Egg Consumption and Stroke Risk: A Systematic Review and Dose-Response Meta-Analysis of Prospective Studies

Abstract

Background: The present study was performed to systematically quantify the association between egg consumption and stroke risk as inconsistent results have been produced. Methods: Three electronic databases (PubMed, Embase, and Cochrane Library), previous reviews, meta-analyses, and bibliographies of relevant articles were retrieved from prospective cohort studies published before July 1, 2020. The random-effects model was employed to estimate summary relative risks (RRs) and 95% confidence intervals (CIs). A dose-response analysis was also performed when data were available. Results: Sixteen publications involving 24 prospective cohort studies were included in our final meta-analysis. No significant association between egg consumption and stroke risk was identified (RR = 0.92, 95% CI: 0.84-1.01) for the highest vs. the lowest quintiles of egg intake. Subgroup analysis indicated that geographic location significantly modified the effect of egg consumption on stroke risk. Higher egg consumption was attributed to a reduced probability of stroke in Asia (RR = 0.83, 95% CI: 0.73-0.94), but not in North America (RR = 0.95, 95% CI: 0.77-1.16) or Europe (RR = 1.02, 95% CI: 0.91-1.16). Dose-response analysis demonstrated a nearly J-shaped curve between egg consumption and risk of stroke. A decreased risk was observed for the intake of one to four eggs weekly and an increased risk for the intake of more than six eggs weekly. The results were significant at an intake of 10 eggs weekly. Conclusions: The evidence from this meta-analysis showed that a J-shaped association exists between egg consumption and stroke risk.

Nutritional Viewpoints on Eggs and Cholesterol

“…Although the dietary pattern of fish and fruit intake correlated with lower hypertension in China, the egg was also a contributor (egg intake ≥150 g/week; adjusted odds ratio, OR = 0.88; p < 0.29) [71]. Higher egg consumption was attributed to a reduced probability of stroke in Asia (RR = 0.83) but not in North America (RR = 0.95) or Europe (RR = 1.02) [91]. In the meta-analysis of prospective cohort studies, egg consumption was associated with a lower risk of hypertension (adjusted RR = 0.79, p = 0.001) [72], while in a study with Australian adults, lower intake of the egg together with other foods resulted in higher systolic blood pressure [73].…”

“…The upper limit of egg consumption is not clear [61], although the meta-analysis showed a J-shaped association between egg consumption and stroke risk [91]. In a series of studies in China, egg consumption results in healthy responses and in one study, egg consumption is associated with lower total mortality [91]. However, consumption of cholesterol from non-egg sources may be detrimental to longevity, thus recommending habitual egg consumption, but not excess from non-egg sources [63].…”

“…A recent dose-responsive meta-analysis of prospective studies showed no significant association between egg consumption and stroke risk (RR = 0.92), but the subgroup analysis resulted in a different association among geographic locations [91]. A decreased risk was observed for the intake of one to four eggs weekly and an increased risk for the intake of more than six eggs weekly.…”

“…The upper limit of egg consumption is not clear [61], although the meta-analysis showed a J-shaped association between egg consumption and stroke risk [91]. In a series of studies in China, egg consumption results in healthy responses and in one study, egg consumption is associated with lower total mortality [91].…”

“…However, in the meta-analysis of prospective studies, the response depends on the amounts of egg consumed. The stroke risk decreases in less than one to four eggs weekly and increases in more than six eggs weekly [91]. In this context, it is interesting to know how hyper-responders respond to egg consumption.…”