Davis, CA, United States
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Turner T.,University of California at Davis | Turner T.,Western Human Nutrition Research Center | Burri B.J.,University of California at Davis | Burri B.J.,Western Human Nutrition Research Center
Chromatographia | Year: 2012

Vitamin A deficiency continues to be a major public health concern in the developing world effecting over 200 million people. Interventions including carotenoid- rich fruits and vegetables, containing α- and β-carotene, and β-cryptoxanthin, are being tested for their potential to alleviate vitamin A deficiency in several countries. Thus, there is a need for a faster isocratic reverse-phase high pressure liquid chromatography (HPLC) method than the methods currently available. Efficient extraction procedures for biological samples are also valuable to save time, materials, and cost. We developed an HPLC method and compared several extraction methods for carotenoids, retinoids, and vitamin E in plasma and human breast milk. The method uses an Agilent 1100 system equipped with a Waters Spherisorb ODS2 column (3 × 125 mm 3 μm) and similar guard column (ThermoScientific ODS2 3 × 20 mm 3 μm). Mobile phase of 7:2:1 acetonitrile:dichloromethane: methanol was run at 0.5 mL min -1, and run times were complete in approximately 8 min. This rapid method uses little solvent and provides excellent results in the analysis of these fat-soluble nutrients. Analyte measurements were repeatable using standards and plasma and were accurate compared to NIST certified and reference serum values. The validated HPLC method was applied to the analysis of plasma samples from a vitamin A intervention study. © 2012 Springer-Verlag.


Burri B.J.,Western Human Nutrition Research Center | Burri B.J.,University of California at Davis | Nguyen T.,Western Human Nutrition Research Center | Neidlinger T.R.,Western Human Nutrition Research Center
Nutrition | Year: 2010

Objective: Studies show low correlations between dietary intake and serum concentrations of lycopene, which make it difficult to assess the effectiveness of dietary interventions with this phytonutrient. We hypothesized that 1) combining food-frequency questionnaires (FFQs) and 3-d diet records (3D-DRs) by the triads method would improve the validity of this relation and 2) correcting dietary information for differences in lycopene absorption from food matrices would further improve validity. Methods: We measured dietary intakes of lycopene from 49 adults by 3D-DR and FFQ. Serum lycopene was measured by high-performance liquid chromatography with diode array detection. Cholesterol and triacylglycerol concentrations were measured spectrophotometrically. Lycopene-containing foods were given absorption factors based on literature and laboratory values. Associations between dietary and serum lycopene were modeled using multiple regression. The triads method was used for validation of relations among FFQ, 3D-DR, and serum lycopene. Results: Raw data showed low correlations between dietary and serum lycopene (r = +0.15 for 3D-DR, +0.35 for FFQ). Mathematical modeling showed that the 3D-DR and FFQ methods must be used to collect accurate dietary information for lycopene. Validity coefficients calculated by the triads method were +0.34 for 3D-DR and +0.78 for FFQ. Correcting for absorption increased the validity coefficient to +0.72 for 3D-DR and from +0.45 to +0.66 for serum lycopene. Conclusion: The relation between dietary intake and serum concentrations of lycopene and other carotenoids can be improved by collecting 3D-DR and FFQ data and by adjusting dietary information for nutrient absorption.


La Frano M.R.,University of California at Davis | La Frano M.R.,Western Human Nutrition Research Center | de Moura F.F.,International Food Policy Research Institute | Boy E.,International Food Policy Research Institute | And 3 more authors.
Nutrition Reviews | Year: 2014

International research efforts, including those funded by HarvestPlus, a Challenge Program of the Consultative Group on International Agricultural Research (CGIAR), are focusing on conventional plant breeding to biofortify staple crops such as maize, rice, cassava, beans, wheat, sweet potatoes, and pearl millet to increase the concentrations of micronutrients that are commonly deficient in specific population groups of developing countries. The bioavailability of micronutrients in unfortified staple crops in developing regions is typically low, which raises questions about the efficacy of these crops to improve population micronutrient status. This review of recent studies of biofortified crops aims to assess the micronutrient bioavailability of biofortified staple crops in order to derive lessons that may help direct plant breeding and to infer the potential efficacy of food-based nutrition interventions. Although reducing the amounts of antinutrients and the conduction of food processing generally increases the bioavailability of micronutrients, antinutrients still possess important benefits, and food processing results in micronutrient loss. In general, biofortified foods with relatively higher micronutrient density have higher total absorption rates than nonbiofortified varieties. Thus, evidence supports the focus on efforts to breed plants with increased micronutrient concentrations in order to decrease the influence of inhibitors and to offset losses from processing. © 2014 International Life Sciences Institute.


