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- Genre: Academic theses
- Genre: Masters Thesis
- Creators: Johnston, Carol
- Member of: Theses and Dissertations
Description
In the United States, two-thirds of adults are considered hypertensive orprehypertensive. In addition, chronic illness, such as hypertension, cardiovascular disease, and type II diabetes, results in $3.5 trillion in annual healthcare cost and is the primary cause of disability and death. As a result, many individuals seek cheaper and simpler alternatives to combat their conditions. In this exploratory analysis, a study assessing nitrate intake and its effects on vascular function in 39 young adult males was investigated for underlying metabolic variations through a liquid chromatography – mass spectrometry-based large-scale targeted metabolomics approach. A two-way repeated measures ANOVA was used, and 18 significant metabolites were discovered across the time, treatment, and time & treatment groups, including prostaglandin E2 (p<0.001), stearic acid (p=0.002), caprylic acid (p=0.016), pentadecanoic acid (p=0.027), and heptadecanoic acid (p=0.005). In addition, log-transformed principal component analysis and orthogonal partial least squares – discriminant analysis models demonstrated distinct separation among the treatment, control, and time variables. Moreover, pathway and enrichment analyses validated the effect of nitrate intake on the metabolite sets and its possible function in fatty acid oxidation. This better understanding of altered metabolic pathways may help explicate the benefits of nitrate on vascular function and reveal any unknown mechanisms of its supplementation.
ContributorsPatterson, Jeffrey (Author) / Gu, Haiwei (Thesis advisor) / Johnston, Carol (Committee member) / Sweazea, Karen (Committee member) / Arizona State University (Publisher)
Created2020
Description
ABSTRACT
Background. College students’ modifiable health behaviors, including unhealthful eating patterns, predispose them to risk for future cardiometabolic conditions.
Purpose. This novel 8-week randomized control parallel-arm study compared the effects of a daily 18-hour Time-Restricted Feeding protocol vs. an 8-hour fast on diet quality in college students. Secondary outcomes were resting morning blood pressure, biomarkers of glucose regulation, biomarkers of lipid metabolism, and anthropometric measures.
Methods. Eighteen healthy college students (age = 23 ± 4 years; BMI = 23.2 ± 2.3 kg/m2; MET = 58.8 ± 32.9 min/wk) completed this study. Participants were randomized to a daily 18-hour fasting protocol (Intervention; n = 8) or a daily 8-hour fasting protocol (Control; n = 10) for eight weeks. One ‘cheat’ day was permitted each week. Outcomes were measured at weeks 0 (baseline), 4, and 8. A non-parametric Mann Whitney U test was used to compare the week 4 change from baseline between groups. Statistical significance was set at p≤0.05.
Results. Diet quality (p = 0.030) and body weight (p = 0.016) improved from baseline to week 4 for the INV group in comparison to the CON group. The data suggest these improvements may be related to reductions in snacking frequency and increased breakfast consumption. Fasting blood glucose and hip circumference tended to improve for the INV group in comparison to the CON group (p = 0.091 and p = 0.100). However, saturated fat intake tended to increase in the INV group in comparison to the CON group (p = 0.064). Finally, there were no treatment differences between groups (p>0.05) for the 4-week change in total calories, dietary vitamin C, added sugars, resting systolic blood pressure, resting diastolic blood pressure, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), low-density lipoprotein (LDL) cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, waist circumference, or MET.
Conclusion. These data, although preliminary, suggest that the 18-hour fasting protocol was effective for improving diet quality and reducing weight in comparison to the 8-hour fasting protocol in healthy college students. Future intervention trials will need to confirm these findings and determine the long-term relevance of these improvements for health outcomes.
Background. College students’ modifiable health behaviors, including unhealthful eating patterns, predispose them to risk for future cardiometabolic conditions.
Purpose. This novel 8-week randomized control parallel-arm study compared the effects of a daily 18-hour Time-Restricted Feeding protocol vs. an 8-hour fast on diet quality in college students. Secondary outcomes were resting morning blood pressure, biomarkers of glucose regulation, biomarkers of lipid metabolism, and anthropometric measures.
