If you’re reading the first sentence of this article that means the headline message (Don’t Eat Eggs!) got your attention.
Unfortunately, those kinds of headlines always get attention, and we see them everywhere whenever a negative study about eggs comes out. Most of those scary headlines lead to click-bait-y blogs that regurgitate the claim that eggs are terrible for you, and we should have known that all along because, you know…the cholesterol and all.
The good news is you’re about to find out why you can ignore the scary stuff and continue to enjoy one of the most perfect foods on earth. (More on that in a moment.)
First, let’s look at the study that caused so much consternation when it was first published in the Journal of the American Medical Association a short time ago, the one called Associations of Dietary Cholesterol or Egg Consumption With Incident Cardiovascular Disease and Mortality.
The two-sentence summary of this study—which is all that many bloggers bother to read—included these words: Among US adults, higher consumption of dietary cholesterol or eggs was significantly associated with higher risk of incident CVD and all-cause mortality.
From that point on—especially if you are an online blogger whose pay is entirely dependent on the number of eyeballs your content generates—it’s a short step to click-producing headlines like “Experts say stop eating eggs!” or “New research: cholesterol in eggs will kill you.”
The serious and well-meaning researchers who published the original study were attempting to take on a thorny problem: What the heck is going on with eggs and cholesterol? (If you’re a consumer, you can well understand why they’re asking this question in the first place.)
The authors of the study begin by admitting that the entire state of research on saturated fat, cholesterol, and heart disease is all over the map. (Note: As the co-author of The Great Cholesterol Myth I can assure you, “all over the map” is an understatement. In our book, cardiologist Stephen Sinatra, M.D., and myself cite over 200 scientific references disputing the notion that cholesterol and saturated fat even cause heart disease in the first place. But I digress.)
The authors of the “anti-egg” study concede that the research on eggs is also all over the map, admitting that we have all been confused by conflicting studies, conflicting reports, and vacillating recommendations. (In fact, eggs are Exhibit A for anyone wanting to make the case that nutritionists keep changing their minds.) Anybody who’s ever seen the famous juxtaposition of these two Time Magazine covers knows exactly what I mean.
So, with no disrespect meant to the serious researchers who really did want to help clear-up some confusion here, their conclusions cry out for context.
The seemingly damning evidence against eggs—from this study—is like a pixel in a rich digital image. It looks like one thing when you’re this close to the page, but when you step back a foot and look at the whole picture, you see it’s an entirely different thing altogether.
This anti-egg study was a statistical study, not a clinical one, where you have actual subjects. There were no groups of randomized matched human participants, no comparison of research subjects that ate eggs compared with a matched group of subjects that didn’t. The study used pooled data from multiple studies done in the past to see if they turned up any connection (correlation) between egg consumption and 1) heart disease and/or 2) all-cause mortality (i.e. dying from anything, including accidents).
By definition, a correlation is a statistical relationship, not a causal relationship. There is a statistical relationship between storks and babies in a certain part of Denmark, but no one there believes that storks bring babies. Umbrellas and rain are also correlated, i.e. umbrellas are observed more frequently when it’s raining, but rain does not cause the sudden creation of hundreds of umbrellas, though an observer from another planet might well think so.
So, this massive study of data is basically one big correlational study to see what numbers rise together, what numbers fall together, and what numbers move in opposite directions in a clear and definable way. When numbers behave this way, they’re said to be correlated. A correlation—or association between two events—is a fact, of that there is no disputing. But whether or not that fact makes the slightest practical difference to your life is an entirely different question.
In my opinion, this very weak mathematical association between eating cholesterol and the risk of heart disease has no practical implications whatsoever. I’ll explain why.
Correlational studies are interesting, even though they’re basically observational studies and are considered the lowest rung in the hierarchy of scientific evidence. They sometimes reveal hilarious findings, such as the demonstrated statistical correlation between the number of films Nicholas Cage appeared in and the number of deaths by drowning in a swimming pool.
And they sometimes reveal findings like the one in the egg-consumption study, which found that the statistically calculated risk of CVD or dying went up by about 3-4%, all things being equal.
For comparison, note that early studies of the effect of smoking on heart disease and cancer showed smoking increased risk by head-spinning amounts like 80% or more.
So when a study shows that eating eggs is correlated with a tiny and likely meaningless uptick in the risk calculator, I—a lifelong egg eater—don’t get worried. That risk calculator includes hundreds if not thousands of other risk factors with far more immediate impact on our health. Some of those risk factors may actually be lowered by eating eggs, but that’s precisely the context that’s missing from the reporting.
As a nutritionist, I’ve always told people that if there was such a thing as a perfect food (there isn’t), the egg would certainly come close. All that wonderful fat, (yup, you read that right), the lutein and zeaxanthin (carotenoids that protect the eyes), the choline for the brain (the reason your grandmother’s generation called the brainiac kids in school “eggheads”), not to mention the protein (most of which is in the yolk).
We know that people who eat a lot of eggs are usually either health nuts like me following diets like Paleo, Keto, Whole30, Ketotarian, Bulletproof and the like—OR (much more likely), the overwhelming majority of people who also consume huge amounts of processed foods, processed meats, refined vegetable oil, and a ton of sugar.
So a very small correlation between the amount of eggs and cholesterol consumed and a very small increase in absolute risk could be due to any number of reasons besides the increased eggs and cholesterol. Maybe those eggs and cholesterol were found in Krispy Kreme donuts!
So is there any real, take-home advice for the consumer from this latest attempt to solve the cholesterol-saturated fat-heart disease dilemma? Not really.
Consuming “half an egg” or x amount of dietary cholesterol may indeed be “associated” with a tiny percentage increase in the possible risk for various diseases, but not consuming that same egg might be associated with lower levels of a dozen other diseases that might be investigated. (For example, with all the talk of the “dangers” of protein, studies show that people who eat the least protein have the weakest bones!)
Remember, statistics are statistics and they don’t always reflect the reality of what we really care about, which, in this case, is heart disease! It’s worth mentioning that not that long ago, the Harvard Medical School Guide to Healthy Eating said this: “No research has ever shown that people who eat more eggs have more heart attacks than people who eat few eggs.”
That statement was true then, and it remains true today.
That’s what we should really care about.
NOTE: For those wanting a fuller discussion of the debate about eggs—a discussion that arrives at the same conclusion I did, albeit with a lot more references—check out the wonderful BBC article The Truth About Eating Eggs.