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Fish Oil Benefits: Breaking Down the Research
Dr. Keith Miller discusses if fish oil consumption can help prevent cardiovascular disease, the other benefits of fish oil, any risks with taking fish oil, and how to incorporate fish oil into your diet.
Featured Speaker:
Dr. Miller is certified by the American Board of Internal Medicine with a subspecialty certification in Cardiovascular Disease. He has expertise in non-invasive imaging, including echocardiography, nuclear stress testing and cardiac computed tomography (CT) scanning. Dr. Miller is an IBHRE Certified cardiac device specialist physician, with expertise in implanted rhythm devices including pacemakers and defibrillators. He has an interest in preventive cardiology, cardiovascular risk assessment and cardiometabolic health.
Keith Miller, MD, PhD
Dr. Keith Miller, MD, PhD, FACC was raised in Omaha, Nebraska, and completed his undergraduate studies at Cornell University in Ithaca, New York. He earned his medical degree and research doctorate degree from the University of Nebraska College of Medicine in Omaha, Nebraska, in 1997. Dr. Miller completed his residency in internal medicine at the University of Iowa Hospitals and Clinics, followed by a fellowship in cardiovascular diseases at the University of Chicago Medical Center in Chicago, Illinois. He joined Bryan Heart in 2003.Dr. Miller is certified by the American Board of Internal Medicine with a subspecialty certification in Cardiovascular Disease. He has expertise in non-invasive imaging, including echocardiography, nuclear stress testing and cardiac computed tomography (CT) scanning. Dr. Miller is an IBHRE Certified cardiac device specialist physician, with expertise in implanted rhythm devices including pacemakers and defibrillators. He has an interest in preventive cardiology, cardiovascular risk assessment and cardiometabolic health.
Transcription:
Fish Oil Benefits: Breaking Down the Research
Melanie Cole (Host): If you’re one of the many that have questions about fish oil and whether you should be taking it or not or if you are, how much should you be taking. Here to answer that today is Dr. Keith Miller. He’s a cardiologist with Bryan Heart. Dr. Miller, I’m so glad to have you on to discuss this today. What a great topic, fascinating segment. Tell us first, what are omega-3 fatty acids and where are they typically found?
Keith Miller, MD, PhD, FACC (Guest): Well I think a lot of people are aware that omega-3 fatty acids are found especially in marine animals. So fish consumption and a lot of the interest in omega-3 fatty acids and fish oils came from the observation that populations who eat a lot of fish are less likely to develop heart disease. So, the epidemiology, the observational studies say if you eat fish once or twice a week; that’s associated with a reduced risk of heart disease. So, lots of animal meats have omega-3 in them but fish, in particular, is a rich source of omega-3s.
Host: Okay, so how is fish oil made then? The caplets and there’s you know people have been hearing Dr. Miller about cod liver oil for a very long time. So, how is this made and put into capsules and what do you think about it? Should we be looking at taking it?
Dr. Miller: Yeah, that’s a great question. And I have to admit, I don’t know exactly the manufacturing process that’s used but I think actually that might be kind of an important point because a couple of the trials that I want to talk about today, used over-the-counter fish oil supplements and there is not a lot of regulation in regards to how those marine omega-3 fatty acid supplements are made or the content of the supplements which are often capsules is not regulated very closely. So, in many cases, it’s not very well defined how those things are made.
But in contrast to that, one of the studies that was published in the last year that got a lot of attention was with a product which is a prescription form of omega-3 fatty acids, it’s called icosapent ethyl brand name is Vascepa and that product is very highly regulated and very highly purified and that actually was the one study that was a very positive study that seemed to provide a very impressive protective benefit. So, I mean if I could, I’d just like to maybe comment on a couple of these trials because I think they are very important and as so many things in nutrition and in medicine; a lot of this starts out with an observation in a population and that’s exactly the way it was with omega-3 fatty acids. The observation being people who eat more fish tend to live longer and have a lower risk of heart disease.
Then came a series of trials looking at well what happens. We think maybe omega-3 fatty acids are one of the main reasons that fish is such a healthy thing in the diets. So, can we extract that out of the fish and use it as a supplement to try and protect us from heart disease? And many of those trials have produced some conflicting results and then attempts to kind of collect all that data and assimilate it into large analyses have really left us confused a little bit about whether these are helpful or not.