Shedd-Wise K.M.,University of California at Davis | Alekel D.L.,Iowa State University | Hofmann H.,Iowa State University | Hanson K.B.,Iowa State University | And 3 more authors.
Journal of Clinical Densitometry | Year: 2011

Soy isoflavones exert inconsistent bone density-preserving effects, but the bone strength-preserving effects in humans are unknown. Our double-blind randomized controlled trial examined 2 soy isoflavone doses (80 or 120. mg/d) vs placebo tablets on volumetric bone mineral density (vBMD) and strength (by means of peripheral quantitative computed tomography) in healthy postmenopausal women (46-63. yr). We measured 3-yr changes in cortical BMD (CtBMD), cortical thickness (CtThk), periosteal circumference (PC), endosteal circumference (EC), and strength-strain index (SSI) at 1/3 midshaft femur (N = 171), and trabecular BMD (TbBMD), PC, and SSI at 4% distal tibia (N = 162). We found no treatment effect on femur CtThk, PC, or EC, or tibia TbBMD or PC. The strongest predictors (negative) of tibia TbBMD and SSI and femur CtBMD were timepoint and bone resorption; whole-body fat mass was protective of SSI. As time since last menstrual period (TLMP) increased (p= 0.012), 120-mg/d dose was protective of CtBMD. The strongest predictors of femur SSI were timepoint, bone resorption, and TLMP (protective). Isoflavone tablets were negative predictors of SSI, but 80-mg/d dose became protective as bone turnover increased (p= 0.011). Soy isoflavone treatment for 3. yr was modestly beneficial for midshaft femur vBMD as TLMP increased and for midshaft femur SSI as bone turnover increased. © 2011 The International Society for Clinical Densitometry.


Roman M.J.,University of California at Davis | Burri B.J.,Western Human Nutrition Research Center | Singh R.P.,University of California at Davis
Journal of Agricultural and Food Chemistry | Year: 2012

The objective of this study was to determine the release and bioaccessibility of β-carotene from fortified almond butter using in vitro digestion models. Two types of fortifiers were investigated: β-carotene oil (oil) and whey protein isolate (WPI)-alginate-chitosan capsules containing β-carotene oil (capsule). Shaking water bath and Human Gastric Simulator (HGS) digestion models assessed the impact of gastric peristalsis on the release of β-carotene. Bioaccessibility of β-carotene was measured as percent recovered from the micelle fraction. There was greater release of β-carotene from oil fortified almond butter in the HGS model (87.1%) due to peristalsis than the shaking water bath model (51.0%). More β-carotene was released from capsule fortified almond butter during intestinal digestion. However, more β-carotene was recovered from the micelle fraction of oil fortified almond butter. These results suggest that a WPI-alginate-chitosan capsule coating may inhibit the bioaccessibility of β-carotene from fortified almond butter. © 2012 American Chemical Society.


Rezvani R.,Laval University | Cianflone K.,Laval University | McGahan J.P.,University of California at Davis | Berglund L.,University of California at Davis | And 3 more authors.
Obesity | Year: 2013

Objective The effects of fructose and glucose consumption on plasma acylation stimulating protein (ASP), adiponectin, and leptin concentrations relative to energy intake, body weight, adiposity, circulating triglycerides, and insulin sensitivity were determined. Design and Methods Thirty two overweight/obese adults consumed glucose-or fructose-sweetened beverages (25% energy requirement) with their ad libitum diets for 8 weeks, followed by sweetened beverage consumption for 2 weeks with a standardized, energy-balanced diet. Plasma variables were measured at baseline, 2, 8, and 10 weeks, and body adiposity and insulin sensitivity at baseline and 10 weeks. Results Fasting and postprandial ASP concentrations increased at 2 and/or 8 weeks. ASP increases correlated with changes in late-evening triglyceride concentrations. At 10 weeks, fasting adiponectin levels decreased in both groups, and decreases were inversely associated with baseline intra-abdominal fat volume. Sugar consumption increased fasting leptin concentrations; increases were associated with body weight changes. The 24-h leptin profiles increased during glucose consumption and decreased during fructose consumption. These changes correlated with changes of 24-h insulin levels. Conclusions The consumption of fructose and glucose beverages induced changes in plasma concentrations of ASP, adiponectin, and leptin. Further study is required to determine if these changes contribute to the metabolic dysfunction observed during fructose consumption. Copyright © 2013 The Obesity Society.


