Matching Items (8)
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- All Subjects: Acetic Acid
- Creators: Johnston, Carol
- Creators: Capaldi Phillips, Elizabeth D
- Member of: ASU Electronic Theses and Dissertations
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 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 unpleasant bitter taste found in many nutritious vegetables may deter their consumption. While bitterness suppression by prototypical tastants is well-studied in the chemical and pharmacological fields, mechanisms to reduce the bitterness of foods such as vegetables remain to be elucidated. Here tastants representing the taste primaries of salty and sweet were investigated as potential bitterness suppressors of three types of Brassicaceae vegetables. The secondary aim of these studies was to determine whether the bitter masking agents were differentially effective for bitter-sensitive and bitter-insensitive individuals. In all experiments, participants rated vegetables plain and with the addition of tastants. In Experiments 1-3, sucrose and NNS suppressed the bitterness of broccoli, Brussels sprouts, and cauliflower, whereas NaCl did not. Varying concentrations of NaCl and sucrose were introduced in Experiment 4 to assess the dose-dependency of the effects. While sucrose was a robust bitterness suppressor, NaCl suppressed bitterness only for participants who perceived the plain Brussels sprouts as highly bitter. Experiment 5, through the implementation of a rigorous control condition, determined that some but not all of this effect can be accounted for by regression to the mean. Individual variability in taste perception as determined by sampling of aqueous bitter, salty, and sweet solutions did not influence the degree of suppression by NaCl or sucrose. Consumption of vegetables is deterred by their bitter taste. Utilizing tastants to mask bitterness, a technique that preserves endogenous nutrients, can circumvent this issue. Sucrose is a robust bitter suppressor whereas the efficacy of NaCl is dependent upon bitterness perception of the plain vegetables.
ContributorsWilkie, Lynn Melissa (Author) / Capaldi Phillips, Elizabeth D (Thesis advisor) / Cohen, Adam (Committee member) / Johnston, Carol (Committee member) / Sanabria, Federico (Committee member) / Arizona State University (Publisher)
Created2014
Description
The unpleasant bitter taste found in many nutritious vegetables may deter people from consuming a healthy diet. We investigated individual differences in taste perception and whether these differences influence the effectiveness of bitterness masking. To test whether phenylthiocarbamide (PTC) `supertasters' also taste salt and sugar with greater intensity, as suggested by Bartoshuk and colleagues (2004), we infused strips of paper with salt water or sugar water. The bitterness rating of the PTC strip had a significant positive linear relationship with ratings of both the intensity of sweet and salt, but the effect sizes were very low, suggesting that the PTC strip does not give a complete picture of tasting ability. Next we investigated whether various seasonings could mask the bitter taste of vegetables and whether this varied with tasting ability. We found that sugar decreased bitterness and lemon decreased liking for vegetables of varying degrees of bitterness. The results did not differ by ability to taste any of the flavors. Therefore, even though there are remarkable individual differences in taste perception, sugar can be used to improve the initial palatability of vegetables and increase their acceptance and consumption.
ContributorsWilkie, Lynn Melissa (Author) / Phillips, Elizabeth D. (Thesis advisor) / Cohen, Adam (Committee member) / Johnston, Carol (Committee member) / Arizona State University (Publisher)
Created2012
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 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
Description
To date, there have not been any studies in a human population that explore the potential of vinegar ingestion in reducing visceral fat, a common yet serious metabolic disease risk factor. However, previous research in animal models exhibit promising findings, showing that vinegar is effective at reducing visceral fat. This is thought to be due to the activation of AMPK (adenosine monophosphate protein kinase) by acetic acid, the active ingredient in vinegar. The purpose of this study was to identify if this potentially groundbreaking relationship exists in human subjects. Healthy, nonsmoking, sedentary adults between the ages 18-45 y and a waist circumference measurement greater than or equal to 33 inches for women and 38 inches for men were recruited for this study. Twenty-three participants completed this 8-week, parallel arm, randomized control trial that tested the efficacy of red wine vinegar consumption (2 tablespoons red wine vinegar, twice per day, before a meal; providing 3.6 g acetic acid) against a placebo (1 apple cider vinegar pill, twice per day, before a meal; providing 0.0225 g acetic acid) for 8 weeks. Participants were randomized into either the vinegar (VIN) or control (CON) group after being stratified by age, gender, waist circumference, and weight. Results found that the VIN group experienced a 2% decrease in visceral fat (cm3, quantified by a DXA scan), but this change did not differ significantly from that of the CON group (p=0.256). The VIN group also experienced a slight decrease in insulin compared to the CON group, but this change was not significantly different than the control change (p=0.125). However, the change in HOMA-IR trended downward in the VIN group (-16%) as compared to the CON group (+9%) (p=0.079) with a large effect size, 0.153. Other parameters did not show statistically significant results between the groups. Further research is indicated in order to examine the potential of vinegar to reduce visceral fat.
