Egg consumption as part of an energy-restricted high-protein diet improves blood lipid and blood glucose profiles in individuals with type 2 diabetes

The role of dietary cholesterol in people with diabetes has been little studied. We investigated the effect of a hypoenergetic high-protein high-cholesterol (HPHchol) diet compared to a similar amount of animal protein (high-protein low-cholesterol, HPLchol) on plasma lipids, glycaemic control and cardiovascular risk markers in individuals with type 2 diabetes. A total of sixty-five participants with type 2 diabetes or impaired glucose tolerance (age 54.4 (SD 8.2) years; BMI 34.1 (SD 4.8) kg/m(2); LDL-cholesterol (LDL-C) 2.67 (SD 0.10) mmol/l) were randomised to either HPHchol or HPLchol. Both hypoenergetic dietary interventions (6-7 MJ; 1.4-1.7 Mcal) and total carbohydrate: protein: fat ratio of 40:30:30% were similar but differed in cholesterol content (HPHchol, 590mg cholesterol; HPLchol, 213mg cholesterol). HPHchol participants consumed two eggs per d, whereas HPHchol participants replaced the eggs with 100 g of lean animal protein. After 12 weeks, weight loss was 6.0 (SD 0.4) kg (P<0.001). LDL-C and homocysteine remained unchanged. All the subjects reduced total cholesterol (-0.3 (SD 0.1) mmol/l, P<0.001), TAG (-0.4 (SD 0.1) mmol/l, P<0.001), non-HDL-cholesterol (HDL-C, -0.4 (SD 0.1) mmol/l, P<0.001), apo-B (-0.04 (SD 0.02) mmol/l, P<0.01), HbA1c (-0.6 (SD 0.1) %, P<0.001), fasting blood glucose (-0.5 (SD 0.2) mmol/l, P<0.01), fasting insulin (-1.7 (SD 0.7) mIU/l, P<0.01), systolic blood pressure (-7.6 (SD 1.7) mmHg, P<0.001) and diastolic blood pressure (-4.6 (SD 1.0) mmHg; P<0.001). Significance was not altered by diet, sex, medication or amount of weight loss. HDL-C increased on HPHchol (+0.02 (SD 0.02) mmol/l) and decreased on HPLchol (-0.07 (SD 0.03) mmol/l, P<0.05). Plasma folate and lutein increased more on HPHchol (P<0.05). These results suggest that a high-protein energy-restricted diet high in cholesterol from eggs improved glycaemic and lipid profiles, blood pressure and apo-B in individuals with type 2 diabetes.