Moderate egg consumption may lower CVD risk in Asians
Eating up to one egg per day does not increase the risk of cardiovascular disease (CVD) and may even reduce such risk among Asian populations, a study has found.
The researchers conducted a prospective cohort study as well as a systematic review and meta-analysis of prospective cohort studies. Participants included 83,349 women from the Nurses’ Health Study (NHS; 1980–2012), 90,214 women from NHS II (1991–2013) and 42,055 men from the Health Professionals’ Follow-up Study (1986–2012) who were free of CVD, type 2 diabetes (T2D) and cancer at baseline.
A total of 14,806 participants had incident CVD in the three cohorts over 32 years of follow-up. Those who consumed more eggs also had a higher body mass index, consumed more red meat and were less likely to be treated with statins. Most participants, though, consumed one to less than five eggs per week. [BMJ 2020;368:m513]
Pooled multivariable analysis revealed no significant association between consumption of at least one egg per day and incident CVD risk, after adjusting for updated lifestyle and dietary factors related to egg intake (hazard ratio for at least one egg per day vs less than one egg per month, 0.93, 95 percent confidence interval [CI], 0.82–1.05).
In the updated meta-analysis of prospective cohort studies (33 risk estimates; n=1,720,108 participants; 139,195 CVD events), an increase of one egg per day did not increase the risk of CVD events (pooled relative risk [RR], 0.98, 95 percent CI, 0.93–1.03; I2, 62.3 percent).
Such results were comparable for coronary heart disease (21 risk estimates; n=1,411,261 participants; 59,713 events; RR, 0.96, 95 percent CI, 0.91–1.03; I2, 38.2 percent) and stroke (22 risk estimates; n=1,059,315 participants; 53,617 events; RR, 0.99, 95 percent CI, 0.91–1.07; I2, 71.5 percent).
Analyses stratified by geographical location (pinteraction=0.07) showed no association between egg consumption and CVD risk among US cohorts (RR, 1.01, 95 percent CI, 0.96–1.06; I2, 30.8 percent) or European cohorts (RR, 1.05, 95 percent CI, 0.92–1.19; I2, 64.7 percent). However, among Asian cohorts, egg intake was inversely associated with CVD risk (RR, 0.92, 95 percent CI, 0.85–0.99; I2, 44.8 percent).
“[M]ean egg consumption in the three US cohorts in our study and in cohorts included in the meta-analysis was relatively low,” the researchers said. “This consumption level should be taken into account when interpreting our results because most participants consumed one to less than five eggs per week, and relatively few participants consumed at least one egg per day.”
Furthermore, the updated meta-analysis suggested an association between higher egg consumption and an increased CVD risk among people with T2D. In an earlier study, insulin resistance was found to be associated with increased endogenous cholesterol synthesis and reduced clearance of cholesterol-rich lipoproteins. [Diabetologia 2015;58:886-899]
“However, data from short-term randomized interventions suggest that higher egg consumption has no deleterious impact on CVD risk factors among people with diabetes,” the researchers said. “Further studies are warranted to understand these discrepancies.” [Can J Diabetes 2017;41:453-463; Am J Clin Nutr 2018;107:921-931]