Egg yolks and cardiovascular risk: myth or reality?
Egg yolks are often scrutinized in nutritional debates due to their cholesterol content. But whether consuming egg yolks can actually cause a heart attack is a complex question and has been the subject of numerous scientific studies.
Nutritional composition of egg yolks
A medium-sized egg contains approximately 70 calories, of which 5 grams are fat, mostly concentrated in the yolk. The yolk also contains around 186 mg of cholesterol, a nutrient often associated with cardiovascular disease. However, egg yolks are also a valuable source of protein, vitamins (A, D, E, K, and several B vitamins), minerals such as phosphorus, selenium, and zinc, as well as antioxidant carotenoids like lutein and zeaxanthin, which are beneficial for eye health.
Cholesterol and heart health
For decades, dietary cholesterol was considered a major risk factor for cardiovascular disease. The prevailing idea was simple: the more cholesterol consumed, the higher the blood cholesterol level, which increases the risk of plaque formation in the arteries and thus myocardial infarction.
However, recent research has nuanced this relationship. Several studies indicate that dietary cholesterol has a relatively limited effect on blood cholesterol levels for most individuals. The human body regulates hepatic cholesterol production: when dietary intake increases, the liver produces less cholesterol, and vice versa. Thus, for most healthy individuals, moderate egg yolk consumption does not significantly raise blood cholesterol nor pose a direct risk of heart attack.
Epidemiological studies
Large-scale studies have examined the association between egg consumption and cardiovascular disease. A 2013 meta-analysis including over 200,000 participants found no significant link between daily egg consumption and heart attack risk in healthy individuals. Some studies even suggest that moderate egg consumption may have neutral or slightly protective effects due to their beneficial nutrients and antioxidants.
It is important to note, however, that the overall dietary context plays a crucial role. Diets high in saturated fats, sugars, and ultra-processed foods can increase cardiovascular risk regardless of egg consumption. Similarly, certain at-risk populations, such as individuals with diabetes, may exhibit a stronger association between egg yolk intake and heart risk.
Nutritional recommendations
Health authorities, such as the American Heart Association, generally recommend limiting dietary cholesterol to about 300 mg per day for the general population, and 200 mg for those at cardiovascular risk. Consuming one egg per day is generally considered safe for most healthy adults.
Additionally, it is advisable to favor healthy cooking methods, such as poached or boiled eggs, and to limit preparations high in added fats, such as fried eggs in large amounts of oil or eggs served with processed meats.
Egg yolks, rich in essential nutrients and antioxidants, do not constitute a direct cause of heart attacks for most people. Moderate consumption, incorporated into a balanced and varied diet, is compatible with good cardiovascular health. The real cardiovascular risk lies more in overall dietary patterns, lifestyle, and individual risk factors, such as obesity, smoking, and physical inactivity.
