Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
Displaying 1 - 3 of 3
Filtering by
- All Subjects: Health Sciences
- Creators: Johnston, Carol S
Description
ABSTRACT Fruit and vegetable intake is not uniform across levels of socioeconomic status (SES) and researchers have identified low SES as a risk factor for poor intake of fruits and vegetables. In an effort to eliminate public health disparities and increase fruit and vegetable intake, the Women, Infant, and Children (WIC) program implemented additional food assistance programs, with a specific emphasis on fresh fruits and vegetables. The Farmers' Market Nutrition Program (FMNP) provides pre-existing WIC clients with coupons to purchase fresh, locally grown produce at farmers' markets. In addition, Congress also approved the WIC Cash Value Voucher (CVV) program, which provides WIC participants with vouchers to purchase fresh fruits and vegetables at farmers' markets or grocery stores. The purpose of this thesis was to investigate the relation of FMNP coupon use with accessibility and WIC CVV redemption rates at farmers' markets. Furthermore, this thesis addressed whether WIC shoppers redeemed a higher percentage of their WIC CVV value at farmers' markets or grocery stores. WIC CVV and FMNP issuance and redemption data were analyzed to establish overall redemption rates and total perecent of WIC CVV value redeemed. Accessibility was assessed using the Geographic Information System, which allowed me to calculate the distance that WIC participants would have to travel to redeem their FMNP coupons at FMNP-approved farmers' markets. The results showed that less than 1% of WIC shoppers redeem their WIC CVVs at farmers'markets in Arizona. However, the redemption of WIC CVV was significantly higher during the months when shoppers had the option of using both WIC CVV and FMNP coupons at farmers' markets. Furthermore, the percent of total CVV value redeemed at farmers' markets was 99%, significantly higher than grocery stores (93.5%). Average FMNP coupon redemption rates for 2008-2010 was 43.3%, well below the national average of 59%. However, my spatial analysis revealed that there was no significant association between the distance traveled to farmers' markets and FMNP redemption rates. This indicates that the distance traveled to farmers' markets is not a major barrier to redemption of FMNP coupons in Arizona.
ContributorsTucker, Wesley Jack (Author) / Wharton, Christopher (Christopher Mack), 1977- (Thesis advisor) / Vaughan, Linda (Committee member) / Johnston, Carol S (Committee member) / Arizona State University (Publisher)
Created2012
Description
Background: Despite the reported improvements in glucose regulation associated with flaxseeds (Linum usitatissimum) few clinical trials have been conducted in diabetic participants. Objective: To evaluate the efficacy of ground flaxseed consumption at attenuating hyperglycemia, dyslipidemia, inflammation, and oxidative stress as compared to a control in adults with non-insulin dependent type 2 diabetes (T2D). Design: In a randomized parallel arm controlled efficacy trial, participants were asked to consume either 28 g/d ground flaxseed or the fiber-matched control (9 g/d ground psyllium husk) for 8 weeks. The study included 17 adults (9 male, 8 females; 46±14 y; BMI: 31.4±5.7 kg/m2) with a diagnosis of T2D ≥ 6 months. Main outcomes measured included: glycemic control (HbA1c, fasting plasma glucose, fasting serum insulin, and HOMA-IR), lipid profile (total cholesterol, LDL-C, HDL-C, total triglycerides, and calculated VLDL-C), markers of inflammation and oxidative stress (TNF-alpha, TBARS, and NOx), and dietary intake (energy, total fat, total fiber, sodium). Absolute net change for measured variables (week 8 values minus baseline values) were compared using Mann-Whitney U non-parametric tests, significance was determined at p ≤ 0.05. Results: There were no significant changes between groups from baseline to week 8 in any outcome measure of nutrient intake, body composition, glucose control, or lipid concentrations. There was a modest decrease in TNF-alpha in the flaxseed group as compared to the control (p = 0.06) as well as a mild decrease in TBARS in the flaxseed as compared to the control group (p = 0.083), though neither were significant. Conclusions: The current study did not detect a measurable association between 28 g/d flaxseed consumption for 8 weeks in T2D participants and improvements in glycemic control or lipid profiles. There was a modest, albeit insignificant, decrease in markers of inflammation and oxidative stress in the flaxseed group as compared to the control, which warrants further study.
ContributorsRicklefs, Kristin (Author) / Sweazea, Karen L (Thesis advisor) / Johnston, Carol S (Committee member) / Gaesser, Glenn (Committee member) / Vega-Lopez, Sonia (Committee member) / Gonzales, Rayna (Committee member) / Arizona State University (Publisher)
Created2015
Description
Background: Postprandial hyperglycemia can increase levels of oxidative stress and is an independent risk factor for complications associated with type 2 diabetes.
