Increased consumption of dietary cholesterol, lutein, and zeaxanthin as egg yolks does not decrease serum concentrations and lipoprotein distribution of other carotenoids, retinol, and tocopherols

摘要

We have previously reported that consumption of lutein and zeaxanthin as 2 and 4 egg yolks per day for 5 weeks significantly increased serum lutein and zcaxanthin concentrations in older adults taking cholesterol-lowering statins. We hypothesized that increased consumption of eggs, lutein, and zeaxanthin may correlate with decreased absorption of other carotenoids and increased absorption of vitamins A and E, thus affecting their serum concentrations and lipoprotein distribution. Fifty-two subjects aged at least 60 years consumed 2 egg yolks per day followed by 4 egg yolks per day for 5 weeks each with a 4-week egg-free period at baseline and between the 2 interventions. Mean serum beta-cryptoxanthin, lycopene, alpha-carotene, beta-carotene, alpha-tocopherol, and retinol concentrations did not change during the 2 and 4 egg yolk phases. Mean serum alpha-cryptoxanthin and gamma-tocopherol concentrations did not change after the 2 egg yolk phase, but increased by 47% (P < .001) and 19% (P < .05), respectively, after the 4 egg yolk phase. The percentage distribution of carotenoids and tocopherols between the high-density lipoprotein (HDL) and non-HDL fractions was not significantly different during the egg yolk phases compared with baseline despite the significant increases in lutein and zeaxanthin carried on HDL and non-HDL fractions. In conclusion, increased dietary cholesterol, lutein, and zeaxanthin consumed as egg yolks did not decrease the absorption of other carotenoids, and increased gamma-tocopherol but not retinol as evidenced by their serum and lipoprotein concentrations. Two and 4 egg yolk consumption increases scrum and retinal lutein and zcaxanthin without altering the serum status of the other carotenoids, tocopherol, and retinal