Dietary Guidelines: “Eat as Little Dietary Cholesterol as Possible”

Michael Greger M.D. FACLM · April 5, 2023 · Volume 61

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Why do the official federal Dietary Guidelines for Americans recommend limiting the intake of dietary cholesterol (found mostly in eggs) as much as possible?

Discuss

Transcript

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

From this 2020 systematic review of the effects of egg consumption on cholesterol, here are the results of more than 50 randomized controlled trials, nearly all of which pointing in the direction of greater LDL blood cholesterol with greater egg intake. And that’s just looking at fasting cholesterol taken in the morning, which is how much your liver is churning out, which is like the baseline on top of which the effects of diet can be assessed. We live most of our lives in a postprandial state, meaning an after-meal state, not a fasting state. And this is what eating more and more dietary cholesterol can do to your blood cholesterol levels immediately after eating––shooting your levels up for hours after a meal. And then what happens after four hours? Lunchtime! And you can whack your arteries with another surge of cholesterol on top of your elevated fasting levels.

Of course, the only reason we care about cholesterol is because we care about heart disease, our #1 killer of men and women. And you do see, for example, significantly higher coronary artery calcium scores in those who eat more eggs, which is a sign of atherosclerotic plaque buildup in the arteries. But does this translate into a higher risk of heart attacks and death? Apparently so. Based on a half-dozen population studies in the U.S., following tens of thousands of people for up to 30 years, each additional half of an egg consumed per day was significantly associated with higher risk of developing cardiovascular disease and dying from all causes put together—in other words, living a significantly shorter lifespan.

But wait a second. Egg consumption commonly correlates with unhealthy behaviors such as inactivity, smoking, and eating all sorts of other bad stuff. How do we know it’s not the saturated fat and animal protein as opposed to the cholesterol? Failure to consider all these factors could lead to different conclusions, but this study comprehensively accounted for all these factors. Also, the study had longer follow-up than the majority of the previous studies, and therefore, it may have provided more power to detect associations with even single food products, such as eggs in this case.

And the study found that the significant associations of dietary cholesterol and death were independent of the quality of the diet. Meaning, if you eat, let’s say, two eggs a day, but the rest of your diet is all vegetables and is low sodium, do those eggs portend any higher level of cardiovascular disease risk? The effect of egg and dietary cholesterol in general remained even after considering an otherwise heart-healthy dietary pattern. So, that significantly increased risk of death tied to just half an egg a day persisted even after taking overall diet quality into account. So, it’s not just like they’re eating more bacon with their eggs.

When we adjust for overall diet quality and the consumption of specific types of food, like red meat or processed meat, like bacon, the association persisted, which suggests that the entire association is not driven by bacon or other foods eaten with eggs. Considering the negative consequences of egg consumption and dietary cholesterol, even in the setting of heart-healthy dietary patterns, the importance of following evidence-based dietary recommendations, such as limiting intake of cholesterol-rich foods, should not be dismissed. But that’s exactly what the 2015 Dietary Guidelines Advisory Committee appeared to try to do, declaring cholesterol is not a nutrient of concern for overconsumption, because available evidence shows no appreciable relationship between consumption of dietary cholesterol and blood cholesterol, consistent with the conclusion of an American Heart Association/American College of Cardiology report. Wait, what?

Here’s a meta-analysis of literally hundreds of studies, published like 25 years ago, conclusively showing that you can decrease blood cholesterol by decreasing dietary cholesterol intake. An interesting thing has since happened with cholesterol research, though. Industry funding of studies increased from zero to now, most cholesterol studies are bought and paid for by the egg industry. And studies funded by the Egg Board tend to use specific design characteristics to minimize the reported negative health effects. So now, anyone limiting their reviews to studies published in recent years—when nearly all studies were industry-funded and specifically designed to bring about certain predetermined outcomes—you can make eggs look more favorable than if you included more objectively designed research. The American Heart Association/American College of Cardiology report, for example, limited their evidence review from 1998 to 2009. They knew about meta-analyses like this one, published in 1997, but didn’t give it full consideration because these studies predated their search time frame.

