One Egg per Day Improves Inflammation when Compared to an Oatmeal-Based Breakfast without Increasing Other Cardiometabolic Risk Factors in Diabetic Patients

Abstract

There is concern that egg intake may increase blood glucose in patients with type 2 diabetes mellitus (T2DM). However, we have previously shown that eggs reduce inflammation in patients at risk for T2DM, including obese subjects and those with metabolic syndrome. Thus, we hypothesized that egg intake would not alter plasma glucose in T2DM patients when compared to oatmeal intake. Our primary endpoints for this clinical intervention were plasma glucose and the inflammatory markers tumor necrosis factor (TNF)-α and interleukin 6 (IL-6). As secondary endpoints, we evaluated additional parameters of glucose metabolism, dyslipidemias, oxidative stress and inflammation. Twenty-nine subjects, 35-65 years with glycosylated hemoglobin (HbA1c) values <9% were recruited and randomly allocated to consume isocaloric breakfasts containing either one egg/day or 40 g of oatmeal with 472 mL of lactose-free milk/day for five weeks. Following a three-week washout period, subjects were assigned to the alternate breakfast. At the end of each period, we measured all primary and secondary endpoints. Subjects completed four-day dietary recalls and one exercise questionnaire for each breakfast period. There were no significant differences in plasma glucose, our primary endpoint, plasma lipids, lipoprotein size or subfraction concentrations, insulin, HbA1c, apolipoprotein B, oxidized LDL or C-reactive protein. However, after adjusting for gender, age and body mass index, aspartate amino-transferase (AST) (p < 0.05) and tumor necrosis factor (TNF)-α (p < 0.01), one of our primary endpoints were significantly reduced during the egg period. These results suggest that compared to an oatmeal-based breakfast, eggs do not have any detrimental effects on lipoprotein or glucose metabolism in T2DM. In contrast, eggs reduce AST and TNF-α in this population characterized by chronic low-grade inflammation.

Keywords: IL-6; TNF-α; diabetes; eggs; glucose; inflammation; lipoproteins.

Figure 1

Flow chart of the study.

Figure 2

Plasma concentrations of glucose (A) and plasma concentrations of interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) (B) after the egg (dark bar) and the oatmeal (white bar). Mean values for plasma glucose were 9.0 ± 3.0 mmol/L and 8.8 ± 2.3 mmol/L after the oatmeal periods. IL-6 were 3.8 ± 2.7 pg/mL following the egg breakfast (p = 0.051) and 5.2 ± 4.8 pg/mL after the oatmeal and for TNF-α were 6.7 ± 2.8 pg/mL after the egg breakfast (p = 0.007) and 7.9 ± 2.7 pg/mL after the oatmeal. *Indicates significantly different p < 0.05 and ** p < 0.01. NS = non-significant.

Figure 3

Concentrations of liver enzymes after the egg (dark bar) and the oatmeal (white bar) periods. ALT did not differ between treatments; However, AST was significantly reduced (p < 0.05) after the egg period (21.9 ± 5.8 vs. 23.7 ± 6.4 IU/L)