Balz Frei
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Balz Frei has a total of 74 co-authors. Here are the top co-authors by number of shared publications:
Hao Wei
7 shared publications- Wei-Jian Zhang
Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA
7 shared publications - Connie M. Weaver
School of Exercise and Nutritional Sciences, San Diego State University, San Diego, CA, United States
5 shared publications - Jeffrey B. Blumberg
Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA 02111, USA
5 shared publications - Steven H. Zeisel
University of North Carolina at Chapel Hill Chapel Hill North Carolina USA
5 shared publications Wei-Jian Zhang
Linus Pauling Institute and Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
5 shared publications
Latest Publications
- Open Access
Multivitamin/Multimineral Supplementation Prevents or Reverses Decline in Vitamin Biomarkers and Cellular Energy Metabolism in Healthy Older Men: A Randomized, Double-Blind, Placebo-Controlled Study
Despite the reported prevalence of micronutrient deficiencies in older adults, it is not yet established whether multivitamin/multimineral (MV/MM) supplements improve blood micronutrient status in individuals over the age of 65. Therefore, a cohort of 35 healthy men (>67 years) was recruited for an MV/MM supplementation trial. The primary endpoint was, as an indicator of micronutrient status, changes in blood micronutrient biomarkers from baseline to at least six months of supplementation with MV/MM or placebo. The secondary endpoint was basal O2 consumption in monocytes as an indicator of cellular metabolism. MV/MM supplementation improved blood concentrations of pyridoxal phosphate, calcifediol, α-tocopherol, and β-carotene concentrations throughout the cohort. By contrast, those in the placebo group generally showed declines in blood vitamin concentrations and an increased prevalence of suboptimal vitamin status during the study period. On the other hand, MV/MM supplementation did not significantly affect blood mineral concentrations, i.e., calcium, copper, iron, magnesium, and zinc. Interestingly, MV/MM supplementation prevented the decline in monocyte O2 consumption rate. Overall, MV/MM use improves or prevents declines in vitamin, but not mineral, status and limits declines in cellular O2 consumption, which may have important implications for metabolism and immune health in healthy older men.
Open AccessMultivitamin/Multimineral Supplementation Prevents or Reverses Decline in Vitamin Biomarkers and Cellular Energy Metabolism in Healthy Older Men: A Randomized, Double-Blind, Placebo-Controlled Study
Despite the reported prevalence of micronutrient deficiencies in older adults, it is not yet established whether multivitamin/multimineral (MV/MM) supplements improve blood micronutrient status in individuals over the age of 65. Therefore, a cohort of 35 healthy men (>67 years) was recruited for an MV/MM supplementation trial. The primary endpoint was, as an indicator of micronutrient status, changes in blood micronutrient biomarkers from baseline to at least six months of supplementation with MV/MM or placebo. The secondary endpoint was basal O2 consumption in monocytes as an indicator of cellular metabolism. MV/MM supplementation improved blood concentrations of pyridoxal phosphate, calcifediol, α-tocopherol, and β-carotene concentrations throughout the cohort. By contrast, those in the placebo group generally showed declines in blood vitamin concentrations and an increased prevalence of suboptimal vitamin status during the study period. On the other hand, MV/MM supplementation did not significantly affect blood mineral concentrations, i.e., calcium, copper, iron, magnesium, and zinc. Interestingly, MV/MM supplementation prevented the decline in monocyte O2 consumption rate. Overall, MV/MM use improves or prevents declines in vitamin, but not mineral, status and limits declines in cellular O2 consumption, which may have important implications for metabolism and immune health in healthy older men.
- Open Access
Mitochondrial Dysfunction and the Glycolytic Switch Induced by Caveolin-1 Phosphorylation Promote Cancer Cell Migration, Invasion, and Metastasis
Cancer cells often display impaired mitochondrial function, reduced oxidative phosphorylation, and augmented aerobic glycolysis (Warburg effect) to fulfill their bioenergetic and biosynthetic needs. Caveolin-1 (CAV1) is a scaffolding protein that promotes cancer cell migration, invasion, and metastasis in a manner dependent on CAV1 phosphorylation on tyrosine-14 (pY14). Here, we show that CAV1 expression increased glycolysis rates, while mitochondrial respiration was reduced by inhibition of the mitochondrial complex IV. These effects correlated with increased reactive oxygen species (ROS) levels that favored CAV1-induced migration and invasion. Interestingly, pY14-CAV1 promoted the metabolic switch associated with increased migration/invasion and augmented ROS-inhibited PTP1B, a phosphatase that controls pY14 levels. Finally, the glycolysis inhibitor 2-deoxy-D-glucose reduced CAV1-enhanced migration in vitro and metastasis in vivo of murine melanoma cells. In conclusion, CAV1 promotes the Warburg effect and ROS production, which inhibits PTP1B to augment CAV1 phosphorylation on tyrosine-14, thereby increasing the metastatic potential of cancer cells.
