Bioavailability of lutein from potatoes.

Rationale:

Lutein and zeaxanthin are two carotenoids which are associated with lowering the risk of cardiovascular disease and age-related macular degeneration. However, consumption of green leafy vegetables which are an important source of lutein/zeaxanthin are decreasing. A potato strain which is especially rich in lutein/zeaxanthin could potentially contribute to the daily intake of lutein/zeaxanthin. However, bioavailability of lutein/zeaxanthin from these potatoes is not yet known.



Objective:

To investigate the bioavailability of lutein/zeaxanthin from lutein/zeaxanthin-rich potatoes in healthy volunteers.



Study design:

Volunteers will receive a single test meal and subsequently plasma will be collected for a time period of 10 days in decreasing frequency.
Study population: Healthy human volunteers between 18 and 30 yrs of age with a BMI between 18.5 and 24.9.



Intervention:

Six volunteers (3 men, 3 women) will ingest mashed potatoes made from lutein/zeaxanthin-rich potatoes which are labeled with the stable isotope 13C.



Main study parameters/endpoints:

The main study parameter is the plasma concentration of 13C- and 12C-lutein/zeaxanthin, which will be monitored during 10 days at time points: 0, 1, 2, 3, 4, 5, 6, 10, 12, 33, 48, 72, 96, 168 and 216 h after ingestion.



Nature and extent of the burden and risks associated with participation, benefit and group relatedness:

The volunteers need to stay one day in the UMCG (day one). A cannula will be inserted for blood collection and 10 blood samples will be collected. The next day the volunteers come back for two single blood collections. The volunteers need to come back for a single blood collection twice on day two and once for another six days. Per time point 5 ml blood will be collected, which amounts to 85 ml over the whole study period. In addition breath (day one) and urine samples (morning of day one and day two) will be collected. The test meals are food products which are not posing any risk to the health of the volunteers. The volunteers will fill in a questionnaire concerning habitual food intake and will register intake of lutein/zeaxanthin rich products during the study period.

Lutein and zeaxanthin are two carotenoids which are associated with lowering the risk of cardiovascular disease and age-related macular degeneration. However, consumption of green leafy vegetables which are an important source of lutein/zeaxanthin are decreasing. A potato strain which is especially rich in lutein/zeaxanthin could potentially contribute to the daily intake of lutein/zeaxanthin. However, bioavailability of lutein/zeaxanthin from these potatoes is not yet known.

1. Breath samples:

One basal breath sample will be collected after placement of the venous cannula. The first 6 hours after ingestion of the test meal samples will be collected half-hourly, the last hours hourly;

2. Blood samples:
On day 1 one basal blood sample will be collected directly after placement of the venous cannula. Then blood samples are collected 1, 2, 3, 4, 5, 6, 8, 10 and 12 h after ingestion of the test meal.
On day 2 on blood sample will be collected in the morning and at the end of the afternoon.
On day 3, 4, 5, 8, 10 one blood sample will be collected in the morning;

3. Urine samples:

One morning urine sample will be collected by the volunteers at home at day 1 and day 2 of the study.

The volunteers will ingest 200 g of mashed lutein/zeaxanthin-rich potatoes of which 50 g is made from 13C-labeled lutein/zeaxanthin-rich potatoes.To the mashed potatoes 7 g olive oil will be added to facilitate absorption of lutein/zeaxanthin in the small intestine. The volunteer will drink 250 mL of water with the mashed potatoes.