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Egg consumption and risk of cardiovascular disease: three large prospective US cohort studies, systematic review, and updated meta-analysis

BMJ 2020; 368 doi: https://doi.org/10.1136/bmj.m513 (Published 04 March 2020) Cite this as: BMJ 2020;368:m513

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Egg consumption and cardiovascular disease

  1. Jean-Philippe Drouin-Chartier, postdoctoral research fellow1,
  2. Siyu Chen, postdoctoral research fellow1,
  3. Yanping Li, senior research scientist1,
  4. Amanda L Schwab, statistician1,
  5. Meir J Stampfer, professor1 2 3,
  6. Frank M Sacks, professor1 3,
  7. Bernard Rosner, professor1 3 4,
  8. Walter C Willett, professor1 2 3,
  9. Frank B Hu, professor1 2 3,
  10. Shilpa N Bhupathiraju, instructor in medicine1 3
  1. 1Department of Nutrition, Harvard T H Chan School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA
  2. 2Department of Epidemiology, Harvard T H Chan School of Public Health, Boston, MA, USA
  3. 3Channing Division of Network Medicine, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
  4. 4Department of Biostatistics, Harvard T H Chan School of Public Health, Boston, MA, USA
  1. Correspondence to: J-P Drouin-Chartier drouinchartier{at}hsph.harvard.edu (or @JP_Drouin_C on Twitter)
  • Accepted 13 January 2020

Abstract

Objective To evaluate the association between egg intake and cardiovascular disease risk among women and men in the United States, and to conduct a meta-analysis of prospective cohort studies.

Design Prospective cohort study, and a systematic review and meta-analysis of prospective cohort studies.

Setting Nurses’ Health Study (NHS, 1980-2012), NHS II (1991-2013), Health Professionals’ Follow-Up Study (HPFS, 1986-2012).

Participants Cohort analyses included 83 349 women from NHS, 90 214 women from NHS II, and 42 055 men from HPFS who were free of cardiovascular disease, type 2 diabetes, and cancer at baseline.

Main outcome measures Incident cardiovascular disease, which included non-fatal myocardial infarction, fatal coronary heart disease, and stroke.

Results Over up to 32 years of follow-up (>5.54 million person years), 14 806 participants with incident cardiovascular disease were identified in the three cohorts. Participants with a higher egg intake had a higher body mass index, were less likely to be treated with statins, and consumed more red meats. Most people consumed between one and less than five eggs per week. In the pooled multivariable analysis, consumption of at least one egg per day was not associated with incident cardiovascular disease risk after adjustment for updated lifestyle and dietary factors associated with egg intake (hazard ratio for at least one egg per day v less than one egg per month 0.93, 95% confidence interval 0.82 to 1.05). In the updated meta-analysis of prospective cohort studies (33 risk estimates, 1 720 108 participants, 139 195 cardiovascular disease events), an increase of one egg per day was not associated with cardiovascular disease risk (pooled relative risk 0.98, 95% confidence interval 0.93 to 1.03, I2=62.3%). Results were similar for coronary heart disease (21 risk estimates, 1 411 261 participants, 59 713 coronary heart disease events; 0.96, 0.91 to 1.03, I2=38.2%), and stroke (22 risk estimates, 1 059 315 participants, 53 617 stroke events; 0.99, 0.91 to 1.07, I2=71.5%). In analyses stratified by geographical location (P for interaction=0.07), no association was found between egg consumption and cardiovascular disease risk among US cohorts (1.01, 0.96 to 1.06, I2=30.8%) or European cohorts (1.05, 0.92 to 1.19, I2=64.7%), but an inverse association was seen in Asian cohorts (0.92, 0.85 to 0.99, I2=44.8%).

Conclusions Results from the three cohorts and from the updated meta-analysis show that moderate egg consumption (up to one egg per day) is not associated with cardiovascular disease risk overall, and is associated with potentially lower cardiovascular disease risk in Asian populations.

Systematic review registration PROSPERO CRD42019129650.

Footnotes

  • Contributors: JPDC and SC contributed equally to the manuscript. JPDC and SNB have full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. SNB, ALS, YL, JPDC, and FBH were involved in the study conception and design. JPDC and SC conducted the systematic review and meta-analysis. JPDC, YL, SC, SNB, and ALS analyzed and interpreted the data. SNB, YL, BR, and FBH provided statistical expertise. JPDC and SNB drafted the manuscript. All the authors participated in the interpretation of the results and critical revision of the manuscript. SNB and FBH are the guarantors. The corresponding author attests that all listed authors meet authorship criteria and that no others meeting the criteria have been omitted.

  • Funding: The Nurses’ Health Study (NHS), NHS II, and Health Professionals’ Follow-Up Study cohorts are supported by the following National Institutes of Health (NIH) grants: P01 CA87969, R01 HL034594, R01 HL088521, UM1 CA186107, UM1 CA176726, UM1 CA167552, R01 HL35464, R01 HL60712, U01 CA167552. JPDC is supported by a Banting postdoctoral fellowship from the Canadian Institutes of Health Research (BPF-156628). FBH is supported by grants HL60712, HL118264, and DK112940 from the NIH. SNB is supported by a career development grant from the NIH (K01 DK107804). The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; or the decision to submit the manuscript for publication.

  • Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: support from the National Institutes of Health and Canadian Institutes of Health Research for the submitted work; JPDC received speaker and consulting honorariums from the Dairy Farmers of Canada, outside the submitted work; YL received grants from California Walnut Commission, outside the submitted work; FBH received research support from the California Walnut Commission and honorariums for lectures from Metagenics and Standard Process and honorariums from Diet Quality Photo Navigation, outside the submitted work; no financial relationships with any organizations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.

  • Ethical approval: The institutional review boards of Brigham and Women’s Hospital and the Harvard T H Chan School of Public Health approved this study. Return of the mailed questionnaire was considered to imply informed consent. Protocol number: 2009-P-002375.

  • Data sharing: Data described in the manuscript, code book, and analytic code will not be made publicly available. Further information including the procedures for obtaining and accessing data from the Nurses’ Health Studies and Health Professionals’ Follow-up Study is described at https://www.nurseshealthstudy.org/researchers (email: nhsaccess@channing.harvard.edu) and https://sites.sph.harvard.edu/hpfs/for-collaborators

  • The manuscript’s guarantors affirm that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.

  • Dissemination to participants and related patient and public communities: No patients were involved in setting the research question or the outcome measures, nor were they involved in the design and implementation of the study. We plan to disseminate these findings to participants in our annual newsletter and to the general public in a press release.

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