2009 Annual Report
1a.Objectives (from AD-416)
The broad objective of this project is to elucidate details of bioavailability and metabolism of phytochemicals and other micronutrients. Specific nutrients of interest are carotenoids and polyphenols, with special emphasis on anthocyanins. Issues under study will include phytonutrient content of foods, comparison of foods as sources of phytonutrients, dose responses of phytonutrients, kinetics of metabolism of phytonutrients and micronutrients, and development of methodologies to label nutrients in plants for subsequent isolation and use in feeding trials.
1b.Approach (from AD-416)
This research will be conducted through plant growth/nutrient accumulation studies, human feeding trials, quantitative chemistry, and kinetic mathematical modeling techniques. Plant growth/nutrient accumulation studies will be used to improve plant isotopic labeling, human feeding trials will be conducted to gather information about nutrient levels in biological samples after nutrient ingestion, gas chromatography, liquid chromatography, and mass spectrometry will be used to quantitate nutrient levels in biological samples; and compartmental modeling techniques will be used to delineate parameters of absorption and metabolism of nutrients.
In the past year, kinetic analysis of beta-carotene based on data from a human feeding study were conducted. In the feeding study, volunteers consumed two doses of beta-carotene, and blood was collected and analyzed for beta-carotene appearance. Mathematical analysis to determine if absorption efficiency was equivalent at the two doses was then conducted. This information was previously unknown, but is very important, since beta-carotene is an important dietary source of vitamin A and because vitamin A deficiency is a major health problem worldwide.
Cell culture studies confirmed the findings from a human feeding trial with Brassica vegetables, a class of vegetables thought to reduce risk of cancer. The human feeding trial suggested that consumption of Brassica vegetables influenced DNA damage in humans, which was confirmed using cell culture techniques.
Kinetic studies of Vitamin K based on data from a human feeding trial in which adult volunteers consumed a large serving of kale in which the nutrients were specially tagged. The appearance of the specially tagged vitamin K was followed in the blood of the volunteers, and mathematical analyses to determine how much of the vitamin K was absorbed and how fast it was removed from the body were completed.
Over the past five years, this project has made significant progress in providing information about bioavailability and metabolism of phytonutrients and micronutrients. Commodities under study included purple carrots, red cabbage, green cabbage, strawberries, kale, acai, jussara, guajiru, and jambalao. Phytonutrients and micronutrients under study included anthocyanins, carotenoids, glucosinolates, isothiocyanates, vitamin E, vitamin K, and molybdenum.
Vitamin K absorption and utilization. Roles for vitamin K in health, including maintaining bone tissue, are becoming increasingly well understood, but the body’s ability to absorb vitamin K from green vegetables, the primary dietary source of vitamin K, is not known. This study provided specific values for vitamin K absorption and for the rate of vitamin K utilized by the body. These data will be useful to health professionals who are designing diets to meet nutritional adequacy.
Beta-carotene dose response. Beta-carotene is an important plant source of vitamin A, but its absorption at different dose sizes in not known. Results of a human feeding study demonstrated that beta-carotene is equally well absorbed at a moderate and a high dose. Health professionals are seeking ways to prevent vitamin A deficiency worldwide, and these results will be helpful as strategies are planned for addressing this global problem.
Charron, C.S., Kurilich, A.C., Clevidence, B.A., Simon, P.W., Harrison, D.J., Britz, S.J., Baer, D.J., Novotny Dura, J. 2009. Bioavailability of Anthocyanins from Purple Carrot Juice: Effects of Acylation and Plant Matrix. Journal of Agricultural and Food Chemistry. 57(4):1226-1230.