to explore heterogeneity but I don't see that they talk about. Did I miss the results of the of the subgroup analyses?
Dr. Adam Sadowski:nope, but. But I think what we should say is that they apparently they started off with 13 000 studies oh yeah oh right, so they start off with 13 000 studies, and then, of 70 that that remained, uh 61 were included, and so that's how they got to nine. Honestly, I'm very skeptical that their search strategy had any sort of relevancy. It's probably 13,631.
Dr. Joshua Goldenberg:It makes no sense.
Dr. Adam Sadowski:Probably picked up anything that had bovine leukemia virus in the title, so it could have been like you know BLV and rats. It probably was not a good search study.
Dr. Joshua Goldenberg:You know BLV and rats it probably was not a good search study. So your point is the upper numbers really high, so it wasn't a very specific search. Like I agree, you're probably right and with everything else we see, I don't know that we give them a pass to say, oh, they were trying to be overly sensitive. But look at the next thing in the Prisma flow chart. So it goes from 13,608 to after removing duplicates and quote irrelevant material or whatever 70. 70. What? What does that mean? So you remove duplicates? Maybe I don't know. You remove 1,000, 2,000. So there's still probably, like I don't know, 10,000 studies and then they remove irrelevant. Who's removing irrelevant? Based on what right that sounds like? I don't know. Is that? Do they mean title and abstract? But no, they don't, because then they take of those 70, 20, they only are screening 20 on title and abstract. Like just to give people context, like we will often screen thousands on title and abstract and somehow they get to 20 by quote removing irrelevant studies in some mysterious way. I don't know what that means.
Dr. Joshua Goldenberg:Removing irrelevant studies? It is the biggest red flag I've ever seen on a Prisma flowchart. I don't know how this passed peer review. Maybe this is not a legit journal, I don't even know, maybe it's one of these predatory journals. This is just beyond absurd how this passed peer review. And then, of those 20 that they actually screened on title and abstract, you know they they looked at 12 on full text and they included nine and they don't give reasons for the exclusion on an individual level. So it is just like I I just don't even know. I don't even know what to say. You go from 13,000 to 70 because quote, unquote, irrelevant. Yeah, you ever seen anything so crazy in your life?
Dr. Adam Sadowski:No.
Dr. Joshua Goldenberg:Oh my gosh, I'm putting that on the wall. I got to take that out and put it on the fridge, like it is, like the strip. That's got to be a teaching example, as like what in the world?
Dr. Adam Sadowski:Yeah, no, that's a good. That's in the world. Yeah, no, that that's a good. That's a good teaching example of like what not to do. This whole paper, honestly, this whole paper is what not to do it's so many red flags.
Dr. Joshua Goldenberg:It's so many red flags. So I mean it's just a great example of you know, if someone just um, you know, was screening through, I mean isn't bmc a decent journal like this is just I don't think this is bmc infectious agents and cancer. I don't know that journal. I just I don't think this is bmc infectious agents and cancer. I don't know that journal. I mean I don't know the space, but yeah, this is just nuts. It's like every red flag in the world. How in the world did it pass peer review? And then I, it's just, yeah, that flow chart is just really something else. Okay, so basically we don't believe a word we see. And so what did they? What did they find? I feel like it's silly to even say it. So their overall meta analytic result was an odds ratio of 2.57. So you're more than two and a half times likely to test positive for this bovine leukemia virus. I guess in your blood, I guess the blood test, if you sorry, if you have breast cancer, you're more than two and a half times more likely, or two and a half times the odds of testing positive for this virus, which would suggest that you know it's a. It increases your risk by two and a half times, or something like that.
Dr. Joshua Goldenberg:Now, of course, as it's very clear, we don't believe a word of this. But even if we did, the other issue is like I don't know what the baseline, like it's, it's like this is. So you can't figure out absolute effects with like these types of studies, right? So you say it's two and a half times, increases your risk two and a half times. Yeah, I don't, I don't know, like, how common are you getting this disease, this virus? And I don't know, I just don't trust any. I, I just want to throw the whole thing out. I don't trust, I don't trust a word of it.
