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Hartnick MD, Marnewick JL, Engel-Hills P, Kemp M, Pretorius K, Lekata S, Uys C. Impact of Chronic Consumption of Herbal Rooibos on Cardiovascular Function in Adults with Cardiovascular Risk. J Med Food 2024. [PMID: 38958559 DOI: 10.1089/jmf.2024.0012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024] Open
Abstract
The prevalence of cardiovascular disease (CVD) has increased in South Africa, emphasizing the importance of prevention strategies. This study used echocardiography to investigate the impact of Rooibos on cardiovascular function in those at risk of CVD. This research aims to contribute to understanding its effects on reducing cardiovascular risk factors. The study design involved a 12-week randomized, parallel, double-blinded, placebo-controlled dietary intervention trial using capsules containing standardized water-soluble extracts of green and traditional fermented Rooibos alongside a placebo control. Echocardiography was incorporated as a diagnostic imaging tool to assess cardiac function in the participant cohort. Aorta (AO) dimensions showed no significant change in any intervention group. Left atrium (LA) reduced in size from 3.832 ± 0.071 cm to 3.675 ± 0.067 cm (P = 0.01). There was no significant change in LA/AO ratio in any intervention group. Interventricular septum diameter in the placebo group decreased from 1.334 ± 0.030 cm to 1.250 ± 0.025 cm (P = 0.002), with no significance in fermented Rooibos, while green Rooibos resulted in a decrease from 1.282 ± 0.036 cm to 1.186 ± 0.029 cm (P = 0.002). Left ventricle posterior wall (LVPW) showed no significant changes in any of the intervention group. The left ventricle mass in the placebo and green Rooibos groups demonstrated no significance changes, while fermented Rooibos caused a decrease from 204.102 ± 7.102 g to 191.394 ± 6.707 g (P = 0.015). The phytochemical bioactive components, such as the polyphenolic antioxidants present in green and fermented Rooibos, improved cardiovascular function. This study confirms the effectiveness of echocardiography as imaging tool for assessing cardiac function in this particular population. Regular Rooibos consumption may offer promising therapeutic benefits for preventing and managing CVD risk.
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Affiliation(s)
- Maria Diana Hartnick
- Department of Medical Imaging and Therapeutic Sciences, Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, Cape Town, South Africa
- Applied Microbial and Health Biotechnology Institute, Cape Peninsula, University of Technology, Cape Town, South Africa
| | - Jeanine L Marnewick
- Applied Microbial and Health Biotechnology Institute, Cape Peninsula, University of Technology, Cape Town, South Africa
| | - Penelope Engel-Hills
- Applied Microbial and Health Biotechnology Institute, Cape Peninsula, University of Technology, Cape Town, South Africa
- Faculty of Health and Wellness Sciences, Cape Peninsula, University of Technology, Cape Town, South Africa
| | - Merlisa Kemp
- Applied Microbial and Health Biotechnology Institute, Cape Peninsula, University of Technology, Cape Town, South Africa
- Faculty of Health and Wellness Sciences, Cape Peninsula, University of Technology, Cape Town, South Africa
| | - Kobus Pretorius
- Applied Microbial and Health Biotechnology Institute, Cape Peninsula, University of Technology, Cape Town, South Africa
- Faculty of Health and Wellness Sciences, Cape Peninsula, University of Technology, Cape Town, South Africa
