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- Genre: Academic theses
- Creators: Johnston, Carol
Description
Background: College students face a particularly high prevalence of body dissatisfaction and weight instability increasing the risk of being unhappy and having a poor quality of life. Time-restricted feeding, a type of intermittent fasting, has gained popularity recently for sustainable weight loss without the characteristic dietary restrictions of most fad diets. A limited number of randomized control trials have looked at the effects of time-restricted feeding in humans, but none have looked at how this dietary regimen impacts happiness and quality of life. Objective: The goal was to examine the effects of an 18-hour daily fasting regimen compared to an 8-hour daily fasting regimen on happiness and quality of life in college students in Arizona.
Methods: Participants included 29 healthy, non-smoking, non-vaping students attending college in Arizona between October 2020 to March 2021. Of the 16 participants allocated to the time-restricted feeding intervention, 8 completed the trial. Of the 13 participants allocated to the control group, 10 completed the trial. The eating window began within one hour of waking up with a 6-hour eating window for the intervention group and 16-hour window for the control group. They could do one cheat day per week. No dietary restrictions were enforced. Participants completed the Oxford Happiness Questionnaire and the WHOQOL-BREF quality of life questionnaire at baseline, week 4, and week 8. Week 8 data were not reported due to data collection changes and cancellations related to the new safety protocols for the COVID-19 pandemic.
Results: Quality of life related to social relationships improved significantly in the intervention group (p=0.026). There was a trend favoring the intervention group as well showing a possible improvement in happiness related to perceived energy levels (p=0.088). No other significant data were reported.
Conclusion: Adherence to an 18-hour time-restricted feeding regimen for 8 weeks may improve quality of life related to social relationships in college students in Arizona. The results of this trial do not suggest a significant impact on overall quality of life or happiness in this population.
ContributorsDe León, Anateresa (Author) / Johnston, Carol (Thesis advisor) / Shepard, Christina (Committee member) / Grant, Shauna (Committee member) / Arizona State University (Publisher)
Created2021
Description
Fish oil has been extensively researched for its protective effects on cognition. More recently, anthocyanins have also gained the attention of the medical community for their potential cognitive benefits. Maqui berries are one of the richest sources of anthocyanins known to science. While there are many randomized controlled trials (RCT) investigating the effects of fish oil and/or anthocyanins on cognition in various populations, there are no RCT that exclusively investigate the cognitive effects of these compounds in adults with Type 2 Diabetes (DM2). The purpose of this double-blinded, placebo-controlled RCT was to investigate the cognitive effects of maqui berry extract and fish oil supplements in adults with DM2 over the course of eight weeks. Adults with DM2 (n=29) were recruited by the researchers and randomized to either Group A or Group B. Because the study is ongoing, it is unknown which group received the intervention. The study used the Stroop Test and Trail Making Test (TMT) to measure cognition at baseline, 4 weeks, and 8 weeks. Anthropometrics, blood glucose, and hemoglobin A1C were also taken at these time points. Sixteen female participants were included in the final analysis. Neither group showed significant improvements in the cognitive tests. However, in Group A, the effect sizes were large for the change in Trail-Making Test A (0.167), Trail Making Test B (0.261), and Trail Making Test B minus A (0.296) scores. In Group A, the change in Trail Making Test B minus A scores between baseline and week 4, and between baseline and week 8 was significant (p=0.053) and produced a large effect size (0.258). The results suggest that fish oil and maqui berry extract may improve cognition in adults with DM2, but further studies with larger sample sizes are needed.
ContributorsDeimeke, Allyson (Author) / Johnston, Carol (Thesis advisor) / Grant, Shauna (Committee member) / Sweazea, Karen (Committee member) / Arizona State University (Publisher)
Created2023
Description
Vitamin D deficiency has been previously associated with a higher Alzheimer’s disease (AD) risk, a condition marked by dependent living and severe cognitive impairment. AD is histologically defined by the presence of brain amyloid beta (Aβ) plaques and neurofibrillary tangles. Ways to enhance Aβ clearance have been examined in order to sustain cognition and delay AD onset. In vitro and in vivo studies suggest that vitamin D might enhance brain Aβ transportation to the periphery by up-regulating P-glycoprotein production. The purpose of this study was to examine the effect of vitamin D supplementation on plasma Aβ in an older population.
