The responses of different dosages of egg consumption on blood lipid profile: An updated systematic review and meta-analysis of randomized clinical trials

Diverse notions exist regarding egg intake, which is one of the main sources of dietary cholesterol, and its effect on blood lipids. We conducted this study to update the previous meta-analysis for their flaw in calculated effect size. PubMed, Scopus, ISI, and Cochrane were searched up to April 2019, for relevant randomized controlled clinical trials. Mean changes in total cholesterol (TC), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), triglyceride (TG), very low-density lipoprotein cholesterol (VLDL-C), LDL-C/HDL-C, TC/HDL-C, apolipoprotein (apo)A1, and apoB100 were assessed. Meta-analysis of 66 RCTs with 3,185 participants revealed that egg consumption can significantly increase TC, LDL-C, HDL-C, TC/HDL-C, apoA1/and B100, but there was no significant effect on other serum lipids. Dose-response analysis showed a linear effect for TC, HDL-C, ApoA1, ApoB100, and nonlinear for LDL-C, and TC/HDL-C. In conclusion, intake of more than one egg daily in less than 12 weeks may increase some blood lipids without any changes in the ratio of LDL-C/HDL-C. PRACTICAL APPLICATIONS: There are controversies reports for egg intake, which is one of the main sources of dietary cholesterol. This study provides comprehensive information about the effect of the number of eggs consumed per day (dietary cholesterol) on blood lipids for nutritionists, physicians, researchers, and the general population. In this regard, our results indicated that there is a linear correlation between consumption of greater than one egg per day in a short time (no long time) and increasing lipid profiles which may increase the risk of cardiovascular diseases. However, consumption of one egg daily can be safe and this can be a useful recommendation for prevention of cardiovascular disease and promotion of healthy life which indeed are the potential or actual uses of this research.