| | - Stanley Lekata
- Center for Postgraduate Studies, Cape Peninsula University of Technology, Cape Town, South Africa
| | - Corrie Uys
- Center for Postgraduate Studies, Cape Peninsula University of Technology, Cape Town, South Africa
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Ortiz-Sánchez D, Bravo-Sánchez A, Ramírez-delaCruz M, Abián P, Abián-Vicén J. Placebo Effect of Caffeine on Physiological Parameters and Physical Performance. Nutrients 2024; 16:1405. [PMID: 38794643 PMCID: PMC11123970 DOI: 10.3390/nu16101405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 05/03/2024] [Accepted: 05/04/2024] [Indexed: 05/26/2024] Open
Abstract
This study aimed to analyse the placebo effect associated with a high dose of caffeine (9 mg/kg) on heart rate and its variability and on strength tests. METHODS 18 participants experienced in strength training (19.7 ± 2.3 years; 72.2 ± 15.0 kg; 169.6 ± 9.0 cm) performed two days of trials (caffeine-informed/placebo-ingested (placebo) and non-ingested (control)). Firstly, heart rate and its variability were measured while participants lay down for 15 min. After that, bench press and squat tests were performed at 3 different loads (50%, 75% and 90% of 1RM). Perception of performance, effort and side effects were also evaluated. RESULTS no differences were found in the vast majority of strength variables analysed. Resting heart rate decreased in the placebo trial (60.39 ± 10.18 bpm control vs. 57.56 ± 9.50 bpm placebo, p = 0.040), and mean RR increased (1020.1 ± 172.9 ms control vs. 1071.5 ± 185.7 ms placebo, p = 0.032). Heart rate variability and perception of performance and effort were similar between conditions (p > 0.05 in all cases). Side effects such as activeness and nervousness were reported while consuming the placebo. CONCLUSIONS the placebo effect did not modify performance in the majority of the strength test variables, HRV and perception of performance and effort. However, resting heart rate was reduced, mean RR increased, and some side effects appeared in the placebo trial.
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Affiliation(s)
- David Ortiz-Sánchez
- Performance and Sport Rehabilitation Laboratory (DEPORSALUD), Faculty of Sports Sciences, University of Castilla-La Mancha, Avenida Carlos III s/n, 45071 Toledo, Spain; (D.O.-S.); (A.B.-S.); (M.R.-d.); (P.A.)
| | - Alfredo Bravo-Sánchez
- Performance and Sport Rehabilitation Laboratory (DEPORSALUD), Faculty of Sports Sciences, University of Castilla-La Mancha, Avenida Carlos III s/n, 45071 Toledo, Spain; (D.O.-S.); (A.B.-S.); (M.R.-d.); (P.A.)
- Faculty of Health Sciences, Universidad Francisco de Vitoria, 28223 Pozuelo de Alarcón, Spain
| | - María Ramírez-delaCruz
- Performance and Sport Rehabilitation Laboratory (DEPORSALUD), Faculty of Sports Sciences, University of Castilla-La Mancha, Avenida Carlos III s/n, 45071 Toledo, Spain; (D.O.-S.); (A.B.-S.); (M.R.-d.); (P.A.)
| | - Pablo Abián
- Performance and Sport Rehabilitation Laboratory (DEPORSALUD), Faculty of Sports Sciences, University of Castilla-La Mancha, Avenida Carlos III s/n, 45071 Toledo, Spain; (D.O.-S.); (A.B.-S.); (M.R.-d.); (P.A.)
- Faculty of Humanities and Social Sciences, Comillas Pontifical University, Calle. Alberto Aguilera 23, 28049 Madrid, Spain
| | - Javier Abián-Vicén
- Performance and Sport Rehabilitation Laboratory (DEPORSALUD), Faculty of Sports Sciences, University of Castilla-La Mancha, Avenida Carlos III s/n, 45071 Toledo, Spain; (D.O.-S.); (A.B.-S.); (M.R.-d.); (P.A.)
