Egg and cholesterol intake and incident type 2 diabetes among French women

Egg consumption is a major source of dietary cholesterol, a nutrient that may disrupt glucose metabolism. We prospectively evaluated the relation between egg consumption and cholesterol-intake and diabetes in 65 364 French disease-free women who responded to a validated diet history questionnaire in 1993. Egg consumption included hardboiled eggs and eggs consumed in an omelette or a mixed dish, and dietary cholesterol was estimated using a French nutrient database. Over 14 years of follow-up, 1803 incident diabetes cases were identified through self-reports, supplementary questionnaires and drug reimbursement information. Multivariable Cox regression models were adjusted for age, education, menopause, menopausal hormone therapy, hypertension and hypercholesterolaemia, BMI, physical activity, smoking, alcohol, fruit, vegetables, processed red meat, coffee and sugar and artificially sweetened beverages. No association was observed between egg consumption and risk of type 2 diabetes. When comparing women who consumed at least five eggs per week with non-consumers, the multivariable hazard ratio (HR) was found to be 1·00 (95 % CI 0·78, 1·29; across categories, P trend=0·11). Women in the highest quintile of dietary cholesterol had a 40 % higher rate of diabetes compared with those in the lowest quintile (HR 1·40; 95 % CI 1·19, 1·63; across quintiles, P trend<0·0001). A 100 mg increase of dietary cholesterol per 4184 kJ (or 1000 kcal) was associated with a 14 % increase in the risk of diabetes (HR 1·14; 95 % CI 1·02, 1·26). In this large prospective cohort, we observed an association between dietary cholesterol and type 2 diabetes, but no association with egg consumption. In the absence of a clear underlying mechanism and potential residual confounding, these results should be interpreted with caution.