Researchers from Canada's Western University have found that eating egg yolk is around two-thirds as bad as smoking for the build-up of plaques in the arteries, which can significantly increase the risk of heart disease.
The researchers based their findings on analysis of more 1,200 patients, drawn from clinics at London Health Sciences Centre's University Hospital.
During the study, researchers asked the participants to fill out questionnaires regarding their lifestyles, including the number of cigarettes they smoked every day and the number of egg yolks they consumed in a week. They then used the ultrasound method to measure the total amount of plaque accumulated in the participants' arteries.
The researchers concluded that egg yolk greatly increases plaque, which in turn accelerates atherosclerosis - or coronary artery disease.
"The mantra 'eggs can be part of a healthy diet for healthy people' has confused the issue. It has been known for a long time that a high cholesterol intake increases the risk of cardiovascular events, and egg yolks have very high cholesterol content. In diabetics, an egg a day increases coronary risk by two to five-fold," said Dr David Spence, professor of Neurology at Western's Schulich School of Medicine & Dentistry.