1a. Objectives (from AD-416)
1. Determine the ability of bioactive plant-based foods, including carotenoid-rich foods to exert biological functions and affect genomic stability. 2. Determine the vitamin A requirement of healthy U.S. adults.
1b. Approach (from AD-416)
3. Progress Report
We have successfully completed the identification of major bioactive components in the bioactive plant foods Angelica keiskei and Glycine max, which are being used for human studies, as well as determined their stability. In addition, absorption kinetics of histidine dipeptides in chicken broth has been determined. We have begun recruitment of older adults (>60 yr, men and post-menopausal women), both with and without metabolic syndrome, to determine the impact of Angelica keiskei and glycine max or histidine dipeptide rich foods and the study is in progress. We have obtained the IRB approval to study the relationship between obesity and macular pigmentation. However, this study was not carried out due to lack of resources. Instead, a pilot study, evaluating the relationships among various measures of lutein and zeaxanthin status, including the macula, was initiated and completed in the past year. We found that this study validated a quick, easy, and inexpensive method to determine individual intake of these carotenoids. We determined the uptake of lutein into neural tissue, i.e. the macula, and have started to look into brain tissue and its possible relationships with cognitive health. We obtained IRB approval to carry out a pilot study entitled ‘Bioavailability of vitamin A in humans’ using the aphereses-autologues technique (using self plasma enriched with labeled vitamin A as an intravenous 'solution' to be re infused back to determine the bioavailability of an oral vitamin A dose) on human volunteers. This pilot study has been completed successfully. We have measured the enrichment of the labeled retinols in human circulations and, using mathematical modeling, determined vitamin A bioavailability. These results provided evidence that the procedures we propose to follow are working properly. A grant proposal will be submitted to obtain funding to carry out a larger definitive study. For publications related to this project, see parent project #1950-51000-073-00D.