Episode 5 with Dr. Tom Brenna
Dr. Brenna shares insights on where interest in omega-3 for the heart and brain began, and what we know about omega-3 and human genes today. Where is DHA found in our bodies? How was that discovered? Hear why research reported in isolation can be confusing and how research design flaws impact results. With fun curiosity about lipid chemistry for 32+ years, Dr. Brenna breaks things down into practical, logical explanations.
- Difference between EPA & DHA (5:5)
- Where DHA is found in the body (6:51)
- Omega-3’s role in cardiovascular health (8:00)
- Omega-3’s role in neurocognitive health (11:38)
- What’s known about genes and omega-3s (16:34)
- Making sense of conflicting information on omega-3s (18:51)
Resources Mentioned in this Episode
- Dr. Tom Brenna
Any statements on this podcast are the opinion of the scientific guest and/or author and have not been evaluated by the FDA. The information we may provide to you is designed for educational purposes only and is not intended to be a substitute for informed medical advice or care. This information should not be used to diagnose, treat, or prevent any health issues or conditions without consulting a health care professional. If you are experiencing a health issue or condition, we suggest you consult with your health care professional.
Hello, and welcome to the science and the story behind omega three, a podcast brought to you by Wiley companies, where we explore one of the most researched nutrients on the planet. Listen in as global omega three experts and researchers translate the science, reveal personal insights and share their stories of discovery while navigating the sea of omega three science. Thanks for joining us today. Now, here’s your host, Greg Lindsey.
Dr. Brennan, thank you so much for being with us today. We are so excited for you to help us weave together some of the news we hear about omega three. But before we dive in, I just want to ask you, you’ve had a 30 plus year career in lipid chemistry and omega three nutrition. What has kept you interested or intrigued by this work?
Well, well, Greg, it’s combination of the depth and many layers that the omega three story has, and a general interest in incorporating very technical aspects of chemical analysis that I can apply to the omega three story. So the kinds of things we do in the laboratory tend to be a bit different than what a lot of omega three people do. And so we get insights that maybe are not as common. And so there’s kind of an endless, endless levels of uncertainty and interest that keeps us engaged over the years, I can always find some other thing to look at and and I tend to be a very curious person. Also, we’ve, we usually think of the mega three story as the kind of stuff we see in the in the in the press with omega three effects on cardiovascular disease, and a few other things like that, and taking fish oil pills or whatever. Something along those lines, we have applied some of these basic science concepts to for instance, ecology and understanding whether whether wild birds require omega threes and how well they do in the nest and things like that. That’s really endlessly interesting stuff. So that’s what’s kept me engaged over the years. And this is not the only thing I do. So it’s always fun to come back to it, though.
So so you referenced it. So Dr. Brenner, we usually hear about omega threes in context of a disease like cardiovascular or a function associated with an organ, like neuro cognitive development of the brain, why isn’t the big picture or really the whole body emphasized?
It, it’s a bit of the way we do science. So when a cardiologist does a study, and they administer omega threes, and they look at some outcome, a cardiology outcomes, so they might look at cholesterol levels, or they might look at cardiovascular events, so major events such as a heart attack, they then write up the paper in that context, and the press picks it up, and it says omega threes do this or do that, for cardiovascular disease. And we tend to implicitly ignore all the other things that omega threes do. So it really is an issue that we that we don’t look at the big picture. I mean, I I’m, at various times, in sometimes in frustration when one sees two or three studies that that don’t come out as, as the way we expect, and I think most people aren’t actually studying the important thing. And I say, Well, you know, I don’t really care why people are taking omega threes, as far as I’m concerned, if they take it to grow hair, that’s fine with me, because it’s going to do, they’re going to do good things all over the body, they’re going to do good things for the brain and the heart and, and in the joints, and, and, and, and so forth. So that’s a perspective that people should always bear in mind when they reading one isolated study.
that’s a that’s a great point. If we talk about specifics, so EPA da chair the key forms of omega three and fish, seafood and fish oil, maybe you can explain the difference between EPA ndhca and I realized this is just the question that could be an entire podcast, but I’d love for you to give listeners just maybe the basic differences between EPA ndhca
EPA and d h are two different omega three fatty acids, they have different chemical structures, the but they’re very closely related from a metabolic point of view, one can be converted into another, we know that. But we also know that metabolically there are barriers of converting EPA to d, h, a and d h A back to EPA. So that’s why the two of them actually are separate and appear separately in, in tissue, and are distributed differently in tissue. They also in tissue have different functions. Some of them are overlapping functions. But they, they will appear differently in membranes, and they, and they have their own distinct functions.
