Sunday Science 2026_09_13 Diet and Coronary Artery Disease
Welcome to Sunday Science, where we dive into a few recent scientific articles and their translation into our modern lives. Here is your host, Brent W. Laartz, M.D. Alright everyone, welcome to Sunday Science, part of the GoUnPro podcast. We are talking this week about vegetarian diets and coronary artery disease. Some people might think that... they already have coronary artery disease or they're already obese and they already have risk factors they already have family history and therefore you know it's too late for them etc right so obviously i'm in good shape i have some family history issues but otherwise I've had a stress test. I know that I do not have significant coronary artery disease right now.
So my changes that I'm making to this mostly vegan diet and whole food diet and the exercises and the sleep and the stress reduction and everything else is coming at a benefit to me. And However, there are some people who may be already 60 years old and have coronary artery disease. We're going to be looking at three articles, basically, in patients who already have coronary artery disease. And the main article we're going to be looking at is this Dean Ornish studies showing that there is a benefit to a vegetarian diet along with a exercise and risk factor modification, those kinds of things. And this is something that really wasn't done before. And it was. a big deal at the time, 1998.That was the year I graduated from medical school, by the way.
And here it is. So this is Dean Ornish article. Let's go also to summarize. Also, we're going to be talking about a Haskell article and a Hensel article, basically similar, but less intensive. Okay, so one of the critiques of the Ornish study is that it would be very difficult to follow and continue and sustain that much of a change in diet and exercise. However, we can show you that a good percentage did sustain that, okay, in the study. And, all right, so let's first start with the Ornish study. Again, these articles are going to be in the show notes, in their citations. So we're going to be looking at them. Okay, so this is Dean Ornish. So this was published in JAMA, December 6th, 1998.
I want you to know our spam call comes in right now. Perfect. All right, so... December 16th, 1998 in JAMA. Okay. So this is the lifestyle heart trial demonstrating that intensive lifestyle changes may lead to regression of coronary atherosclerosis after one year. And they also then took this to five years. Okay. So a total of five years. And so they basically took 20 of 28 patients completed the five-year follow-up and they made and maintained that comprehensive lifestyle changes for five years. Whereas a control group of 15 of 20 patients completed five-year follow-up as well. So they made moderate changes. So again here, Very interesting, and we'll go over this a little bit about how much of moderate changes those patients in the control group made and how they still had coronary artery events and they had a worsening in their arterioles.
atherosclerosis by arteriogram, okay? So arteriogram is where they put dye into your arteries, and they look at the coronary arteries to see the actual change in the atheromas, let's say, for example, all right? So in these experimental group, and let's go over this here real quick, just about. what this meant. So it meant a vegetarian diet, stress management, and intensive exercise. And the fat intake was brought down to a 10% fat diet. And there were other changes made as well. The total adherence score in the experimental group was about 0.62 at baseline based on questionnaires and 1.29 at one year and 1.06 at five years. These people did a great job of following the diet and the persons in the control group had a adherence score of about a 0.
60 and a baseline 0.64 at one year and 0.72 at five years. So actually some improvement in their, in their scores, right? So the Experimental group exercised at baseline 2.66 times per week and 2.38 times per week for baseline for the control group, and then that increased to almost five times per week and 2.87, so a slight increase. There again, also at five years, 4.34 times per week. So a slight decrease from one year and 3.57 at five years for the control group. So you can see they went almost up to four. So you're already showing some change in exercise, even in the control group. And again, this is kind of the usual therapy thing.
And this is what I don't like that, you know, and we could, we've talked ad nauseum about the standard American diet, which is sad. And maybe we could think about what is the sad standard American, um, changes in what we as doctors recommend for people to do. Okay, well, you should lower your cholesterol, you should exercise a little more, you should have stress management, and nothing is really done about it. And that's why these people in the control group who were told to follow their doctor's recommendations, I guess that's why they increased a little bit, but Obviously, we're going to talk about that. We will gloss over a little bit about the stress management that changed as well.
Fat intake, a number of grams per day at baseline, pretty similar, around 60 grams per day of fat, and it was 29 to 30% of the energy intake. And that changed in the experimental group down to 12.71 grams per day. So a decrease of, you know, 40, 50 grams, 50 grams. And percentage of energy intake was only 6.22%. In the control arm, 52 grams and percentage was still about 28%.So really not that much of a change. Let's look at then at five years, there was 17.34 grams per day. So a little bit of an increase from base from the one year to 7.34 grams per day of fat. and 8.51% of energy intake. And the control arm at five years decreased a little bit as well, down to 44 grams and 25% of energy intake.