Open AccessMitochondrial Dysfunction and the Glycolytic Switch Induced by Caveolin-1 Phosphorylation Promote Cancer Cell Migration, Invasion, and Metastasis
Cancer cells often display impaired mitochondrial function, reduced oxidative phosphorylation, and augmented aerobic glycolysis (Warburg effect) to fulfill their bioenergetic and biosynthetic needs. Caveolin-1 (CAV1) is a scaffolding protein that promotes cancer cell migration, invasion, and metastasis in a manner dependent on CAV1 phosphorylation on tyrosine-14 (pY14). Here, we show that CAV1 expression increased glycolysis rates, while mitochondrial respiration was reduced by inhibition of the mitochondrial complex IV. These effects correlated with increased reactive oxygen species (ROS) levels that favored CAV1-induced migration and invasion. Interestingly, pY14-CAV1 promoted the metabolic switch associated with increased migration/invasion and augmented ROS-inhibited PTP1B, a phosphatase that controls pY14 levels. Finally, the glycolysis inhibitor 2-deoxy-D-glucose reduced CAV1-enhanced migration in vitro and metastasis in vivo of murine melanoma cells. In conclusion, CAV1 promotes the Warburg effect and ROS production, which inhibits PTP1B to augment CAV1 phosphorylation on tyrosine-14, thereby increasing the metastatic potential of cancer cells.
- Open Access
- 1 July 2019
- Published by Wiley in Journal of Food Quality
- Vol. 2019, 1-17
Effect of Different Commercial Fertilizers, Harvest Date, and Storage Time on Two Organically Grown Blackberry Cultivars: Physicochemical Properties, Antioxidant Properties, and Sugar Profiles
Despite increased consumer interest in organic produce, little is known about how different organic production methods affect both the traditional measures of quality and the naturally occurring health promoting (bioactive) compounds of food. In this study, “Obsidian” and “Triple Crown” blackberries (bothRubushybrids) were cultivated organically and fertilized with either soy meal, fish emulsion/hydrolysate blend, or processed poultry litter fertilizers at a fixed rate. Fruits were hand-harvested three times during their peak production period and stored at 4°C and 85% RH for up to 12 d. Fertilizer effects on the physicochemical properties were minor, while harvest period had a stronger effect, though that trend varied by year. Antioxidant and sugar profile data revealed an interesting pattern: “Obsidian” had ORAC and lower sugar than “Triple Crown” at harvest and also had greater differentiation due to fertilizer treatments. Fertilizer effects differed based on harvest date and cultivar, with late harvest fruit fertilized with fish emulsion fertilizer showing higher TPC and ORAC than other fertilizer treatments, while the early and middle harvest fruit showed similar or greater responses to soy meal-based fertilizer. Time of harvest and length of storage also affected the antioxidant properties and sugar profiles in different ways depending on fruit cultivar, again with the “Obsidian” fruit showing greater variability in general. This study demonstrated that the two cultivars of organically grown blackberry fruit have different physicochemical and antioxidant properties, thus potentially different shelf lives in the fresh market.
- 1 July 2019
- Published by Wiley in Journal of Food Quality
- Vol. 2019, 1-17
Open AccessEffect of Different Commercial Fertilizers, Harvest Date, and Storage Time on Two Organically Grown Blackberry Cultivars: Physicochemical Properties, Antioxidant Properties, and Sugar Profiles
Despite increased consumer interest in organic produce, little is known about how different organic production methods affect both the traditional measures of quality and the naturally occurring health promoting (bioactive) compounds of food. In this study, “Obsidian” and “Triple Crown” blackberries (bothRubushybrids) were cultivated organically and fertilized with either soy meal, fish emulsion/hydrolysate blend, or processed poultry litter fertilizers at a fixed rate. Fruits were hand-harvested three times during their peak production period and stored at 4°C and 85% RH for up to 12 d. Fertilizer effects on the physicochemical properties were minor, while harvest period had a stronger effect, though that trend varied by year. Antioxidant and sugar profile data revealed an interesting pattern: “Obsidian” had ORAC and lower sugar than “Triple Crown” at harvest and also had greater differentiation due to fertilizer treatments. Fertilizer effects differed based on harvest date and cultivar, with late harvest fruit fertilized with fish emulsion fertilizer showing higher TPC and ORAC than other fertilizer treatments, while the early and middle harvest fruit showed similar or greater responses to soy meal-based fertilizer. Time of harvest and length of storage also affected the antioxidant properties and sugar profiles in different ways depending on fruit cultivar, again with the “Obsidian” fruit showing greater variability in general. This study demonstrated that the two cultivars of organically grown blackberry fruit have different physicochemical and antioxidant properties, thus potentially different shelf lives in the fresh market.