This study was a parallel-arm, double-blinded, randomized control trial. Participants consumed either a vitamin D supplement or placebo once a week for eight weeks (n=23). Only vitamin D insufficient (serum total 25-OH, D < 30 ng/mL) people were included in the study, and all participants were considered to be cognitively normal (MMSE scores > 27). Serum total 25-OH, D and plasma Aβ1-40 measurements were recorded before and after the eight-week trial. The plasma Aβ1-40 change was compared between the vitamin D group and control group.
The vitamin D group experienced a 45% greater change in plasma Aβ1-40 than the control group. The effect size was 0.228 when controlling for baseline plasma Aβ1-40 (p=0.045), 0.197 when controlling for baseline plasma Aβ1-40 and baseline physical activity (p=0.085), and 0.179 when controlling for baseline plasma Aβ1-40, baseline physical activity, and age (p=0.116). In conclusion, vitamin D supplementation might increase brain Aβ clearance in humans, but physical activity and age also appear to modulate Aβ metabolism.
This study was a parallel-arm, double-blinded, randomized control trial. Participants consumed either a vitamin D supplement or placebo once a week for eight weeks (n=23). Only vitamin D insufficient (serum total 25-OH, D < 30 ng/mL) people were included in the study, and all participants were considered to be cognitively normal (MMSE scores > 27). Serum total 25-OH, D and plasma Aβ1-40 measurements were recorded before and after the eight-week trial. The plasma Aβ1-40 change was compared between the vitamin D group and control group.
The vitamin D group experienced a 45% greater change in plasma Aβ1-40 than the control group. The effect size was 0.228 when controlling for baseline plasma Aβ1-40 (p=0.045), 0.197 when controlling for baseline plasma Aβ1-40 and baseline physical activity (p=0.085), and 0.179 when controlling for baseline plasma Aβ1-40, baseline physical activity, and age (p=0.116). In conclusion, vitamin D supplementation might increase brain Aβ clearance in humans, but physical activity and age also appear to modulate Aβ metabolism.
ContributorsMiller, Brendan Joseph (Author) / Johnston, Carol (Thesis advisor) / Whisner, Corrie (Committee member) / Tasevska, Natasha (Committee member) / Arizona State University (Publisher)
Created2015
Description
Plant-based eaters are known to reap nutritional benefits due to their dietchoice, but it is important to evaluate dietary differences that may put them at a disadvantage compared to omnivores. Stark differences exist in daily intakes of protein between vegans and omnivores, which may lead to several risks including decreased strength and bone density. The purpose of this study was to analyze the differences in protein intake, lean mass, strength, and bone density in vegans versus omnivores in order to support the argument for an increased recommended daily allowance (RDA) for protein for plant-based eaters. Participants in this study were assigned to groups based on omnivorous (n = 25) or vegan (n = 19) dietary pattern. Nineteen matched pairs were created based on age and BMI. Data was collected at a single lab visit and included health history and physical activity readiness questionnaires, 24-hr food recall, and anthropometric measures. Bone mineral density (BMD) was measured using DEXA and strength was assessed using hand and Biodex dynamometers. Statistical analyses were conducted using independent samples t-tests and Pearson’s correlation tests to evaluate differences in body composition, bone density, strength, and dietary intake between the two groups with significance set at p.05. Differences were seen in daily calorie (p=.007), protein (p<.001), fat (p<.001), and fiber (p=.009) intake. Lean mass (p=.282) and bone density (p=.651) were not different between groups, but lower body strength was different (p=.008). There was a correlation between lower body strength and protein intake (p<.001), and lean mass was correlated with lower body strength (p<.001), grip strength (p<.001), and bone density (p<.001), but not
i
LBM (p=0.158). Correlations were also observed between BMD and lower body strength (p=.004). These data suggest that there is a significant difference between protein intake in vegans versus omnivores, which appears to have a positive association with strength. BMD also has a positive association with strength as well as lean mass. Cumulatively, the results suggest that it may be beneficial for vegans to increase daily protein intake.
