NO YOLK – THE MEDIA REPORTS EGG YOLKS AS DANGEROUS AS CIGARETTES

Since the recent study published in Atherosclerosis entitled “Egg Yolk Consumption and Carotid Plaque,” the media has been all a buzz about vilification of the egg yolk, calling it just as harmful as smoking cigarettes. Some headlines include: “Study: Eggs are Nearly as Bad for You as Smoking Cigarettes,” and “Egg Yolks MORE Dangerous Than Smoking?”

 
In this study, about 1200 patients of a vascular prevention clinic at a university hospital completed questionnaires about lifestyle and medications. This included egg yolks eaten per week multiplied by number of years, and cigarette packs smoked multiplied by number of years. Arterial plaque was also measured.

Here is how the researchers interpreted their results: “Our findings suggest that regular consumption of egg yolk should be avoided by persons at risk of cardiovascular disease. This hypothesis should be tested in a prospective study with more detailed information about diet, and other possible confounders such as exercise and waist circumference.”

NOTE: See how far removed the above reported results are from the media-hyped-sensationalized interpretation?

All study types have limitations, and only a randomized controlled trial can show cause and effect. The study in question, called an “observational” study, has many known flaws and weaknesses by design, and cannot imply causality between egg yolks and heart disease. (This is why the authors suggest the need for a prospective study, as quoted above.)
Further, confounding factors that were not adjusted for include waist circumference, alcohol intake, saturated fat intake, and exercise.

The truth is, that the evidence over the years regarding egg yolks and cardiovascular disease has been mixed. In fact, some studies even support moderate egg intake. A Harvard study with over 100,000 participants found no significant difference in risk of cardiovascular disease with consumption of less than one egg per week vs. one egg per day. A recent study in the Journal of Lipids found a more favorable ratio of HDL (good cholesterol) to LDL (bad cholesterol) in subjects with high cholesterol on lipid lowering drugs when three eggs per day were eaten.

The 2010 Dietary Guidelines recognize eggs as a nutritious food, and I agree. For a mere 70 calories you get 13 essential vitamins and minerals. They are a source of vitamin D, which is not abundant in the food supply, and contain folate, iron, and antioxidants like vitamin E, selenium, and beta carotene. (The beta carotene is what makes the yolk yellow.) One egg has 6 grams of high quality protein. That is a lot of nutritional bang for your buck.

The best evidence we have now, which probably sounds cliché at this point, is everything in moderation. If you are exercising regularly, and eating a variety of fruits and vegetables daily, then you can probably safely enjoy eggs without detriment to your lipid profile.

So, when I see headlines that say egg yolks are as bad as smoking, I say “REALLY?” When it comes to reporting the science of nutrition, journalists should leave it to the experts who know how to decipher the literature, and properly interpret the data to make the best recommendations.