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Search Results: 1 - 10 of 312105 matches for " Richard J. Bloomer "
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Decreased blood antioxidant capacity and increased lipid peroxidation in young cigarette smokers compared to nonsmokers: Impact of dietary intake
Richard J Bloomer
Nutrition Journal , 2007, DOI: 10.1186/1475-2891-6-39
Abstract: We compared resting plasma antioxidant reducing capacity (ARC; expressed in uric acid equivalents), serum trolox-equivalent antioxidant capacity (TEAC), whole blood total glutathione, plasma malondialdehyde (MDA), and plasma oxidized low density lipoprotein (oxLDL) between 15 young (24 ± 4 years), novice smokers (pack-year history: 3 ± 2) and 13 nonsmokers of similar age (24 ± 5 years). Detailed dietary records were maintained during a seven-day period for analysis of total energy, macro- and micronutrient intake.ARC (0.0676 ± 0.0352 vs. 0.1257 ± 0.0542 mmol·L-1; mean ± SD, p = 0.019), TEAC (0.721 ± 0.120 vs. 0.765 ± 0.130 mmol·L-1, p = 0.24) and glutathione (835 ± 143 vs. 898 ± 168 μmol·L-1, p = 0.28) were lower in smokers compared to nonsmokers, with only the former being statistically significant. MDA (0.919 ± 0.32 vs. 0.647 ± 0.16 μmol·L-1, p = 0.05) and oxLDL were both higher in smokers compared to nonsmokers (229 ± 94 vs. 110 ± 62 ng·mL-1, p = 0.12), although only the MDA comparison was of statistical significance. Interestingly, these findings existed despite no differences in dietary intake, including antioxidant micronutrient consumption, between both smokers and nonsmokers.These data, with specificity to young, novice cigarette smokers, underscore the importance of smoking abstinence. Future studies with larger sample sizes, inclusive of smokers of different ages and smoking histories, are needed to extend these findings.Production of reactive oxygen species (ROS) in quantities that overwhelm the endogenous antioxidant defense system is referred to as oxidative stress and involves the oxidation of molecules in ways that impair cellular function. Chronic oxidative stress has a strong association with numerous disease states including cardiovascular disease (CVD), with several excellent reviews of associated mechanisms relating oxidative stress with CVD recently presented [1-4]. Cigarette smokers have an increased risk of CVD, possibly mediated by elevated l
Chronic Marijuana Smoking Does Not Negatively Impact Select Blood Oxidative Stress Biomarkers in Young, Physically Active Men and Women  [PDF]
Richard J. Bloomer, Matthew Butawan, Nicholas J. G. Smith
Health (Health) , 2018, DOI: 10.4236/health.2018.107071
Abstract: Background: The smoking of Cannabis sativa, the marijuana plant, is increasing in popularity among young adults, even those who may be engaged in regular exercise (i.e., athletes). Research has shown the plant to have antioxidant and analgesic properties, but the effects on oxidative stress are conflicting. The purpose of this study was to measure blood oxidative stress and cardio-metabolic parameters in physically active men and women who regularly smoke marijuana. Methods: A total of 43 marijuana smokers (23 ± 4 years) and 22 non-smokers (24 ± 7 years), who did not smoke tobacco products, participated in this study. Both smokers and non-smokers engaged in regularly exercise, totaling several hours per week (6.4 ± 4.0 and 6.8 ± 4.4, respectively). Smokers reported using marijuana frequently during the week (4.5 ± 2.3 sessions) for a minimum of three consecutive months prior to participating in the study. Blood samples were collected from participants following a 12-hour fast (all food, drink [except water] and smoking) and analyzed for malondialdehyde, advanced oxidation protein products, glucose, cholesterol, and triglycerides. Heart rate and blood pressure was also measured and recorded. Results: No differences of statistical significance were noted for any variable (p > 0.05), with very similar values noted between smokers and non-smokers. Conclusions: In a sample of young, physically active men and women, regular marijuana smoking is not associated with untoward effects on select biomarkers of oxidative stress and cardio-metabolic health. These findings do not suggest that marijuana smoking can be done without harm, as limitations of this study need to be considered.
