Matching Items (9)
Filtering by

Clear all filters

151503-Thumbnail Image.png
Description
Objective: Vinegar consumption studies have demonstrated possible therapeutic effects in reducing HbA1c and postprandial glycemia. The purpose of the study was to closely examine the effects of a commercial vinegar drink on daily fluctuations in fasting glucose concentrations and postprandial glycemia, and on HbA1c, in individuals at risk for Type

Objective: Vinegar consumption studies have demonstrated possible therapeutic effects in reducing HbA1c and postprandial glycemia. The purpose of the study was to closely examine the effects of a commercial vinegar drink on daily fluctuations in fasting glucose concentrations and postprandial glycemia, and on HbA1c, in individuals at risk for Type 2 Diabetes Mellitus (T2D). Design: Thirteen women and one man (21-62 y; mean, 46.0±3.9 y) participated in this 12-week parallel-arm trial. Participants were recruited from a campus community and were healthy and not diabetic by self-report. Participants were not prescribed oral hypoglycemic medications or insulin; other medications were allowed if use was stable for > 3 months. Subjects were randomized to one of two groups: VIN (8 ounces vinegar drink providing 1.5 g acetic acid) or CON (1 vinegar pill providing 0.04 g acetic acid). Treatments were taken twice daily immediately prior to the lunch and dinner meals. Venous blood samples were drawn at trial weeks 0 and 12 to measure insulin, fasting glucose, and HbA1c. Subjects recorded fasting glucose and 2-h postprandial glycemia concentrations daily using a glucometer. Results: The VIN group showed significant reductions in fasting capillary blood glucose concentrations (p=0.05) that were immediate and sustained throughout the duration of the study. The VIN group had reductions in 2-h postprandial glucose (mean change of −7.6±6.8 mg/dL over the 12-week trial), but this value was not significantly different than that for the CON group (mean change of 3.3±5.3 mg/dL over the 12-week trial, p=0.232). HbA1c did not significantly change (p=0.702), but the reduction in HbA1c in the VIN group, −0.14±0.1%, may have physiological relevance. Conclusions: Significant reductions in HbA1c were not observed after daily consumption of a vinegar drink containing 1.5 g acetic acid in non-diabetic individuals. However, the vinegar drink did significantly reduce fasting capillary blood glucose concentrations in these individuals as compared to a vinegar pill containing 0.04 g acetic acid. These results support a therapeutic effect for vinegar in T2D prevention and progression, specifically in high-risk populations.
ContributorsQuagliano, Samantha (Author) / Johnston, Carol (Thesis advisor) / Appel, Christy (Committee member) / Dixon, Kathleen (Committee member) / Arizona State University (Publisher)
Created2013
Description
The omega-3 fatty acids in fatty fish and fish oil, eicosapentanoic acid (EPA) and docosahexanoic acid (DHA), have been associated with a reduction in risk for cardiovascular disease. Blood type is a known contributor to risk for cardiovascular events. This study evaluated the effect of fish oil supplements on cardiovascular

The omega-3 fatty acids in fatty fish and fish oil, eicosapentanoic acid (EPA) and docosahexanoic acid (DHA), have been associated with a reduction in risk for cardiovascular disease. Blood type is a known contributor to risk for cardiovascular events. This study evaluated the effect of fish oil supplements on cardiovascular risk markers in adults with blood types A or O. An 8-week parallel-arm, randomized, double-blind trial was conducted in healthy adult men and women with either blood type A (BTA) or blood type O (BTO). Participants were randomized to receive fish oil supplements (n=10 [3 BTA/7 BTO]; 2 g [containing 1.2 g EPA+DHA]/d) or a coconut oil supplement (n=7 [3 BTA/4 BTO]; 2 g/d). Markers that were examined included total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), high-sensitivity C-reactive protein (hsCRP), and hemoglobin A1C (HbA1C). Results indicated that the percent change in LDL cholesterol was significantly greater in the coconut oil group vs the fish oil group (-14.8±12.2% vs +2.8±18.9% respectively, p=0.048). There were no other significant differences between treatment groups, or between blood types A and O, for the other cardiovascular risk markers. Further research with a larger and more diverse sample may yield a more conclusive result.
ContributorsHerring, Dana (Author) / Johnston, Carol (Thesis advisor) / Vega-Lopez, Sonia (Committee member) / Shepard, Christina (Committee member) / Arizona State University (Publisher)
Created2014
151225-Thumbnail Image.png
Description
Many people with or at risk for diabetes have difficulty maintaining normal postprandial blood glucose levels (120-140 mg/dl). Research has shown that vinegar decreases postprandial glycemia. The purpose of this study was to examine a possible mechanism by which vinegar decreases postprandial glycemia, particularly the effect of vinegar ingestion on

