Back in the ’70s, a kind of hysteria evolved among health experts and consumers in the U.S. because of a possible association between eggs and cardiovascular disease. “Eggs were viewed almost as poison pills because they are high in cholesterol,” says Walter Willett, M.D., Dr.P.H., a professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health.
A Medley of Nutrients
One large egg gives you 70 calories, 6 grams of protein, 2 grams of saturated fat, about 185 milligrams of cholesterol, and a long list of important nutrients.
Eggs contain lecithin, a type of fat that plays a role in keeping the bladder and immune system healthy. And they’re one of the few foods that have high levels of choline, an essential nutrient that aids brain development. Egg yolks also contain phosvitin, a protein that maintains healthy skin, and carotenoids—such as carotene, lutein, and zeaxanthin—compounds that have antioxidant and anti-inflammatory properties and are thought to play a role in reducing macular degeneration and age-related cataract formation.
If you see an omega-3 claim on a label, it means that hens were given feed that included flax, marine algae, fish oils, or other ingredients to boost the level of omega-3 fatty acids in their eggs. Omega-3s are polyunsaturated fats that are important for heart and brain health. But the amount in eggs varies and is typically far less than the amount of omega-3s in a serving of fatty fish, such as salmon or sardines.
But What About All That Cholesterol?
In the past, the Dietary Guidelines for Americans suggested limiting dietary cholesterol intake to no more than 300 milligrams per day, because high cholesterol in your blood can cause plaque buildup in your arteries and increase the risk of heart attack and stroke.
Given that, the 185 milligrams of cholesterol in a large egg may seem like a lot, but scientists have largely debunked the claim that eating eggs can raise the cholesterol levels in your body. A small study published in the journal Nutrients in 2013 found that college students who ate two eggs for breakfast five times a week for 14 weeks had cholesterol levels that were no different from those who ate an egg-free breakfast for the same amount of time. Similar results have been found in middle-aged men, pre- and postmenopausal women, and adults age 40 to 65.
And it’s becoming clearer that other factors, such as ethnicity, genes, weight, age, and hormonal changes after menopause, may have more of an effect on cholesterol levels than the food you eat.
As a result, public-health experts have removed the upper cholesterol limit in the 2015-2020 Dietary Guidelines for Americans, saying instead to limit your intake. The guidelines also emphasize the importance of keeping the amount of saturated fat in your diet to no more than 10 percent of total calories. Eggs are low in saturated fat; a large one has 2 grams compared with about 6 grams in 3½ ounces of top sirloin steak or about 7 grams in a tablespoon of butter.
How Many Should You Eat?
Studies do suggest that eggs may increase the risk of heart disease in people already at higher risk, such as those who have diabetes or those who are “hyper-responders”—people who have unusually high spikes in their cholesterol after eating cholesterol-rich foods. They should watch their intake, Willett says.
For others, approach your egg-eating habits the way you would for any food—in moderation. “An egg a day is fine,” says Maxine Siegel, R.D., who heads Consumer Reports’ food-testing department.
Also keep in mind that many claims you see on cartons (see “Decoding Egg-Label Lingo,” below) don’t have much bearing on the actual nutrition of an egg. There’s also no nutritional difference between brown and white eggs. “Many people believe brown eggs are ‘healthier,’” says Siegel, “but egg color depends on the breed of the chicken and has no bearing on the nutrients inside.”
How to Keep Your Eggs Fresh and Safe
The fresher the egg, the better it will taste, so buy them with a carton date as far in the future as possible. But even if you’re eating the freshest egg, you still need to watch out for nasty bacteria.
“If salmonella is present in a laying hen’s reproductive tract, the bacteria may contaminate the egg during its formation,” says James Rogers, Ph.D., director of food safety and research at Consumer Reports. “The egg industry has attempted to reduce the numbers of infected hens, but there is still always the possibility of foodborne illness if you eat undercooked or raw eggs.”
About 79,000 people are sickened each year from eating eggs contaminated with salmonella, and 30 people die, according to the Food and Drug Administration (FDA). These tips will help you reduce the chances of food poisoning from eggs.
Keep them cold. Always purchase eggs that have been kept refrigerated at the grocery store. And store them in your fridge at 40° F or below as soon as you get home. To avoid temperature swings, don’t put them in the fridge door; instead, place them on a back shelf.
Check for cracks. A broken or cracked shell can allow bacteria from the outside in. Check your eggs for cracks before you buy and cook them. If you spot a cracked egg, toss it.
Store them in their carton. The cushioning of the cardboard prevents cracking and also keeps them from absorbing smelly fridge odors and food flavors.
Eat them quickly. Eggs can keep for up to a month in your fridge, but the sooner you eat them, the better they’ll taste. (A cloudy egg white is a sign of a fresh egg, according to the Department of Agriculture.) The FDA recommends you eat them within three weeks of purchasing them.
Decoding Egg-Label Lingo
Cage-free, farm-fresh, natural, pasture-raised—what does it all mean? In some cases, nothing at all, says Charlotte Vallaeys, Consumer Reports’ senior policy analyst and food-label expert. “Egg labels can sometimes amount to little more than marketing hype,” she says.
Many egg labels refer to the way the chickens were fed or raised, and may mislead consumers. The best animal-welfare standards for laying hens give the birds what they need to engage in natural behavior—such as perching and foraging—and provide adequate light, space, and fresh air. “Certain terms seem to imply that the chickens are raised under such conditions, but that’s not what they mean at all,” Vallaeys says.
Here’s how to separate the reality from the hype on egg cartons.