Eggs are a rich source of dietary cholesterol, and because of this, they have been infamous in the past. In a world trying to understand and make a difference with high cholesterol and cardiovascular disease, eggs have become a natural target for those who want to live healthier lives.
However, eggs contain a wide range of very important nutrients and are eaten by people all over the world. Studies looking at the link between egg consumption and cardiovascular disease (CVD) have yielded conflicting results, so the link remains a matter of debate.
A 2018 study published in the journal Heart looked at data from about half a million adults in China. The researchers found that those who ate eggs 3 to 6 times a week had a significantly lower risk of developing cardiovascular disease, hypertension, and stroke compared to those who ate eggs more or less frequently.
Now a new study has once again tried to establish whether eating eggs is good or bad for our cardiovascular health by looking at the role of cholesterol metabolism in the blood. The authors of a study published in the journal eLife conducted a population-based study examining how egg consumption affects biochemical markers of cardiovascular health that are found in the blood.
“Few studies have looked at the role that plasma cholesterol metabolism plays in the relationship between egg consumption and cardiovascular disease risk, so we wanted to help fill that gap,” said study lead author Lang Pan of Peking University.
For the study, the experts selected 4,778 participants from the Kadori China Biobank – 3,401 of them had cardiovascular disease, and 1,377 did not. The team then used guided nuclear magnetic resonance to measure the levels of 225 different metabolites present in each participant’s plasma. The researchers identified 24 of these metabolites that were statistically associated with self-reported egg consumption levels.
Of these 24 metabolites associated with egg consumption, 14 have been linked specifically to heart disease. The researchers found that participants who ate fewer eggs had lower blood levels of beneficial metabolites and higher levels of harmful metabolites than those who ate eggs more frequently.
In particular, the results of the analysis showed that people who ate eggs moderately had higher blood levels of a protein called apolipoprotein A1, a building block of high-density lipoprotein (HDL), which is also sometimes called “good lipoprotein”. These people had more large HDL molecules in their blood; these molecules help clear cholesterol from blood vessels, thereby protecting them from blockages that can lead to heart attacks and strokes.
“Taken together, our results provide a potential explanation for how eating moderate amounts of eggs may help protect against heart disease,” said study co-author Professor Kanqing Yu. “More studies are needed to test the causal role of lipid metabolites in the relationship between egg consumption and CVD risk”
“This study may also have implications for China’s national dietary guidelines,” added study senior author Professor Liming Li. “Current health guidelines in China suggest eating one egg a day, but data show that the average intake is below this level. Our work highlights the need for additional strategies to encourage moderate egg consumption in the population to help reduce the overall risk of cardiovascular disease.” .