ContributorsBaker, Olivia (Author) / Johnston, Carol (Thesis advisor) / Mayol-Kreiser, Sandra (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2018
Description
Epidemiological studies have identified obesity as a risk factor for numerous chronic diseases such as adult onset diabetes, hypertension, and hypercholesterolemia. In both humans and laboratory animals, high-fat diets have been shown to cause obesity. Increases in dietary fat lead to increased energy consumption and, consequently, significant increases in body fat content. CD36 has been implicated in fat perception, preference, and increased consumption, but it is yet to be tested using a behavior paradigm. To study the effect of CD36 on fat taste transmission and fat consumption, four CD36 knockout (experimental) mice and four Black 6 wildtype (control) mice underwent 20 days of fat preference and perception testing. Both groups of mice were exposed to foods with progressively increasing fat content (10%, 12.5%, 15% 17.5%, 20%, 45%) in order to assess the effect of CD36 on fat preference. Afterward, the mice were subjected to an aversive conditioning protocol designed to test the effect of CD36 on fat taste perception; development of a conditioned taste aversion was indicative of ability to taste fat. Especially, knockout mice exhibited diminished preference for and reduced consumption of fat during preference testing and were unable to identify fat taste as the conditioned stimulus during aversive conditioning. A repeated measures ANOVA with Bonferroni correction revealed a significant main effect of group on fat consumption, energy intake, and weight. Linear regression revealed CD36 status to account for a majority of observed variance in fat consumption across both phases of the experiment. These results implicate CD36 in fat taste perception and preference and add to the growing body of evidence suggesting fat as a primary taste.
ContributorsJasbi, Paniz (Author) / Johnston, Carol (Thesis advisor) / Lespron, Christy (Committee member) / Wadhera, Devina (Committee member) / Arizona State University (Publisher)
Created2018
Description
Objectives: To investigate the potential of vinegar supplementation as a means for reducing visceral fat in healthy overweight and obese adults, and to evaluate its effects on fasting blood glucose and fasting insulin.
Subjects and Methods: Forty-five sedentary overweight and obese adult participants with a waist circumference greater than 32 inches for women and 37 inches for men were randomly assigned to one of two groups, the vinegar group (VIN, n=21) or the control group (CON, n=24), and instructed to consume either two tablespoons of liquid red wine vinegar (3.6g acetic acid) or a control pill (0.0225g acetic acid) twice daily at the beginning of a meal for 8 weeks. Participants were also instructed to maintain normal diet and physical activity levels. Anthropometric measures, dual-energy x-ray absorptiometry (DXA) scans, blood samples, and 24-hour dietary recalls were collected at baseline and at end of trial. A compliance calendar was provided for daily tracking of vinegar supplementation.
Results: Compliance to vinegar supplementation averaged 92.7 ±13.3% among the VIN group and 89.1 ±18.9% among the CON group. There were no statistically significant differences in anthropometric measurements between baseline and week 8: weight (P=0.694), BMI (P=0.879), and waist circumference (P=0.871). Similarly, DXA scan data did not show significant changes in visceral fat (P=0.339) or total fat (P=0.294) between baseline and week 8. The VIN group had significant reductions in fasting glucose (P=0.003), fasting insulin (P <0.001), and homeostatic model assessment of insulin resistance scores (P <0.001) after treatment.
Conclusions: These data do not support the findings from previous studies that indicated a link between vinegar supplementation and increased fat metabolism, specifically visceral fat reduction.