- Open Access
Contribution of Dietary Supplements to Nutritional Adequacy by Socioeconomic Subgroups in Adults of the United States
Many Americans have inadequate intakes of several nutrients, and the Dietary Guidelines for Americans 2015–2020 identified vitamins A, C, D, and E, in addition to calcium, magnesium, iron, potassium, choline, and fiber as “underconsumed nutrients”. Based on nationally representative data on 10,698 adults from National Health and Nutrition Examination Surveys (NHANES), 2009–2012, assessments were made of socioeconomic differences, based on the Poverty Income Ratio (PIR), in terms of the association of dietary supplement use on nutrient intake and nutrient inadequacies. Compared to food alone, the use of any dietary supplement plus food was associated with significantly (p < 0.01) higher intakes of 15–16 of 19 nutrients examined in all socioeconomic groups; and significantly reduced rates of inadequacy for 10/17 nutrients in the subgroup PIR > 1.85 (not poor), but only 4–5/17 nutrients (calcium and vitamins A, C, D, E) for the poor and nearly poor subgroups (PIR < 1.35 and PIR 1.35 to ≤1.85, respectively). An increased prevalence of intakes above the Tolerable Upper Intake Level (UL) was seen for 3–9/13 nutrients, but all were less than 5% in the PIR subgroups. In conclusion, dietary supplement use was associated with an increased micronutrient intake, decreased inadequacies, and a slight increase in the prevalence of intakes above the UL, with greater benefits seen in the PIR > 1.85 subgroup.
Open AccessContribution of Dietary Supplements to Nutritional Adequacy by Socioeconomic Subgroups in Adults of the United States
Many Americans have inadequate intakes of several nutrients, and the Dietary Guidelines for Americans 2015–2020 identified vitamins A, C, D, and E, in addition to calcium, magnesium, iron, potassium, choline, and fiber as “underconsumed nutrients”. Based on nationally representative data on 10,698 adults from National Health and Nutrition Examination Surveys (NHANES), 2009–2012, assessments were made of socioeconomic differences, based on the Poverty Income Ratio (PIR), in terms of the association of dietary supplement use on nutrient intake and nutrient inadequacies. Compared to food alone, the use of any dietary supplement plus food was associated with significantly (p < 0.01) higher intakes of 15–16 of 19 nutrients examined in all socioeconomic groups; and significantly reduced rates of inadequacy for 10/17 nutrients in the subgroup PIR > 1.85 (not poor), but only 4–5/17 nutrients (calcium and vitamins A, C, D, E) for the poor and nearly poor subgroups (PIR < 1.35 and PIR 1.35 to ≤1.85, respectively). An increased prevalence of intakes above the Tolerable Upper Intake Level (UL) was seen for 3–9/13 nutrients, but all were less than 5% in the PIR subgroups. In conclusion, dietary supplement use was associated with an increased micronutrient intake, decreased inadequacies, and a slight increase in the prevalence of intakes above the UL, with greater benefits seen in the PIR > 1.85 subgroup.
- Open Access
Contribution of Dietary Supplements to Nutritional Adequacy in Various Adult Age Groups
Many Americans have inadequate intakes of several nutrients. The Dietary Guidelines for Americans 2015–2020 specifically identified vitamins A, C, D and E, calcium, magnesium, iron, potassium, choline and fiber as “underconsumed nutrients”. Based on nationally representative data in 10,698 adults from National Health and Nutrition Examination Surveys (NHANES), 2009–2012, assessments were made of age-group differences in the impact of dietary supplements on nutrient intake and inadequacies. Compared to food alone, use of any dietary supplement plus food was associated with significantly (p < 0.01) higher intakes of 15–16 of 19 nutrients examined in all age groups; and significantly reduced rates of inadequacy for 10/17, 8/17 and 6/17 nutrients examined among individuals age ≥71, 51–70 and 19–50 years, respectively. Compared to the other age groups, older adults (≥71 years) had lower rates of inadequacy for iron and vitamins A, C, D and E, but higher rates for calcium. An increased prevalence of intakes above the Tolerable Upper Intake Level was seen for 8–9 of 13 nutrients, but were mostly less than 5% of the population. In conclusion, dietary supplement use is associated with increased micronutrient intake, decreased inadequacies, and slight increases in prevalence above the UL, with greater benefits seen among older adults.