ContributorsNadalet, Camila R (Author) / Johnston, Carol (Thesis advisor) / Shepard, Christina (Committee member) / Hooshmand, Shirin (Committee member) / Arizona State University (Publisher)
Created2023
Description
Gastrointestinal (GI) complaints are prevalent among athletes. Fermented foods with pre-or probiotic features may relieve GI symptoms by improving gut health. This study aimed is to examine the impact of a nutritional supplement containing fermented whey protein with Galacto-oligosaccharide (GOS) fiber on GI distress among well-trained athletes over time by analyzing self-reported GI complaints without a control group. This quasi-experimental clinical trial consisted of a 3-week baseline period, reflected by two baseline measurements on Day 1 and Day 22, which was followed by a 3-week intervention period, reflected by a post-intervention measurement on Day 43, in which athletes added 15g of a fermented whey protein product to their diet. The primary outcome was based on the self-reported gastrointestinal symptom rating scale (GSRS), and the secondary outcome was based on a daily questionnaire, in which daily GI complaints and exercise occurrences were reported. Tertiary outcomes included a 24-hour diet recall (ASA24) and self-reported diet quality (REAP). Outcomes obtained during baseline (Day 1 and Day 22 average) were compared to those post-intervention (Day 43). Statistical significance was set at P<0.05. A total of n=50 athletes (24.7±4.5 years) with GI issues were included in the study. Five individual items of the GSRS including abdominal pain, acid reflux, bloating, burping, and loose stools reflected significantly lower scores on Day 43 in comparison to baseline (P≤0.028). A total of 78% reported GI complaints at baseline, and 61% of the participants reported lower GI complaints on Day 43 after supplementation in comparison to baseline (P=0.004). Further research is needed to explore the potential benefits of a hydrolyzed and fermented whey protein with prebiotics in a more controlled setting among athletic populations.
ContributorsClear, Anna Marie Grace (Author) / Wardenaar, Floris (Thesis advisor) / Johnston, Carol (Committee member) / Wharton, Christopher (Committee member) / Arizona State University (Publisher)
Created2023
Description
Sleep is an essential biological requirement to sustain human life and a critical component for athletes. There has been a rising trend for poor sleep in the general population and the problem persists as well within the athletic population. Research has demonstrated numerous benefits of optimized sleep on athletic performance and athlete wellness. Further investigation of potential dietary strategies to improve self-perceived sleep quality is warranted. This study examined the differences in perceived sleep quality and wellness between a 3-week baseline period and after a 3-week supplementation period, in which participants consumed a dietary supplement containing fermented whey protein + galacto-oligosaccharides (GOS) + casein protein daily. Validated questionnaires, namely, Athens Insomnia Scale (AIS), Physical Health Questionnaire (PHX), Kessler-6 Mental Stress Scale (K6) were used to measure perceived sleep quality and wellness on Day 1, Day 22 and Day 43. Additionally, multiple 24-h dietary recalls (ASA24), and food quality using the validated Rapid Eating Assessments for Participants (REAP) questionnaire, were used to assess dietary patterns throughout the study, while exercise occurrence was tracked through a self-developed daily questionnaire. A total of 54 healthy active adults (age=18-35yrs) experiencing gastro-intestinal (GI) complaints were included in the trial, and 50 participants were included in the final analysis. Significantly lower AIS-8 total scores were found on Day 43 compared to Day 22 while controlled for Day 1 (Day 43: 4.36 ± 3.68 versus Day 22: 5.02 ± 4.11, F=4.379 (1, 50), p=0.042), while no differences were found for wellbeing (p≥ 0.180). Dietary intake, food quality and exercise frequency did not change over time (p≥0.080). These results suggested that a daily protein + GOS supplement was associated with a decrease in AIS-8 total scores suggesting improved perceived sleep quality among athletes after 3 weeks. A controlled research study should confirm these results in the future. More research is required to assess the effects of protein + prebiotic supplementation on sleep parameters among athletes.
ContributorsChan, Yat (Author) / Wardenaar, Floris (Thesis advisor) / Johnston, Carol (Committee member) / Wharton, Christopher (Committee member) / Arizona State University (Publisher)
Created2023
Description
The glycation of plasma proteins leading to the production of advanced glycation end products (AGEs) and subsequent damage is a driving factor in the pathophysiology of diabetic complications. The overall research objective was to elucidate the mechanisms by which birds prevent protein glycation in the presence of naturally high plasma glucose concentrations. This was accomplished through the specific purpose of examining the impact of temperature and glucose concentration on the percent glycation of chicken serum albumin (CSA) in comparison to human serum albumin (HSA). Purified CSA and HSA solutions prepared at four different glucose concentrations (0 mM, 5.56 mM, 11.11 mM, and 22.22 mM) were incubated at three different temperatures (37.0°C, 39.8°C, and 41.4°C) on separate occasions for seven days with aliquots extracted on days 0, 3, and 7. Samples were analyzed by LC-ESI-MS for percent glycation of albumin. The statistically significant interaction between glucose concentration, temperature, albumin type, and time as determined by four-way repeated measures ANOVA (p = 0.032) indicated that all independent variables interacted to affect the mean percent glycation of albumin. As glucose concentration increased, the percent glycation of both HSA and CSA increased over time at all temperatures. In addition, HSA was glycated to a greater extent than CSA at the two higher glucose concentrations examined for all temperature conditions. Temperature differentially affected percent glycation of HSA and CSA wherein glycation increased with rising temperatures for HSA but not CSA. The results of this study suggest an inherent difference between the human and chicken albumin that contributes to the observed differences in glycation. Further research is needed to characterize this inherent difference in an effort to elucidate the mechanism by which birds protect plasma proteins from glycation. Future related work has the potential to lead to the development of novel therapies to prevent or reverse protein glycation prior to the formation of AGEs in humans, thus preventing the development and devastating effects of numerous diabetic complications.
