Submitted to: American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/13/1996
Publication Date: N/A
Citation: Interpretive Summary: Many indicators of health status for human beings are measured in blood components. Some of these indicators may be affected by normal cyclic phenomena which could alter the interpretation of data unless the cyclic parameters are well understood. This research documents the influence of menstrual cycle of carotenoid concentrations in blood plasma in twelve healthy women. The diet was strictly controlled during the two menstrual cycles in which fluctuations were observed. Generally plasma carotenoid concentrations were at their lowest at menses and rose significantly thereafter. Beta carotene levels were highest during the late follicular phase whereas plasma lycopene and phytofluene concentrations peaked at mid luteal phase. Plasma lutein zeaxanthin and anhydrolutein levels were highest during the last three phases of the menstrual cycle. These cyclic fluctuation may affect the estimation of plasma carotenoid disease risk relationship in studies of premenopausal women. The data from this study are important in terms of assisting scientists in scheduling blood sampling relative to specific periods of the menstrual cycle when the most precise data for plasma carotenoids are required.
Technical Abstract: This is the first controlled diet study to examine the fluctuation of plasma carotenoids, lioproteins, and serum hormone concentrations by phase of the menstrual cycle. Non-smoking, premenopausal women (N=12), with confirmed ovulatory cycles, were given a standard diet of 10mg/d total carotenoids for 2 cycles under isoenergetic conditions. Blood was drawn for simultaneous measurement of carotenoids, lipoproteins, and hormones on menses days 1-2, 4-6, 11 through the day post LH surge, and 7-8 days post LH surge, representing the menses, early and late follicular, and mid luteal phases, respectively. Regression modeling with adjustment for plasma cholesterol concentrations was used to compare mean individual and total plasma carotenoid concentrations by phase of the cycle. Plasma carotenoid concentrations were at their lowest at menses and significantly higher thereafter, except for a-carotene. Compared with plasma concentrations menses, B-carotene pea phase. Plasma lutein zeaxanthin and anhydrolutein concentrations were higher by 8-11% (P</_0.02), respectively, during the last 3 phases. Plasma lycopene and phytofluence concentrations peaked (increased by 12%, P=0.004; and by 21%, P=0.006 respectively) at the mid luteal phase. This cyclic fluctuation may affect the estimation of the plasma carotenoid disease relation in studies of premenopausal women.