CNA/THE NEW YORK TIMES – Eggs can’t catch a break. They’re scarce on store shelves. If you do manage to track some down, you may have to shell out considerable cash, as eggs reach record prices.
An avian flu outbreak in the United States killed millions of hens in 2022, eliminating a critical egg supply. And now, a frenetic flurry of misinformation is being volleyed between pro- and anti-egg camps on social media. To Joe Rogan, eggs cause blood clots. To some on Twitter sharing screenshots of the abstract of a scholarly paper, yolks can ward off COVID-19.
This is not the first egg war. For the last 60 years or so, scientists have sparred over whether eggs are bad for the heart, said professor of nutrition Walter Willett at the Harvard TH Chan School of Public Health. Nutritionists have debated whether the high levels of cholesterol found in eggs outweigh the punch of protein they offer.
“They’ve been pooh-poohed for so long,” said assistant professor of medicine Dr Selvi Rajagopal at Johns Hopkins University School of Medicine – alternately valourised and demonised. Claims floating around social media that eggs can cure COVID-19, or lead to blood clots, are “just unsubstantiated”, she said.
Here’s what we do know about the benefits, and risks, of eggs.
HOW DID EGGS GET SUCH A BAD REP?
In the 1960s and 1970s, Dr Willett said, doctors raised concerns about whether foods high in cholesterol could elevate the amount of it in your blood. They suspected that high levels of certain lipoproteins, which ferry cholesterol throughout the body, could form plaque on the walls of your blood vessels. Since eggs are rich in cholesterol – a single egg yolk can contain around 200 milligrammes – and high lipid levels have been linked to poor cardiovascular health, some targetted them as an easy dietary fix: Ditch the eggs Benedict, and protect your heart.
But over the past decade or so, Dr Rajagopal said, researchers have questioned whether eating cholesterol-rich foods actually raises your lipid levels. The existing evidence hasn’t established that the average person will definitively gain “bad” cholesterol, known as LDL-C, based on their diet.
Saturated fat is a far more pressing culprit in heart disease, said, senior clinical nutritionist Samantha Heller at NYU Langone Health – and while eggs contain high amounts of cholesterol, “if you eat a cheese omelette today and you haven’t eaten one in a while, your arteries aren’t going to clog immediately”, she said. Eggs are also high in protein, making them an alternative to meat, which tends to be high in saturated fat.
In 1968, the American Heart Association recommended that Americans consume no more than three eggs per week; by 2015, though, that thinking had largely shifted. The current US dietary guidelines no longer use that weekly limit, and instead promote eggs as a “nutrient-dense” protein source.
ARE EGGS ALL THEY’RE CRACKED UP TO BE?
Eggs contain vitamins B, E and D, and they’re low in saturated fat. “You get high protein for low calories,” said researcher and dietitian Bethany Doerfler at Northwestern University Feinberg School of Medicine. They also contain nutrients that are beneficial for your eyes and bones, Heller said.
“There’s really more pros than cons,” said registered dietitian Beth Czerwony with the Cleveland Clinic’s Center for Human Nutrition, adding that some eggs are enriched with omega-3 fatty acids, depending on what hens have been fed.
That doesn’t, however, make eggs an unimpeachable superfood. Consuming an excess of eggs still carries some risk of cardiovascular disease, Doerfler said. But eating them in moderation, like one full egg (including the yolk) per day, is safe for people who don’t have underlying cardiovascular issues, she said. (You can also “bank” your eggs, she added, skipping them for a few days and then having the occasional three-egg omelette.) If you’re concerned about cholesterol, you can also stick to egg whites – but the yolk is also where most of an egg’s vitamins lie, so the drawbacks of skipping the yolk might outweigh the benefits.