Purpose: The association between egg consumption and cardiovascular disease (CVD) or type 2 diabetes (T2D) remains controversial. We investigated the association between egg consumption and risk of CVD (primary outcome), T2D and mortality in the Caerphilly prospective cohort study (CAPS) and National Diet and Nutritional Survey (NDNS).
Methods: CAPS included 2512 men aged 45-59 years (1979-1983). Dietary intake, disease incidence and mortality were updated at 5-year intervals. NDNS included 754 adults aged 19-64 years from 2008 to 2012.
Results: Men free of CVD (n = 1781) were followed up for a mean of 22.8 years, egg consumption was not associated with new incidence of CVD (n = 715), mortality (n = 1028) or T2D (n = 120). When stroke (n = 248), MI (n = 477), heart failure (n = 201) were investigated separately, no associations between egg consumption and stroke and MI were identified, however, increased risk of stroke in subjects with T2D and/or impaired glucose tolerance (IGT, fasting plasma glucose ≥ 6.1 mmol/L), adjusted hazard ratios (95% CI) were 1.0 (reference), 1.09 (0.41, 2.88), 0.96 (0.37, 2.50), 1.39 (0.54, 3.56) and 2.87 (1.13, 7.27) for egg intake (n) of 0 ≤ n ≤ 1, 1 < n ≤ 2, 2 < n ≤ 3, 3 < n < 5, and n ≥ 5 eggs/wk, respectively (P = 0.01). In addition, cross-sectional analyses revealed that higher egg consumption was significantly associated with elevated fasting glucose in those with T2D and/or IGT (CAPS: baseline P = 0.02 and 5-year P = 0.04; NDNS: P = 0.05).
Conclusions: Higher egg consumption was associated with higher blood glucose in subjects with T2D and/or IGT. The increased incidence of stroke with higher egg consumption among T2D and/or IGT sub-group warrants further investigation.
Keywords: All-cause mortality; Cardiovascular disease; Eggs; Impaired glucose tolerance; Type 2 diabetes.