Eggs and Cholesterol: New study, old story

A new study1 published in the Journal of the American Medical Association examining the relationship between dietary cholesterol and egg consumption with regard to cardiovascular disease risk provides interesting new data to consider as part of the broader context of the scientific literature in this area.

The authors report:

  • Small but statistically significant increases in cardiovascular risk with dietary cholesterol and egg consumption in six U.S.-based cohorts totaling over 29,000 participants.
  • These findings contrast with previous meta-analyses2,3 of observational cohorts not included in the present study that reported no relationship with egg consumption and cardiovascular risk in cohorts totaling almost 350,000 participants.
  • Furthermore, additional studies have shown small but statistically significant favorable relationships with egg consumption and cardiovascular risk in non-U.S. cohorts4,5, while randomized controlled trials consistently show egg intake does not negatively impact cardiovascular disease risk factors6.

The inconsistency of this new study with that of other recent studies demonstrates the importance of additional research to further explore this area, including the need to understand the unique contribution of eggs as part of healthy eating patterns set forth in the Dietary Guidelines for Americans.

The fact that studies outside the U.S. appear to show favorable relationships with egg intake and cardiovascular risk may speak to the importance of what other foods are consumed with eggs as part of the overall diet pattern, as recent research has demonstrated the importance of separating eggs from other foods to understand their independent impact on health outcomes7.

References

  1. Zhong et al. Associations of dietary cholesterol or egg consumption with incident cardiovascular disease and mortality. JAMA. 2019;321(11):1081-1095.
  2. Shin JY, Xun P, Nakamura Y, He K. Egg consumption in relation to risk of cardiovascular disease and diabetes: a systematic review and meta-analysis. Am J Clin Nutr. 2013 Jul;98(1):146-59.
  3. Rong Y, Chen L, Zhu T, Song Y, Yu M, Shan Z, Sands A, Hu FB, Liu L. Egg consumption and risk of coronary heart disease and stroke: dose-response meta-analysis of prospective cohort studies. BMJ. 2013 Jan 7;346:e8539.
  4. Qin C, Lv J, Guo Y, Bian Z, Si J, Yang L, Chen Y, Zhou Y, Zhang H, Liu J, Chen J, Chen Z, Yu C, Li L; China Kadoorie Biobank Collaborative Group. Associations of egg consumption with cardiovascular disease in a cohort study of 0.5 million Chinese adults. Heart. 2018 Nov;104(21):1756-1763.
  5. Virtanen JK, Mursu J, Virtanen HE, Fogelholm M, Salonen JT, Koskinen TT, Voutilainen S, Tuomainen TP. Associations of egg and cholesterol intakes with carotid intima-media thickness and risk of incident coronary artery disease according to apolipoprotein E phenotype in men: the Kuopio Ischaemic Heart Disease Risk Factor Study. Am J Clin Nutr. 2016 Mar;103(3):895-901.
  6. Blesso CN, Fernandez ML. Dietary Cholesterol, Serum Lipids, and Heart Disease: Are Eggs Working for or Against You? Nutrients. 2018 Mar 29;10(4). pii: E426. doi: 10.3390/nu10040426. Review.
  7. Sabaté J, Burkholder-Cooley NM, Segovia-Siapco G, Oda K, Wells B, Orlich MJ, Fraser GE. Unscrambling the relations of egg and meat consumption with type 2 diabetes risk. Am J Clin Nutr. 2018 Nov 1;108(5):1121-1128.