Dr. Joshua Goldenberg:Now, that doesn't mean it doesn't have this risk, right, and it doesn't mean that, you know, I. Just so. Here's the here's, the here's. The question for relevance is how many people walking around on Earth have this virus in them at any given time? And then of those, how many develop into breast cancer, like that's the question, I suppose. So this type of study would be enough to say there's a signal there, but we can't figure out like the absolute risk, like how risky it is to be having milk, how risky it is to be having pasteurized milk right? So these are like good questions and it could be that you know breast cancer is horrible, so maybe we just want to be super, super, super strict.
Dr. Adam Sadowski:Well, also also, you know, remember it's an association and it's association and causation are not the same thing. This could have been peanut butter jelly sandwiches for all intents and purposes, like seriously, right.
Dr. Joshua Goldenberg:Well, let's talk about that for a second. You know, they don't, you know, and, to be fair, it's a systematic review, so they're not going into how the studies did pick their controls. But that's a big issue. It's like I don't know. There's probably a lot of associations between you know, people that have breast cancer and other risk factors that are associated with, I don't know, getting this stuff. It may not necessarily be the virus. It's like you said, association, not necessarily causation. That being said, that's how we find harms and that's how we find risk. Right, that's why we do these studies. But we just have to take them with a grain of salt and at this point, just like, yeah, the whole salt shaker. So I don't know.
Dr. Joshua Goldenberg:I my take home is I have no idea. Now I know a little bit more about what bovine leukemia virus is. I find it interesting. I now know that your dad grew up on a farm and that you guys still have the farm and that you have milk in the fridge which I think is so cool from the farm. I think that's awesome and I know all these things, but I don't know that there's an association with breast cancer. It doesn't mean there's not, but it's just so terribly flawed that I really just can't believe a word.
Dr. Adam Sadowski:Based on this paper. We can't make anything really of it. It was not, it was. It was just a poor paper.
Dr. Joshua Goldenberg:It might be the worst paper I've seen this year. It might be, yeah, it might be the worst paper I've seen in the past five years. Wow so, and you know, it's just such an important take home because the abstract looked fine Like. I read the abstract first and I was like okay, so I'm getting a sense of things, this is interesting, I'm curious. And then, as soon as you look under the hood, it just reeks just absolutely reeks. So this is why, yeah, go ahead.
Dr. Adam Sadowski:Oh sorry, I was going to say that case control studies are better for more rare events. I don't know if we can qualify breast cancer as rare yeah, but how else would you find?
Dr. Joshua Goldenberg:oh, you would do like cohorts.
Dr. Adam Sadowski:You're thinking cohorts like um, like a cohort study maybe a cohort, but like I don't know, it would be better. I don't know.
Dr. Joshua Goldenberg:I just feel like it would be better if it was more of a like, more of a rare outcome yeah, I'm just trying to think like how you would even do that, because you would need a cohort of people that have this bovine uh virus and then you'd have to watch them, or you'd have a, you know, you'd have great chart records of people and then you'd look at the ones with breast cancer and then you'd go back and see you know how many of them had, you know, leukemia exposure or bovine leukemia virus exposure. I don't know, I'm not sure the best way to do this. It's an interesting question, but I think, regardless, the methods were just so horrific. But that is going up on my wall, all right, ladies and gentlemen.
Dr. Adam Sadowski:In better news, in better news listeners. I do have a paper that I am interested in talking about looking at. It was published in the bmj and it was a meta-analysis. Uh, looking at real bmj or bmj open or bmj zillion things, bmj, bmj bmj, bmj okay, all right, I'm listening, I'm listening and it was a meta-analysis looking at psilocybin for depression oh, is that the one that everyone was pissed off about?