Hormonal response to lipid and carbohydrate meals during the acute postprandial period
Rick J Alleman, Richard J Bloomer
Journal of the International Society of Sports Nutrition , 2011, DOI: 10.1186/1550-2783-8-19
Abstract: We compared the hormonal response to lipid and carbohydrate meals of different caloric content during the acute postprandial period. Nine healthy men (22 ± 2 years) consumed in a random order, cross-over design one of four meals/beverages during the morning hours in a rested and fasted state: dextrose at 75 g (300 kcals), dextrose at 150 g (600 kcals), lipid at 33 g (300 kcals), lipid at 66 g (600 kcals). Blood samples were collected Pre meal, and at 0.5 hr, 1 hr, 2 hr, and 3 hr post meal. Samples were assayed for testosterone, cortisol, and insulin using ELISA techniques. Area under the curve (AUC) was calculated for each variable, and a 4 × 5 ANOVA was used to further analyze data.A meal × time effect (p = 0.0003) was noted for insulin, with values highest for the dextrose meals at the 0.5 hr and 1 hr times, and relatively unaffected by the lipid meals. No interaction (p = 0.98) or meal (p = 0.39) effect was noted for testosterone, nor was an interaction (p = 0.99) or meal (p = 0.65) effect noted for cortisol. However, a time effect was noted for both testosterone (p = 0.04) and cortisol (p < 0.0001), with values decreasing during the postprandial period. An AUC effect was noted for insulin (p = 0.001), with values higher for the dextrose meals compared to the lipid meals (p < 0.05). No AUC effect was noted for testosterone (p = 0.85) or cortisol (p = 0.84).These data indicate that 1) little difference is noted in serum testosterone or cortisol during the acute postprandial period when healthy men consume lipid and dextrose meals of different size; 2) Both testosterone and cortisol experience a drop during the acute postprandial period, which is similar to what is expected based on the normal diurnal variation--feeding with lipid or dextrose meals does not appear to alter this pattern; 3) dextrose meals of either 75 g or 150 g result in a significant increase in serum insulin, in particular at 0.5 hr and 1 hr post-ingestion; 4) lipid meals have little impact on se
Impact of a Dietary Supplement Containing Rosemary and Daylily on Biochemical Markers of Cognitive Health, Sleep Quality and Related Variables in Men and Women  [PDF]
Richard J. Bloomer, John J. MacDonnchadh, Ryan G. Moran, Judi Quilici Timmcke, Bolin Qin
Health (Health) , 2016, DOI: 10.4236/health.2016.813132
Abstract: Background: We investigated the influence of a botanical agent to improve sleep quality and associated measures in men and women with self-reported difficulty sleeping. Methods: 32 individuals were randomly assigned in double blind manner to ingest a botanical agent (CLOCK?, containing Rosemary [Rosmarinus officinalis] and Daylily [Hemerocallis fulva]) or a placebo over a 6-week intervention. During weeks 1 and 2, subjects ingested one serving of the assigned condition, followed by a two-week washout. During weeks 5 and 6, subjects ingested two servings of the condition. The Leeds Sleep Evaluation Questionnaire was used as an outcome measure, as were subjective measures of sleep quality, energy level, and mood. Blood samples collected pre- and post-intervention were assayed for acetylcholine (ACH), brain-derived neurotrophic factor (BDNF), irisin, and melatonin. Results: No differences were noted between conditions in measures of sleep (p > 0.05). While no differences of statistical significance were noted in subjective feelings, during weeks 5 and 6 as compared to baseline, subjects assigned to the supplement noted an 8% increase in attentiveness, an 11% increase in alertness, a 12% increase in focus, a 14% increase in feeling energetic, a 12% increase in enthusiasm, a 23% increase in feeling well rested, an 11% decrease in feeling sluggish, and a 16% decrease in feeling depressed, without the same improvement observed for subjects in the placebo group. All biochemical measures were increased from pre- to post-treatment with two servings of the supplement; the largest percent increase noted for BDNF (27%) and the largest effect size noted for irisin (d = 1.36). Biochemical values for the placebo condition were unchanged. Conclusions: CLOCK? may have an impact on certain measurements of mood, with a significant impact on the biochemical marker, BDNF. Future studies using a larger sample size and perhaps a cross-over design may help to further clarify the impact of this dietary supplement on aspects of sleep quality, mood, and other related variables.