Nonetheless, the information about eating fish and fish being a part of a healthy diet that protects us from heart disease is so much a part of our understanding now that omega-3 fatty acid supplementation is still a part of the American Heart Association guidelines for the secondary prevention of heart disease and of course, we always recommend fish consumption for protection of people from heart disease. Now in the last year, comes along these three trials that really tested this hypothesis and one was called The VITAL Trial, one was called The ASCEND Trial and then there’s a third trial. The first two were done basically with the types of omega-3 fatty acids over-the-counter supplements at the same dose recommended by the American Heart Association which is one gram per day. And in one of the trials; they looked at primary prevention for men over 50 or women over 55 and they enrolled over 25,000 people and followed them for five years. And they tested omega-3 fatty acids versus placebo and they were able to show no difference in major cardiovascular events. So, there was no benefit that they could document in this huge trial for five years. And again, that was the same dose that was recommended by the American Heart Association.
And then there was a second trial that looked at diabetics over 15,000 of them, who did not have a history of heart disease, gave them the same dose of fish oil, again an over-the-counter one gram per day supplement, followed them for seven years and again, they could not demonstrate a significant reduction in cardiovascular events in these two groups. Some people have started to kind of try and dissect the data and say well what’s going on because we really think this is the healthy part of fish or at least one of them and some people have pointed out that the people in these trials who have the lowest self-reported fish consumption may have benefitted a little bit. So, maybe that’s part of the answer is it depends on how much fish you consume at baseline.
But the truth is, we really don’t know yet. And the topline data on this is that over-the-counter supplementation did not seem to protect people.
Host: So interesting. So, we’ve also heard besides cardioprotective and we hear about those kinds of things. We’ve heard the benefits can be mood, depression, joint health, lubrication, cholesterol lowering, weight loss, skin. I mean we are hearing that it’s like kind of a super supplement but along the lines of your studies, Dr. Miller, if some of these studies are showing no difference; if someone is coming to you and they are going in for surgery, do they have to discontinue their fish oil and if so, then why?
Dr. Miller: I don’t tell them to. Sometimes surgeons will. I’m a cardiologist. I don’t do open heart surgery so I don’t have to deal directly with that question but there are some orthopedic surgeons who may say yeah you should withhold your aspirin and at the same time withhold your fish oil. I don’t think there’s a lot of evidence for that and in fact, these large – and by the way, these were well-conducted studies, published in the New England Journal of Medicine. So, very high quality data. And they did not document a significant increase in major bleeding risk so, I don’t think that’s a major issue. But I do want to say, I don’t think we know everything about this story yet.
And there’s one really, really impressive positive note in this area that came out within the last year. Those were the two negative studies. Let me tell you about the positive one because it’s stunning and this was a study called REDUCE-IT. Again, this was a very highly credible study and published in the New England Journal of Medicine. And they looked at over 8000 patients with established cardiovascular disease or they had diabetes plus additional risk factors. And they were already taking a statin, cholesterol lowering drug, so they were already getting the standard of care protective, preventive therapy that we recommend for all the patients that have already had a cardiovascular event.
So, they were well treated but they still had elevated triglycerides, and this is one of the circulating lipid forms that we see in patients and there is a risk associated with having an elevated triglyceride level. And omega-3 fatty acids are particularly good at lowering triglycerides so the thought was, maybe if we can target people that still had high triglyceride levels in spite of being on good cholesterol drug, maybe they would be the ones that benefit. So, they studied these people and I think the key here is that in this study, they used this highly purified form of one of the types of omega-3 fatty acids which is EPA, it’s called icosapent ethyl and again the brand name is Vascepa. It’s not FDA approved for this indication but in this study, they gave patients two grams of this omega-3 fatty acid twice a day. So, four grams total a day versus placebo.
And they followed them for five years. And in this study, they were able to show a 25% reduction in the primary in point which was heart attack, stroke, cardiovascular death and some coronary revascularization, so getting a stent. An amazing result so that was an absolute 4.8% risk reduction. They looked at a secondary in point which is just heart attack, stroke and death. That was reduced 26% and if you just looked at cardiovascular death alone; there was a 20% lower risk of death. A 20% lower risk of death in people getting a fish oil supplement, really a highly purified form of omega-3 fatty acids versus placebo.
