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1.
Effects of Daily Matcha and Caffeine Intake on Mild Acute Psychological Stress-Related Cognitive Function in Middle-Aged and Older Adults: A Randomized Placebo-Controlled Study.
Baba, Y, Inagaki, S, Nakagawa, S, Kobayashi, M, Kaneko, T, Takihara, T
Nutrients. 2021;(5)
Abstract
Matcha, a type of green tea, has a higher amino acid content than other types of tea. We previously examined the ability of matcha to improve cognitive function in older adults and determined that continuous matcha intake improves attention and executive function. This study aimed to compare the effects of matcha and caffeine and clarify the differences between these effects. The study was registered at the University Hospital Medical Information Network (UMIN000036578). The effect of single and continuous intake was compared, and the usefulness of continuous intake was evaluated under the stress condition. The Uchida-Kraepelin test (UKT) was used to induce mild acute stress, and the Cognitrax was used to evaluate cognitive function. A single dose of caffeine improved attentional function during or after stress loading. The reduced reaction time in the Cognitrax, observed following a single dose of matcha, was likely due to caffeine. The matcha group showed an increase in the amount of work after continuous intake, whereas the caffeine group only showed an increase in the amount of work for the UKT after a single dose. Ingesting matcha with caffeine improves both attention and work performance when suffering from psychological stress compared with caffeine alone.
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2.
Effect of SunGold Kiwifruit and Vitamin C Consumption on Ameliorating Exercise-Induced Stress Response in Women.
Ali, A, Mehta, S, Starck, C, Wong, M, O'Brien, WJ, Haswell, C, McNabb, W, Rutherfurd-Markwick, K, Ahmed Nasef, N
Molecular nutrition & food research. 2021;(10):e2001219
Abstract
INTRODUCTION Markers of oxidative and psychological stress are elevated during high-intensity exercise. Additionally, when energy intake does not match expenditure, women who actively participate in sports and exercise are at risk of developing menstrual dysfunction, infertility, and osteoporosis. Vitamin C is known to reduce exercise-induced stress. Here, this study investigates the efficacy of consuming vitamin C from SunGold kiwifruit compared to in isolation, in ameliorating exercise-induced stress in recreationally active women. METHODS AND RESULTS Ten eumenorrheic women are recruited in this crossover study and attended three exercise and one rest trial. In the exercise trials, participants consumed 300 mg vitamin C from kiwifruit or drink, or have a placebo drink, followed by 30-min exercise on a cycle ergometer at 60% power. During rest visit, participants sat quietly and consumed a placebo drink. Salivary uric acid (oxidative stress) and cortisol (psychological stress) are measured before and immediately after exercise for 2 h. Both vitamin C and kiwifruit reduced exercise-induced uric acid, immediately after exercise. Vitamin C drink continued to decrease uric acid for a further 30 min and slightly attenuated exercise-induced cortisol. CONCLUSIONS Consuming liquid vitamin C prior to high-intensity cycling appears more effective than eating kiwifruit, in ameliorating exercise-induced stress in recreationally active women of reproductive age.
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3.
Hair Cortisol Concentration, Weight Loss Maintenance and Body Weight Variability: A Prospective Study Based on Data From the European NoHoW Trial.
Larsen, SC, Turicchi, J, Christensen, GL, Larsen, CS, Jørgensen, NR, Mikkelsen, MK, Horgan, G, O'Driscoll, R, Michalowska, J, Duarte, C, et al
Frontiers in endocrinology. 2021;:655197
Abstract
UNLABELLED Several cross-sectional studies have shown hair cortisol concentration to be associated with adiposity, but the relationship between hair cortisol concentration and longitudinal changes in measures of adiposity are largely unknown. We included 786 adults from the NoHoW trial, who had achieved a successful weight loss of ≥5% and had a body mass index of ≥25 kg/m2 prior to losing weight. Hair cortisol concentration (pg/mg hair) was measured at baseline and after 12 months. Body weight and body fat percentage were measured at baseline, 6-month, 12-month and 18-month visits. Participants weighed themselves at home ≥2 weekly using a Wi-Fi scale for the 18-month study duration, from which body weight variability was estimated using linear and non-linear approaches. Regression models were conducted to examine log hair cortisol concentration and change in log hair cortisol concentration as predictors of changes in body weight, change in body fat percentage and body weight variability. After adjustment for lifestyle and demographic factors, no associations between baseline log hair cortisol concentration and outcome measures were observed. Similar results were seen when analysing the association between 12-month concurrent development in log hair cortisol concentration and outcomes. However, an initial 12-month increase in log hair cortisol concentration was associated with a higher subsequent body weight variability between month 12 and 18, based on deviations from a nonlinear trend (β: 0.02% per unit increase in log hair cortisol concentration [95% CI: 0.00, 0.04]; P=0.016). Our data suggest that an association between hair cortisol concentration and subsequent change in body weight or body fat percentage is absent or marginal, but that an increase in hair cortisol concentration during a 12-month weight loss maintenance effort may predict a slightly higher subsequent 6-months body weight variability. CLINICAL TRIAL REGISTRATION ISRCTN registry, identifier ISRCTN88405328.