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Lenasi H, Rihar E, Filipič J, Klemenc M, Fister P. The Effect of Caffeine on Heart Rate Variability in Newborns: A Pilot Study. Life (Basel) 2023; 13:1459. [PMID: 37511834 PMCID: PMC10381585 DOI: 10.3390/life13071459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/17/2023] [Accepted: 06/23/2023] [Indexed: 07/30/2023] Open
Abstract
Neonatal apnoea can be treated with caffeine, which affects the central nervous and cardiovascular systems. Heart rate variability (HRV) reflects the activity of the autonomic nervous system (ANS) and might be used as a measure of ANS maturation in newborns. We aimed to establish the effect of caffeine on HRV in newborns and investigated the potential correlation between HRV and postmenstrual age (PMA). In 25 haemodynamically stable newborns hospitalized due to apnoea and treated with caffeine (2.5 mg/kg), we assessed breathing frequency, arterial oxygen saturation, body temperature, and the heart rate while they were sleeping. We assessed HRV by spectral analysis using fast Fourier transformation. The same protocol was reapplied 100 h after caffeine withdrawal to assess the control parameters. Caffeine increased breathing frequency (p = 0.023) but did not affect any other parameter assessed including HRV. We established a positive correlation between postmenstrual age and HRV during treatment with caffeine as well as after caffeine had been withdrawn (total power: p = 0.044; low-frequency band: p = 0.039). Apparently, the maintenance dose of caffeine is too low to affect the heart rate and HRV. A positive correlation between PMA and HRV might reflect maturation of the ANS, irrespective of caffeine treatment.
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Affiliation(s)
- Helena Lenasi
- Institute of Physiology, Medical Faculty, University of Ljubljana, Zaloška cesta 4, 1000 Ljubljana, Slovenia
| | - Eva Rihar
- Children's Hospital, University Medical Centre Ljubljana, Zaloška cesta 2, 1000 Ljubljana, Slovenia
| | - Jerneja Filipič
- Children's Hospital, University Medical Centre Ljubljana, Zaloška cesta 2, 1000 Ljubljana, Slovenia
| | - Matjaž Klemenc
- Department of Cardiology, General Hospital Dr. Franc Derganc, Ulica Padlih Borcev 13A, 5290 Šempeter pri Gorici, Slovenia
| | - Petja Fister
- Children's Hospital, Pediatric Intensive Care Unit, University Medical Centre Ljubljana, Bohoričeva ulica 20, 1000 Ljubljana, Slovenia
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Automated Detection of Caffeinated Coffee-Induced Short-Term Effects on ECG Signals Using EMD, DWT, and WPD. Nutrients 2022; 14:nu14040885. [PMID: 35215531 PMCID: PMC8875083 DOI: 10.3390/nu14040885] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 02/17/2022] [Accepted: 02/17/2022] [Indexed: 01/27/2023] Open
Abstract
The effect of coffee (caffeinated) on electro-cardiac activity is not yet sufficiently researched. In the current study, the occurrence of coffee-induced short-term changes in electrocardiogram (ECG) signals was examined. Further, a machine learning model that can efficiently detect coffee-induced alterations in cardiac activity is proposed. The ECG signals were decomposed using three different joint time–frequency decomposition methods: empirical mode decomposition, discrete wavelet transforms, and wavelet packet decomposition with varying decomposition parameters. Various statistical and entropy-based features were computed from the decomposed coefficients. The statistical significance of these features was computed using Wilcoxon’s signed-rank (WSR) test for significance testing. The results of the WSR tests infer a significant change in many of these parameters after the consumption of coffee (caffeinated). Further, the analysis of the frequency bands of the decomposed coefficients reveals that most of the significant change was localized in the lower frequency band (<22.5 Hz). Herein, the performance of nine machine learning models is compared and a gradient-boosted tree classifier is proposed as the best model. The results suggest that the gradient-boosted tree (GBT) model that was developed using a db2 mother wavelet at level 2 decomposition shows the highest mean classification accuracy of 78%. The outcome of the current study will open up new possibilities in detecting the effects of drugs, various food products, and alcohol on cardiac functionality.
