Review published in Advances in Nutrition concludes the recommendation of habitual egg consumption as part of a healthy diet “should be done with caution.”
Should we limit egg consumption? According to the Dietary Guidelines for Americans, 2020-2025, eggs are nutrient dense and can be part of a healthy dietary pattern. Nonetheless, the association between egg consumption and health has been the subject of debate for many years, with some studies finding evidence of a link between egg consumption and a higher risk of non-communicable diseases such as cardiovascular disease as well as an overall higher risk of mortality. Other studies, on the other hand, have not supported these findings.
Published in Advances in Nutrition, “Egg Consumption and Risk of All-cause and Cause-specific Mortality: A Systematic Review and Dose-response Meta-analysis of Prospective Studies” takes a fresh look at the current body of evidence to assess the association between egg consumption and the risk of both all-cause and cause-specific mortality in the general population. In addition to conducting a systematic review of the relationship between egg consumption and mortality, the authors conducted a dose-response meta-analysis to determine the degree to which each additional egg consumed may affect mortality.
In order to conduct their research, the authors performed a search of the scientific literature published up until March 2021 to locate relevant prospective cohort studies (i.e., studies that track a group of subjects over a given period of time). Their efforts led them to 33 studies that met their criteria. These studies collectively enrolled 2,216,720 participants.
Following their analysis, the authors concluded that “higher egg consumption was not associated with risk of mortality from all causes, cardiovascular disease, coronary heart disease, stroke, and respiratory disease.” On the other hand, the authors did find that “higher egg consumption was associated with an increased risk of cancer mortality.” Several mechanisms may underlie the association between egg consumption and cancer. For example, the authors noted that eggs are particularly high in choline, which plays an essential role in cell functions that promote cancer growth and progression.”
Interestingly, the authors did find that each additional egg consumed per week was associated with a 2% increased risk of all-cause mortality and a 4% increased risk of cancer mortality. Additionally, this review found that each additional egg consumed per week was associated with a 4% lower risk of mortality from stroke.
In short, the authors’ findings “did not support the hypothesis that higher egg consumption is related to increased risk of mortality from most causes; however, egg consumption was associated with an elevated risk of cancer mortality.” The authors therefore caution that “the recommendation of habitual egg consumption as part of a healthy diet, as recommended in the 2020–2025 Dietary Guidelines for Americans, should be done with caution.” The authors did note some limitations of their review. In particular, they observed “considerable evidence of heterogeneity between studies, which could be explained by the variation in study location, follow-up duration, gender, dietary assessment methods, number of participants, and covariate adjustment.” As a result, questions about the effect of egg consumption on health and mortality remain unresolved. The authors therefore call for additional research, particularly among individuals with cancer, heart disease, and diabetes. Additional studies are also needed in low-income and African countries, where eggs may be the main dietary source to meet protein requirements.