2007 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.
This project, which falls under National Program 107 Component 2, “Bioavailability of Nutrients and Food Components,” has made notable progress in delineating absorption, distribution, and elimination of nutrients and phytochemicals in humans. Research in 2007 focused predominantly on anthocyanins, which are red, purple, and blue pigments found in fruits, vegetables, and ornamental crops. Dietary intake of anthocyanins has been associated with reduction of chronic disease risk. In collaboration with Embrapa of Brazil, several tropical fruits were analyzed for anthocyanins. Specific structures of anthocyanins were characterized in several understudied fruits from South America, including jussara, jambalão, guajiru, and acerola, and the investigators determined the content of each type of anthocyanin in these fruits. Building on previous research, the bioavailability of anthocyanin pigments from red cabbage was studied. A clinical feeding study was conducted in which volunteers consumed steamed red cabbage in three dose levels. In addition, a clinical feeding study was conducted in which volunteers consumed pureed strawberries in three dose levels, and the investigators showed that the body’s ability to absorb the anthocyanin pigments from strawberries was not saturated at the three doses that were administered. In preparation to label anthocyanins with tags that will permit their metabolic tracing in the human body, numerous plant growth studies to determine conditions which are favorable for growing strawberries and red cabbage in sealed, environmentally-controlled growth chambers were conducted. Specific information includes efficiency of absorption and metabolism of nutrients and plant phytochemicals, including carotenoids, vitamins, minerals, and anthocyanins, as well as new methodologies to assess these issues.
“Red Cabbage Anthocyanin Absorption”
A kinetic study of red cabbage anthocyanin absorption and elimination in adult volunteers was conducted. Volunteers were provided with three different levels of red cabbage on three different occasions and provided urine samples for analysis. The urine samples were analyzed by specialty chromatographic methods to determine how well the anthocyanins were absorbed. The investigators found that anthocyanin absorption increased with increasing red cabbage dose, thus the body’s absorption system was not saturated, as often happens with increasing doses of nutrients; therefore, red cabbage provides more anthocyanin when consumed in larger doses. Specific chemical features of anthocyanins which impact absorption efficiency were also determined. Health professionals seek firm information on which to base dietary intake recommendations. These results will benefit consumers and health professionals as diets are planned. This work falls under National Program 107 Component 2, “Bioavailability of Nutrients and Food Components”.
“Molybdenum Intake and Metabolism”
A kinetic study was conducted in which molybdenum storage and elimination was determined for different intake levels of dietary molybdenum. This research identified the specific control points for regulating the body’s exposure to molybdenum, and provided evidence for why molybdenum toxicity and deficiency are very rare in humans. The specific effect of dietary intake on changes in molybdenum storage and elimination in humans was demonstrated. Health professionals seek firm information on which to base dietary intake recommendations. In collaboration with the Western Human Nutrition Research Center, a kinetic study of molybdenum metabolism in adult volunteers was conducted. The Western Human Nutrition Research Center conducted a clinical study in which the volunteers consumed specially tagged molybdenum doses while receiving different background molybdenum diets. The Food Components and Health Laboratory at the Beltsville Human Nutrition Research Center completed the kinetic analysis of molybdenum levels in blood, urine, and feces throughout the study to demonstrate which pathways of metabolism adapt to increasing levels of dietary molybdenum. These results will benefit consumers and health professionals as diets are planned. This work falls under National Program 107 Component 2, “Bioavailability of Nutrients and Food Components”.
“Metabolism of Different Forms of Vitamin E”
In collaboration with the University of California at Davis, a kinetic study was conducted that showed how the body regulates alpha-tocopherol (vitamin E) exposure, and has demonstrated specific differences in metabolism of the natural and synthetic forms. Generally, this project provides valuable information for the Institute of Medicine to use in establishing intake recommendations. Health professionals seek firm information on which to base dietary intake recommendations. The University of California at Davis conducted a clinical study in which a volunteer consumed specially tagged vitamin E doses, and provided blood, urine, and fecal samples to be analyzed for the tagged dose. The Food Components and Health Laboratory at the Beltsville Human Nutrition Research Center completed the kinetic analysis to demonstrate which pathways of metabolism differ between synthetic and natural alpha-tocopherol. These results will benefit consumers and health professionals as diets are planned. This work falls under National Program 107 Component 2, “Bioavailability of Nutrients and Food Components".
5.Significant Activities that Support Special Target Populations
|Number of non-peer reviewed presentations and proceedings||16|
|Number of newspaper articles and other presentations for non-science audiences||3|
Charron, C.S., Clevidence, B.A., Britz, S.J., Novotny Dura, J. 2007. The effect of dose size on bioavailability of acylated and nonacylated anthocyanins from red cabbage (Brassica oleracea L. var. capitata). Journal of Agricultural and Food Chemistry. 55(13):5354-5362.
Novotny Dura, J., Turnlund, J.R. 2007. Molybdenum intake influences molybdenum kinetics in humans. Journal of Nutrition. 137:37-42.
Clifford, A.J., Demoura, F.F., Ho, C.C., Chuang, J.C., Follett, J., Fadel, J.G., Vogel, J.S., Novotny Dura, J., Cohn, W. 2006. A feasibility study to quantify in vivo human alpha-tocopherol metabolism. American Journal of Clinical Nutrition. 84(6):1430-1441.