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Caffeine increases performance and leads to a cardioprotective effect during intense exercise in cyclists. Sci Rep 2021; 11:24327. [PMID: 34934054 PMCID: PMC8692308 DOI: 10.1038/s41598-021-03158-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 11/29/2021] [Indexed: 11/29/2022] Open
Abstract
The present study was designed to investigate the effects of different caffeine dietary strategies to compare the impact on athletic performance and cardiac autonomic response. The order of the supplementation was randomly assigned: placebo(4-day)-placebo(acute)/PP, placebo(4-day)-caffeine(acute)/PC and caffeine(4-day)-caffeine(acute)/CC. Fourteen male recreationally-trained cyclists ingested capsules containing either placebo or caffeine (6 mg kg-1) for 4 days. On day 5 (acute), capsules containing placebo or caffeine (6 mg kg-1) were ingested 60 min before completing a 16 km time-trial (simulated cycling). CC and PC showed improvements in time (CC vs PP, Δ - 39.3 s and PC vs PP, Δ - 43.4 s; P = 0.00; ƞ2 = 0.33) and in output power (CC vs PP, Δ 5.55 w and PC vs PP, Δ 6.17 w; P = 0.00; ƞ2 = 0.30). At the final of the time-trial, CC and PC exhibited greater parasympathetic modulation (vagal tone) when compared to the PP condition (P < 0.00; ƞ2 = 0.92). Our study provided evidence that acute caffeine intake (6 mg∙kg-1) increased performance (time-trial) and demonstrated a relevant cardioprotective effect, through increased vagal tone.
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Alcohol and Placebo: The Role of Expectations and Social Influence. Int J Ment Health Addict 2021. [DOI: 10.1007/s11469-020-00321-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
AbstractThe placebo effect is frequently present in our lives when an expectation, associated with any psychoactive material, leads to subjective and physiological changes. The present work studies the role of expectancies associated with ethanol/alcohol in changes to the subjective state. In experimental situations, we examine how these expectations—with or without social influences—affect participants when consuming alcoholic, pseudo-alcoholic, or non-alcoholic cocktails. Psychological and physical changes can, to a significant extent, arise from an expectation-driven placebo effect. We suggest that expectations of inebriation formed by socialization and experiences can explain most of the behavioural changes following alcohol consumption. These effects seem to be stronger if the alcohol consumption happens in a social context and weaker if it is individually. Regarding the information effect, we suppose that the expectations will positively affect the drunkenness, i.e. toward the placebo “direction”: those who believe they are consuming a non-alcoholic cocktail will be less inebriated than those who know their drink contains alcohol. In this study, we successfully demonstrate the expectation-induced classical placebo effect in the misinformed participants who were, in fact, consuming non-alcoholic drinks. The “social” alcohol consumption further enhances the true or believed effects of the alcohol, and thus the participants reported their subjective feelings in lines with their manipulated expectations. As regards the effect of the alcohol, therefore, many other factors contribute in addition to the alcohol itself, the most important of which seem to be group effect, suggestions and expectations.
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7
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Delang N, Irwin C, Cox GR, McCartney D, Desbrow B. Belief in caffeine's ergogenic effect on cognitive function and endurance performance: A sham dose-response study. Hum Psychopharmacol 2021; 36:e2792. [PMID: 33939237 DOI: 10.1002/hup.2792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 04/13/2021] [Indexed: 11/07/2022]
Abstract
This study aimed to determine if belief in caffeine's ergogenic potential influences choice reaction time (CRT) and/or running performance. Twenty-nine healthy individuals (23.7 ± 5 years, 16 males) completed two trials (one week apart). Before the trials, participants indicated their "belief" in caffeine's ergogenic effects and previous "experience" using caffeine for performance. On arrival, participants randomly received either sham "Low (100mg; LD)" or "High (300mg; HD)" dose caffeine capsules 30-min before commencing the CRT test, followed by a 10km run. Paired samples t-tests determined differences between trials for CRT latency (Ex-Gaussian analysis; μ-, σ- and τ-) and running performance using the entire cohort and sub-groups exhibiting strong "beliefs"+/-"experience". Sham caffeine dose did not influence CRT (μ-, σ- and τ-respectively, LD: 400 ± 53ms vs. HD: 388 ± 41ms; LD: 35 ± 18ms vs. HD: 34 ± 17ms; LD: 50 ± 24ms vs. HD: 52 ± 19ms, all p's > 0.05). Neither belief (n = 6), nor belief + experience (n = 4), influenced this effect. Furthermore, caffeine dose did not influence run time (LD: 49.05 ± 3.75min vs. HD: 49.06 ± 3.85min, p = 0.979). Belief (n = 9) (LD: 48.93 ± 3.71min vs. HD: 48.9 ± 3.52min, p = 0.976), and belief + experience (n = 6) (LD: 48.68 ± 1.87min vs. HD: 49.55 ± 1.75min, p = 0.386) didn't influence this effect. A dose-response to sham caffeine ingestion was not evident on cognitive or endurance performance in healthy individuals, regardless of their convictions about caffeine's ergogenicity.