ContributorsZuck, Jessica (Author) / Sweazea, Karen (Thesis advisor) / Johnston, Carol (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2016
Description
Background: Effective glucose management using exercise modalities in older patients with type 2 diabetes and activities of daily living (ADL) disabilities are unknown.
Purpose: The study investigated the acute effects of motor-assisted cycling and functional electrical stimulation (FES) cycling on the 2-h postprandial glucose responses compared with sitting control in older adults with type 2 diabetes and ADL disabilities.
Methods: The study used a 3×3 crossover study design. Nine participants were randomly assigned to one of the three treatment sequences: ABC, BCA, and CAB. (A, motor-assisted cycling; B, FES cycling; C, sitting control). Linear mixed models (LMM) with Bonferroni post-hoc tests were used to test the mean differences for the 2-h postprandial glucose, estimated by the area under the curve (AUC) and incremental AUC (iAUC), between intervention and control treatments after adjustment for covariates (e.g., age, sex, and race).
Results: There were significant mean differences for iAUC (p = 0.005) and AUC (p = 0.038) across motor-assisted cycling, control, and FES cycling treatments. The FES cycling had a lower mean of 2-hour postprandial iAUC as compared with sitting control (iAUC 3.98 mmol∙h/L vs 6.92 mmol∙h/L, p = 0.006, effect size [ES] = 1.72) and the motor-assisted cycling (iAUC, 3.98 mmol∙h/L vs 6.19 mmol∙h/L , p = 0.0368, ES = 1.29), respectively. The FES cycling also had a lower mean of the 2-hour postprandial AUC as compared with sitting control (AUC, 18.29 mmol∙h/L vs 20.95 mmol∙h/L, p = 0.043, ES = 0.89), but had an AUC similar to the motor-assisted cycling (18.29 mmol∙h/L vs 20.23 mmol∙h/L , p = 0.183, ES = 0.19). There were no statistical differences in iAUC (6.19 mmol∙h/L vs 6.92 mmol∙h/L) and AUC (20.23 mmol∙h/L vs 20.95 mmol∙h/L) between the motor-assisted cycling and sitting control (all p>0.05).
Conclusion: Performing 30 minutes of FES cycling on a motor-assisted bike (40 Hz, 39 rpm, 25-29 mA) significantly decreased the 2-h postprandial glucose levels in older adults with type 2 diabetes and ADL disabilities. These findings suggested that FES cycling can be a promising exercise modality for glucose management in diabetic patients with ADL disabilities.
Purpose: The study investigated the acute effects of motor-assisted cycling and functional electrical stimulation (FES) cycling on the 2-h postprandial glucose responses compared with sitting control in older adults with type 2 diabetes and ADL disabilities.
Methods: The study used a 3×3 crossover study design. Nine participants were randomly assigned to one of the three treatment sequences: ABC, BCA, and CAB. (A, motor-assisted cycling; B, FES cycling; C, sitting control). Linear mixed models (LMM) with Bonferroni post-hoc tests were used to test the mean differences for the 2-h postprandial glucose, estimated by the area under the curve (AUC) and incremental AUC (iAUC), between intervention and control treatments after adjustment for covariates (e.g., age, sex, and race).