Use of a Standing Desk Increases Energy Expenditure in Obese but Not Normal Weight Subjects  [PDF]
Nicholas J. G. Smith, Matt Butawan, Jade Caldwell, Richard J. Bloomer
Health (Health) , 2018, DOI: 10.4236/health.2018.107070
Abstract: Background: The use of standing desks has been associated with greater metabolic cost as compared to traditional seated desks. However, it is unclear as to the metabolic impact of standing desks in normal weight versus obese men and women. Methods: We compared the metabolic cost of using a standing and seated desk in 14 obese and 19 normal weight men and women. Subjects reported to the lab on a single occasion and participated in two, 30-minute sessions of standing and seated desk work (i.e., typing), in random order. Expired gases were collected during the 2-hour period and calorie expenditure was estimated using indirect calorimetry. Results: We noted a significant (p = 0.013) increase in energy expenditure of 7.4 kcal30 minutes1 (+14.7%) during standing as compared to seated for the obese group. No significant difference in energy expenditure was noted for the normal weight group (p = 0.674). A condition effect was noted for heart rate and diastolic blood pressure, with standing being significantly higher than seated for both variables (p < 0.05). No group, condition, or group × condition effects were noted for typing performance or subjective feelings (p > 0.05). Conclusion: The use of a standing desk modestly increases energy expenditure in obese subjects but does not have the same effect in those of normal weight. It is unknown whether the increased energy expenditure would be maintained over time in the obese subjects/individuals, as they may adapt to the standing position. Moreover, if normal weight individuals choose a standing desk, they should do so for reasons unrelated to increased energy expenditure (e.g., improved spine health, greater feeling of productivity).
The impact of religious fasting on human health
John F Trepanowski, Richard J Bloomer
Nutrition Journal , 2010, DOI: 10.1186/1475-2891-9-57
Abstract: Fasting is defined as a partial or total abstention from all foods, or a select abstention from prohibited foods. As a potential non-pharmacological intervention for improving health and increasing longevity, fasting has been the subject of numerous scientific investigations. The three most commonly studied fasts are caloric restriction (CR), alternate-day fasting (ADF), and dietary restriction (DR). A summary of the main findings is presented below.CR is the reduction of kilocalorie (kcal) intake by a certain percentage (typically 20 - 40%) of ad libitum consumption. CR has been demonstrated to improve health and increase longevity in a diverse group of species, including: dog, fruit fly, nematode, rodent, rotifer, spider, non-human primate, and zebrafish [1]. Additionally, CR appears to delay the onset of the following diseases: autoimmune diseases, atherosclerosis, cardiomyopathies, cancer, diabetes, renal diseases, neurodegenerative diseases, and respiratory diseases [2,3]. Regarding cardiovascular health, the following changes have been noted following a CR regimen: decreases in resting heart rate (HR) and blood pressure (BP); increases in HR variability; and improvements in left ventricular function, post-exercise recovery of both HR and BP, and flow-mediated vasodilation [4]. Regarding glucoregulatory health, CR has been shown to decrease fasting glucose and insulin levels, increase insulin sensitivity, decrease body fat percentage, and lower the incidence of diabetes [5,6].ADF consists of alternating 24-hour periods: during the "feast period," fasters may consume food ad libitum; during the "fast period," food consumption is restricted or halted altogether. Water is allowed ad libitum during all times. Animal ADF trials have reported extended lifespan [1] as well as the retardation or altogether prevention of the development of many morbidities, including: cardiovascular disease, kidney disease, cancers, and diabetes [4,7]. ADF has been noted to elicit the f
Systemic Oxidative Stress Is Increased to a Greater Degree in Young, Obese Women Following Consumption of a High Fat Meal
Richard J. Bloomer,Kelsey H. Fisher-Wellman
Oxidative Medicine and Cellular Longevity , 2009, DOI: 10.4161/oxim.2.1.7860
Abstract: High fat meals induce oxidative stress, which is associated with the pathogenesis of disease. Obese individuals have elevated resting biomarkers of oxidative stress compared to non-obese. We compared blood oxidative stress biomarkers in obese (n = 14; 30 ± 2 years; BMI 35 ± 1 kg•m−2) and non-obese (n = 16; 24 ± 2 years; BMI 23 ± 1 kg•m−2) women, in response to a high fat meal. Blood samples were collected pre-meal (fasted), and at 1, 2, 4 and 6 hours post meal, and assayed for trolox equivalent antioxidant capacity (TEAC), xanthine oxidase activity (XO), hydrogen peroxide (H2O2), malondialdehyde (MDA), triglycerides (TAG), and glucose. An obesity status effect was noted for all variables (p < 0.001; MDA p = 0.05), with obese women having higher values than non-obese, except for TEAC, for which values were lower. Time main effects were noted for all variables (p ≤ 0.01) except for TEAC and glucose, with XO, H2O2, MDA and TAG increasing following feeding with a peak response at the four or six hour post feeding time point. While values tended to decline by six hours post feeding in the non-obese women (agreeing with previous studies), they were maintained (MDA) or continued to increase (XO, H2O2 and TAG) in the obese women. While no interaction effects were noted (p > 0.05), contrasts revealed greater values in obese compared to non-obese women for XO, H2O2, MDA, TAG and glucose, and lower values for TEAC at times from 1–6 hours post feeding (p ≤ 0.03). We conclude that young, obese women experience a similar pattern of increase in blood oxidative stress biomarkers in response to a high fat meal, as compared to non-obese women. However, the overall oxidative stress is greater in obese women, and values appear to remain elevated for longer periods of time post feeding. These data provide insight into another potential mechanism related to obesity-mediated morbidity.