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Affiliation(s)
- Nathan Delang
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, Australia
| | - Christopher Irwin
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, Australia.,The Hopkins Centre, Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| | - Gregory R Cox
- Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Queensland, Australia
| | - Danielle McCartney
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, Australia
| | - Ben Desbrow
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, Australia
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Mendes GF, Reis CEG, Nakano EY, Zandonadi RP. Brief Version of Caffeine Expectancy Questionnaire in Brazil. Front Nutr 2021; 8:695385. [PMID: 34277689 PMCID: PMC8277974 DOI: 10.3389/fnut.2021.695385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/08/2021] [Indexed: 12/24/2022] Open
Abstract
The use of extensive questionnaires has the limitation of filling time bias, related to the ability to focus and accurately respond to many items, justifying the necessity for a brief version. This study aimed to build a brief version of the Caffeine Expectancy Questionnaire in Brazil (B-CaffEQ-BR) composed of 21 items divided into seven factors, with as adequate consistency and reproducibility as the full version. Quantitative procedures using statistical modeling were applied using the CaffEQ-BR (full version) database keeping the Mean Absolute Error (MAE) (based on the full version) <0.5 and Cronbach's α and Intraclass Correlation Coefficient (ICC) ≥0.7. The expert panel (n = 3), in a blind design, evaluated the semantic structuring within the options indicated by previous statistical modeling until the agreement of the expert panel. The participants (n = 62), Brazilian adults who were regular caffeine consumers (175.8 ± 94.4 mg/day), of whom 62.9% were women, 33.1 ± 9.7 years, 24.5 ± 3.8 kg/m2, and 62.9% of whom self-identified as white, were asked to respond twice to the online questionnaire in 48-72 h. The first sample (n = 40) tested interobserver reproducibility with the double application of B-CaffEQ-BR. Another sample (n = 22) answered the CaffEQ-BR (full version) and B-CaffEQ-BR, and the last sample (n = 18) performed the reverse process. The B-CaffEQ-BR presented excellent internal consistency (Cronbach's α ≥ 0.729) and overall reproducibility (ICC ≥ 0.915) for the entire questionnaire and its seven factors. The B-CaffEQ-BR can be a valuable tool in caffeine research with the Brazilian adult population.