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4.
Matcha consumption maintains attentional function following a mild acute psychological stress without affecting a feeling of fatigue: A randomized placebo-controlled study in young adults.
Baba, Y, Kaneko, T, Takihara, T
Nutrition research (New York, N.Y.). 2021;:44-52
Abstract
Tea is a beverage commonly consumed worldwide. Matcha is a type of green tea produced by drying and grinding tea leaves (Camellia sinensis L.) into a fine powder. Matcha contains catechin, theanine, and caffeine, which affect cognitive function. Epidemiological studies conducted in Japan have shown that green tea consumption improves cognitive impairment. Previously, we found that daily matcha intake improves attention and executive function in middle-aged and older people. However, its effect on cognitive function in younger adults remains unclear. Moreover, it is unclear which cognitive functions are impaired by stress. This study aimed to clarify whether the administration of matcha improves the attentional function of young adults after mild acute stress and which cognitive function is improved. We included 42 participants aged 25 to 34 years who consumed 2 g of matcha daily for 2 weeks. The Uchida-Kraepelin test was used to induce mild acute psychological stress. Memory, attention, facial expression recognition, working memory, visual information, and motor function were evaluated. Reaction times on the Stroop test for attentional function were significantly lower in the matcha group than in the placebo group. Correct hits in the emotion perception test increased significantly for participants in the matcha group compared to those in the placebo group. We found no significant between-group differences in the other tests. In conclusion, after 2 weeks of matcha intake, the attentional function was maintained after mild acute psychological stress. Thus, matcha might improve cognitive function during or after stress conditions in young adults.
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5.
Acute and Chronic Effects of Green Oat (Avena sativa) Extract on Cognitive Function and Mood during a Laboratory Stressor in Healthy Adults: A Randomised, Double-Blind, Placebo-Controlled Study in Healthy Humans.
Kennedy, DO, Bonnländer, B, Lang, SC, Pischel, I, Forster, J, Khan, J, Jackson, PA, Wightman, EL
Nutrients. 2020;(6)
Abstract
Green oat (Avena sativa) extracts contain several groups of potentially psychoactive phytochemicals. Previous research has demonstrated improvements in cognitive function following a single dose of these extracts, but not following chronic supplementation. Additionally, whilst green oat extracts contain phytochemicals that may improve mood or protect against stress, for instance species-specific triterpene saponins, to date this possibility has not been examined. The current study investigated the effects of a single dose and four weeks of administration of a novel, Avena sativa herbal extract (cognitaven®) on cognitive function and mood, and changes in psychological state during a laboratory stressor. The study adopted a dose-ranging, double-blind, randomised, parallel groups design in which 132 healthy males and females (35 to 65 years) received either 430 mg, 860 mg, 1290 mg green oat extract or placebo for 29 days. Assessments of cognitive function, mood and changes in psychological state during a laboratory stressor (Observed Multitasking Stressor) were undertaken pre-dose and at 2 h and 4 h post-dose on the first (Day 1) and last days (Day 29) of supplementation. The results showed that both a single dose of 1290 mg and, to a greater extent, supplementation for four weeks with both 430 mg and 1290 mg green oat extract resulted in significantly improved performance on a computerised version of the Corsi Blocks working memory task and a multitasking task (verbal serial subtractions and computerised tracking) in comparison to placebo. After four weeks, the highest dose also decreased the physiological response to the stressor in terms of electrodermal activity. There were no treatment-related effects on mood. These results confirm the acute cognitive effects of Avena sativa extracts and are the first to demonstrate that chronic supplementation can benefit cognitive function and modulate the physiological response to a stressor.
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6.
Effect of sugar administration on cortisol responses to acute psychosocial stress.
