Does Dietary Cholesterol (Eggs) Raise Blood Cholesterol?


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.

The question “Does egg feeding (in other words dietary cholesterol) affect the level of cholesterol in the blood?” was answered 40 years ago. Give someone half a cup of eggs a day, and within two, three, four weeks their cholesterol keeps going up. And then, stop the eggs by switching to an egg substitute, and the cholesterol comes down. Or start people on the egg substitute, and not much happens, but then start feeding eggs, and their cholesterol shoots right up.

Put people on a cholesterol-free diet, and their cholesterol drops; then add some egg yolk cholesterol, and their cholesterol goes up; take it away, and their cholesterol goes down. You could do this all year.

And it’s within days. After 10 days of eggs, and cholesterol shot up 50 points. Take the eggs away, and it comes back down. You can reproduce this effect over and over and over and over (though evidently penguin omelets are only about half as deadly).

Switch people from a high-cholesterol diet to a cholesterol-free diet, and you can drop blood cholesterol levels as much as a hundred points. Okay, but that was giving people more than a half cup of egg yolks a day. But even just a single egg a day can increase people’s LDL cholesterol 12 percent. Put all such studies together in this 2020 meta-analysis, more than 50 randomized controlled trials feeding people eggs, and egg consumption significantly increases LDL-cholesterol, period.

Now, studies funded by the American Egg Board use a variety of methods to try to minimize the reported negative health effects of eggs by, for example, claiming that dietary cholesterol affects only certain people. That’s actually been put to the test, and only 3 percent were even potentially “nonresponders” to dietary cholesterol, and even these probably evidenced some adverse response.

Wait, then how was the American Egg Board able to design a study in which egg intake did not change blood cholesterol? By feeding them sufficiently large quantities of dairy and meat. See, there’s a plateau effect. Though all lines of evidence converge to indicate that dietary cholesterol is a major factor in promoting hardening of the arteries, confusion about dietary cholesterol has arisen because above a certain ceiling, you basically max out cholesterol absorption.

Check it out. If you’re eating a strictly plant-based diet, with a baseline of zero cholesterol intake, and you start adding meat, dairy, or eggs to your diet, you can get a dramatic rise in blood cholesterol. But as your diet starts out more and more meaty, you can saturate your system and basically max out on the additional effect. So, no wonder the American Egg Board packed in the extra meat and dairy to mask the egg effect.

A systematic review of egg industry funding and cholesterol research sought out to see if industry-funded studies were more likely to report conclusions that were not supported by their own objective findings. Of the non-industry-funded studies on the effect of egg ingestion on cholesterol, cholesterol increases were reported in about 90 percent. Among industry-funded studies, cholesterol increases were reported in about 90 percent. In other words, even the egg industry-funded studies showed eggs increased blood cholesterol, and not a single study funded by anyone showed a significant decrease.

Okay, but here’s the crazy part. About half of the industry-funded studies reported conclusions that were discordant with their own results. In other words, they found that cholesterol went up. But if you read their conclusions, they exonerated eggs. That’s why you can’t just read the abstract. You actually have to see what they found. “Readers, editors, and the public should remain alert to funding sources in interpreting study findings and conclusions.”

Please consider volunteering to help out on the site.


Please enter your comment!
Please enter your name here