Stanhope K.L.,University of California at Davis | Bremer A.A.,University of California at Davis | Bremer A.A.,Vanderbilt University | Medici V.,University of California at Davis | And 11 more authors.
Journal of Clinical Endocrinology and Metabolism | Year: 2011

Context: The American Heart Association Nutrition Committee recommends women and men consume no more than 100 and 150 kcal of added sugar per day, respectively, whereas the Dietary Guidelines for Americans, 2010, suggests a maximal added sugar intake of 25% or less of total energy. Objective: To address this discrepancy, we compared the effects of consuming glucose, fructose, or high-fructose corn syrup (HFCS) at 25% of energy requirements (E) on risk factors for cardiovascular disease. Participants, Design and Setting, and Intervention: Forty-eight adults (aged 18-40 yr; body mass index 18-35 kg/m 2) resided at the Clinical Research Center for 3.5 d of baseline testing while consuming energy-balanced diets containing55%E complex carbohydrate. For 12 outpatient days, they consumed usual ad libitum diets along with three servings per day of glucose, fructose, or HFCS-sweetened beverages (n = 16/group), which provided 25% E requirements. Subjects then consumed energy-balanced diets containing 25% E sugar-sweetened beverages/30% E complex carbohydrate during 3.5 d of inpatient intervention testing. Main Outcome Measures: Twenty-four-hour triglyceride area under the curve, fasting plasma low-density lipoprotein (LDL), and apolipoprotein B (apoB) concentrations were measured. Results: Twenty-four-hour triglyceride area under the curve was increased compared with baseline during consumption of fructose (+4.7 ± 1.2 mmol/liter x 24 h, P = 0.0032) and HFCS (+1.8 ± 1.4 mmol/liter x 24 h, P = 0.035) but not glucose (-1.9 ± 0.9 mmol/liter x 24 h, P = 0.14). Fasting LDL and apoB concentrations were increased during consumption of fructose (LDL: +0.29 ± 0.082 mmol/liter, P = 0.0023; apoB: +0.093 ± 0.022 g/liter, P = 0.0005) and HFCS (LDL: +0.42 ± 0.11 mmol/liter, P < 0.0001; apoB: +0.12 ± 0.031 g/liter, P < 0.0001) but not glucose (LDL: +0.012 ± 0.071 mmol/liter, P = 0.86; apoB: +0.0097 ± 0.019 g/liter, P = 0.90). Conclusions: Consumption of HFCS-sweetened beverages for 2 wk at 25% E increased risk factors for cardiovascular disease comparably with fructose and more than glucose in young adults. Copyright © 2011 by The Endocrine Society.


Cox C.L.,University of California at Davis | Stanhope K.L.,University of California at Davis | Schwarz J.M.,Touro College | Schwarz J.M.,University of California at San Francisco | And 6 more authors.
Journal of Clinical Endocrinology and Metabolism | Year: 2011

