6 clinically proven reasons why eggs are great for heart health

By John Murphy, MDLinx
Published April 17, 2020

Key Takeaways

Despite decades of bad press, eggs are not the enemy when it comes to heart health, researchers have shown in recent years. Some research suggests that eating an egg a day might even keep cardiovascular disease (CVD) away. 

How did eggs get such a bad name? Back in 1968, experts proclaimed that high dietary cholesterol equaled high blood cholesterol, which equaled high CVD risk. But, following this, observational studies and randomized trials reported contradictory findings linking eggs to CVD. 

More recently, however, investigators who’ve studied dietary lipids and CVD incidence have shown that dietary cholesterol is not an independent risk factor for heart disease.

Furthermore, eggs are great nutrition. They’re considered the highest form of complete protein, containing all of the essential amino acids. One large egg, for example, contains 6 g of protein and 14 important nutrients—including folate, iron, zinc, choline, and vitamins A, B12, D, and E—all for just 70 calories.

Let’s set the record straight on eggs’ relationship to heart disease. 

Eggs-emplary evidence

heart shaped egg

Have you heard the news? Eating one egg per day isn’t linked to increased risk of CVD, according to a new study and meta-analysis led by researchers at Harvard University’s T.H. Chan School of Public Health, Boston, MA. The researchers determined this by analyzing health data from 173,563 women and 42,055 men in the Nurses’ Health Study I & II and the Health Professionals Follow-Up Study. After adjusting for confounding factors like high BMI and red meat consumption, they found that “consumption of at least one egg per day was not associated with incident cardiovascular disease risk.” 

For added evidence, they also performed the largest-ever meta-analysis on the subject,  which supported their finding in US and European populations. But, in Asian populations, they found that egg consumption may be associated with lower CVD risk.

“Recent studies reignited the debate on this controversial topic, but our study provides compelling evidence supporting the lack of an appreciable association between moderate egg consumption and cardiovascular disease,” said first author Jean-Philippe Drouin-Chartier, PhD, postdoctoral fellow, Department of Nutrition, Harvard T.H. Chan School of Public Health.

Too much (and too little) of a good thing

eggs in a basket

A recent study by researchers in China found that people who eat just a handful of eggs per week have lower CVD risks than both people who eat too many eggs and those who eat no eggs (or nearly no eggs). The study involved more than 100,000 adults.

Specifically, people who consumed 3 to 6 eggs per week had the lowest risk of incident CVD, stroke, and all-cause mortality. By comparison, those who ate 10 or more eggs per week had 39% higher risk of incident CVD, 18% higher risk of stroke, and 13% higher risk of all-cause mortality. Similarly, those who ate less than 1 egg per week had 22% higher risk of incident CVD, 27% higher risk of stroke, and 29% higher risk of all-cause mortality. 

“Our findings identified that both low and high consumption were associated with increased risk of incident CVD and all-cause mortality, highlighting that moderate egg consumption of 3–< 6/week should be recommended for CVD prevention in China,” the researchers concluded. 

Keep your sunny side up

sunny side up eggs

In a prospective study that included more than half a million Chinese adults, researchers in China and the United Kingdom showed that eating an egg a day was associated with significantly lower risks of heart disease and stroke.  

The researchers found that, compared with people who ate no eggs, people who ate eggs daily (up to <1 egg/day) had an 11% lower risk of CVD, a 12% lower risk of ischemic heart disease, a 14% lower risk of major cardiac events, and an 18% lower risk of CVD death.

“In particular, daily egg consumers (up to <1 egg/day) had a 26% lower risk of hemorrhagic stroke, a stroke subtype with a higher prevalence rate in China than in high-income countries,” the researchers wrote. 

Eat ’em by the dozen

dozen eggs

But, what if you don’t eat just one egg per day? What if you frequently eat more than one egg per day? 

Eating 12 eggs per week for 1 year had no effect on serum markers of CVD, according to the authors of a small, intervention trial (45 participants, ≥ 50 years of age ) published in the Journal of Nutrition & Intermediary Metabolism

For this study, the researchers divided the participants into two groups. Participants in one group ate 12 eggs per week for a year while those in the other group ate no eggs for a year. At the end of the trial period, the egg-eating group showed no changes in serum cholesterol, lipoprotein cholesterol, and triglycerides levels compared with their levels at the beginning of the study, and showed insignificant changes compared with the no-eggs group. The same held true for levels of serum apolipoprotein A-1, apolipoprotein B, lipoprotein (a), and high sensitive C reactive protein. 

“This study suggests that the consumption of 12 eggs per week for 1 year does not significantly alter fasting serum lipids, lipoprotein cholesterol, or other biomarkers of CVD in older adults,” the authors concluded. 

Eggs-traordinary results worldwide

egg world

Much of the research about eggs comes from investigators in the United States and China. To find out the effects of egg consumption not only in these countries but around the world, researchers in Canada recently conducted an analysis of 3 international studies that included more than 177,000 people at different income levels from 50 countries across 6 continents. 

The upshot from all this global data? “We did not find significant associations between egg intake and blood lipids, mortality, or major CVD events,” the authors concluded. 

While some researchers have indicated that people who eat a high number of eggs (≥1/day) are at greater risk for heart failure, this large international analysis by Canadian researchers found no such association. 

“Moderate egg intake, which is about one egg per day in most people, does not increase the risk of cardiovascular disease or mortality even if people have a history of cardiovascular disease or diabetes,” said first author Mahshid Dehghan, PhD, investigator in Nutrition Epidemiology at the Population Health Research Institute and senior research associate, Department of Medicine, McMaster University, Hamilton, ON. 

“Also, no association was found between egg intake and blood cholesterol, its components or other risk factors,” she added. “These results are robust and widely applicable to both healthy individuals and those with vascular disease.” 

Eggs over easy, hold the bacon

eggs on toast

Finally, if all this evidence isn’t enough, take it from the American Heart Association (AHA), which recently published an advisory statement about dietary cholesterol in Circulation

“As per the Advisory, in general, egg intake was not significantly associated with the risk of cardiovascular disease in the studies that [we] examined,” the AHA said in a separate statement. “It is reasonable to eat one whole egg (or its equivalent such as 3 ounces of shrimp) daily as part of a heart-healthy diet for healthy individuals.”

“However,” the organization noted, “it remains a good practice, generally speaking, to limit major sources of dietary cholesterol and saturated fat.”

What does the AHA mean by this? In its advisory, the organization explained: “It is difficult to distinguish between the effect of dietary cholesterol per se and the effect of dietary patterns high in cholesterol or saturated fat, for example, sausage or bacon eaten with eggs...This is of particular concern in the United States, where eggs are frequently accompanied by bacon or sausage.”

So, for heaven’s sake, eat your eggs. But, for your heart’s sake, skip the bacon.

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