Egg intake does not increase T2D risk

Moderate consumption of eggs is not largely associated with a heightened risk of type 2 diabetes (T2D), results of a systematic review and meta-analysis have shown.

A total of 82,750 women from the Nurses’ Health Study (NHS; 1980–2012), 89,636 women from the NHS II (1991–2017), and 41,412 men from the Health Professionals Follow-up Study (HPFS; 1986–2016) who were free of T2D, cardiovascular disease, and cancer at baseline were followed in this study.

A validated food-frequency questionnaire was used to assess egg consumption among participants every 2–4 years. Cox proportional hazard models were then used to estimate hazard ratios (HRs) and 95 percent confidence intervals (CIs).

Overall, 20,514 incident cases of T2D were recorded in the NHS, NHS II, and HPFS during 5,529,959 person-years of follow-up. The pooled multivariable model, adjusted for updated body mass index, lifestyle, and dietary confounders, revealed a 14-percent (95 percent CI, 7–20) higher T2D risk for an increase of 1 egg/day.

In random-effects meta-analysis of 16 prospective cohort studies (n=589,559; 41,248 incident T2D cases), the pooled relative risk (RR) of T2D was 1.07 (95 percent CI, 0.99–1.15; I², 69.8 percent) for each 1 egg/day. However, significant differences were noted by geographic region (p_interaction=0.01).

Each 1 egg/day correlated with increased T2D risk among US studies (RR, 1.18, 95 percent CI, 1.10–1.27; I², 51.3 percent), but not among European (RR, 0.99, 95 percent CI, 0.85–1.15; I², 73.5 percent) or Asian studies (RR, 0.82, 95 percent CI, 0.62–1.09; I², 59.1 percent).

“Whether the heterogeneity of the associations among US, European, and Asian cohorts reflects differences in egg consumption habits warrants further investigation,” the investigators said.