Methods. Eighteen healthy college students (age = 23 ± 4 years; BMI = 23.2 ± 2.3 kg/m2; MET = 58.8 ± 32.9 min/wk) completed this study. Participants were randomized to a daily 18-hour fasting protocol (Intervention; n = 8) or a daily 8-hour fasting protocol (Control; n = 10) for eight weeks. One ‘cheat’ day was permitted each week. Outcomes were measured at weeks 0 (baseline), 4, and 8. A non-parametric Mann Whitney U test was used to compare the week 4 change from baseline between groups. Statistical significance was set at p≤0.05.
Results. Diet quality (p = 0.030) and body weight (p = 0.016) improved from baseline to week 4 for the INV group in comparison to the CON group. The data suggest these improvements may be related to reductions in snacking frequency and increased breakfast consumption. Fasting blood glucose and hip circumference tended to improve for the INV group in comparison to the CON group (p = 0.091 and p = 0.100). However, saturated fat intake tended to increase in the INV group in comparison to the CON group (p = 0.064). Finally, there were no treatment differences between groups (p>0.05) for the 4-week change in total calories, dietary vitamin C, added sugars, resting systolic blood pressure, resting diastolic blood pressure, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), low-density lipoprotein (LDL) cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, waist circumference, or MET.
Conclusion. These data, although preliminary, suggest that the 18-hour fasting protocol was effective for improving diet quality and reducing weight in comparison to the 8-hour fasting protocol in healthy college students. Future intervention trials will need to confirm these findings and determine the long-term relevance of these improvements for health outcomes.
ContributorsMayra, Selicia (Author) / Johnston, Carol (Thesis advisor) / Sears, Dorothy (Committee member) / Swan, Pamela (Committee member) / Sweazea, Karen (Committee member) / Wharton, Christopher (Christopher Mack), 1977- (Committee member) / Arizona State University (Publisher)
Created2020
Description
The assessment and evaluation of dietary intake and nutrition knowledge in female athletes is especially important due to the high prevalence of inadequate intake in this population (Black et al., 2019). This study evaluated 1) the relationship of nutrition knowledge and dietary intake among collegiate female athletes at the National Collegiate Athletic Association (NCAA) Division I, National Junior College Athletic Association (NJCAA), and Club sport levels and 2) the impact of competition level on this relationship as well. Participants (NCAA DI, n=51; NJCAA, n = 36; Club, n = 37) in this study answered two questionnaires, the Nutrition Sport Knowledge Questionnaire (NSKQ) and the Rapid Eating Assessment for Participants (REAP) questionnaire to assess knowledge and dietary intake. Participants also provided anthropometric and demographic information. The NSKQ was scored as a whole and for each of the four subcategories. REAP was scored both by tallying the number of “usually/often” frequency responses and given a numeral score to estimate diet quality. Statistical analysis was conducted using Kruskal-Wallis, Chi-square and Spearman’s correlation tests to compare differences within subgroups of participants and evaluate any relationships that may exist between nutrition knowledge and dietary intake with significance set at p≤0.05. Differences in nutrition knowledge between competition groups were significant, H(2)= 16.94, p< 0.001. NCAA DI (p<0.001) and Club (p<0.001) athletes had higher nutrition knowledge than athletes at the NJCAA level. This was true for overall knowledge as well as knowledge subcategories. However, minimal relationships between nutrition knowledge and dietary intake were found. The overall correlation value was rs(118)= -0.10 (95%CI: -0.28 to 0.08), p>0.05. This suggests those with higher nutrition knowledge did not necessarily have better dietary intake. Improvements in the assessment of nutrition knowledge and quick assessment of dietary quality and the relation between both is needed.
ContributorsSkinner, Jensen Drew (Author) / Wardenaar, Floris (Thesis advisor) / Johnston, Carol (Committee member) / Yudell, Amber (Committee member) / Arizona State University (Publisher)
Created2020
Description
Introduction: A diet high in fermented, oligio-, di-, monosaccharide, and polyols
(FODMAP) has been shown to exacerbate symptoms of irritable bowel syndrome
(IBS). Previous literature has shown significant improvement in IBS symptoms after
adherence to a low FODMAP diet (LFD). However, dietary adherence to the LFD is
difficult with patients stating that information provided by healthcare providers
(HCPs) is generalized and nonspecific requiring them to search for supplementary
information to fit their needs. Notably, studies that have used a combination of
online and in-person methods for treatment have shown improved adherence to the
LFD. Objective: To determine whether a novel artificial intelligence (AI) dietary
mobile application will improve adherence to the LFD compared to a standard online
dietary intervention (CON) in populations with IBS or IBS-like symptoms over a 4-
week period. Methods: Participants were randomized into two groups: APP or CON.
