The purpose of this study is to determine how well the body absorbs the carotenoid beta-cryptoxanthin (BCX) from a type of corn that has been naturally bred (not genetically engineered) to contain higher amounts of BCX than traditional breeds of corn. Because this new type of corn contains higher amounts of BCX, it appears more orange in color than traditional types of corn. Understanding how well the body can absorb the BCX from the corn may help companies develop food products that may have improved nutritional quality.
Randomized, blinded, 3 x 3 crossover intervention. Each treatment will last 12 d, followed by a 7-d wash-out period. After the washout, subjects will go back to their regular diet for two weeks before beginning the next cycle. Subjects will report to the research kitchen in the Nutritional Sciences building for their breakfast. Maize will be incorporated into two muffins. Other food choices will be yogurt and other low-fiber foods. Blood samples will be taken at baseline and days 3, 6, 9, 12, 15, and 19. Natural abundance measurements of 13-carbone to 12-carbon will be taken at baseline, day 12 and day 19. Retinol isotope dilution testing will be done at the end of the study to determine total body stores of vitamin A in the subjects. This will include the day 19 blood sample of intervention phase 3 and a final blood sample 14 days after the isotope dose administration.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
SINGLE
Enrollment
10
The whole grain orange maize will be milled and prepared into muffins to be consumed daily. Muffins will contain a target of 500 µg beta-cryptoxanthin per day.
The refined grain orange maize will be degermed, milled, and prepared into muffins to be consumed daily. Muffins will contain a target of 500 µg beta-cryptoxanthin per day.
The whole grain white maize will be milled and prepared into muffins to be consumed daily. Muffins will contain minimal beta-cryptoxanthin, matched for dry maize weight.
University of Wisconsin-Madison Nutritional Sciences
Madison, Wisconsin, United States
Serum beta-cryptoxanthin concentration area under the curve ((µmol/L)*t)
Serum beta-cryptoxanthin concentration area under the curve calculated from samples on days 0, 3, 6, 9, 12, 15, 19 of treatment phase
Time frame: 19 days with blood samples drawn on days 0, 3, 6, 9, 12, 15, 19 of treatment phase
Serum retinol carbon-13 natural abundance (δ 13C‰)
Change in serum retinol carbon-13 natural abundance will be assessed from beginning to after each treatment period. This will be done on baseline, day 12 and day 19 blood samples.
Time frame: 19 days and will be measured on days 0, 12, and 19
Vitamin A total body stores (µmol vitamin A) by retinol isotope dilution
After a blood draw, a carbon-13 labeled vitamin A oral dose will be given to subjects after all treatments. After 14 days, another blood draw will be taken to determine dilution of the stable isotope dose. This will used the final blood sample of intervention phase 3 and a final blood draw 14 days later.
Time frame: 14 days and will include the final blood of phase three and another sample 14 days later
Vitamin A estimated total liver reserves (µmol vitamin A/g liver) by retinol isotope dilution
After a blood draw, a carbon-13 labeled vitamin A oral dose will be given to subjects after all treatments. After 14 days, another blood draw will be taken to determine dilution of the stable isotope dose. This will used the final blood sample of intervention phase 3 and a final blood draw 14 days later.
Time frame: 14 days and will include the final blood of phase three and another sample 14 days later
Serum zeaxanthin, lutein, and beta-carotene concentration area under the curves ((µmol/L)*t)
Serum carotenoid concentration area under the curves calculated from samples on days 0, 3, 6, 9, 12, 15, 19 of treatment phase
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Time frame: 19 days with blood samples drawn on days 0, 3, 6, 9, 12, 15, 19 of treatment phase