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Affiliation(s)
- Guilherme Falcão Mendes
- Department of Nutrition, School of Health Sciences, University of Brasilia (UnB), Brasilia, Brazil
| | | | - Eduardo Yoshio Nakano
- Department of Statistics, Central Institute of Sciences, University of Brasilia (UnB), Brasilia, Brazil
| | - Renata Puppin Zandonadi
- Department of Nutrition, School of Health Sciences, University of Brasilia (UnB), Brasilia, Brazil
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Mendes GF, Reis CEG, Nakano EY, da Costa THM, Saunders B, Zandonadi RP. Translation and Validation of the Caffeine Expectancy Questionnaire in Brazil (CaffEQ-BR). Nutrients 2020; 12:E2248. [PMID: 32731330 PMCID: PMC7468745 DOI: 10.3390/nu12082248] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 07/18/2020] [Accepted: 07/22/2020] [Indexed: 12/30/2022] Open
Abstract
Caffeine is the world's most commonly used stimulant of the central nervous system. Caffeine is present in coffee and other beverages such as tea, soft drinks, and cocoa-based foods. The caffeine expectancy questionnaire was developed to investigate the effects of caffeine expectations and thus contribute to knowledge about its usage and subjective effects (response expectancies). This study aimed to evaluate caffeine expectation psychometrically in a sample of the Brazilian population. The original version of the "Caffeine Expectancy Questionnaire (CaffEQ)" was translated and validated into Brazilian-Portuguese and adapted to Brazilian culture to be used in the Brazilian adult (19-59 y) population. After the translation and back-translation processes of the original CaffEQ questionnaire, the content and semantic validation were performed by a group of experts. The Brazilian-Portuguese version of the questionnaire consists of 47 items, in seven factors, which assess subjective perceptions about the effects of caffeine. Interobserver reproducibility and internal consistency of the questionnaire were tested with a convenience sample (n = 50) of Brazilian adult consumers of caffeine sources, who completed the Brazilian CaffEQ (CaffEQ-BR) on two occasions separated by 24 h. All of the 47 questions were adequate regarding reliability, clarity, and comprehension. Psychometric properties could be replicated consistently. Appropriate internal consistency and validation were confirmed by Cronbach's alpha (α) 0.948, and an intraclass correlation coefficient of 0.976 was observed. The CaffEQ-BR was applied using a web-based platform to a convenience sample of Brazilian adults from all 27 Brazilian states (n = 4202 participants), along with measures of sociodemographic and caffeine consumption data. Factor validity was verified by confirmatory factor analysis. The seven factors presented a good fit for Root Mean Square Error of Approximation-RMSEA = 0.0332 (95% CI: 0.0290-0.0375). By confirming the validity and reliability of CaffEQ-BR, a useful tool is now available to assess caffeine expectations in the Brazilian adult population.
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Affiliation(s)
- Guilherme Falcão Mendes
- Department of Nutrition, School of Health Sciences, University of Brasilia (UnB), Campus Darcy Ribeiro, Asa Norte, Brasilia DF 70910-900, Brazil; (C.E.G.R.); (T.H.M.d.C.)
| | - Caio Eduardo Gonçalves Reis
- Department of Nutrition, School of Health Sciences, University of Brasilia (UnB), Campus Darcy Ribeiro, Asa Norte, Brasilia DF 70910-900, Brazil; (C.E.G.R.); (T.H.M.d.C.)
| | - Eduardo Yoshio Nakano
- Department of Statistics, Central Institute of Sciences, University of Brasilia (UnB), Campus Darcy Ribeiro, Asa Norte, Brasilia DF 70910-900, Brazil;
| | - Teresa Helena Macedo da Costa
- Department of Nutrition, School of Health Sciences, University of Brasilia (UnB), Campus Darcy Ribeiro, Asa Norte, Brasilia DF 70910-900, Brazil; (C.E.G.R.); (T.H.M.d.C.)
| | - Bryan Saunders
- Applied Physiology and Nutrition Research Group, School of Physical Education and Sport; Rheumatology Division; Faculdade de Medicina FMUSP, University of São Paulo, Sao Paulo 01246-903, Brazil;
- Institute of Orthopaedics and Traumatology, Faculty of Medicine FMUSP, University of São Paulo, Sao Paulo 01246-903, Brazil
| | - Renata Puppin Zandonadi
- Department of Nutrition, School of Health Sciences, University of Brasilia (UnB), Campus Darcy Ribeiro, Asa Norte, Brasilia DF 70910-900, Brazil; (C.E.G.R.); (T.H.M.d.C.)
