An egg a day is OK

Consuming up to one egg per day does not appear to be associated with cardiovascular disease (CVD) risk, according to a new study and meta-analysis led by researchers at Harvard T.H. Chan School of Public Health.

“Recent studies reignited the debate on this controversial topic, but our study provides compelling evidence supporting the lack of an appreciable association between moderate egg consumption and cardiovascular disease,” said first author Jean-Philippe Drouin-Chartier, visiting scientist in the Department of Nutrition and assistant professor at Laval University in Québec, Canada. The study was published online today in the BMJ.

The relationship between egg consumption and CVD risk has been a topic of intense debate in the scientific community in recent decades. Just in the past 12 months, three published studies have reported conflicting results.

The new findings update a 1999 study — the first major analysis of eggs and cardiovascular disease — that found no association between eggs and CVD risk. That study was led by Frank Hu, Fredrick J. Stare Professor of Nutrition and Epidemiology, chair of the Department of Nutrition, and a co-author of the current study.

For this study, researchers analyzed health data from 173,563 women and 90,214 men participating in the Nurses’ Health Study (NHS) I and II, and the Health Professionals Follow-Up Study (HPFS) who were free of CVD, type 2 diabetes, and cancer at baseline. They used repeated measures of diet — up to 32 years of follow-up — to gain a detailed picture of potentially confounding lifestyle factors such as high body mass index and red meat consumption. The researchers also conducted the largest meta-analysis of this topic, including 28 prospective cohort studies with up to 1.7 million participants.

The analysis of NHS and HPFS participants found no association between moderate egg consumption and risk of CVD. Results from the meta-analysis supported this finding in U.S. and European populations; however, some evidence suggested that moderate egg consumption may be associated with lower CVD risk in Asian populations although this may be confounded by the overall dietary pattern.

Study co-author Shilpa Bhupathiraju, research scientist in the Harvard Chan School Department of Nutrition and associate epidemiologist at Brigham and Women’s Hospital, said that while moderate egg consumption can be part of a healthy eating pattern, it is not essential. “There is a range of other foods that can be included in a healthy breakfast, such as whole grain toasts, plain yogurt, and fruits.”

Other Harvard Chan School authors of the study included Siyu Chen, Yanping Li, Amanda Schwab, Meir Stampfer, Frank Sacks, Bernard Rosner, and Walter Willett.

The NHS, NHS II and HPFS 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. Drouin-Chartier is supported by a Banting Postdoctoral Fellowship from the Canadian Institutes of Health Research (BPF-156628). Hu is supported by grants HL60712, HL118264, and DK112940 from the NIH. Bhupathiraju is supported by a Career Development Grant from the NIH (K01 DK107804).