Moderate egg consumption, defined as up to one egg per day, was not linked to CVD risk, according to a study published in The BMJ.

The study also found that moderate egg consumption may be associated with lower CVD risk in Asian patients.

“Our main finding that no evidence supports a higher risk of CVD associated with moderate egg consumption (up to 1 egg per day) can be easily translated into practice,” Jean-Philippe Drouin-Chartier, RD, PhD, assistant professor in the faculty of pharmacy and researcher at NUTRISS Center of INAF at Université Laval in Quebec City and visiting scientist in the department of nutrition at Harvard T.H. Chan School of Public Health, told Healio. “Still, while moderate egg consumption can be part of a healthy eating pattern, they are not essential. There is a range of other foods that can be included in a healthy breakfast, such as whole grain toasts, plain yogurt and fruits.”

Prospective cohort study

Researchers analyzed data from 83,349 women from the Nurses’ Health Study, 90,214 women from the Nurses’ Health Study II and 42,055 men from the Health Professionals’ Follow-Up Study who were free from CVD, cancer and diabetes at baseline.

Patients from all three cohorts completed questionnaires to collect information on disease risk factors, disease diagnosis, lifestyle characteristics, drug use and food frequency, which asked patients how often they consumed whole eggs in the past year.

The primary endpoint was incident CVD, defined as fatal CHD, nonfatal MI, and fatal and nonfatal stroke.

During 5,540,314 person-years of follow-up, 14,806 patients developed incident CVD. Patients with a higher egg intake were less likely to be treated with statins, had a higher BMI and had higher intakes of unprocessed red meat, calories, bacon and other unprocessed meats, whole milk, potatoes, refined grains, coffee and sugar-sweetened beverages. In 1998-1999, 1.24% of patients ate at least one egg per day, and of these patients, 0.2% consumed at least two eggs per day.

After adjusting for lifestyle and dietary characteristics linked to egg intake, consuming at least one egg per day was not associated with incident CVD risk compared with consuming less than one egg per month in a pooled multivariable analysis (HR = 0.93; 95% CI, 0.82-1.05).

An increase in egg consumption of one per day was also not linked to CVD risk in an updated meta-analysis of prospective cohort studies (RR = 0.98; 95% CI, 0.93-1.03; I² = 62.3%). Results were similar for stroke (RR = 0.99; 95% CI, 0.91-1.07; I² = 71.5%) and CHD (RR = 0.96; 95% CI, 0.91-1.03; I² = 38.2%).

When stratified by geographical location, there was no association between egg consumption and CVD risk in European cohorts (RR = 1.05; 95% CI, 0.92-1.19; I² = 64.7%) and U.S. cohorts (RR = 1.01; 95% CI, 0.96-1.06; I² = 30.8%), although there was an inverse association for Asian cohorts (RR = 0.92; 95% CI, 0.85-0.99; I² = 44.8%).

“Recent studies reignited the debate on this controversial topic, but our study provides compelling evidence supporting the lack of an appreciable association between moderate egg consumption and cardiovascular disease,” Drouin-Chartier said in an interview.

‘Convincingly null’

In a related editorial, Andrew O. Odegaard, PhD, assistant professor of epidemiology at University of California, Irvine School of Medicine, wrote: “The results of this study are convincingly null save for a couple of subgroup findings. Yet, we should not put all our eggs in this observational basket for formal guidance on eating eggs. Given the unique challenges in nutrition research, it is necessary to triangulate evidence from different study designs and populations to provide the most robust basis to answer questions about diet and disease.” – by Darlene Dobkowski