Many people with or at risk for diabetes have difficulty maintaining normal postprandial blood glucose levels (120-140 mg/dl). Research has shown that vinegar decreases postprandial glycemia. The purpose of this study was to examine a possible mechanism by which vinegar decreases postprandial glycemia, particularly the effect of vinegar ingestion on gut fermentation. In this parallel arm randomized control trial, the effects of daily ingestion of vinegar on gut fermentation markers were observed among adults at risk for type 2 diabetes in Phoenix, Arizona. Subjects (n=14) were randomly assigned to treatments consisting of a vinegar drink (1.5g acetic acid) or a placebo (2 vinegar pills containing 40mg acetic acid each). All participants were required to consume the vinegar drink (16 oz) or 2 placebo pills every day for 12 weeks. At week 12, participants filled out a questionnaire to report gastrointestinal (GI) symptoms and three consecutive breath samples were taken from each subject to measure fasting breath hydrogen (BH2) with a breath analyzer. Fasting BH2 measures for the vinegar drink group (16.1+11.8 ppm) were significantly different than those from the pill group (3.6+1.4) with a partial eta squared of 0.39 (p=0.023). After adjusting for age as a confounding factor (r=0.406) and removing an outlier, fasting BH2 measures for the vinegar drink group (4.3+1.1 ppm) were still significantly different than those from the pill group (3.6+1.4) with a partial eta squared of 0.35 (p=0.045). Participants in both groups reported mild changes in GI symptoms. In conclusion, adults at risk for type 2 diabetes that consume 2 tablespoons of vinegar a day may have increased gut fermentation compared to those who do not consume vinegar.
ContributorsWhite, Serena (Author) / Johnston, Carol (Thesis advisor) / Appel, Christy (Committee member) / Martin, Keith (Committee member) / Arizona State University (Publisher)
Created2013
151273-Thumbnail Image.png
Description
ABSTRACT This randomized, controlled, double-blind crossover study examined the effects of a preprandial, 20g oral dose of apple cider vinegar (ACV) on colonic fermentation and glycemia in a normal population, with the ultimate intention of identifying the mechanisms by which vinegar has been shown to reduce postprandial glycemia and insulinemia.

ABSTRACT This randomized, controlled, double-blind crossover study examined the effects of a preprandial, 20g oral dose of apple cider vinegar (ACV) on colonic fermentation and glycemia in a normal population, with the ultimate intention of identifying the mechanisms by which vinegar has been shown to reduce postprandial glycemia and insulinemia. Fifteen male and female subjects were recruited, ages 20-60y, who had no prior history of gastrointestinal (GI) disease or resections impacting normal GI function, were non-smokers, were non-vegetarian/vegan, were not taking any medications known to alter (glucose) metabolism, and were free of chronic disease including diabetes. Subjects were instructed to avoid exercise, alcohol and smoking the day prior to their trials and to consume a standardized, high-carbohydrate dinner meal the eve prior. There was a one-week washout period per subject between appointments. Breath hydrogen, serum insulin and capillary glucose were assessed over 3 hours after a high-starch breakfast meal to evaluate the impact of preprandial supplementation with ACV or placebo (water). Findings confirmed the antiglycemic effects of ACV as documented in previous studies, with significantly lower mean blood glucose concentrations observed during ACV treatment compared to the placebo at 30 min (p=0.003) and 60 min (p=0.005), and significantly higher mean blood glucose concentrations at 180 min (p=0.045) postprandial. No significant differences in insulin concentrations between treatments. No significant differences were found between treatments (p>0.05) for breath hydrogen; however, a trend was observed between the treatments at 180 min postprandial where breath hydrogen concentration was visually perceived as being higher with ACV treatment compared to the placebo. Therefore, this study failed to support the hypothesis that preprandial ACV ingestion produces a higher rate of colonic fermentation within a 3 hour time period following a high-carbohydrate meal. Due to variations in experiment duration noted in other literature, an additional study of similar nature with an expanded specimen collections period, well beyond 3 hours, is warranted.
ContributorsMedved, Emily M (Author) / Johnston, Carol (Thesis advisor) / Sweazea, Karen (Committee member) / Shepard, Christina (Committee member) / Arizona State University (Publisher)
Created2012
153648-Thumbnail Image.png
Description
The effects of iron and chromium blood concentrations have been linked to blood glucose control in diabetics. It is suggested that iron causes oxidative stress in the beta cells of the pancreas and adipocytes creating insulin insufficiency and resistance. Chromium is believed to increase the action of insulin