And we have never seen anything like that in this area. So, it’s such an important proof of concept that there really is something beneficial there. And as far as all the other benefits that are touted, mood and other things; I guess the way I think about that is not all of that stuff may be studied at the level of a randomized controlled study but I’m open minded about it because I think there’s a lot of things that we don’t know and many people will perceive a benefit and when a patient tells me I think this really is helping me; I am saying to them well as long as it’s not causing you harm I say go for it. And especially if it’s not unreasonably expensive.
So, I think there’s a role for these things. I think this last study the REDUCE-IT study is a really interesting one. I think the authors of that study emphasized that we have to be careful not to try an extend the positive results of this study which used a very specific form of omega-3 fatty acids in a highly purified prescription drug. We can’t extend that to over-the-counter supplements which aren’t as highly purified, and their content isn’t as regulated. But it’s a really interesting result and I think there will be a lot more study on this.
Host: So, then what’s the take home message Dr. Miller, very briefly tell us what you would like us to take away from this as we are doing our own research so we can be out own best health advocate. As a cardiologist, what would you like us to think about if we are thinking about taking fish oil?
Dr. Miller: Well I think the first thing if you go and just look at the evidence based stuff that I just talked about; is if you have a history of heart disease of any kind, you’ve had stents, angioplasties, bypass or a coronary event; talk to your doctor and ask them if they think something like this might be beneficial for you. Because this is a very powerful study and I think it will influence behavior and opinions about fish oil supplementation and oega-3 fatty acids.
As far as over-the-counter supplementation; it’s just really hard to make a very strong argument for it as a physician. And I think my biggest message for patients is we in cardiology and in our culture have a long history of trying to find that essential element of what we know is a healthy food like beta carotene from carrots and extracting that thing out of that healthy food and making it into a supplement and thinking that’s going to help our health. And for the most part, everyone of those when really put to a rigorous test has failed to protect us from heart disease. So, I would much rather see people eating a healthy diet, a balanced diet that is more leaning towards plant-based diet and with some healthy fish incorporated on a regular basis.
Maybe particularly if you are not a fish lover or if you just don’t incorporate fish into your diet; there may be a role for omega-3 supplementation. That right now, the evidence for that is a little bit soft. It doesn’t seem to be harmful, so if you perceive a benefit; I’d say go for it.
Host: Wow. What a great segment. You are such an excellent guest. Thank you so much for coming on and telling us about the studies and clearing up some of the confusion and the questions that we have. And thanks to our Bryan Foundation partner, Sampson Construction. And that wraps up this episode of Bryan Health Podcast. Head on over to our website at www.byranheart.org for more information and to get connected with one of our providers. If you found this podcast as interestingas I did, please share with your friends, share with your family, share on social media because these are questions that so many of us have and we’re learning from the experts at Bryan Health together. And be sure not to miss all the other fascinating podcasts in the library. Until next time, I’m Melanie Cole.
Fish Oil Benefits: Breaking Down the Research
Melanie Cole (Host): If you’re one of the many that have questions about fish oil and whether you should be taking it or not or if you are, how much should you be taking. Here to answer that today is Dr. Keith Miller. He’s a cardiologist with Bryan Heart. Dr. Miller, I’m so glad to have you on to discuss this today. What a great topic, fascinating segment. Tell us first, what are omega-3 fatty acids and where are they typically found?
Keith Miller, MD, PhD, FACC (Guest): Well I think a lot of people are aware that omega-3 fatty acids are found especially in marine animals. So fish consumption and a lot of the interest in omega-3 fatty acids and fish oils came from the observation that populations who eat a lot of fish are less likely to develop heart disease. So, the epidemiology, the observational studies say if you eat fish once or twice a week; that’s associated with a reduced risk of heart disease. So, lots of animal meats have omega-3 in them but fish, in particular, is a rich source of omega-3s.
Host: Okay, so how is fish oil made then? The caplets and there’s you know people have been hearing Dr. Miller about cod liver oil for a very long time. So, how is this made and put into capsules and what do you think about it? Should we be looking at taking it?