Dietary cholesterol also likewise decreased markedly. Okay. So, all right. So that was basically... In a nutshell, the changes that were made, and there was some decrease in calories, not a lot in either arm, total calories. All right, so then let's look at the results of that kind of intensive change. And we're talking, these people were mostly vegetarian at the in the experimental arm, okay? Mostly vegetarian and decreased fat, decreased cholesterol, okay? So the gist of this study was that of the experimental arm, there was a regression. of these coronary artery plaques of 4.5% at one year and 7.9% at five years. Nothing really has shown this kind of thing except for intensive other types of therapy now that we have as far as medications.
But if you can, instead of taking a medication, if you could potentially change your to what is really overall a better quality diet, and you can regress coronary artery disease. In the control arm, their lesions were 5.4% worse at one year and 27.7% worse at five years. And that is the standard American. regimen that we doctors recommend. And it's really glossed over every single time. And I talked to a couple of patients of mine. I'm not really, I'm an infectious disease physician and I study microbiome and I study that kind of thing. So I am able to give some patients some recommendations. But I'll tell you, I hear coronary artery disease patients tell me what their cardiologist tells them. And it's usually not that significant.
If you really have coronary artery disease and you don't want to die earlier and you don't want to have an earlier death, don't listen to the standard American regimen. It needs to be an intensive regimen, okay? In this study, there were also 25 versus 45 coronary events, and that had a relative risk ratio of 2.47. So the patients in the control arm that did the standard American regimen. had 2.47 times more likely to have a coronary event within that five years. The critiques of this, again, not sustainable, not replicated. It hasn't been replicated in other studies. And we'll look at some of this as far as the studies go, that really the regimen that they also included medications too. So, and this low-fat, low-cholesterol diet was not a vegetarian diet.
It was low-fat, low-cholesterol. Okay, so they also, okay, so let's go on to the Haskell study. This is the Stanford Coronary Risk Intervention Project. This is from the journal Circulation. This was from March of 1994. So this was around the same time, right? And they use quantitative arteriography as well. And they had a risk program, low fat, low cholesterol diet, exercise, weight loss, smoking cessation, medications to Favorably alter lipoprotein profiles. That versus the standard changes that people were recommended. And those people had, there were a lot of different changes to their profiles as far as high-density lipoprotein cholesterol increased by 12%. LDL and lipoprotein cholesterol B both decreased 22%. Plasma triglycerides dropped by 20%, body weight decreased by 4%, exercise capacity increased, intake of dietary fat decreased 24%, cholesterol decreased 40%, okay, compared with relatively small changes in the usual care group.
In this study, the risk reduction group showed a rate of narrowing of disease coronary artery segments that was 47% less than that for subjects in the usual care group. Again, there was not the regression we saw in the other study, but three deaths occurred in each group. There were 25 hospitalizations versus 44, so there was a 39% reduction in. uh hospitalizations and there are no difference in deaths again this intensive multi-factor study did decrease events and it did decrease the rate of increase but this kind of intervention is nowhere near what we saw in the Ornish article okay so again Ornish has been, you know, amongst the carnivore and amongst some of the other diet proponents, he's been lambasted and every single one of these people who are espousing the carnivore diet and the Atkins diet that is high in fat and meat process.
every one of their arguments does not hold weight. The only argument that could hold weight in some of these is that it does impact weight loss. But there are study after study after study showing that inflammation, coronary artery disease, and cholesterol, and there's one study that showed coronary, sorry, not coronary, but carotid artery thickening over one year time with a carnivore diet. All right. So again, here are usual treatments worsened by coronary arteriography here again in this study, whereas there was still a worsening, but 47% less than the usual treatments. Okay, so all right, so let's go on to then the Hensel article. This is an interesting article because it does incorporate a little bit more intensive lifestyle intervention. And there was, they had 92 patients.
with non-obstructive, less than 70% stenosis of coronary artery disease, and they randomized to either the DISCO, which was dietary intervention to stop coronary atherosclerosis in computed. tomography. So they were using CT angiography. And they basically, this study had approached the DASH nutrition model together with optimal medical therapy versus optimal medical therapy optimal medical therapy, which is that standard risk diet and exercise and medication. Okay, so the outcome was change in atheroma volume and plaque composition. So the changes here showed, and I don't have any... graphs to show you here. There is a really good graph in this article showing the difference. And essentially, in the disco intervention, the non-calcified plaque portion actually decreased by 1.7% versus in the control arm, a change of minus 0.7%.
