Consuming egg yolk decreases body weight and increases serum HDL and brain expression of TrkB in male SD rats.

BACKGROUND

Egg yolks contain large amounts of cholesterol and are suspected to be harmful after long-term consumption. In this experiment, 63 rats were used to evaluate the effect of egg white (EW) and egg yolk (EY) supplementation on serum lipids and brain cognition. The feeding time lasted 4 weeks after a 1-week acclimation.

RESULTS

Body weight was significantly higher in rats fed 132.0 g kg EW and significantly lower when fed 40 g kg EY (P < 0.05). Total cholesterol and low-density lipoprotein increased in rats fed 72.0 g kg EW compared with rats from NC and EY groups (P < 0.05). High-density lipoprotein (HDL) was higher in rats fed 40 g kg EY and decreased when fed 72.0 g kg EW (P < 0.05). Rats fed a diet with EY exhibited abundant neurons in the CA1 hippocampus and complete subcellular structures. Rats fed 132 g kg EW exhibited shrunken cells and swollen mitochondria. Brain-derived neurotrophic factor had constitutively low expression among groups, while tyrosine kinase B (TrkB) exhibited higher expression levels in rats fed a diet containing EY compared with other groups (P < 0.05).

CONCLUSION

EY consumption reduced body weight and increased HDL levels. Diet containing EY could improve cognition through enhanced trkB expression. © 2019 Society of Chemical Industry.