Dietary Effect of Docosahexaenoic Acid-rich Eggs on Serum Lipids in Healthy Human Subjects: A Randomized Double-Blind Controlled Study

The effect of docosahexaenoic acid-rich eggs on human serum lipids was investigated in 27 healthy volunteers (11 males and 16 females, average age: 44.7 years old) under the condition of a randomized double-blind controlled study. The subjects were randomly divided into two groups, and the test group was given daily two eggs enriched with docosahexaenoic acid (DHA) for 12-week period. Subjects in the control group were given daily two eggs obtained from hens fed a normal diet. The amounts of DHA in the foods were 8.31 ± 0.98 mg/g yolk in the DHA-rich eggs and 1.30 ±0.24 mg/g yolk in the control eggs, respectively. The levels of total cholesterol (TC) in the two groups were not significantly different from the initial values, except at 2 weeks in the control (p < 0.05), during the test period (12 weeks). The level of LDL-cholesterol (LDL-C) in the test group fed DHA-rich eggs was slightly increased at 2 weeks (p < 0.05), but reduced to the initial values at 4 weeks and thereafter (not significantly different). The level of HDL-cholesterol (HDL-C) in the test food group was significantly higher than that in the control in the subjects with TC ≤ 220 mg/dl at 8 weeks (p < 0.05). The DHA concentration of serum total lipid in the test group had increased significantly at 4 weeks (p < 0.05), but in comparison, it had decreased in the control (not significantly different). In conclusion, the dietary effect of DHA-rich eggs on human serum lipids is limited, but the intake of DHA-rich eggs maintains higher levels of HDL-C and DHA in the subjects compared to those in the control subjects fed normal eggs during the 12-week test period.