Dr. Miller: Yeah, that’s a great question. And I have to admit, I don’t know exactly the manufacturing process that’s used but I think actually that might be kind of an important point because a couple of the trials that I want to talk about today, used over-the-counter fish oil supplements and there is not a lot of regulation in regards to how those marine omega-3 fatty acid supplements are made or the content of the supplements which are often capsules is not regulated very closely. So, in many cases, it’s not very well defined how those things are made.
But in contrast to that, one of the studies that was published in the last year that got a lot of attention was with a product which is a prescription form of omega-3 fatty acids, it’s called icosapent ethyl brand name is Vascepa and that product is very highly regulated and very highly purified and that actually was the one study that was a very positive study that seemed to provide a very impressive protective benefit. So, I mean if I could, I’d just like to maybe comment on a couple of these trials because I think they are very important and as so many things in nutrition and in medicine; a lot of this starts out with an observation in a population and that’s exactly the way it was with omega-3 fatty acids. The observation being people who eat more fish tend to live longer and have a lower risk of heart disease.
Then came a series of trials looking at well what happens. We think maybe omega-3 fatty acids are one of the main reasons that fish is such a healthy thing in the diets. So, can we extract that out of the fish and use it as a supplement to try and protect us from heart disease? And many of those trials have produced some conflicting results and then attempts to kind of collect all that data and assimilate it into large analyses have really left us confused a little bit about whether these are helpful or not.
Nonetheless, the information about eating fish and fish being a part of a healthy diet that protects us from heart disease is so much a part of our understanding now that omega-3 fatty acid supplementation is still a part of the American Heart Association guidelines for the secondary prevention of heart disease and of course, we always recommend fish consumption for protection of people from heart disease. Now in the last year, comes along these three trials that really tested this hypothesis and one was called The VITAL Trial, one was called The ASCEND Trial and then there’s a third trial. The first two were done basically with the types of omega-3 fatty acids over-the-counter supplements at the same dose recommended by the American Heart Association which is one gram per day. And in one of the trials; they looked at primary prevention for men over 50 or women over 55 and they enrolled over 25,000 people and followed them for five years. And they tested omega-3 fatty acids versus placebo and they were able to show no difference in major cardiovascular events. So, there was no benefit that they could document in this huge trial for five years. And again, that was the same dose that was recommended by the American Heart Association.
And then there was a second trial that looked at diabetics over 15,000 of them, who did not have a history of heart disease, gave them the same dose of fish oil, again an over-the-counter one gram per day supplement, followed them for seven years and again, they could not demonstrate a significant reduction in cardiovascular events in these two groups. Some people have started to kind of try and dissect the data and say well what’s going on because we really think this is the healthy part of fish or at least one of them and some people have pointed out that the people in these trials who have the lowest self-reported fish consumption may have benefitted a little bit. So, maybe that’s part of the answer is it depends on how much fish you consume at baseline.
But the truth is, we really don’t know yet. And the topline data on this is that over-the-counter supplementation did not seem to protect people.
Host: So interesting. So, we’ve also heard besides cardioprotective and we hear about those kinds of things. We’ve heard the benefits can be mood, depression, joint health, lubrication, cholesterol lowering, weight loss, skin. I mean we are hearing that it’s like kind of a super supplement but along the lines of your studies, Dr. Miller, if some of these studies are showing no difference; if someone is coming to you and they are going in for surgery, do they have to discontinue their fish oil and if so, then why?
Dr. Miller: I don’t tell them to. Sometimes surgeons will. I’m a cardiologist. I don’t do open heart surgery so I don’t have to deal directly with that question but there are some orthopedic surgeons who may say yeah you should withhold your aspirin and at the same time withhold your fish oil. I don’t think there’s a lot of evidence for that and in fact, these large – and by the way, these were well-conducted studies, published in the New England Journal of Medicine. So, very high quality data. And they did not document a significant increase in major bleeding risk so, I don’t think that’s a major issue. But I do want to say, I don’t think we know everything about this story yet.
And there’s one really, really impressive positive note in this area that came out within the last year. Those were the two negative studies. Let me tell you about the positive one because it’s stunning and this was a study called REDUCE-IT. Again, this was a very highly credible study and published in the New England Journal of Medicine. And they looked at over 8000 patients with established cardiovascular disease or they had diabetes plus additional risk factors. And they were already taking a statin, cholesterol lowering drug, so they were already getting the standard of care protective, preventive therapy that we recommend for all the patients that have already had a cardiovascular event.
