The cholesterol in delicious egg yolks accelerates atherosclerosis (the build-up of plaque in our arteries) almost as much as smoking.

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PROBLEM: Last year, the average American consumed 247 eggs -- over 40 percent more than the world per-capita average. Because egg yolks are high in cholesterol, eating whole eggs increases cholesterol, a known risk factor for coronary artery disease (CAD) and heart attacks. Previous research also links CAD with cigarette smoke.

METHODOLOGY: Canadian researchers examined 1,231 patients at London's Health Sciences Centre's University Hospital. The average age of all the patients was 62. Ultrasound measurements of the carotid arteries established the presence and quantity of atherosclerotic plaque, and the scans were accompanied by lifestyle surveys. Smoking was measured in pack-years (number of packs per day multiplied by the number of years spent smoking). Egg yolk consumption was measured in egg yolk-years.

RESULTS: Aging was associated with a linear increase in arterial plaque after age 40, but smoking and egg consumption were each independently associated with an exponential increase in plaque. Egg consumption had two-thirds of the effect of smoking.

CONCLUSION: Egg yolks are almost as bad for your carotid arteries as smoking.