Oxidative Stress and Antioxidant Defense Mechanisms Linked to Exercise During Cardiopulmonary and Metabolic Disorders
Kelsey Fisher-Wellman,Heather K. Bell,Richard J. Bloomer
Oxidative Medicine and Cellular Longevity , 2009, DOI: 10.4161/oxim.2.1.7732
Abstract: Oxidative stress has been implicated in the pathophysiology of multiple human diseases, in addition to the aging process. Although various stimuli exist, acute exercise is known to induce a transient increase in reactive oxygen and nitrogen species (RONS), evident by several reports of increased oxidative damage following acute bouts of aerobic and anaerobic exercise. Although the results are somewhat mixed and appear disease dependent, individuals with chronic disease experience an exacerbation in oxidative stress following acute exercise when compared to healthy individuals. However, this increased oxidant stress may serve as a necessary “signal” for the upregulation in antioxidant defenses, thereby providing protection against subsequent exposure to prooxidant environments within susceptible individuals. Here we present studies related to both acute exercise-induced oxidative stress in those with disease, in addition to studies focused on adaptations resulting from increased RONS exposure associated with chronic exercise training in persons with disease.
Postprandial Oxidative Stress in Exercise Trained and Sedentary Cigarette Smokers
Richard J. Bloomer,Kelsey H. Fisher-Wellman
International Journal of Environmental Research and Public Health , 2009, DOI: 10.3390/ijerph6020579
Abstract: Cigarette smokers experience an exaggerated triglyceride (TAG) and oxidative stress response to high fat feeding. Exercise training may serve to attenuate the rise in these variables, by improving TAG clearance and antioxidant defense. We compared blood TAG, antioxidant capacity, and oxidative stress biomarkers in exercise trained (>2 hrs per wk) and untrained smokers matched for age, in response to a high fat test meal. We report here that low volume exercise training can attenuate postprandial lipid peroxidation, but has little impact on blood TAG and other markers of oxidative stress. Higher volumes of exercise may be needed to allow for clinically meaningful adaptations in postprandial lipemia and oxidative stress.
A dual investigation of the effect of dietary supplementation with licorice flavonoid oil on anthropometric and biochemical markers of health and adiposity
Zach W Bell, Robert E Canale, Richard J Bloomer
Lipids in Health and Disease , 2011, DOI: 10.1186/1476-511x-10-29
Abstract: We investigated the effects of LFO in two separate studies. Study 1 included a sample of overweight or grade I-II obese men and women (N = 22) who followed their usual dietary and physical activity programs. Study 2 included a sample of athletic men who followed their usual dietary and physical activity programs but consumed a daily supplemental meal (25% above daily energy requirements) in an attempt to induce a state of overfeeding. In both studies, subjects were randomly assigned (double-blind) to either LFO or a placebo for eight weeks, and anthropometric and multiple biochemical outcomes (e.g., markers of oxidative stress, markers of insulin sensitivity, blood lipids, etc.) were obtained before and following the intervention.No differences of statistical significance were noted between LFO and placebo for any measured variable in Study 1 or Study 2. When investigating the percent change from baseline for data in Study 2, although not of statistical significance, subjects in the LFO condition experienced less overall fat gain, as well as attenuation in the elevation in selected blood lipids (e.g., cholesterol, LDL-C, and triglycerides).These combined data indicate little effect of LFO supplementation within a sample of overweight/obese men and women or athletic men, with the possible exception of attenuation in body fat gain and selected components of the blood lipid panel in response to an overfeeding condition.Licorice flavonoid oil (LFO) has been reported to minimize body weight and visceral adipose tissue gain in obese mice [1,2], and to result in a decrease in body weight and body fat in humans [3]. However, human studies to date have focused primarily on anthropometric outcomes (e.g., abdominal fat assessment via computed tomography [CT] scans), while also including measures of blood glucose and lipids. No human study has included other important biomarkers of metabolic and cardiovascular health such as adiponectin, resistin, C-reactive protein, and measur
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