Open AccessContribution of Dietary Supplements to Nutritional Adequacy in Various Adult Age Groups
Many Americans have inadequate intakes of several nutrients. The Dietary Guidelines for Americans 2015–2020 specifically identified vitamins A, C, D and E, calcium, magnesium, iron, potassium, choline and fiber as “underconsumed nutrients”. Based on nationally representative data in 10,698 adults from National Health and Nutrition Examination Surveys (NHANES), 2009–2012, assessments were made of age-group differences in the impact of dietary supplements on nutrient intake and inadequacies. Compared to food alone, use of any dietary supplement plus food was associated with significantly (p < 0.01) higher intakes of 15–16 of 19 nutrients examined in all age groups; and significantly reduced rates of inadequacy for 10/17, 8/17 and 6/17 nutrients examined among individuals age ≥71, 51–70 and 19–50 years, respectively. Compared to the other age groups, older adults (≥71 years) had lower rates of inadequacy for iron and vitamins A, C, D and E, but higher rates for calcium. An increased prevalence of intakes above the Tolerable Upper Intake Level was seen for 8–9 of 13 nutrients, but were mostly less than 5% of the population. In conclusion, dietary supplement use is associated with increased micronutrient intake, decreased inadequacies, and slight increases in prevalence above the UL, with greater benefits seen among older adults.
- Open Access
Contribution of Dietary Supplements to Nutritional Adequacy in Race/Ethnic Population Subgroups in the United States
The U.S. Centers for Disease Control and Prevention has reported that nutritional deficiencies in the U.S. population vary by age, gender, and race/ethnicity, and could be as high as nearly one third of certain population groups. Based on nationally representative data in 10,698 adults from National Health and Nutrition Examination Surveys (NHANES) primarily from 2009–2012, assessments were made of race/ethnic differences in the impact of dietary supplements on nutrient intake and prevalence of inadequacies. Compared to food alone, use of any dietary supplement plus food was associated with significantly higher intakes of 14 to 16 of 19 nutrients examined in all race/ethnic groups; and significantly (p < 0.01) reduced rates of inadequacy for 8/17 nutrients examined in non-Hispanic whites, but only 3–4/17 nutrients (calcium, and vitamins A, D, and E) for other race/ethnic groups. Across race/ethnic groups an increased prevalence of intakes above the Tolerable Upper Intake Level (UL) was seen for 1–9/13 nutrients, but all were less than 5% of the population. In conclusion, use of dietary supplements is associated with increased micronutrient intake, decreased nutrient inadequacies, and slight increases in prevalence above the UL in all race/ethnicities examined, with greater benefits among non-Hispanic whites.
Open AccessContribution of Dietary Supplements to Nutritional Adequacy in Race/Ethnic Population Subgroups in the United States
The U.S. Centers for Disease Control and Prevention has reported that nutritional deficiencies in the U.S. population vary by age, gender, and race/ethnicity, and could be as high as nearly one third of certain population groups. Based on nationally representative data in 10,698 adults from National Health and Nutrition Examination Surveys (NHANES) primarily from 2009–2012, assessments were made of race/ethnic differences in the impact of dietary supplements on nutrient intake and prevalence of inadequacies. Compared to food alone, use of any dietary supplement plus food was associated with significantly higher intakes of 14 to 16 of 19 nutrients examined in all race/ethnic groups; and significantly (p < 0.01) reduced rates of inadequacy for 8/17 nutrients examined in non-Hispanic whites, but only 3–4/17 nutrients (calcium, and vitamins A, D, and E) for other race/ethnic groups. Across race/ethnic groups an increased prevalence of intakes above the Tolerable Upper Intake Level (UL) was seen for 1–9/13 nutrients, but all were less than 5% of the population. In conclusion, use of dietary supplements is associated with increased micronutrient intake, decreased nutrient inadequacies, and slight increases in prevalence above the UL in all race/ethnicities examined, with greater benefits among non-Hispanic whites.
