Carotenoid Absorption and Metabolism From Green-leafy Vegetable Matrices

Overview

Absorption and metabolism of carotenoids from two types of spinach preparations will be investigated in two study groups, short bowel/ileostomy and healthy, respectively. The study will be conducted as a randomised, controlled, 2-way crossover study in 24 participants (12 in each group), randomized to two sequences (1-2, 2-1) of interventions with a more and a less bio-accessible spinach preparation. The serum, chylomicron and fecal/effluent levels of lutein and beta-carotene will be determined.

Absorption and metabolism of carotenoids from two types of spinach preparations will be investigated in two study groups, short bowel/ileostomy and healthy, respectively. The study will be conducted as a randomised, controlled, 2-way crossover study. Twenty four participants (12 in each group) will be randomized to two sequences (1-2, 2-1) of interventions with a more and a less bio-accessible spinach preparation (differentiates only on the basis of particle size). The intervention period is sub-divided into three parts: run-in period (48 hours) with a standardized low-carotenoid diet, 0-24 hours (follow-up period 1 (FP1)) and 24 hours - 2 weeks (FP2). The intervention periods will be separated by a wash-out period of at least 14 days. At start of each intervention, the intervention meal (breakfast) is served, followed by standardized, carotenoid-free meals in the following 24 hours. Participants will in FP1 and FP2 receive an intervention meal every second day. Participants will otherwise keep their habitual diets during these follow-up periods. Study participants are asked to collect urine during 24 hours before and after the first intervention meal in each period. They will also collect feces/ileostomy efflux for 24 hours before and after initiation of the intervention for short bowel/ileostomy patients and for 48 periods in the healthy volunteers, respectively. Overnight-fasting serum samples are drawn at day 1, 7 and 15 of each intervention period. On day 1 plasma samples are drawn at 0,1, 3, 4, 6, 7, 9 and 24 hours post first intervention meal. Plasma and effluent levels of lutein and beta-carotene will be determined and chylomicrons are also separated from these samples for determination of carotenoids. Volunteers also have their macula examined for density of the yellow spot before and after the intervention. Plasma and effluent levels of other carotenoids as well as fat-soluble vitamins are also determined. The samples will also be subjected to metabolic profiling for further exploration and hypothesis generation.

Conditions

Interventions

Eligibility

Locations (2)

Outcomes