Context: Results from animal studies suggest that consumption of large amounts of fructose can promote inflammation and impair fibrinolysis. Data describing the effects of fructose consumption on circulating levels of proinflammatory and prothrombotic markers in humans are unavailable. Objective: Our objective was to determine the effects of 10 wk of dietary fructose or glucose consumption on plasma concentrations of monocyte chemoattractant protein-1 (MCP-1), plasminogen activator inhibitor-1 (PAI-1), E-selectin, intercellular adhesion molecule-1, C-reactive protein, and IL-6. Design and Setting: This was a parallel-arm study with two inpatient phases (2 wk baseline, final 2 wk intervention), conducted in a clinical research facility, and an outpatient phase (8 wk) during which subjects resided at home. Participants: Participants were older (40-72 yr), overweight/obese (body mass index = 25-35 kg/m 2) men (n = 16) and women (n = 15). Interventions: Participants consumed glucose- or fructose-sweetened beverages providing 25% of energy requirements for 10 wk. Blood samples were collected at baseline and during the 10th week of intervention. Main Outcome Measures: Fasting concentrations of MCP-1 (P = 0.009), PAI-1 (P = 0.002), and E-selectin (P = 0.048) as well as postprandial concentrations of PAI-1 (P < 0.0001) increased in subjects consuming fructose but not in those consuming glucose. Fasting levels of C-reactive protein, IL-6, and intercellular adhesion molecule-1 were not changed in either group. Conclusions: Consumption of fructose for 10 wk leads to increases of MCP-1, PAI-1, and E-selectin. These findings suggest the possibility that fructose may contribute to the development of the metabolic syndrome via effects on proinflammatory and prothrombotic mediators. Copyright © 2011 by The Endocrine Society.


Cox C.L.,University of California at Davis | Stanhope K.L.,University of California at Davis | Schwarz J.M.,Touro College | Graham J.L.,University of California at Davis | And 5 more authors.
Nutrition and Metabolism | Year: 2012

Background: Prospective studies in humans examining the effects of fructose consumption on biological markers associated with the development of metabolic syndrome are lacking. Therefore we investigated the relative effects of 10 wks of fructose or glucose consumption on plasma uric acid and RBP-4 concentrations, as well as liver enzyme (AST, ALT, and GGT) activities in men and women. Methods. As part of a parallel arm study, older (age 40-72), overweight and obese male and female subjects (BMI 25-35kg/m2) consumed glucose- or fructose-sweetened beverages providing 25% of energy requirements for 10 wks. Fasting and 24-h blood collections were performed at baseline and following 10 wks of intervention and plasma concentrations of uric acid, RBP-4 and liver enzyme activities were measured. Results: Consumption of fructose, but not glucose, led to significant increases of 24-h uric acid profiles (P<0.0001) and RBP-4 concentrations (P=0.012), as well as plasma GGT activity (P=0.04). Fasting plasma uric acid concentrations increased in both groups; however, the response was significantly greater in subjects consuming fructose (P=0.002 for effect of sugar). Within the fructose group male subjects exhibited larger increases of RBP-4 levels than women (P=0.024). Conclusions: These findings suggest that consumption of fructose at 25% of energy requirements for 10 wks, compared with isocaloric consumption of glucose, may contribute to the development of components of the metabolic syndrome by increasing circulating uric acid, GGT activity, suggesting alteration of hepatic function, and the production of RBP-4. © 2012 Cox et al.; licensee BioMed Central Ltd.


Cox C.L.,University of California at Davis | Stanhope K.L.,University of California at Davis | Schwarz J.M.,Touro College | Graham J.L.,University of California at Davis | And 5 more authors.
European Journal of Clinical Nutrition | Year: 2012

Background/Objectives:The results of short-term studies in humans suggest that, compared with glucose, acute consumption of fructose leads to increased postprandial energy expenditure and carbohydrate oxidation and decreased postprandial fat oxidation. The objective of this study was to determine the potential effects of increased fructose consumption compared with isocaloric glucose consumption on substrate utilization and energy expenditure following sustained consumption and under energy-balanced conditions.Subjects/Methods:As part of a parallel arm study, overweight/obese male and female subjects, 40-72 years, consumed glucose-or fructose-sweetened beverages providing 25% of energy requirements for 10 weeks. Energy expenditure and substrate utilization were assessed using indirect calorimetry at baseline and during the 10th week of intervention.Results:Consumption of fructose, but not glucose, led to significant decreases of net postprandial fat oxidation and significant increases of net postprandial carbohydrate oxidation (P<0.0001 for both). Resting energy expenditure (REE) decreased significantly from baseline values in subjects consuming fructose (P=0.031) but not in those consuming glucose.Conclusions:Increased consumption of fructose for 10 weeks leads to marked changes of postprandial substrate utilization including a significant reduction of net fat oxidation. In addition, we report that REE is reduced compared with baseline values in subjects consuming fructose-sweetened beverages for 10 weeks. © 2012 Macmillan Publishers Limited. All rights reserved.

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