Where is da ha found in the body?
The ha is found in essentially all neural tissue. So it’s very high in the brain, in the neural parts of the retina, which really is a part of the brain. It’s high in the peripheral nervous system that is the part of the nervous system that’s outside the skull. And it’s high in some specific places. An example would be the testes, it’s it’s high in the testes. Those are the biggies. There are other pockets of the HA in various places. But those are the ones that always come to mind.
Switching gears, I have a question, and that’s why is a dietary supply of omega three important for pregnant moms and infants? And do moms in infants need just tha or both EPA and DOJ?
Well, the why is it important for moms and infants? We know from many decades of research that da j is important for building the structural material of the brain. And we also have significant amount of data in fact that data is becoming clearer and clearer that at least in pregnancy, d h A is required to bring pregnancies to a normal term timing in other words, nine months. There, there is a very strong evidence, the highest level of medical evidence as it is known and in meta analyses, that 500 milligrams a day of the HA is specifically associated with the prevention of early preterm birth, and that would be what I normally call dangerous. preterm birth, that is before 34 weeks of gestation out of a 40 week normal pregnancy. And we are seeing and we’ll continue to see randomised trials emerge showing that that this is the case for DOJ specifically. So there, there is a lot of good evidence that EPA itself, separate from tha has metabolic effects, but in particular, on the reduction, and even treatment of depression, so neurocognitive health, particularly in moms, but then in nonpregnant, non lactating adults, men and non pregnant non lactating women, there are quite a few studies showing that EPA is important for for mood, which of these days is really quite a big deal, right? So my view of the data is that it almost looks like EPA is required for proper mood, and many, many people. Some of this is being clarified because of genetics. And we’re still pretty early days in understanding how genetic makeup actually affects our dietary requirements. You could call it Gina type directed nutrition, which is something that’s understood in a little bit in some areas of pharmacology but hasn’t really penetrated into nutrition as much as it as it is I’m sure it will we call it nutrigenomics or nutrigenetics or something along those lines. But at any rate, when we understand a little bit better about what factors in the genome and our individual person by person genotype affect our requirement for EPA, I think we’re going to see that some people need a lot more than others.
That that is fascinating. So I’m going to jump to a topic that’s been very, very high profile because of Heart Health Month and that is We hear a lot about omega threes for cardiovascular health. And I just like to understand your opinion of why people got interested in omega threes for cardiovascular health, if you could maybe give us a little background on how that that came about.
Yeah. So back when I was an aspiring scientist, or perhaps even before that, it was in really the 1970s, that a pair of researchers from Denmark, went to Greenland and studied the natives of that area and their cardiovascular disease and finally had very low cardiovascular disease and then connected that to their intake of marine foods, specifically fish, and, and marine mammals. And they also showed that a very high amount of intake of these omega threes from fish caused a very high amount of EPA in the blood and that very high amount of EPA blood and very high relative to, let’s say, Americans, and that very high level, reduce the tendency of blood to clot, the tendency of blood to clot is closely related to cardiovascular disease. So that was actually the 1970s, there was a series of four papers, let’s say, that really got people going on a cardiovascular story. And at that time, EPA was the one that everyone was emphasizing for cardiovascular disease that’s gone back and forth. Over the I got, I got involved in science probably well, in the late 70s. And I was an undergrad and in nutrition major, and worked in a weapons lab and learned about a lot of this stuff. And I just kind of watched it go from EPA being a really good guy to dhk being a really good guy to EPA being a good guy, and it just kind of goes back and forth, people switch between the two and, and casually, they throw in another omega three called DPA. But we’ll won’t get into that one. At any rate, it’s been, it’s kind of been like that. So that’s really the origin of the cardiovascular story. There is another part of the cardiovascular story that’s relevant, which is the reduction in the tendency of the heart to stop beating upon a heart attack. So we call that a ventricular arrhythmia. And those events so so when a person has heart attack, the heart can stop beating. And if a shock is not administered, then you get sudden death. That’s why people die of sudden death at heart attack. Well, it was shown in roughly around 1990, that an infusion of omega threes could make the heart much more robust to that phenomena. And that that was replicated in human studies afterwards. And so there’s really two things one is that you don’t have as many heart attacks. The second is you don’t die of a heart attack. As as often when EPA DOJ are higher in the diet.