Dr. Kim Williams was President of the American College of Cardiology around the time of this saga. Let’s hear it straight from the horse’s mouth. Despite research studies over several decades indicating that dietary cholesterol increases serum cholesterol levels, their 2013 report stated that there was insufficient evidence to determine whether lowering dietary cholesterol helps, but this was based on that limited time search. People didn’t understand that, but that’s what the Dietary Guidelines Advisory Committee cited. After clarification by the American College of Cardiology, of which he was President, the final, official 2015 – 2020 Dietary Guidelines for Americans that was published followed the position of the Institution of Medicine, and told people to “eat as little dietary cholesterol as possible.” And here they are. Here are the Dietary Guidelines. As recommended by the Institution of Medicine, individuals should eat as little dietary cholesterol as possible. This was reiterated in the 2020 – 2025 Dietary Guidelines: dietary cholesterol consumption should be as low as possible. The National Academy’s Institute of Medicine is who determines the Recommended Daily Allowances. And they’re very explicit that based on all the evidence—not just a sliver in time—when it comes to dietary cholesterol, which is found in all meat, dairy, and eggs, intake should be as low as possible, because any intake level above zero increases LDL cholesterol concentration in the blood, and therefore carries increased risk of coronary heart disease, our #1 killer.

After conviction for false advertising, suggesting eggs were healthy, which I detailed in one of my videos, the egg industry has spent hundreds of millions of dollars trying to convince the public, physicians, and policymakers that dietary cholesterol and egg yolk are harmless. But in reality, regular consumption of egg yolks should be avoided by people at risk for cardiovascular disease, which essentially means all North Americans who expect to live past middle age.

Please consider volunteering to help out on the site.

Sources

Acknowledgements

Motion graphics by Avo Media

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

From this 2020 systematic review of the effects of egg consumption on cholesterol, here are the results of more than 50 randomized controlled trials, nearly all of which pointing in the direction of greater LDL blood cholesterol with greater egg intake. And that’s just looking at fasting cholesterol taken in the morning, which is how much your liver is churning out, which is like the baseline on top of which the effects of diet can be assessed. We live most of our lives in a postprandial state, meaning an after-meal state, not a fasting state. And this is what eating more and more dietary cholesterol can do to your blood cholesterol levels immediately after eating––shooting your levels up for hours after a meal. And then what happens after four hours? Lunchtime! And you can whack your arteries with another surge of cholesterol on top of your elevated fasting levels.

Of course, the only reason we care about cholesterol is because we care about heart disease, our #1 killer of men and women. And you do see, for example, significantly higher coronary artery calcium scores in those who eat more eggs, which is a sign of atherosclerotic plaque buildup in the arteries. But does this translate into a higher risk of heart attacks and death? Apparently so. Based on a half-dozen population studies in the U.S., following tens of thousands of people for up to 30 years, each additional half of an egg consumed per day was significantly associated with higher risk of developing cardiovascular disease and dying from all causes put together—in other words, living a significantly shorter lifespan.

But wait a second. Egg consumption commonly correlates with unhealthy behaviors such as inactivity, smoking, and eating all sorts of other bad stuff. How do we know it’s not the saturated fat and animal protein as opposed to the cholesterol? Failure to consider all these factors could lead to different conclusions, but this study comprehensively accounted for all these factors. Also, the study had longer follow-up than the majority of the previous studies, and therefore, it may have provided more power to detect associations with even single food products, such as eggs in this case.

And the study found that the significant associations of dietary cholesterol and death were independent of the quality of the diet. Meaning, if you eat, let’s say, two eggs a day, but the rest of your diet is all vegetables and is low sodium, do those eggs portend any higher level of cardiovascular disease risk? The effect of egg and dietary cholesterol in general remained even after considering an otherwise heart-healthy dietary pattern. So, that significantly increased risk of death tied to just half an egg a day persisted even after taking overall diet quality into account. So, it’s not just like they’re eating more bacon with their eggs.