Zänkert, S, Kudielka, BM, Wüst, S
Psychoneuroendocrinology. 2020;:104607
Abstract
Sugar administration prior acute psychosocial stress exposure was shown to enhance subsequent salivary cortisol responses. However, this finding is based on studies that have administered high doses of glucose to male subjects after long fasting periods. Therefore, in the present study, we investigated the effect of different sugar-containing drinks on acute cortisol stress responses under experimental conditions that are commonplace in stress research and our sample included females and males. Our primary aim was to derive feasible recommendations for a standardized sugar administration in future studies. Of the 103 healthy young participants (49 females, 54 males), 72 were confronted with the Trier Social Stress Test after being randomly assigned to one of three sugar conditions (200 ml of grape juice, a 75 g glucose or a 75 g maltodextrin drink); 31 subjects served as control sample and were exposed to the TSST without sugar administration. Cortisol stress responses were significantly enhanced in the grape juice as well as the glucose group as compared to the control group. Post hoc analysis revealed that this effect seemed to be more pronounced in males than in females. We did not find a significant effect of maltodextrin. Cortisol responder rates in all three experimental groups were higher than in the control group. Our results suggest that, at least in males, the administration of 200 ml of grape juice is sufficient to facilitate HPA axis reactivity and to minimize confounding effects due to interindividual differences in energy availability while being exposed to a laboratory stress paradigm. The unexpected gender-specific effect is of potential relevance and should be scrutinized in future studies.
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7.
Snacking on Whole Almonds for Six Weeks Increases Heart Rate Variability during Mental Stress in Healthy Adults: A Randomized Controlled Trial.
Dikariyanto, V, Smith, L, Chowienczyk, PJ, Berry, SE, Hall, WL
Nutrients. 2020;(6)
Abstract
Cardiac autonomic regulation can be indirectly measured by heart rate variability (HRV). Low HRV, which can be induced by mental stress, is a predictor of risk of sudden cardiac death. Few studies have investigated cause-and-effect relationships between diet and HRV. Nut consumption is associated with CVD risk reduction, but the impact on HRV, particularly in response to stress, is unclear. Men and women (30-70 y) with above average risk of developing CVD were randomly assigned in a 6-week randomized, controlled, parallel arm trial to consume either whole almond or isocaloric control snacks (20% of daily estimated energy requirement). Control snacks contained the average nutrient profile of UK snacks. Five-minute periods of supine heart rate (HR) and HRV were measured at resting and during mental stress (Stroop color-word test) at baseline and six weeks. High frequency (HF) power, which reflects parasympathetic regulation of HR, was increased following almonds during the mental stress task relative to control (mean difference between groups 124 ms2; 95% CI 11, 237; p = 0.031, n = 105), but other indices were unaffected. Snacking on whole almonds instead of typical snacks may reduce risk of CVD partly by ameliorating the suppression of HRV during periods of mental stress.
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8.
An 8-Week Relaxation Program Consisting of Progressive Muscle Relaxation and Mindfulness Meditation to Reduce Stress and Attenuate Stress-Driven Eating.
Masih, T, Dimmock, JA, Epel, E, Guelfi, KJ
Applied psychology. Health and well-being. 2020;(1):188-211
Abstract
BACKGROUND Stress is often associated with the intake of energy-dense palatable foods. This trial examined the feasibility and preliminary efficacy of an 8-week worksite-based relaxation intervention to address psychological stress and unhealthy food intake. METHODS Thirty-six men and women were exposed to an acute stressor, while physiological and psychological responses were assessed, prior to being offered a test meal. Participants were then randomised to a relaxation intervention (RELAX; face-to-face classes and daily home practice of progressive muscle relaxation and mindfulness meditation), or a wait-list control (CON). All measures were repeated after the intervention. RESULTS Intervention compliance was high (80% ± 19% face-to-face; 79% ± 18% home practice), and each session acutely reduced perceived stress (p < .001) and increased relaxation (p < .001). After 8 weeks, trait mindfulness was increased (p = .025), along with reduced tension (p = .013) and increased relaxation (p < .05) post-acute stressor in the intervention group. There was no effect of the intervention on palatable eating, cravings, or energy intake at a laboratory test meal, with small associated effect sizes (d = 0.01-0.3). CONCLUSIONS The program studied here is feasible and sessions transiently reduce perceived stress and improve mindfulness; however, the program may not influence the physiological response to an acute stressor or appetite and eating variables.
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9.
The clinical effect of dexmedetomidine combined with parecoxib sodium on sedation, antianxiety and prevention of intubation stress in patients undergoing functional endoscopic sinus surgery: a randomised controlled trial.