Results: There were significant mean differences for iAUC (p = 0.005) and AUC (p = 0.038) across motor-assisted cycling, control, and FES cycling treatments. The FES cycling had a lower mean of 2-hour postprandial iAUC as compared with sitting control (iAUC 3.98 mmol∙h/L vs 6.92 mmol∙h/L, p = 0.006, effect size [ES] = 1.72) and the motor-assisted cycling (iAUC, 3.98 mmol∙h/L vs 6.19 mmol∙h/L , p = 0.0368, ES = 1.29), respectively. The FES cycling also had a lower mean of the 2-hour postprandial AUC as compared with sitting control (AUC, 18.29 mmol∙h/L vs 20.95 mmol∙h/L, p = 0.043, ES = 0.89), but had an AUC similar to the motor-assisted cycling (18.29 mmol∙h/L vs 20.23 mmol∙h/L , p = 0.183, ES = 0.19). There were no statistical differences in iAUC (6.19 mmol∙h/L vs 6.92 mmol∙h/L) and AUC (20.23 mmol∙h/L vs 20.95 mmol∙h/L) between the motor-assisted cycling and sitting control (all p>0.05).
Conclusion: Performing 30 minutes of FES cycling on a motor-assisted bike (40 Hz, 39 rpm, 25-29 mA) significantly decreased the 2-h postprandial glucose levels in older adults with type 2 diabetes and ADL disabilities. These findings suggested that FES cycling can be a promising exercise modality for glucose management in diabetic patients with ADL disabilities.
Contributorsma, tongyu (Author) / Lee, Chong (Thesis advisor) / Hooker, Steven (Committee member) / Shaibi, Gabriel (Committee member) / Johnston, Carol (Committee member) / Ringenbach, Shannon (Committee member) / Arizona State University (Publisher)
Created2019
Description
Healthy lifestyle behaviors including quality nutrition have been shown to successfully prevent chronic disease or minimize symptoms. However, many physicians lack the knowledge and skills to provide adequate nutrition counseling and education for their patients. A major component of this problem is that medical schools are not required to teach nutrition education. The purpose of this feasibility study was to compare the changes in the perceived importance of nutrition in the medical field in medical students before and after participating in a week-long interactive nutrition course in order to determine if a week-long course can positively influence students’ perceptions of nutrition. Ultimately by changing these perceptions, medical students may be able to better help patients prevent chronic disease. The participants were first year medical students at the Mayo Clinic School of Medicine (Scottsdale, AZ) who chose to participate in this medical school “Selective”. The study included a five-day curriculum of case-studies, lectures from specialized health professionals, and a cooking class led by a chef who trained in France. An anonymous pre- and post-study questionnaire with five-point Likert scale questions was used to measure changes in attitudes. The data suggest that students’ perceptions regarding the importance and relevance of nutrition in the medical shifted slightly more positive after attending this Selective, although these shifts in attitude were not statistically significant. Limitations of this study include a small sample size and selection bias, which may have decreased the potential of having significant results. Both of these factors also make the results of this study less generalizable to all medical students. This study supports the need for a larger experimental study of a similar design to verify that an interactive, evidence-based nutrition class and culinary experience increases medical students’ positive perceptions of nutrition in the medical field.
ContributorsBaum, Makenna (Author) / Johnston, Carol (Thesis advisor) / Levinson, Simin (Committee member) / Sears, Dorothy (Committee member) / Arizona State University (Publisher)
Created2020
Description
This study was designed to examine the associations between food skills, resilience, and coping during the Covid-19 pandemic. Between April and June of 2020, a sample of 154 students, faculty, and staff from Arizona State University were surveyed. Each respondent was administered a survey containing demographic questions, a food skill questionnaire, and the 14-item Resilience Scale (RS). Results indicate that food skill was correlated with resilience (p<0.001) at an r=0.364 and r2=0.1243 and that resilience was correlated with coping during the Covid-19 pandemic (p<0.001) at an r=0.455. Correlations were also run between resilience score and the separate domains of food skill score: all domains remained significantly associated with resilience score (p<0.001) with a r=0.340 and r2=0.1173 for ‘Food Selection and Planning,’ r=0.312 and r2=0.0958 for ‘Food Preparation,’ and r=0.294 and r2=0.0767 for ‘Food Safety.’ Data seems to be consistent with contemporary research suggesting positive associations between diet quality and physiological resilience and positive associations between resilience and coping during the Covid-19 pandemic.
ContributorsPhares, Savanna Julene (Author) / Johnston, Carol (Thesis advisor) / McCoy, Maureen (Committee member) / Irving, Andrea (Committee member) / Arizona State University (Publisher)
Created2020