Egg yolk consumption and carotid plaque

J. David Spence^a^,^,,
David J.A. Jenkins^b,
Jean Davignon^c^,^d^,^e

^a Stroke Prevention & Atherosclerosis Research Centre, Robarts Research Institute, 1400 Western Road, London, ON N6G 2V2, Canada
^b Canada Research Chair in Nutrition and Metabolism, Risk Factor Modification Centre, St. Michael's Hospital, Toronto, ON, Canada
^c Clinique de nutrition métabolisme et athérosclérose, Institut de recherches cliniques de Montréal, Canada
^d University of Montreal, Canada
^e McGill University, Montréal, QC, Canada

Received 11 February 2012. Revised 17 July 2012. Accepted 18 July 2012. Available online 31 July 2012.

http://dx.doi.org/10.1016/j.atherosclerosis.2012.07.032, How to Cite or Link Using DOI

Abstract

Background

Increasingly the potential harm from high cholesterol intake, and specifically from egg yolks, is considered insignificant. We therefore assessed total plaque area (TPA) in patients attending Canadian vascular prevention clinics to determine if the atherosclerosis burden, as a marker of arterial damage, was related to egg intake. To provide perspective on the magnitude of the effect, we also analysed the effect of smoking (pack-years).

Methods

Consecutive patients attending vascular prevention clinics at University Hospital had baseline measurement of TPA by duplex ultrasound, and filled out questionnaires regarding their lifestyle and medications, including pack-years of smoking, and the number of egg yolks consumed per week times the number of years consumed (egg-yolk years).

Results

Data were available in 1262 patients; mean (SD) age was 61.5 (14.8) years; 47% were women. Carotid plaque area increased linearly with age after age 40, but increased exponentially with pack-years of smoking and with egg-yolk years. Plaque area in patients consuming <2 eggs="eggs" per="per" week="week">n

= 388) was 125 ± 129 mm², versus 132 ± 142 mm² in those consuming 3 or more eggs per week (n = 603); (p < 0.0001 after adjustment for age). In multiple regression, egg-yolk years remained significant after adjusting for coronary risk factors.

Interpretation

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.

Highlights

► Carotid total plaque area (TPA) increases linearly with age. ► TPA increases exponentially with smoking pack-years. ► TPA increases exponentially with egg-yolk years. ► The effect size of egg yolks appears to be approximately 2/3 that of smoking. ► Probably egg yolks should be avoided by persons at risk of vascular disease.