Subjects and Methods: Forty-five sedentary overweight and obese adult participants with a waist circumference greater than 32 inches for women and 37 inches for men were randomly assigned to one of two groups, the vinegar group (VIN, n=21) or the control group (CON, n=24), and instructed to consume either two tablespoons of liquid red wine vinegar (3.6g acetic acid) or a control pill (0.0225g acetic acid) twice daily at the beginning of a meal for 8 weeks. Participants were also instructed to maintain normal diet and physical activity levels. Anthropometric measures, dual-energy x-ray absorptiometry (DXA) scans, blood samples, and 24-hour dietary recalls were collected at baseline and at end of trial. A compliance calendar was provided for daily tracking of vinegar supplementation.
Results: Compliance to vinegar supplementation averaged 92.7 ±13.3% among the VIN group and 89.1 ±18.9% among the CON group. There were no statistically significant differences in anthropometric measurements between baseline and week 8: weight (P=0.694), BMI (P=0.879), and waist circumference (P=0.871). Similarly, DXA scan data did not show significant changes in visceral fat (P=0.339) or total fat (P=0.294) between baseline and week 8. The VIN group had significant reductions in fasting glucose (P=0.003), fasting insulin (P <0.001), and homeostatic model assessment of insulin resistance scores (P <0.001) after treatment.
Conclusions: These data do not support the findings from previous studies that indicated a link between vinegar supplementation and increased fat metabolism, specifically visceral fat reduction.
ContributorsGonzalez, Lisa Ann (Author) / Johnston, Carol (Thesis advisor) / Mayol-Kreiser, Sandra (Committee member) / McCoy, Maureen (Committee member) / Arizona State University (Publisher)
Created2019
Description
Background: Acetic acid in vinegar has demonstrated antiglycemic effects in previous studies; however, the mechanism is unknown.
Objective: To determine whether acetic acid dissociates in the addition of sodium chloride and describe a flavorful vinaigrette that maintains the functional properties of acetic acid.
Design: Phase I - Ten healthy subjects (23-40 years) taste tested five homemade vinaigrette and five commercial dressings. Perceived saltiness, sweetness, tartness, and overall tasted were scored using a modified labeled affective magnitude scale. Each dressing was tested three times for pH with a calibrated meter. Phase II – Randomized crossover trial testing six dressings against a control dressing two groups of nine healthy adult subjects (18-52 years). Height, weight and calculated body mass index (BMI) were performed at baseline. Subjects participated in four test sessions each, at least seven days apart. After a 10-hour fast, participants consumed 38g of the test drink, followed by a bagel meal. Capillary blood glucose was obtained at fasting, and every 30 minutes over a 2-hour period the test meal.
Results: Dressing pH reduced as sodium content increased. In the intervention trials, no significant differences were observed between groups (p >0.05). The greatest reduction in postprandial glycemia (~21%) was observed in the dressing containing 200 mg of sodium. Effect size was large in both group 1 (η2=0.161) and group 2 (η2=0.577).
Conclusion: The inclusion of sodium into acetic acid may impair its ability to attenuate blood glucose after a meal.
Objective: To determine whether acetic acid dissociates in the addition of sodium chloride and describe a flavorful vinaigrette that maintains the functional properties of acetic acid.
Design: Phase I - Ten healthy subjects (23-40 years) taste tested five homemade vinaigrette and five commercial dressings. Perceived saltiness, sweetness, tartness, and overall tasted were scored using a modified labeled affective magnitude scale. Each dressing was tested three times for pH with a calibrated meter. Phase II – Randomized crossover trial testing six dressings against a control dressing two groups of nine healthy adult subjects (18-52 years). Height, weight and calculated body mass index (BMI) were performed at baseline. Subjects participated in four test sessions each, at least seven days apart. After a 10-hour fast, participants consumed 38g of the test drink, followed by a bagel meal. Capillary blood glucose was obtained at fasting, and every 30 minutes over a 2-hour period the test meal.
Results: Dressing pH reduced as sodium content increased. In the intervention trials, no significant differences were observed between groups (p >0.05). The greatest reduction in postprandial glycemia (~21%) was observed in the dressing containing 200 mg of sodium. Effect size was large in both group 1 (η2=0.161) and group 2 (η2=0.577).
Conclusion: The inclusion of sodium into acetic acid may impair its ability to attenuate blood glucose after a meal.
ContributorsBonsall, Amber K (Author) / Johnston, Carol (Thesis advisor) / Mayol-Kreiser, Sandra (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2017