Dr. Adam Sadowski:I don't know. I did share it with you. I it was published recently. Um, I do think that that people it seems it the psilocybin for, uh, mental health stuff is really kind of really expanding, yeah, but with, like just the general media and, yeah, people's interest. So I so I do think it's a relevant topic, uh, mental health is also important and so, um, I think I think our listeners would appreciate it. I thought the paper was pretty cool. Um, so write into us if you guys want to, if you guys want to hear it on the next episode no, let's definitely do it.
Dr. Joshua Goldenberg:I know which one you're talking about, but the reason I held off on it before was I thought I saw on the news that all these statisticians were writing in saying they saw flaws in the methods and I was waiting for like a formal author response, did they? When you pulled the paper, which was probably more recently, did they have a author response at all? Well, I bookmarked it, so give me one second author response at all. Well, I bookmarked it, so give me one second. Sure, yeah, I was curious about that. Something about, I think what it was, if I'm remembering correctly, was they think there was a. They were assuming they put things in a standard error instead of standard deviation, and that is an easy mistake to make on meta analysis extraction and it makes a huge impact on the overall results because it impacts the confidence intervals.
Dr. Joshua Goldenberg:And I think some statisticians were looking at this. They're like, wow, this is way too precise, there's something missing. And then they tried to look at the data and they're like we think they just made some errors here. Yeah, so let's wait to see what the formal author responses. But yeah, then I definitely, because it could be that you said, yeah, we made a mistake. Mistakes happen, but it doesn't impact the results of the study. In which case, yeah, I definitely want to review it.
Dr. Adam Sadowski:Yeah, raised about standard error in calculation of standardized mean differences. This is likely to have overestimated the benefits and they're actively in review process of it.
Dr. Joshua Goldenberg:Okay, so they're still doing it. Okay, so let's hang tight until they actually review it, because obviously, if there's no effect after they fix the errors, then so this is a thing too. Is that when you start looking, when you have really sexy topics like this, everyone looks really really closely with like fine-tooth comb, which is important but they can find all sorts of tiny errors, like we put this in as a standard error instead of a standard deviation. That doesn't necessarily mean you throw out the paper. You know you have to say okay, like once we fix it, like what's the actual result? It could be a meaningless difference or it could make all the difference. So let's wait to see how this one shuffles out.
Dr. Adam Sadowski:Excellent, all righty.
Dr. Joshua Goldenberg:Cool, all righty. Thanks everybody. Thanks for listening and we'll talk to you next time. If you enjoy this podcast, chances are that one of your colleagues and friends probably would as well. Please do us a favor and let them know about the podcast and, if you have a little bit of extra time, even just a few seconds, if you could rate us and review us on Apple Podcasts or any other distributor, it would be greatly appreciated. It would mean a lot to us and help get the word out to other people that would really enjoy our content. Thank you, hey y'all. This is Josh.
Dr. Joshua Goldenberg:You know we talked about some really interesting stuff today. I think one of the things we're going to do that's relevant. There is a course we have on Dr Journal Club called the EBM Boot Camp. That's really meant for clinicians to sort of help them understand how to critically evaluate the literature, et cetera, et cetera Some of the things that we've been talking about today. Go ahead and check out the show notes link. We're going to link to it directly. I think it might be of interest. Don't forget to follow us on social and interact with us on social media at DrJournalClub DrJournalClub on Twitter, we're on Facebook, we're on LinkedIn, et cetera, et cetera, so please reach out to us. We always love to talk to our fans and our listeners. If you have any specific questions you'd like to ask us about research, evidence, being a clinician, et cetera, don't hesitate to ask. And then, of course, if you have any topics that you'd like us to cover on the pod, please let us know as well.
Introducer:Thank you for listening to the Doctor Journal Club podcast, the show that goes under the hood of evidence-based integrative medicine. We review recent research articles, interview evidence-based medicine thought leaders and discuss the challenges and opportunities of integrating evidence-based and integrative medicine. Be sure to visit www. drjournalclub. com to learn more.