Eating 1 egg a day does not increase mortality, major CVD risk
Moderate egg consumption (1/day) is not associated with an increased risk of mortality or major cardiovascular disease (CVD), according to a study. There is also no association between egg intake or dietary cholesterol and blood lipids.
A total of 146,011 individuals from 21 countries in the Prospective Urban Rural Epidemiology (PURE) study were analysed. Country-specific validated food-frequency questionnaires were used to record the consumption of eggs.
The researchers also examined 31,544 patients with vascular disease in two multinational prospective studies: Ongoing Telmisartan Along and in Combination with Ramipril Global End Point Trial (ONTARGET) and Telmisartan Randomized Assessment Study in ACEI Intolerant Subjects with Cardiovascular Disease (TRANSCEND).
Hazard ratios (HRs) were calculated using multivariable Cox frailty models with random intercepts to account for clustering by study centre separately within each study.
Overall, 14,700 composite events (8,932 deaths and 8,477 CVD events) were recorded in the PURE study. After controlling for CVD history, higher intake of egg (≥7 vs <1 egg/week intake) did not significantly correlate with blood lipids, composite outcome (HR, 0.96, 95 percent confidence interval [CI], 0.89–1.04; ptrend=0.74), total mortality (HR, 1.04, 95 percent CI, 0.94–1.15; ptrend=0.38), or major CVD (HR, 0.92, 95 percent CI, 0.83–1.01; ptrend=0.20). [Am J Clin Nutr 2020;111:795-803]
In the ONTARGET and TRANSCEND studies, results were similar for composite outcome (HR, 0.97, 95 percent CI, 0.76–1.25; ptrend=0.09), total mortality (HR, 0.88, 95 percent CI, 0.62–1.24; ptrend=0.55) and major CVD (HR, 0.97, 95 percent CI, 0.73–1.29; ptrend=0.12).
“Our results of no association between moderate egg intake and health outcomes are generally consistent with the majority of previous studies,” the researchers said.
In a comprehensive review of randomized trials and observational studies, egg intake showed no adverse impact on serum cholesterol and CVD risk among healthy individuals and patients with type 2 diabetes. [Eur J Clin Nutr 2018;72:44-56]
Moreover, the Health Professionals Follow-Up Study (n=37,851) and the Nurses’ Health Study (n=80,082) did not find an association between egg intake ≤1 egg/day and an increased risk of coronary artery disease or stroke. [JAMA 1999;281:1387-1394]
Meta-analyses of observational studies likewise found no significant association between egg intake and CVD events or mortality. [BMJ 2013;346:e8539; Crit Rev Food Sci Nutr 2017;59:1-20]
“Our findings are robust and widely applicable because for both healthy individuals and patients with vascular disease, results are consistent,” the researchers noted.
Several competing factors may explain the neutral association between egg intake and health outcomes. Dietary cholesterol confers a modest effect on blood total cholesterol and low-density lipoprotein (LDL) cholesterol. However, the phospholipid in egg elevates high-density cholesterol, potentially offsetting the impact of egg on LDL cholesterol. [Cardiovasc Drugs Ther 1995;9:779-784]
“The effects of egg consumption may also vary across populations with varying diet quality, such as a low- or high-carbohydrate diet,” the researchers said.
“To the best of our knowledge, our study represents one of the largest studies assessing the association of egg intake with blood lipids and blood pressure, as well as mortality and cardiovascular events in different regions of the world,” they added.