The intervention group was provided access to an AI mobile application, a dietary
resource verified by registered dietitians which uses artificial intelligence to
individualize dietary guidance in real-time with the ability to scan menus and
barcodes and provide individuals with food scores based on their dietary preferences.
Primary measures included mobile app engagement, dietary adherence, and
manifestation of IBS-like symptoms. Baseline Results: A total of 58 participants
were randomized to groups. This is an ongoing study and this thesis details the
methodology and baseline characteristics of the participants at baseline and
intervention start. Validation of the application could improve the range of offerings
for lifestyle diseases treatable through dietary modification.
(FODMAP) has been shown to exacerbate symptoms of irritable bowel syndrome
(IBS). Previous literature has shown significant improvement in IBS symptoms after
adherence to a low FODMAP diet (LFD). However, dietary adherence to the LFD is
difficult with patients stating that information provided by healthcare providers
(HCPs) is generalized and nonspecific requiring them to search for supplementary
information to fit their needs. Notably, studies that have used a combination of
online and in-person methods for treatment have shown improved adherence to the
LFD. Objective: To determine whether a novel artificial intelligence (AI) dietary
mobile application will improve adherence to the LFD compared to a standard online
dietary intervention (CON) in populations with IBS or IBS-like symptoms over a 4-
week period. Methods: Participants were randomized into two groups: APP or CON.
The intervention group was provided access to an AI mobile application, a dietary
resource verified by registered dietitians which uses artificial intelligence to
individualize dietary guidance in real-time with the ability to scan menus and
barcodes and provide individuals with food scores based on their dietary preferences.
Primary measures included mobile app engagement, dietary adherence, and
manifestation of IBS-like symptoms. Baseline Results: A total of 58 participants
were randomized to groups. This is an ongoing study and this thesis details the
methodology and baseline characteristics of the participants at baseline and
intervention start. Validation of the application could improve the range of offerings
for lifestyle diseases treatable through dietary modification.
ContributorsRafferty, Aaron (Author) / Johnston, Carol (Thesis advisor) / Hall, Richard (Committee member) / Fitton, Renee (Committee member) / Arizona State University (Publisher)
Created2020
Description
The popularity of intermittent fasting has grown in recent years and is a commonly discussed diet topic on the internet and social media. Time-restricted feeding (TRF) is one particular intermittent fasting regime that allows participants to pick windows of time per day in which they can eat or fast. While current randomized controlled trials show positive effects of TRF on weight loss, body composition, glucose, insulin, and blood pressure, there is a gap in the literature of the its effect on cognition although animal studies suggest a positive effect. The purpose of this 8-week randomized controlled trial was to investigate the effect of 18-hour time-restricted feeding on healthy, Arizona State university students. Students (n= 29) were recruited by the research team and were randomized to either an 18-hour intervention (INV) group or an 8-hour control (CON) group. INV participants were instructed to consume food within the first hour of waking and cease their eating period after 6 hours to begin their 18-hour fast. Participants were not given any other dietary restrictions and were allowed to eat ad libitum during their eating periods. Cognitive tests (Stroop Test and Trail Making Test) and blood draws were taken at baseline, week 4, and week 8. The present study demonstrated high attrition, with 7 participants dropping out of the study after their baseline visit. Interruption of the COVID-19 pandemic also impacted the data analysis, with the removal of week 8 data. Despite limitations, statistically significant differences between the INV group and CON group were seen in the Trail Making Test B at week 4 (p= 0.031). Statistically significant differences were not seen in any of the other cognitive outcomes measured (Stroop Test, Trail Making Test A, serum BDNF, serum ketones). However, a significant inverse relationship was seen between serum ketones and Trail Making Test B. In conclusion, this study suggests that TRF may have a favorable effect on cognitive acuity among university students.
