Call it argumentum ad hominem, association fallacy or nutrition science’s most unfortunate hasty generalization: The smear campaign against eggs is one of the longest and most misguided in culinary history. Luckily, new scientific evidence is debunking the myths, and we’re slowly getting the message that eggs aren’t evil or unhealthy; they’re just misunderstood. At the center of the confusion: cholesterol.
In 1977, the USDA issued its first “Dietary Goals for the American People,” which included limiting dietary cholesterol intake to 300 milligrams per day. The thinking at that time was that dietary cholesterol had a direct effect on serum or blood cholesterol levels, a known risk factor for heart disease. A single egg contains 185 milligrams of cholesterol—more than half of the USDA’s recommended daily amount—so the poor orb was presumed guilty by association and banished to the naughty list.
But more recent research has revealed that our earlier studies were flawed. “Essentially, everything we thought we knew about dietary cholesterol affecting blood cholesterol levels came from diets that were also rich in saturated fat (not only from eggs but also full-fat dairy, butter, meat and cheese) and relatively low in fruits and vegetables,” says David Katz, M.D., director of Yale University’s Yale-Griffin Prevention Research Center and the president of the American College of Lifestyle Medicine. “We [deduced that] all fatty food was bad, and we lumped cholesterol in there; it took awhile to sort out that not all fat is created equal,” says Katz. “We did what we tend to do, which is throw the baby out with the bath water.”
“When [researchers] looked at the effect of dietary cholesterol intake on overall blood cholesterol, they found limited evidence that there is a link,” says Janet de Jesus, a registered dietician and public health advisor with the National Institutes of Health. In response to the updated science, the USDA, American Heart Association and American College of Cardiology recently revised their guidelines. In fact, they removed the cholesterol level recommendations all together. “They’re not saying eat as much as you want, but there’s more evidence that reducing saturated fat and trans fat is more important for lowering LDL (bad) cholesterol,” says de Jesus. “For the most part, if you lower saturated fat intake, you’ll lower dietary cholesterol.”
BUT WAIT, THERE’S MORE
Katz and other researchers have studied the effect of egg intake on blood pressure, platelet stickiness and other indicators associated with heart disease. “Over and over again, there’s just no there there,” says Katz, who points to yet another argument in the egg’s favor: paleoanthropology.
Anthropologists agree, says Katz, that our ancestors—who show very few indications of heart disease—ate eggs. And while they also ate plenty of meat, as the popular paleo diet reminds us, it was very different from the meat we consume today. Wild game was lower in total fat and much lower in saturated fat than today’s domesticated meat. “That part of the puzzle suggests that we are well adapted to dietary cholesterol and not so well adapted to a high intake of saturated fat, another argument that the two of those should be unbundled,” says Katz.
THE NITTY GRITTY
So the evidence is mounting that despite relatively high cholesterol levels, eggs aren’t unhealthy. But are they healthy? That depends on how you consume them, say Katz and de Jesus.
Egg white has the highest-quality protein of any food source. “It’s used routinely as the reference standard for optimal protein because it has the perfect distribution of essential amino acids and other vitamins and minerals like biotin,” says Katz.
As far as the yolk, it contains most of the total fat. But remember, says de Jesus, it’s polyunsaturated fat—the good kind. If you throw away the yolk, you’re also throwing away a good source of vitamins A, D, E and K. “I think it’s a disservice to vilify eggs,” says de Jesus. More important than whether you include them in your diet or not, she says, is how you prepare them.
“People tend to fry eggs or serve them with bacon or in cheesy omelets that bring in extra fat.”
Whether eating eggs converts net benefit to you is a matter of what the eggs are replacing, according to Katz. “There is a critical blind spot in nutritional epidemiology,” he says. “We often fail to consider that if people are going to eat less of X, they’re going to eat more of Y. We gave people the advice to stop eating eggs, and I don’t think we considered carefully enough what they would replace them with. I think we now know the answer because America runs on Dunkin’. Essentially we started eating more bagels and donuts. The net effect of that was harm, not benefit. It’s a mistake to eat more eggs in place of vegetables, fruit, lentils, beans, nuts and whole grains, but turning to eggs for breakfast in the place of empty starchy sugary nonsense [is advisable] because you’re not just benefiting from what you’re adding but also what you’re taking away. The same would be true of eating more eggs but not eating as much deli meat or as much fatty meat. You’re trading up there.”