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Just omega three in heart health is such an important topic. And I’d love to explore that more. But we have limited time today. So I want to jump to the brain or neuro cognitive health. And I know that’s a big leap from cardiovascular health. But curious, why did people suspect that omega three had a role in neuro cognitive health?
Yeah, that’s a great question. And it actually has a fairly simple answer. Why did people suspect that calcium had something to do with bones? Because calcium is always found in bones. That’s why so the reason that people thought that omega threes had something to do with neurocognitive health is that omega three and specifically da che is always found in brain tissue. And even from the from the earliest days, the discovery of the HA came from a sample of pig brain actually, that’s where it was first isolated and then characterized later on. Studies in the 1970s. Among many species, 25 3040 species of animals found that the HA levels are virtually the same in all species, while other fatty acids are very different. And their nbha levels are different in other organs, from species to species, but all species have about the same amount of the HA in their brains. So okay, that’s beginning to sound a lot like calcium, isn’t it calcium in the bones, you can’t make good bones without calcium. You can’t make good brains without the HA So that’s what got people really interested in the first place.
So what is the best evidence then for the role of omega three in neuro cognitive health?
Well, I would cite that first bit of evidence that D ij is always present in neural tissue. And I would second site what I would call preclinical data, we talked about preclinical data, that would be animal studies that show that when omega threes are reduced in the diet, and when there’s an omega three deficiency, you get all manner of neurocognitive abnormalities, anything you can measure, from the biochemical to the running of mazes, to sensitivity, to neurotoxins, to you name it, is messed up in the offspring. So if you if you make, if you make a pregnant animal deficient in omega threes, you can look anywhere you want, you find a mess. And so that is number one that really says, Look, this thing is this, these omega threes are critical for brain development. And then we have numerous studies that show that adding da che to, let’s say, infant formulas, and that was one of the areas that was studied early on in the 90s. Improves cognitive performance in infants. But importantly, also in some of the most compelling data is on vision, where vision, visual development is accelerated in infants. And we think of vision as a separate thing from the brain. But it really isn’t. The neural part of the retina is the part of the brain that we can see, we can see it. And it’s the part of the brain that’s looking out on the world. And so it really is a part of the brain. And there are certain aspects of it that can be measured much more conveniently than deep brain structures. And so there’s there’s, there’s very good evidence on that, and in my opinion, showing that more da j is associated with faster visual development.
A lot of great information. So my question what happens if we do not have enough omega three in our bodies?
Well, attention has turned in, in recent years away from the early days of what we used to call acute deficiency conditions that is keeping an animal alive and apparently healthy to to simply look at, let’s say, in normal activity levels, to considering omega threes as a specific case of a nutrient. And their role in both development and neural development is not an easy thing to measure, and also for the reduction of chronic disease risk. So we talked about that also as a requirement. And in in recent years, we’ve come to clarify that omega threes, at least against the background of our current, we call them Western diets, let’s just say the American food supply, but I think this applies all over the world is really beginning to apply. And in some developing countries. That adequate omega three is required for forces for lowering of chronic disease, and for for neuro development for reasons that we’ve discussed.
Dr. Brenda, I read an article recently, and knowing you were going to be with us today, I wanted to ask the question, we hear about genes, what’s known about genes and omega three.
Oh, my. So Greg, people have been studying genes and omega three, for several years now. There’s a considerable amount that is known about the inter individual variability in the use, and the metabolism of omega threes and omega sixes, because that’s, we talk about omega threes a lot, that’s a subject of this conversation. But if from a metabolic point of view, the Omega sixes are in there. And we know that among the strongest influences that the genome has, uh, nutrients, and nutrient utilization is actually on these omega threes and omega sixes as they come into the body. Now, these are still relatively early days. I mean, we like to say that we’ve sequenced the genome and it sounds like we know everything there is to know about it. Don’t believe any of that. We’ve sequenced a lot of the genome, but but we haven’t sequenced all of it. We’ve sequenced the genes that code for proteins we’ve sequenced but we don’t know what a third of those Proteins do, we don’t know how a lot of them are regulated in there’s layer upon layer of subtlety about how this all works and and and my head spins when I read the literature and and and see yet another thing that has popped up that affects metabolism it points to yet another set of genes that I might have to look at in order to understand exactly what’s going on. So let’s just say that we’ve got a pretty good idea. In fact, I think it’s a lock that some of the most important influences of the genome on human metabolic status and nutritional status operate at the level of these these omega threes and omega sixes.