ContributorsKravat, Natalie (Author) / Johnston, Carol (Thesis advisor) / Gu, Haiwei (Committee member) / Sears, Dorothy (Committee member) / Arizona State University (Publisher)
Created2021
Description
Background: Research has found that nearly a quarter of the American population follows a gluten-free diet in some capacity, while only about 1% of the population is diagnosed with celiac disease. Although the amount of research-based evidence supporting any health benefits of a gluten-free diet in an individual without a gluten- related disorder is limited, the number of people claiming to follow a gluten-free diet continues to rise. Also, despite an increasing belief that gluten is harmful for health, the potentially undesirable effects of gluten substitutions used in gluten-free foods are largely unknown. Due to the protein network encapsulating starch granules, gluten is thought to lengthen the amount of time needed during starch digestion, thereby reducing postprandial glycemia. Therefore, it is predicted that breads containing gluten will produce a lower glycemic response compared to gluten-free breads. Aim: The aim of this study was to investigate the glycemic response of gluten-free bread made with different types of flour compared to bread made with gluten-containing wheat flour. Methods: This study involved a 3-week, randomized, single blind crossover study in which 17 healthy individuals were asked to consume a different type of bread each week, 2 of which were gluten-free. Blood glucose was taken by finger prick at fasting as a baseline measurement, then for 2 hours after bread consumption in 30-minute increments. Results: Across the three groups, there was no significant difference in iAUC values after 120 minutes (p=0.192 ). The greatest mean was seen in the gluten-containing bread (145.3 ± 82.6), then the gluten-free bread made with rice flour (125.5 ± 62.8), and lastly the gluten-free bread made with potato and fava bean flour (112.4 ± 64.5). Conclusion: The inconsistent results of this study compared to previous, similar studies suggests that the postprandial glycemic response of gluten-free products can not be generalized as a whole, but instead is dependent on the type of product and the ingredients used to replace the gluten. Although the results did not show a significant difference, it does argue against the belief that gluten-free products are invariably better for health in the general, non-gluten sensitive population.
ContributorsWaznik, Lauren LaRue (Author) / Johnston, Carol (Thesis advisor) / Mayol-Kreiser, Sandra (Committee member) / Dixon, Kathleen (Committee member) / Arizona State University (Publisher)
Created2019
Description
Background: Individuals in the general populations with a known gluten disorder is believed to be 6% and it is unclear why the gluten free diet (GFD) has risen sharply (28%) in recent years. However, science has revealed that gluten can cause colonic changes in those undiagnosed with a known gluten disorder. The ramifications of these changes are unknown. Three common ingredients found in gluten free products, such as pasta, are corn quinoa and rice. Evidence from the scientific literature has shown that corn and quinoa can produce more colonic hydrogen than refined wheat and rice, indicating that corn and quinoa have a reduced glycemic effect. Since rice and wheat have similar glycemic responses, corn and quinoa pastas would be expected to have a lower glycemic response than rice and wheat pasta
.
Aim The aim of his study was to examine the glycemic response to three different types of pasta: wheat, rice and corn. Breath hydrogen, assessment of mood states, blood glucose and insulin were collected after ingestion of these pastas to determine the glycemic effects of these foods.
Methods: A double blinded crossover study design was utilized on a group of healthy individuals, and the test meals of wheat, rice and combinations of rice/corn, and corn/quinoa pastas were consumed one week apart in random order. Collections of fasting venous blood samples for insulin analysis, capillary blood from a finger stick for glucose analysis, breath hydrogen samples and satiety scales were used for glycemic response and mood states were collected prior to the meal (baseline) and then again after ingestion of the test meals. Attempts were made to explore the glycemic response of these test meals in relation to mood states.
Results: The glucose response showed no significant difference at baseline (p = .683) among all groups and no significant differences were seen post treatment at 30 minutes (p = .875). However, after 60 minutes all of the glucose concentrations began to decline except for the rice pasta which peaked at 90 minutes and the wheat pasta gave the most sustained decrease. The AUC glucose values showed no significant difference at both 120 (p=0.196) and 240 (p=0.734) minutes but with wheat pasta producing the lowest mean value. The POMS scores showed no significant differences between groups over time (p=.239) but the wheat group produced the highest score (worsening moods states).
