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A new study that concludes one egg a day doesn’t necessarily increase heart disease risk is the latest in a long line of conflicting research. Getty Images
  • A new study concludes that eating one egg a day may not significantly increase your cholesterol levels or risk of heart disease.
  • The research is the latest in a long line of studies that present conflicting conclusions on how healthy eggs are in a person’s daily diet.
  • One expert told Healthline that an egg a day is probably OK for most people, but you should be careful not to overdo it on omelets and other egg-based breakfast foods.

A Funny or Die sketch set in 1979 begins with a man sitting down for breakfast of steak, eggs, and toast.

Suddenly, a bright light flashes in the next room and a stranger walks into the kitchen, startling the man and his wife.

“Wait! Stop! Don’t eat that food,” the stranger says.

Confused, the man asks, “Why?”

“The eggs,” the stranger says. “They’re full of cholesterol.”

The couple seems confused because few people in the late 1970s were worried about the goopy substance that can clog your arteries.

The stranger warns the couple that eating one egg a day drastically increases the chance of a heart attack.

The time traveling dietitian leaves, only to return again from the future, declaring there’s two types of cholesterol and eggs have both the good and bad kind.

This goes on for some time, as the man comes back again and again, updating the couple on what scientists in the future will learn about the other foods on the man’s plate.

While a comical rendition of evolving food science, the skit is still relatively accurate in terms of what studies have shown in terms of eggs, what’s in them, and whether they’re part of a healthy diet.

That debate remains important as people in the United States continue to consume eggs more than they have in nearly half a century. On average, we eat 289 eggs per year, or more than five per week.

That comes as new dietary guidelines drop restrictions on cholesterol, reflecting the views of many nutritionists that an egg’s cheaply provided nutrient content outweighs other concerns.

Much like the time traveling dietician points out, nutritionists now say dietary cholesterol isn’t as lethal as we thought some 40 years ago.

But experts agree that diet is a tricky thing to study because not everyone eats in a vacuum, consuming the same thing day-in and day-out in a controlled and easy-to-study environment.

For example, a bacon cheeseburger topped with a fried egg and served with a side of french fries. What, of those components — beef, pork fat, cheese, egg, bun, fries dipped in sugar-laden ketchup, egg — is the main culprit?

Some heart experts may argue the egg might not be the worst offender.

Dr. Sanjiv Patel, an interventional cardiologist at MemorialCare Heart and Vascular Institute at Orange Coast Medical Center in California, says it’s still a good idea to limit your daily dietary cholesterol intake and eat a variety of foods such as fruits, vegetables, nuts, lean meats, and fish.

“Eggs are safe, as long as not consumed in high numbers daily,” Patel told Healthline.

The latest in the long saga of the egg’s long pile of scientific research comes out of the Population Health Research Institute (PHRI) of McMaster University and Hamilton Health Sciences in Ontario, Canada.

There, researchers used data from about 177,000 people involved in one of three long-term studies conducted in 50 countries.

The researchers had a simple premise: Since they find eggs to be “a rich source of essential nutrients,” they wanted to check what the available facts have to say on their impact on preventable diseases, as there’s contradictory evidence as to what their cholesterol content means to human health.

Using data from PHRI studies named PURE, ONTARGET, and TRANSCEND, the researchers counted 12,701 deaths and 13,658 cardiovascular disease “events,” such as a heart attack.

With that data, researchers reported they didn’t find any “significant” connections between eating eggs, the collection of cholesterol in the blood, premature deaths, or major cardiovascular disease events.

That led researchers to conclude that, for most people, eating one egg per day doesn’t increase their risk of cardiovascular disease or death, even if their risk factors would suggest otherwise.

The researchers further concluded there’s no link between the number of eggs a person eats and the cholesterol that ends up in their blood.

But before you go and order a 12-egg omelet on your next brunch outing, pause and consider where the study found its home.

The new study was published in the latest edition of The American Journal of Clinical Nutrition, a publication of the American Society for Nutrition. The journal is highly regarded in many circles, but it’s not without its critics.

As Healthline has previously reported, food activists have voiced their skepticism of the American Society for Nutrition, as its board’s conflict of interest disclosures are numerous.

Over the past 3 decades, The American Journal of Clinical Nutrition has published studies that show varying results when examining eggs and people’s cholesterol levels, including when fat and cholesterol became the dietary villain.

For example, one study published in the nutrition journal in 1982 found normal consumption of eggs had no effect on the cholesterol levels or incidents of coronary heart disease, but it only looked at 912 people. They used data from the ongoing Framingham Heart Study that has looked at common factors or characteristics that contribute to cardiovascular disease since its inception in 1948.

More recently, in a study published in the journal in 2001, a research team at Wageningen University in the Netherlands analyzed 17 studies involving 556 subjects to examine the effects of egg consumption on the risk of coronary heart disease.

Assuming that a single egg contains 200 milligrams of cholesterol, the researchers found eating one additional egg daily could increase a person’s risk of a heart attack by about 2 percent.

“The calculated increase in risk may be small in an individual patient, but in view of the widespread consumption of diets high in cholesterol it may be substantial at the population level,” the researchers noted in their study.

But the researchers also noted that there’s more to an egg than just cholesterol. It also brings potential heart disease-preventing things such as vitamin E, folate, other B vitamins, and unsaturated fatty acids, even if these levels don’t negate the fact that in the United States, eggs contribute to nearly a third of total dietary cholesterol.

“Thus, in view of the relatively small contribution of eggs to the intake of nutrients that may be beneficial in preventing coronary heart disease, the recommendation to limit the consumption of eggs may still be valid for the prevention of coronary heart disease,” the 2001 study found.

This is just one example of how confusing it can be for people who want to eat well, or at least avoid foods that have been shown to increase a person’s risk of preventable diseases.

But for Patel, the latest research that vindicates eggs is good news for breakfast lovers, but, as with everything, they should be consumed in moderation.

“You can rest easy about having that egg or two on your plate in the morning,” he said, “but again, you should not consume a high number of them.”