But an overall coronary artery plaque total increased by 1.1% in the control arm. There was a little bit of an increase in the fibrous portion of plaque as well and a slight increase in the dense calcium in the intervention arm. But again, that really robust decrease, 1.7%.in the non-calcified plaque in the disco intervention arm all right so again small differences here but again there in this study this was from 2021 journal of sorry in the from the American College of Cardiology Foundation the JACC. All right. So we'll, again, we'll post that in the show notes to show you where this is coming from. This is a little bit more recent study. So again, 2021 showing differences and a decrease in the plaque, although total also increased barely, but a big difference between 0.
127 versus 0.033 as far as the p values and change so there's no change in the total in the experimental arm versus the control arm and then a reduction of the non-calcified plaque again here that non-calcified plaque is the part that is potentially modifiable your deep calcium, not very modifiable. Your fibroma might not be very modifiable and it might actually increase if some of your plaque is going to move to that fibrous plaque. And it's this portion that is the atheroma, the fatty portion of the plaque. that is potentially modifiable. And this was decreased in the intensive study. And the DASH diet, you know, the DASH diet is certainly not a vegetarian diet. It is mostly plant-based and you are, it is recommended to eat four to five servings of vegetables, four to five servings of fruits.
And your low-fat and fat-free dairy is there, and your lean meat. So in general, on a DASH diet, only eating poultry, fish, and lean cuts, and you're instructed to use healthy fats and oils, you know, the avocado and olive oil versus the non. tropical sorry the non uh low fat oils and and saturated fats and you're staying away from palm and coconut oil was what i was trying to get at there and then limiting uh sweets and added sugars okay so dash diet is not anywhere near the intensive changes that the Ornish diet was And it did show some decreasing in the atheroma. Okay, so a great study. We'll show you some more of these types of studies. And we'll look at different diets overall in the long run.
Again, what I am trying to espouse to. is not necessarily a completely vegetarian diet but when i do eat meats which is only a few times a week it's chicken and fish okay maybe turkey right so trying to stay away from pork and beef toward these and increasing the vegetarian aspect all right so again i think that the most study would tell you again we just showed you two articles showing one with really good inputs and improvements into health And that is the Ornish type diet, the vegetarian type diet. And then another one showing also a decrease in worsening. in this Hensel article with the dash guy okay so again these dash diets mediterranean diets pescatarian diets we talked about this several weeks ago when we had a Sunday science about mortality and the use of different diets and those improving with pescatarian diets a little bit better, actually, scoring than the vegetarian diets.
So again, here, we don't have the pescatarian diets in any of these articles here. However, just a few more articles, just a few more things that I can bring to the table to show you. That that standard American diet is sad. And not only that, but the standard American regimen of our usual advice to patients is not adequate. We need to do more. And we need more studies like these showing this. and a few more studies like we did before about carnivore diets and their issues. And we'll show you some more articles in the future. I'm not a one-trick pony here. I don't want to be the... strict vegan diet only there are some things that are missing in a vegan diet vegetarian diet and supplements mightn't be needed okay so again what people critique the Ornish diet are suggesting is that you're going to lack nutrients you're going to lack certain healthy fats, and those healthy fats are the omega-3s.
Certain vitamins might be missing, vitamin D and B12. Okay, so those are the things that are critiques and well taken and well adhered to as far as Supplements can be taken to not have to eat red meat just so that you can get your B12 and your omega-3, right? And there's not omega-3 in red meat. It's there in fish. I think that may be why, in one of the studies we outlined several weeks ago, as to why pescatarians fare better. than the vegetarian and vegan diet. So, all right. So again, thank you for joining me on another Sunday Science. We will be looking at, like we did today, some very seminal original, the OG for dietary intervention.
to some more modern articles again we'll show you the latest and also some of the historical okay so thank you for joining me I love that you're here with me listening to the science I will be here for the duration and again the goal of all of this is to live longer, but to live longer, healthier. Okay, so getting to 110, manifesting the 110, and that manifesting 110 requires that kind of an intensive diet and interventions like the Ornish diet interventions. It's very difficult to do these kind of things, to accomplish these things overnight. and by, you know, wholesale exchange of diets, very difficult. And that's why we're doing this gradually over 52 weeks in our other podcasts that we've talked about everything. So again, thank you very much for joining me. We'll see you soon.
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