Conclusion: These results indicate that the formulation and processing of gluten free pastas may affect the rate and absorption and the subsequent glycemic response after the consumption of these foods. Whether or not wheat contains an ingredient that slows absorption and/or negatively affects mood remains undetermined warrants future research in this area.
.
Aim The aim of his study was to examine the glycemic response to three different types of pasta: wheat, rice and corn. Breath hydrogen, assessment of mood states, blood glucose and insulin were collected after ingestion of these pastas to determine the glycemic effects of these foods.
Methods: A double blinded crossover study design was utilized on a group of healthy individuals, and the test meals of wheat, rice and combinations of rice/corn, and corn/quinoa pastas were consumed one week apart in random order. Collections of fasting venous blood samples for insulin analysis, capillary blood from a finger stick for glucose analysis, breath hydrogen samples and satiety scales were used for glycemic response and mood states were collected prior to the meal (baseline) and then again after ingestion of the test meals. Attempts were made to explore the glycemic response of these test meals in relation to mood states.
Results: The glucose response showed no significant difference at baseline (p = .683) among all groups and no significant differences were seen post treatment at 30 minutes (p = .875). However, after 60 minutes all of the glucose concentrations began to decline except for the rice pasta which peaked at 90 minutes and the wheat pasta gave the most sustained decrease. The AUC glucose values showed no significant difference at both 120 (p=0.196) and 240 (p=0.734) minutes but with wheat pasta producing the lowest mean value. The POMS scores showed no significant differences between groups over time (p=.239) but the wheat group produced the highest score (worsening moods states).
Conclusion: These results indicate that the formulation and processing of gluten free pastas may affect the rate and absorption and the subsequent glycemic response after the consumption of these foods. Whether or not wheat contains an ingredient that slows absorption and/or negatively affects mood remains undetermined warrants future research in this area.
ContributorsSnyder, Darren (Author) / Johnston, Carol (Thesis advisor) / Ohri-Vachaspati, Punam (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2015
Description
There is a considerable amount of research stating that vegetarian diets have an alkalizing effect while the typical western diet is acid-forming. There is substantial evidence regarding the health benefits of an alkaline diet. Although vegetarian diets demonstrate the ability to foster these health benefits, many people are still not willing to adopt a completely vegetarian diet. PURPOSE: To evaluate the effect of following a vegan diet two or three days per week on acid-base balance in a healthy college student population aged 18-30. METHODS: In a one-week interventional design, 23 people were randomly assigned to follow a vegan diet 2 days per week (VEG2;n=7), 3 days per week(VEG3;n=8), or 7 days per week (VEG7;n=8). Urine pH and dietary PRAL were assessed in each group at baseline and after the one-week intervention. RESULTS: There was no significant difference in urinary pH between the three groups (p=0.12). The change in PRAL values after the dietary intervention was different between the 3 groups (p=0.03). CONCLUSION: Adherence to a vegan diet 2 or 3 days per week did not show a significant change in urinary pH or PRAL.
ContributorsCosgrove, Kelly (Author) / Johnston, Carol (Thesis advisor) / Sweazea, Karen (Committee member) / Mayol-Kreiser, Sandra (Committee member) / Arizona State University (Publisher)
Created2015
Description
Diabetes is the 7th leading cause of death globally. In 2018, 34.2 million Americans had type 2 diabetes. Many symptoms of diabetes are similar to those of scurvy or vitamin C deficiency. Vitamin C marginality and inadequacy are more prevalent in Type 2 Diabetes/prediabetes than with normal glucose tolerance. Intracellular vitamin C inadequacy is suspected due to competition between dehydroascorbic acid and glucose at GLUT 1 and 3 cellular receptors. Erythrocyte osmotic fragility is noted in Gulo -/- knockout mice unable to synthesize endogenous vitamin C. The ascorbate deficient red blood cells presented with low cytoskeletal B-spectrin, spherocyte appearance, and impaired deformability. This cross-sectional study investigated the relationships between diabetes status, erythrocyte osmotic fragility, and serum vitamin C status. Participants were aged 18-65, non-smoking, reported no unresolved health complications, and denied prior vitamin C supplementation. Those with T2D indicated diagnosis of >1 year. All participants provided written informed consent and the study was approved by the local Institutional Review Board in January 2021. Participants provided one fasted blood sample. Erythrocyte osmotic fragility was measured via UV/Vis spectrophotometry with various concentrations of sodium chloride (0.85% - 0.10%) to induce osmotic stress. In addition, plasma was extracted and mixed 1:1 with 10% (w/v) metaphosphoric acid in 2 mmol/L disodium EDTA and centrifuged. The supernatant was stored at -80°C until analysis with isocratic reverse-phase UV-HPLC separation.