The effects of iron and chromium blood concentrations have been linked to blood glucose control in diabetics. It is suggested that iron causes oxidative stress in the beta cells of the pancreas and adipocytes creating insulin insufficiency and resistance. Chromium is believed to increase the action of insulin through its biologically active molecule chromodulin. Both of these mechanisms are not clear. This 20 week case study tests the feasibility of combining iron depletion therapy followed by chromium supplementation to improve insulin sensitivity. This single case study followed a protocol of two blood donations separated by eight weeks followed by chromium supplementation of 250 µg of chromium picolinate once a day four weeks after the second blood donation. Fasting blood draws were taken at baseline, post blood draws and pre and post chromium supplementation. Results were not promising for the first hypothesis of lowering HbA1c, but the results were promising for the second hypothesis of improving insulin sensitivity by lowering the HOMA score.
ContributorsJarrett, Nia (Author) / Johnston, Carol (Thesis advisor) / Lespron, Christy (Committee member) / Mayol-Kreiser, Sandra (Committee member) / Arizona State University (Publisher)
Created2015
155582-Thumbnail Image.png
Description
Curcumin is an active ingredient of Curcuma longa (Turmeric) and is studied extensively for its antioxidant, anti-inflammatory, anti-bacterial, anti-viral, and anti-cancer properties. The purpose of this study was to examine the effects of turmeric on blood glucose and plasma insulin levels. The study utilized a placebo-controlled, randomized cross-over

Curcumin is an active ingredient of Curcuma longa (Turmeric) and is studied extensively for its antioxidant, anti-inflammatory, anti-bacterial, anti-viral, and anti-cancer properties. The purpose of this study was to examine the effects of turmeric on blood glucose and plasma insulin levels. The study utilized a placebo-controlled, randomized cross-over design with participants serving as their own control. Eight glucose tolerant healthy participants completed the full study. Three-weeks washout period was kept in between six-weeks. Prior to the test meal day, participants were asked to eat a bagel with their evening dinner. During the day of the test meal, participants reported to the test site in a rested and fasted state. Participants completed mashed potato meal tests with 500 mg of turmeric powder or placebo mixed in water, followed by 3 weeks of 500 mg turmeric or placebo supplement ingestion at home. During this visit blood glucose finger picks were obtained at fasting, 30, 60, 90, and 120 min post-meal. Blood plasma insulin at fasting and at 30 min after the test meal were also obtained. During week 4, participants reported to the test site in a rested and fasted state where fasting blood glucose finger pricks and blood plasma insulin were measured. During week 5 to 7, participants were given a washout time-period. During week 8, entire process from week 1 to 4 was repeated by interchanging the groups. Compared to placebo, reduction in postprandial blood glucose and insulin response were non-significant after ingestion of turmeric powder. Taking turmeric for 3 weeks had no change in blood glucose and insulin levels. However, taking turmeric powder supplements for 3 weeks, showed a 4.4% reduction in blood glucose. Change in insulin at 30 min were compared with baseline insulin level showing no significant change between placebo and turmeric group. Fasting insulin after 3-weeks consumption of turmeric did not show any significant change, but showed a larger effect size (0.08). Future research is essential to examine the turmeric powder supplement benefits over a long period of time in healthy adults and whether it is beneficial in preventing the occurrence of type 2 diabetes.
ContributorsOza, Namrata (Author) / Johnston, Carol (Thesis advisor) / Mayol-Kreiser, Sandra (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2017
168610-Thumbnail Image.png
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

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
154340-Thumbnail Image.png
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

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
187834-Thumbnail Image.png
Description

This feasibility study explored the use of an evolutionary mismatch narrative in nutritional education intervention aiming to reduce ultra-processed foods in the diets of veterans with type 2 diabetes and improve diabetic outcomes. Ultra-processed foods are foods that are primarily manufactured through industrial processes. These foods are high in calories

This feasibility study explored the use of an evolutionary mismatch narrative in nutritional education intervention aiming to reduce ultra-processed foods in the diets of veterans with type 2 diabetes and improve diabetic outcomes. Ultra-processed foods are foods that are primarily manufactured through industrial processes. These foods are high in calories but low in nutritional content. Diets high in these foods have been linked to increased health risks. One of the major health risks is type 2 diabetes. Type 2 diabetes is a chronic disease that is developed when cells become unable to properly utilize insulin. Over time this may lead to additional health conditions such as nerve damage, cardiovascular disease, and renal disease. Evolutionary mismatch narrative nutritional intervention offers a different approach to nutritional education to help reduce ultra-processed foods in diets. This study was a randomized controlled feasibility study at the Phoenix VA. Eleven participants were enrolled and randomly selected to be given either an evolutionary mismatch narrative education intervention or general nutritional education about ultra-processed foods. 24-hour diet recalls and blood chemistry were collected and analyzed. Blood chemistry provided diabetes related measurements which included glucose, HbA1c, insulin, HOMA-IR, and C-reactive protein. Statistically significant findings in this study included percentage of ultra-processed foods decreasing for both control and experimental groups from week 0 to week 4 (p=0.014), and C-reactive protein levels between the control and experimental groups (p=0.042). However, baseline C-reactive protein concentrations were lower in the experimental group such that normalizing for group differences at baseline revealed no significant difference in C-reactive protein change between interventions (p = 1.000). There were no other statistically significant values regarding diabetes related measurements. The results from this study suggest that nutritional education in general may help decrease ultra-processed food consumption.

ContributorsLiang, Nathan Adam (Author) / Sweazea, Karen (Thesis advisor) / Basile, Anthony J (Committee member) / Johnston, Carol (Committee member) / Arizona State University (Publisher)
Created2023