Ask A Heart Surgeon: What Do Eggs Do To Your Heart?

Ajouté : 2026-06-01

[00:00:01]Hi everyone, Dr. Michael Richmond, double board certified cardiothoracic surgeon. So, today's topic is what does eating eggs do to your heart? Some always asked, "Do I eat eggs?" And the answer is, "I only eat egg whites." Now, that has nothing to do with the data or literature. It's a personal decision, but I'll explain why. So, I wanted to become a heart surgeon since fifth grade, believe it or not, and a cardiologist who was a neighbor. Now, that you guys always ask me the difference between a cardiologist and a heart surgeon. Cardiologists do not operate. They're not surgeons. They don't open up the chest.

[00:00:37]Okay? Heart surgeons open up the chest. We do valves, we do bypasses, we do transplants. So, getting back to the story, the neighbor gave me a book called The Living Heart by Michael DeBakey, who's the father of heart surgery. And I remember seeing a picture of a heart artery, and there was cholesterol, and it was yellowish. Okay? It was talking about that. Then in high school, I spent a summer at Cedars-Sinai Medical Center in Los Angeles doing [snorts] heart research. And I saw a human cadaver heart for the first time, and I remember seeing an artery that had a yellow plaque in it.

[00:01:15]Yolks yellow, you know, atherosclerotic plaques.

[00:01:19]Then during college, I spent a year, besides going to school, working at the National Institutes of Health in the Division of Heart, Lung, and Blood. And I literally saw hundreds of hearts. And the common denominator was that the plaques in the arteries were yellow. So, yolks of eggs are obviously yellow, and you can put two and two together. And that's why I eat egg whites.

[00:01:42]Okay, so now let's start with the talk.

[00:01:44]For years, obviously, eggs have been the center of controversy and clinical debate. Are they good for you, and are they bad for you? And the confusion comes from seemingly contradictory studies. But fortunately now recent evidence has clarified things.

[00:02:01]And basically, what it has shown that for most healthy people, moderate egg intake, which is up to one whole egg daily, does not significantly raise your total cholesterol, your LDL cholesterol, which is your bad cholesterol, or your triglycerides, which are the storage form of fats. As the 2020 American Heart Association concluded, dietary pattern matters far more than any single food. So, what actually happens to your lipids when you eat eggs? The changes are modest and highly variable. Total cholesterol goes up about 5 to 11 mg per deciliter per every 300 mg of dietary cholesterol ingested. The LDL cholesterol, the bad cholesterol, rises 4 to 7 mg per deciliter.

[00:02:45]But crucially, a 2025 randomized controlled trial found that when eggs are part of a low saturated fat diet, the LDL cholesterol, the bad cholesterol, actually went down compared to when you eat keto or carnivore, a high saturated fat diet without eggs.

[00:03:03]And the effect on triglycerides are neutral. So, there was really no significant effect in most trials.

[00:03:10]One caution though is high egg intake can shift the LDL-P, the bad cars, the uh cars that travel the cholesterol into the wall of the artery, and make them smaller and more nasty, more atherogenic.

[00:03:26]Okay? So, and we don't want those.

[00:03:29]So, now, let's talk about what is the effect on the coronary arteries, the heart arteries. And that depends on who you are. And this is where the story actually really gets nuanced. For healthy populations, the news is reassuring and good. There was a massive 2020 study in the British Medical Journal that looked at people and covered over 5.5 million person years and they found no association between moderate egg intake and coronary artery disease or stroke.

[00:04:03]However, risk varies dramatically by subgroup. So, the first group, in diabetic patients, this had the clearest signal for harm. A Korean study found that consuming four or more eggs per week was linked to a nearly threefold higher risk of cardiovascular disease in people with type 2 diabetes than people with a high genetic risk. A 2023 Chinese study that showed people who are high risk and who ate 10 or more eggs per week had a higher than threefold risk of coronary artery disease. And then [snorts] there's also geographic variation. Asian cohorts often show inverse associations, which eggs are linked to a lower stroke risk, while US cohorts show no or positive association, but this likely reflect reflects the dietary uh, content. Like, the Asians eat boiled eggs with vegetables versus what do we eat? Fried eggs with butter and bacon, you know, all bad. So, why would eggs harm arteries even if fasting cholesterol looks fine? And the answer is probably TMAO, which I have talked about in my video about eating red meat and TMAO and the effect on the coronary arteries.

[00:05:20]>> [snorts] >> Egg yolks are rich in something called phosphatidylcholine, and the bacteria in your intestine converts this into TMA, which then the liver oxidizes into TMAO. And elevated TMAO is linked to atherosclerosis progression and increased cardiovascular risk independent of traditional lipid panels.

[00:05:42]So, this explains why some individuals experience harm from eggs despite only modest changes in their bad cholesterol, their LDL cholesterol. Additionally, eggs may increase type 2 diabetes risk through mechanisms involving impaired glucose metabolism. And as usual, this is still debated. So, here's the bottom line for practice. Healthy individuals up to one whole egg daily is acceptable within a heart-healthy dietary pattern.

[00:06:12]For vegetarians, they may eat more eggs since they lack um any other animal cholesterol source.

[00:06:19]Now, patients who have abnormal cholesterol, diabetes, or heart failure, exercise caution. Really, don't eat egg yolks. Eat egg whites. Now, older adults with normal cholesterol, up to two eggs daily can be acceptable.

[00:06:34]Now, the two practical takeaways from all this are saturated fats matter more than dietary cholesterol. Eggs with butter and bacon or sausage are risky.

[00:06:46]Eggs alone, poached with vegetables, much less risky. And then, we'll also talk about hyper-responders to dietary cholesterol because like in yesterday's video, I talked about that. So, if you're unsure, do a 1-month trial of reduced egg intake, and then recheck your lipids and see what happens. Okay, so with that, hope you learned something. Thank you so much for listening and have a great night.