- Open Access
Impact of Frequency of Multi-Vitamin/Multi-Mineral Supplement Intake on Nutritional Adequacy and Nutrient Deficiencies in U.S. Adults
Although >50% of U.S. adults use dietary supplements, little information is available on the impact of supplement use frequency on nutrient intakes and deficiencies. Based on nationally representative data in 10,698 adults from the National Health and Nutrition Examination Surveys (NHANES) 2009 to 2012, assessments were made of intakes from food alone versus food plus multi-vitamin/multi-mineral supplements (MVMS) of 17 nutrients with an Estimated Average Requirement (EAR) and a Tolerable Upper Intake Level (UL), and of the status of five nutrients with recognized biomarkers of deficiency. Compared to food alone, MVMS use at any frequency was associated with a lower prevalence of inadequacy (p < 0.01) for 15/17 nutrients examined and an increased prevalence of intakes >UL for 7 nutrients, but the latter was ≤4% for any nutrient. Except for calcium, magnesium, and vitamin D, most frequent MVMS use (≥21 days/30 days) virtually eliminated inadequacies of the nutrients examined, and was associated with significantly lower odds ratios of deficiency for the examined nutrient biomarkers except for iron. In conclusion, among U.S. adults, MVMS use is associated with decreased micronutrient inadequacies, intakes slightly exceeding the UL for a few nutrients, and a lower risk of nutrient deficiencies.
Open AccessImpact of Frequency of Multi-Vitamin/Multi-Mineral Supplement Intake on Nutritional Adequacy and Nutrient Deficiencies in U.S. Adults
Although >50% of U.S. adults use dietary supplements, little information is available on the impact of supplement use frequency on nutrient intakes and deficiencies. Based on nationally representative data in 10,698 adults from the National Health and Nutrition Examination Surveys (NHANES) 2009 to 2012, assessments were made of intakes from food alone versus food plus multi-vitamin/multi-mineral supplements (MVMS) of 17 nutrients with an Estimated Average Requirement (EAR) and a Tolerable Upper Intake Level (UL), and of the status of five nutrients with recognized biomarkers of deficiency. Compared to food alone, MVMS use at any frequency was associated with a lower prevalence of inadequacy (p < 0.01) for 15/17 nutrients examined and an increased prevalence of intakes >UL for 7 nutrients, but the latter was ≤4% for any nutrient. Except for calcium, magnesium, and vitamin D, most frequent MVMS use (≥21 days/30 days) virtually eliminated inadequacies of the nutrients examined, and was associated with significantly lower odds ratios of deficiency for the examined nutrient biomarkers except for iron. In conclusion, among U.S. adults, MVMS use is associated with decreased micronutrient inadequacies, intakes slightly exceeding the UL for a few nutrients, and a lower risk of nutrient deficiencies.
- Open Access
- 1 October 2016
- Published by Elsevier in Redox Biology
- Vol. 9, 220-228
Quercetin affects glutathione levels and redox ratio in human aortic endothelial cells not through oxidation but formation and cellular export of quercetin-glutathione conjugates and upregulation of glutamate-cysteine ligase
- 1 October 2016
- Published by Elsevier in Redox Biology
- Vol. 9, 220-228
Open AccessQuercetin affects glutathione levels and redox ratio in human aortic endothelial cells not through oxidation but formation and cellular export of quercetin-glutathione conjugates and upregulation of glutamate-cysteine ligase
- Open Access
- 1 October 2016
- Published by Elsevier in Redox Biology
- Vol. 9, 104-113
Quercetin inhibits LPS-induced adhesion molecule expression and oxidant production in human aortic endothelial cells by p38-mediated Nrf2 activation and antioxidant enzyme induction
- 1 October 2016
- Published by Elsevier in Redox Biology
- Vol. 9, 104-113
Open AccessQuercetin inhibits LPS-induced adhesion molecule expression and oxidant production in human aortic endothelial cells by p38-mediated Nrf2 activation and antioxidant enzyme induction
- 1 September 2016
- Vol. 65, S1-S8
Vitamin and Mineral Intake Is Inadequate for Most Americans: What Should We Advise Patients About Supplements?
This supplement examines the role of vitamin and mineral supplements in increasing nutrient intake and reducing nutrient deficiencies and inadequacies. Although research is needed to study the effects of dietary supplements on chronic disease outcomes, US health care providers need to know how to advise their patients about adding vitamins and minerals to their diets.
- 1 September 2016
- Vol. 65, S1-S8
Vitamin and Mineral Intake Is Inadequate for Most Americans: What Should We Advise Patients About Supplements?
This supplement examines the role of vitamin and mineral supplements in increasing nutrient intake and reducing nutrient deficiencies and inadequacies. Although research is needed to study the effects of dietary supplements on chronic disease outcomes, US health care providers need to know how to advise their patients about adding vitamins and minerals to their diets.