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Galindo MN, Navarro JF, Cavas M. The Influence of Placebo Effect on Craving and Cognitive Performance in Alcohol, Caffeine, or Nicotine Consumers: A Systematic Review. Front Psychiatry 2020; 11:849. [PMID: 33005155 PMCID: PMC7479236 DOI: 10.3389/fpsyt.2020.00849] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 08/04/2020] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE The present systematic review aims to analyze the evidence about the influence of placebo effect on craving and cognitive performance in alcohol, caffeine, and nicotine consumers. METHODS Relevant studies were identified via Pubmed, Web of Science, and Scopus databases (up to March 2020). Only those papers published between 2009 and 2019 were searched. RESULTS Of the 115 preliminary papers, 8 studies of database search and 9 of the manual search were finally included in this review. Findings showed that while alcohol expectancies increased craving, caffeine and nicotine expectancies tend to decrease it. Alcohol expectancies caused similar or slower reaction time when alcohol was not consumed, impairments on inhibitory control (especially after alcohol consumption) and similar post-error slowing. The effect of caffeine and nicotine on reaction time has not been elucidated yet, however, caffeine expectancies have been shown to improve accuracy and the attentional filtering of distracting stimuli. CONCLUSIONS Alcohol, caffeine, and nicotine expectancies play an important role on craving. Although expectancies produce an effect on cognitive performance, caffeine and nicotine beliefs show an ambiguous impact on reaction time. Only the influence of alcohol expectancies on reaction time has been clarified. Furthermore, caffeine beliefs enhance accuracy.
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Affiliation(s)
- María Nerea Galindo
- Department of Psychobiology, School of Psychology, University of Málaga, Málaga, Spain
| | | | - María Cavas
- Department of Psychobiology, School of Psychology, University of Málaga, Málaga, Spain
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Juliano LM, Kardel PG, Harrell PT, Muench C, Edwards KC. Investigating the role of expectancy in caffeine withdrawal using the balanced placebo design. Hum Psychopharmacol 2019; 34:e2692. [PMID: 30861208 DOI: 10.1002/hup.2692] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 11/20/2018] [Accepted: 01/18/2019] [Indexed: 01/11/2023]
Abstract
OBJECTIVE This study investigated psychological influences on drug withdrawal symptomatology using a caffeine-based model. METHODS Using the 2 × 2 balanced placebo design caffeine dose (given caffeinated vs decaffeinated coffee) was crossed with dose expectancy (told caffeine vs. decaf) among 87 (16-hr abstinent) regular coffee consumers in a 2-day study. RESULTS There were effects of expectancy and pharmacology that differed depending on the measure. Those told decaf reported greater caffeine cravings than those told caffeine 45 min and 8 hr postmanipulation. There were no expectancy effects on withdrawal symptoms or cognitive performance. There were pharmacological effects on all measures. Those given decaf reported greater withdrawal symptoms and showed poorer cognitive performance 45 min and 8 hr postmanipulation, with effects for headache and flu-like symptoms first emerging 8 hr postmanipulation (i.e., 24 hr abstinence in given decaf conditions). Caffeine readministration alleviated all withdrawal symptoms and cognitive decrements within 45 min. No drug by expectancy interactions were observed. CONCLUSIONS These findings confirm a strong pharmacological basis for caffeine withdrawal and an important role of cognition in drug craving. Future research should investigate the role of expectancy in drug withdrawal and craving and the potential use of expectancy manipulations in symptom prevention and management.