So, they were well treated but they still had elevated triglycerides, and this is one of the circulating lipid forms that we see in patients and there is a risk associated with having an elevated triglyceride level. And omega-3 fatty acids are particularly good at lowering triglycerides so the thought was, maybe if we can target people that still had high triglyceride levels in spite of being on good cholesterol drug, maybe they would be the ones that benefit. So, they studied these people and I think the key here is that in this study, they used this highly purified form of one of the types of omega-3 fatty acids which is EPA, it’s called icosapent ethyl and again the brand name is Vascepa. It’s not FDA approved for this indication but in this study, they gave patients two grams of this omega-3 fatty acid twice a day. So, four grams total a day versus placebo.
And they followed them for five years. And in this study, they were able to show a 25% reduction in the primary in point which was heart attack, stroke, cardiovascular death and some coronary revascularization, so getting a stent. An amazing result so that was an absolute 4.8% risk reduction. They looked at a secondary in point which is just heart attack, stroke and death. That was reduced 26% and if you just looked at cardiovascular death alone; there was a 20% lower risk of death. A 20% lower risk of death in people getting a fish oil supplement, really a highly purified form of omega-3 fatty acids versus placebo.
And we have never seen anything like that in this area. So, it’s such an important proof of concept that there really is something beneficial there. And as far as all the other benefits that are touted, mood and other things; I guess the way I think about that is not all of that stuff may be studied at the level of a randomized controlled study but I’m open minded about it because I think there’s a lot of things that we don’t know and many people will perceive a benefit and when a patient tells me I think this really is helping me; I am saying to them well as long as it’s not causing you harm I say go for it. And especially if it’s not unreasonably expensive.
So, I think there’s a role for these things. I think this last study the REDUCE-IT study is a really interesting one. I think the authors of that study emphasized that we have to be careful not to try an extend the positive results of this study which used a very specific form of omega-3 fatty acids in a highly purified prescription drug. We can’t extend that to over-the-counter supplements which aren’t as highly purified, and their content isn’t as regulated. But it’s a really interesting result and I think there will be a lot more study on this.
Host: So, then what’s the take home message Dr. Miller, very briefly tell us what you would like us to take away from this as we are doing our own research so we can be out own best health advocate. As a cardiologist, what would you like us to think about if we are thinking about taking fish oil?
Dr. Miller: Well I think the first thing if you go and just look at the evidence based stuff that I just talked about; is if you have a history of heart disease of any kind, you’ve had stents, angioplasties, bypass or a coronary event; talk to your doctor and ask them if they think something like this might be beneficial for you. Because this is a very powerful study and I think it will influence behavior and opinions about fish oil supplementation and oega-3 fatty acids.
As far as over-the-counter supplementation; it’s just really hard to make a very strong argument for it as a physician. And I think my biggest message for patients is we in cardiology and in our culture have a long history of trying to find that essential element of what we know is a healthy food like beta carotene from carrots and extracting that thing out of that healthy food and making it into a supplement and thinking that’s going to help our health. And for the most part, everyone of those when really put to a rigorous test has failed to protect us from heart disease. So, I would much rather see people eating a healthy diet, a balanced diet that is more leaning towards plant-based diet and with some healthy fish incorporated on a regular basis.
Maybe particularly if you are not a fish lover or if you just don’t incorporate fish into your diet; there may be a role for omega-3 supplementation. That right now, the evidence for that is a little bit soft. It doesn’t seem to be harmful, so if you perceive a benefit; I’d say go for it.
Host: Wow. What a great segment. You are such an excellent guest. Thank you so much for coming on and telling us about the studies and clearing up some of the confusion and the questions that we have. And thanks to our Bryan Foundation partner, Sampson Construction. And that wraps up this episode of Bryan Health Podcast. Head on over to our website at www.byranheart.org for more information and to get connected with one of our providers. If you found this podcast as interestingas I did, please share with your friends, share with your family, share on social media because these are questions that so many of us have and we’re learning from the experts at Bryan Health together. And be sure not to miss all the other fascinating podcasts in the library. Until next time, I’m Melanie Cole.