Purpose: To evaluate the acute effects of a 15-min postmeal walk on glucose control and markers of oxidative stress following a high-carbohydrate meal.
Methods: Ten obese subjects (55.0 ± 10.0 yrs) with impaired fasting glucose (107.1 ± 9.0 mg/dL) participated in this repeated measures trial. Subjects arrived at the laboratory following an overnight fast and underwent one of three conditions: 1) Test meal with no walking or fiber (CON), 2) Test meal with 10g fiber and no walking (FIB), 3) Test meal with no fiber followed by a 15-min treadmill walk at preferred walking speed (WALK). Blood samples were taken over four hours and assayed for glucose, insulin, thiobarbituric reactive substances (TBARS), catalase, uric acid, and total antioxidant capacity (TAC). A repeated measures ANOVA was used to compare mean differences for all outcome variables.
Results: The 2hr and 4hr incremental area under the curve (iAUC) for glucose was lower in both FIB (2hr: -93.59 mmol∙120 min∙L-1, p = 0.006; 4hr: -92.59 mmol∙240 min∙L-1; p = 0.041) and WALK (2hr: -77.21 mmol∙120 min∙L-1, p = 0.002; 4hr: -102.94 mmol∙240 min∙L-1; p = 0.005) conditions respectively, compared with CON. There were no differences in 2hr or 4hr iAUC for glucose between FIB and WALK (2hr: p = 0.493; 4hr: p = 0.783). The 2hr iAUC for insulin was significantly lower in both FIB (-37.15 μU ∙h/mL; p = 0.021) and WALK (-66.35 μU ∙h/mL; p < 0.001) conditions, compared with CON, and was significantly lower in the WALK (-29.2 μU ∙h/mL; p = 0.049) condition, compared with FIB. The 4hr iAUC for insulin in the WALK condition was significantly lower than both CON (-104.51 μU ∙h/mL; p = 0.001) and FIB (-77.12 μU ∙h/mL; p = 0.006) conditions. Markers of oxidative stress were not significantly different between conditions.
Conclusion: A moderate 15-minute postmeal walk is an effective strategy to reduce postprandial hyperglycemia. However, it is unclear if this attenuation could lead to improvements in postprandial oxidative stress.
Purpose: To evaluate the acute effects of a 15-min postmeal walk on glucose control and markers of oxidative stress following a high-carbohydrate meal.
Methods: Ten obese subjects (55.0 ± 10.0 yrs) with impaired fasting glucose (107.1 ± 9.0 mg/dL) participated in this repeated measures trial. Subjects arrived at the laboratory following an overnight fast and underwent one of three conditions: 1) Test meal with no walking or fiber (CON), 2) Test meal with 10g fiber and no walking (FIB), 3) Test meal with no fiber followed by a 15-min treadmill walk at preferred walking speed (WALK). Blood samples were taken over four hours and assayed for glucose, insulin, thiobarbituric reactive substances (TBARS), catalase, uric acid, and total antioxidant capacity (TAC). A repeated measures ANOVA was used to compare mean differences for all outcome variables.
Results: The 2hr and 4hr incremental area under the curve (iAUC) for glucose was lower in both FIB (2hr: -93.59 mmol∙120 min∙L-1, p = 0.006; 4hr: -92.59 mmol∙240 min∙L-1; p = 0.041) and WALK (2hr: -77.21 mmol∙120 min∙L-1, p = 0.002; 4hr: -102.94 mmol∙240 min∙L-1; p = 0.005) conditions respectively, compared with CON. There were no differences in 2hr or 4hr iAUC for glucose between FIB and WALK (2hr: p = 0.493; 4hr: p = 0.783). The 2hr iAUC for insulin was significantly lower in both FIB (-37.15 μU ∙h/mL; p = 0.021) and WALK (-66.35 μU ∙h/mL; p < 0.001) conditions, compared with CON, and was significantly lower in the WALK (-29.2 μU ∙h/mL; p = 0.049) condition, compared with FIB. The 4hr iAUC for insulin in the WALK condition was significantly lower than both CON (-104.51 μU ∙h/mL; p = 0.001) and FIB (-77.12 μU ∙h/mL; p = 0.006) conditions. Markers of oxidative stress were not significantly different between conditions.
Conclusion: A moderate 15-minute postmeal walk is an effective strategy to reduce postprandial hyperglycemia. However, it is unclear if this attenuation could lead to improvements in postprandial oxidative stress.
ContributorsKnurick, Jessica (Author) / Johnston, Carol S (Thesis advisor) / Sweazea, Karen L (Committee member) / Gaesser, Glenn A (Committee member) / Shaibi, Gabriel Q (Committee member) / Lee, Chong D (Committee member) / Arizona State University (Publisher)
Created2015