When we adjust for overall diet quality and the consumption of specific types of food, like red meat or processed meat, like bacon, the association persisted, which suggests that the entire association is not driven by bacon or other foods eaten with eggs. Considering the negative consequences of egg consumption and dietary cholesterol, even in the setting of heart-healthy dietary patterns, the importance of following evidence-based dietary recommendations, such as limiting intake of cholesterol-rich foods, should not be dismissed. But that’s exactly what the 2015 Dietary Guidelines Advisory Committee appeared to try to do, declaring cholesterol is not a nutrient of concern for overconsumption, because available evidence shows no appreciable relationship between consumption of dietary cholesterol and blood cholesterol, consistent with the conclusion of an American Heart Association/American College of Cardiology report. Wait, what?

Here’s a meta-analysis of literally hundreds of studies, published like 25 years ago, conclusively showing that you can decrease blood cholesterol by decreasing dietary cholesterol intake. An interesting thing has since happened with cholesterol research, though. Industry funding of studies increased from zero to now, most cholesterol studies are bought and paid for by the egg industry. And studies funded by the Egg Board tend to use specific design characteristics to minimize the reported negative health effects. So now, anyone limiting their reviews to studies published in recent years—when nearly all studies were industry-funded and specifically designed to bring about certain predetermined outcomes—you can make eggs look more favorable than if you included more objectively designed research. The American Heart Association/American College of Cardiology report, for example, limited their evidence review from 1998 to 2009. They knew about meta-analyses like this one, published in 1997, but didn’t give it full consideration because these studies predated their search time frame.

Dr. Kim Williams was President of the American College of Cardiology around the time of this saga. Let’s hear it straight from the horse’s mouth. Despite research studies over several decades indicating that dietary cholesterol increases serum cholesterol levels, their 2013 report stated that there was insufficient evidence to determine whether lowering dietary cholesterol helps, but this was based on that limited time search. People didn’t understand that, but that’s what the Dietary Guidelines Advisory Committee cited. After clarification by the American College of Cardiology, of which he was President, the final, official 2015 – 2020 Dietary Guidelines for Americans that was published followed the position of the Institution of Medicine, and told people to “eat as little dietary cholesterol as possible.” And here they are. Here are the Dietary Guidelines. As recommended by the Institution of Medicine, individuals should eat as little dietary cholesterol as possible. This was reiterated in the 2020 – 2025 Dietary Guidelines: dietary cholesterol consumption should be as low as possible. The National Academy’s Institute of Medicine is who determines the Recommended Daily Allowances. And they’re very explicit that based on all the evidence—not just a sliver in time—when it comes to dietary cholesterol, which is found in all meat, dairy, and eggs, intake should be as low as possible, because any intake level above zero increases LDL cholesterol concentration in the blood, and therefore carries increased risk of coronary heart disease, our #1 killer.

After conviction for false advertising, suggesting eggs were healthy, which I detailed in one of my videos, the egg industry has spent hundreds of millions of dollars trying to convince the public, physicians, and policymakers that dietary cholesterol and egg yolk are harmless. But in reality, regular consumption of egg yolks should be avoided by people at risk for cardiovascular disease, which essentially means all North Americans who expect to live past middle age.

Please consider volunteering to help out on the site.

Motion graphics by Avo Media

Doctor's Note

I gave testimony to the Dietary Guidelines Committee for these new recommendations. Watch it here.

For more on the false advertising of the egg industry, check out Eggs and Cholesterol: Patently False and Misleading Claims.

Trans fat and saturated fat should also be limited as much as possible. See: Trans Fat, Saturated Fat, and Cholesterol: Tolerable Upper Intake of Zero.

You may be interested in my newer video, Dietary Cholesterol and Inflammation from Abdominal Obesity.

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