Participant characteristics did not differ significantly between groups apart from age (p< 0.01) and HbA1c (p=0.002). Data are presented for adults with T2D (n=14; 36% female; 55.5±8.2 y; 31.5±9.0 kg/m2; HbA1c: 7.4±1.9%; plasma vitamin C: 36.0±12.2 uM) and without T2D (n=16; 69% female; 38.7±13.5 y; 26.8±6.6 kg/m2; A1c: 5.4±0.3%; plasma vitamin C: 34.8±10.9uM). Erythrocyte osmotic fragility was significantly elevated (+4.4% hemolysis) in adults without T2D at 0.35% saline (p=0.039). Greater VC status (>30 uM) was associated with lower hemolysis at 0.35% NaCl (p=0.031). Erythrocyte osmotic stability was linked to greater vitamin C intake at 0.20% saline in those without T2D (p =0.019).
In this pilot study, vitamin C status did not differ significantly by diabetes status. Vitamin C status was directly linked to erythrocyte osmotic stability in adults without T2D.
ContributorsLundy, Ciara Cheyanne (Author) / Johnston, Carol (Thesis advisor) / Sweazea, Karen (Committee member) / Alexon, Christy (Committee member) / Arizona State University (Publisher)
Created2022
Description
Urinary tract infections (UTIs) disrupt military women’s service obligations and health. Females are more susceptible to UTIs due to their unique anatomical features and hormone fluctuations affecting vaginal flora. During phase 1 of the menstrual cycle (onset of bleeding, menstrual cycle days 1-5), estrogen levels significantly decrease and inhibit the growth of lactobacilli, good bacteria that are essential in warding off harmful bacteria and infections, particularly pathogens of UTIs. To reduce UTI onset, it is recommended to frequently urinate with sufficient urine void volume to facilitate washing out harmful bacteria from the bladder and urethra. While menstruating, increased fluid consumption to support urination frequency and void volume may be critical, as the urethra and urinary tract are more predisposed to pathogenic bacteria found. Yet, there is a lack of research investigating the impact of hydration on urinary tract health during menstruation. The study sought to examine the effects of increased water fluid intake on the uropathogenic bacterial activity of underhydrated menstruating premenopausal females. Thirteen females underwent a 2x2 randomized crossover trial to evaluate the effectiveness of a) additional 1.89 L of water fluid intake and b) maintain habitual fluid intake on two subsequent phase 1 menses. At each phase 1 menses, fluid intake was gathered on days 2 and 5 to determine the fluid amount consumed. First-morning urinations on days 3 and 6 assessed urogenital bacterial activity. Combining data collection days 2 and 5 per intervention (INT) and control (CON), the mean±SD for total fluid intake was INT 2.99±1.05 and CON 1.85±0.89, resulting in a 62% increase, p< 0.001, η2= 0.459. For days 2 and 5, a 48% and 80% increase in total fluid in from CON to INT was found, ps< 0.01. However, only four cultures detected uropathogenic bacteria from four participants, with no patterns between conditions or days, making it difficult to determine the effectiveness of the intervention. Though the intervention results were undetermined, military women’s hydration, menstruation, and urinary tract health remain prominent health concerns. Efforts to assess their fluid consumption and urination behaviors during menstruation and UTI risks are warranted.
ContributorsVento, Kaila Ann (Author) / Wardenaar, Floris C (Thesis advisor) / Johnston, Carol (Committee member) / Kavouras, Stavros (Committee member) / Koskan, Alexis (Committee member) / Lynch, Heidi (Committee member) / Arizona State University (Publisher)
Created2022