Gu, X, Tan, X, Chen, J, Wang, J, Lu, Y, Zhang, L
BMC anesthesiology. 2020;(1):166
Abstract
BACKGROUND To investigate the effect of intravenous injection of dexmedetomidine combined with parecoxib sodium on sedation and anxiety and stress response of tracheal intubation in patients undergoing functional endoscopic sinus surgery. METHODS One hundred twenty patients undergoing endoscopic sinus surgery were randomly divided into four groups: group DP, group D, group P and group N. The blood pressure (BP), heart rate (HR), blood oxygen saturation (SPO2), EEG, bispectral index (BIS), Ramsay sedation score and state anxiety questionnaire (SAI) were recorded before administration (T0), 10 min (T1), 20 min (T2) and 30 min (T3) after administration. After 30 min, endotracheal intubation was performed after anesthesia induction. The BP, HR, SPO2 were recorded 1 min before intubation (T4), intubation (T5), 3 min (T6) after intubation, 5 min (T7) after intubation, and blood samples were collected from patients before administration and after intubation 2 min to detect serum cortisol (Cor), adrenalin (E) norepinephrine (NE) and blood glucose (BS). RESULTS There was no significant difference in Ramsay sedation score before anesthesia, but the Ramsay sedation score in group D、DP was significantly higher than that in group P and group N, the BIS, BP, HR and anxiety scores were significantly lower than those in the group P and group N (p < 0.05). There was no significant difference in Ramsay sedation score, BIS value, anxiety score and BP, HR between group D and group DP (p > 0.05). Compared with T4, there was no significant difference in BIS and BP, HR in group D, group DP and group P (p > 0.05), but the BIS, BP and HR in group N were significantly higher than T4, (p < 0.05). Three minutes after intubation there was no statistical difference in the changes of Cor, E, NE and BS values compared with before intubation in group P and group DP (p > 0.05), but the changes of Cor, E, NE and BS values were significantly lower than that in group N (p < 0.05). Compared with T0, the values of NE, E, Cor, BS decreased in group D, DP and P at T4, group DP decreased more significantly than group D (p < 0.05). while the NE, E, Cor, BS of T6 are at the same level as the base value. In group N, the NE, E, Cor, BS of T4 were at the same level of T0, but significantly higher at T6.And at T6, NE and E in group D, P and N were significantly different from those in group DP (p < 0.05). CONCLUSION Preoperative intravenous infusion of dexmedetomidine combined with parecoxib sodium by functional nasal endoscopy can not only calm and resist anxiety, but also better prevent stress response of endotracheal intubation, which is a safe and effective way of preoperative medication. TRIAL REGISTRATION ChiCTR-OPN-17010444 . Prospectively registered on 16 January 2017.
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10.
Assessment of stress markers in restrained individuals following physical stress with and without sham CED activation.
Sloane, C, Mash, DC, Chan, TC, Kolkhorst, F, Neuman, T, Castillo, EM, Lasoff, D, Wardi, G, Xie, X, Vilke, GM
Journal of forensic and legal medicine. 2020;:101982
Abstract
INTRODUCTION Law enforcement and pre-hospital care personnel often confront individuals who must be physically restrained. Many are under the influence of illicit substances, and law enforcement officers may need to use a controlled electrical device (CED) to gain control of the individual and they are often placed into the prone maximum restraint (PMR) position. These techniques have previously been evaluated for their physiologic effects. The purpose of this study was to investigate the psychological effects of anticipating and experiencing a sham CED activation in healthy human subjects who were exercised and restrained compared with no sham activation by assessing the differences in a panel of several known biomarkers of stress. METHODS We performed a randomized, crossover controlled human subject trial to study the stress associated with exercise, physical exhaustion, and restraint with and without an added psychological stress simulating the field use of a CED. Twenty five total subjects; each subject performed two different trials each consisting of a brief period of intense exercise on a treadmill to exhaustion followed by placement in the PMR with and without induced psychological stress. Blood samples were collected for analysis pre and post exercise, as well as 10 min after completion of the exercise. A panel of hormones and stress markers were measured. RESULTS We found no significant differences in any of the stress biomarkers measured between the two study groups. A trend towards higher levels of copeptin was measured in the sham CED activation arm. CONCLUSION During a brief period of intense exercise followed by the psychological stress of anticipated CED application, there did not appear to be statistically significant changes in the stress panel of biomarkers measured, only a trend towards significance for higher copeptin levels in the patients exposed to the psychological stress.