Smoking Has A New Partner In Crime: It’s Called Egg Yolk
August 15, 2012

Smoking Has A New Partner In Crime: The Egg Yolk

Lawrence LeBlond for - Your Universe Online

The debate whether eggs are good or bad for you has been akin to roller coaster ride for decades. Adding to the debate is new research from Western University in Ontario, Canada that shows eating egg yolks is just as bad for you as lighting up that next cigarette.

Dr. David Spence, the researcher conducting the research, said that regular consumption of yolk -- the yellow part of the egg -- accelerates atherosclerosis (coronary artery disease) in a manner similar to smoking cigarettes. Egg yolk contains cholesterol and having too much is definitely a bad thing. Cholesterol boosts the formation of plaque in arteries and when the plaque ruptures it can cause heart attacks and strokes.

Spence, a Professor of Neurology at Western´s Schulich School of Medicine & Dentistry and the Director of its Stroke Prevention and Atherosclerosis Research Centre (SPARC) at the Robarts Research Institute, said Canadians are being led to believe that eggs are a healthy part of their diet, according to “propaganda” from the egg industry.

“The mantra ℠eggs can be part of a healthy diet for healthy people´ has confused the issue,” alerted Spence. “It has been known for a long time that a high cholesterol intake increases the risk of cardiovascular events, and egg yolks have a very high cholesterol content. In diabetics, an egg a day increases coronary risk by two to five-fold.”

His study, published Tuesday in the journal Atherosclerosis, included the survey of more than 1,200 patients. Through the survey, he found that regular consumption of egg yolk is about two-thirds as bad as smoking when it comes to increased build-up of the dangerous plaque.

To put it into perspective, a jumbo egg contains as much as 237 milligrams of cholesterol, said Spence. “It's more than the cholesterol in a Hardee's monster thick burger which is two-thirds of a pound of beef, three slices of cheese and four slices of bacon,” he noted.

Karen Harvey, a nutrition officer with Egg Farmers of Canada and a registered dietitian, stands by the safety of eating egg yolks on a daily basis.

“We have decades of clinical research demonstrating no link between egg consumption and an increased risk of heart disease,” Harvey told CBC News.

Spence argued that the egg industry is selective about what it shares with the public. “They're just like the tobacco industry.” According to Canada´s food guide, two eggs are a healthy alternative to eating meat. However, Spence said that would be well over anyone´s recommended daily intake of cholesterol.

In Spence´s survey, the men and women involved the study had a mean age of 61.5. They were patients attending vascular prevention clinics at London Health Sciences Center´s University Hospital. Ultrasound was used to establish a measurement of total plaque area and questionnaires were filled out regarding their lifestyle and medications including pack-years of smoking (number of packs per day of cigarettes times the number of years), and the number of egg yolks consumed per week times the number of years consumed (egg yolk-years).

Spence and colleagues found carotid plaque area increased linearly with age after age 40, but increased exponentially with pack-years of smoking and egg yolk-years. In other words, compared to age, both tobacco smoking and egg yolk consumption accelerate atherosclerosis.

“They end up clogging arteries and put you at the risk of heart diseases. Undue consumption of egg yolk is a high risk factor for those already prone to heart problems,” Dr Praveen Chandra, head of interventional cardiology at Medanta Medcity Hospital, told Mail Online.

Spence added that the effect of egg yolk consumption over time on increasing the amount of plaque in the arteries was independent of sex, cholesterol, blood pressure, smoking, body mass index and diabetes. He further added that all people who are already at risk of cardiovascular disease should avoid eating egg yolk altogether.

He acknowledged that further research was needed to take possible confounders such as exercise and waist circumference into consideration.