Cracking a second egg into the pan has long been considered a minor diet challenge. Over the generations, doctors have warned against cholesterol, and health guidelines have called for moderation. Millions of Americans have replaced egg yolks with whites, wondering if their breakfast is secretly harming them.
However, a comprehensive scientific analysis published in the journal Poultry Science now suggests that these warnings were exaggerated.
This analysis combines evidence from clinical trials, large-scale observational studies, and population data from 142 countries to study the effect of eggs on the heart.
The conclusion, based mostly on observational and ecological research, was more “forgiving” than most people expected.
For most individuals, eating eggs in moderation does not appear to increase the risk of heart disease, but may, in some cases, provide even slight protection.
Nowhere is the importance of this finding more evident than in Japan, where Japanese adults consume eggs at a rate nearly twice the global average. However, “Japan consistently ranks among the countries with the lowest rates of ischemic heart disease, which are diseases caused by reduced blood flow to the heart muscle.”
Researchers stress that comparisons between countries, such as this study, identify associations, not causes, and that many other factors, in addition to eggs, differ from one country to another.
Much of the concern about eggs is due to their cholesterol content. For decades, a simple belief has prevailed: the more dietary cholesterol one consumes, the higher its concentration in the blood, which harms the arteries. But in reality, it’s more complicated.
A meta-analysis of 28 randomized studies showed that eating more eggs leads to only small increases in total cholesterol and bad cholesterol (LDL).
On the other hand, eating eggs increases the beneficial cholesterol (HDL), which helps eliminate harmful fats from the bloodstream.
As a result, their ratio, an important clinical indicator of heart disease risk, remains constant. Researchers estimate that the increase in total cholesterol resulting from eating eggs is approximately 2 to 3% per egg, which is a much smaller effect than the effect of saturated fats found in red meat and butter, for example.
According to studies, the benefits of eggs are not limited to protein and cholesterol only, but their yolk is rich in lutein and zeaxanthin, two antioxidant compounds that help protect cholesterol in the blood from damage that increases the possibility of it accumulating on the walls of the arteries.