Dr. Brown, I think the last question I want to ask you today is there’s so many conflicting reports in the news about omega three, how do our listeners make sense of all this information?
Right. So there’s a bit of background that one ought to think about when you when you when you think about a study, so almost all studies are designed, where there’s an experimental group in a control group. And, and you administer omega three to one group or more omega three, two to one group, and then and none or less to a control group and you compare an outcome. So that outcome could be visual acuity, it could be depression, it could be some aspect of cardiovascular health. And your hypothesis typically will be that the omega three group will be superior to the control group. Okay, fair enough. What we talk about almost exclusively, is we say that the study was positive, if it confirms the hypothesis, or at least is consistent with the hypothesis that omega three has a positive influence on the on the outcome. Or we say that the study was an often people will apply the word negative when there wasn’t any difference. But what that ignores is a very important subtlety that that never makes it into the into the new stories, which is that those studies could just as easily find that there’s a negative effect of omega threes. So there are really three outcomes, one is positive one is neutral, much better word, no difference, and one is negative, you almost never see negative, I really have to scan my memory banks to even think of anything that’s ever been seen that was negative. So So one thing to remember is that the studies almost universally, are either positive, or neutral. Now, that points to a positive overall effect. And so so what you can have confidence in at the very least, in reading these studies, is to understand that the omega threes aren’t going to do harm, the omega threes are going to have a positive effect, or at least do no harm. And, but on net, one expects that there’s going to be a positive effect. And there’s subtle reasons why that’s the case. We’ve seen a lot of studies, clinical studies, where omega threes are are administered to individuals, regardless of their omega three status. But so this is a little bit like administering a vitamin C to people who are not vitamin C deficient. So if you’re not deficient in the in the nutrient, then administering it to you giving it to you isn’t going to help anything if you’re not deficient. I mean, a friend of mine likes to say that, in frustration over one of these things, he says, Yes, it is true that omega three did not improve depression and people who are not depressed. So it and so we actually see a fair amount of that. And so if you have a study where half the people have no omega three deficiency, and half the people do have some kind of an omega three deficiency, the ones that have no omega three deficiency are going to be averaged in with the others, and you may end up with a null result. So that’s a subtlety that the layman your listeners may not really get, but it really is there. And some of the sages in this field I have in mind, the late great Sheila Ennis, of Vancouver, Canada. And she had wrote several papers towards the end of her life that pointed out that maybe 10% of people might be deficient for a particular outcome. But then you have everybody in that everybody thrown into the group, and it just washes out the effect. And so we need to design our studies better. That’s actually part of it. And some people are starting to do that. And so when you say, Well, I’m only going to measure the people that are in the in the in the bottom half that come in, in the bottom half of the omega three status in my, among my participants. And and when you do that, you begin to see much more significant effects, actually. So. So in that sense, you can think of it a little a little like a vitamin. Where I mean, people think about a vitamin is they don’t, they’re not taking a multivitamin, because they think they’re deficient in vitamins, they’re taking a multivitamin, because they think they may not be getting enough of this or enough of that, and it’s not going to hurt so. So I might as well take it, there’s a little bit of mindset like that, that that really does apply. And I think that’s a it’s a reasonable way to think about it as a layman.
Thank you so much for addressing that question. And for summing that up so well and for really helping us make sense of all this today. I’m going to put you on the spot and ask you to come back for another podcast because I feel like we’re just hitting the tip of the iceberg and all the great information that you have.
Oh, I’ll be glad to do that anytime.
And, and I want to thank you again, Dr. Brenda, and thank you to our listeners. And as always be healthy, be well and fight the good fight.
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Any statements on this podcast or the opinion of the scientific guests and or author and have not yet been evaluated by the FDA? The information we may provide to you is designed for educational purposes only is not intended to be a substitute for informed medical advice or care. This information should not be used to diagnose, treat or prevent any health issues or conditions without consulting a health care professional. If you are experiencing a health issue or condition we suggest you consult with your healthcare professional