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Affiliation(s)
- Laura M Juliano
- Department of Psychology, American University, Washington, DC, USA
| | - Peter G Kardel
- Department of Psychology, American University, Washington, DC, USA.,Moran Company, Arlington, Virginia, USA
| | - Paul T Harrell
- Department of Psychology, American University, Washington, DC, USA.,Division of Community Health & Research, Department of Pediatrics, Eastern Virginia Medical School, Norfolk, Virginia, USA
| | - Christine Muench
- Department of Psychology, American University, Washington, DC, USA.,Section on Clinical Genomics and Experimental Therapeutics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland, USA
| | - Kathryn C Edwards
- Department of Psychology, American University, Washington, DC, USA.,Behavioral Health Group, Westat, Rockville, Maryland, USA
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12
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Shabir A, Hooton A, Tallis J, F Higgins M. The Influence of Caffeine Expectancies on Sport, Exercise, and Cognitive Performance. Nutrients 2018; 10:E1528. [PMID: 30336606 PMCID: PMC6212857 DOI: 10.3390/nu10101528] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 10/13/2018] [Accepted: 10/15/2018] [Indexed: 11/29/2022] Open
Abstract
Caffeine (CAF) is widely consumed across sport and exercise for its reputed ergogenic properties, including central nervous stimulation and enhanced muscular force development. However, expectancy and the related psychological permutations that are associated with oral CAF ingestion are generally not considered in most experimental designs and these could be important in understanding if/how CAF elicits an ergogenic effect. The present paper reviews 17 intervention studies across sport, exercise, and cognitive performance. All explore CAF expectancies, in conjunction with/without CAF pharmacology. Thirteen out of 17 studies indicated expectancy effects of varying magnitudes across a range of exercise tasks and cognitive skills inclusive off but not limited to; endurance capacity, weightlifting performance, simple reaction time and memory. Factors, such as motivation, belief, and habitual CAF consumption habits influenced the response. In many instances, these effects were comparable to CAF pharmacology. Given these findings and the lack of consistency in the experimental design, future research acknowledging factors, such as habitual CAF consumption habits, habituated expectations, and the importance of subjective post-hoc analysis will help to advance knowledge within this area.
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Affiliation(s)
- Akbar Shabir
- Sport, Outdoor and Exercise Science, Kedleston Campus, University of Derby, Kedleston Road, Derby DE22 1GB, UK.
| | - Andy Hooton
- Sport, Outdoor and Exercise Science, Kedleston Campus, University of Derby, Kedleston Road, Derby DE22 1GB, UK.
| | - Jason Tallis
- Centre for Applied Biological and Exercise Sciences, Coventry University, Priory Street, Coventry CV1 5FB, UK.
| | - Matthew F Higgins
- Sport, Outdoor and Exercise Science, Kedleston Campus, University of Derby, Kedleston Road, Derby DE22 1GB, UK.
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Pires FO, Dos Anjos CAS, Covolan RJM, Fontes EB, Noakes TD, St Clair Gibson A, Magalhães FH, Ugrinowitsch C. Caffeine and Placebo Improved Maximal Exercise Performance Despite Unchanged Motor Cortex Activation and Greater Prefrontal Cortex Deoxygenation. Front Physiol 2018; 9:1144. [PMID: 30246799 PMCID: PMC6113857 DOI: 10.3389/fphys.2018.01144] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 07/30/2018] [Indexed: 11/13/2022] Open
Abstract
Caffeine (CAF) is an ergogenic aid used to improve exercise performance. Independent studies have suggested that caffeine may have the ability to increase corticospinal excitability, thereby decreasing the motor cortex activation required to generate a similar motor output. However, CAF has also been suggested to induce a prefrontal cortex (PFC) deoxygenation. Others have suggested that placebo (PLA) may trigger comparable effects to CAF, as independent studies found PLA effects on motor performance, corticospinal excitability, and PFC oxygenation. Thus, we investigated if CAF and CAF-perceived PLA may improve motor performance, despite the likely unchanged MC activation and greater PFC deoxygenation. Nine participants (26.4 ± 4.8 years old, VO2MAX of 42.2 ± 4.6 mL kg-1 min-1) performed three maximal incremental tests (MITs) in control (no supplementation) and ∼60 min after CAF and PLA ingestion. PFC oxygenation (near-infrared spectroscopy at Fp1 position), MC activation (EEG at Cz position) and vastus lateralis and rectus femoris muscle activity (EMG) were measured throughout the tests. Compared to control, CAF and PLA increased rectus femoris muscle EMG (P = 0.030; F = 2.88; d = 0.84) at 100% of the MIT, and enhanced the peak power output (P = 0.006; F = 12.97; d = 1.8) and time to exhaustion (P = 0.007; F = 12.97; d = 1.8). In contrast, CAF and PLA did not change MC activation, but increased the PFC deoxygenation as indicated by the lower O2Hb (P = 0.001; F = 4.68; d = 1.08) and THb concentrations (P = 0.01; F = 1.96; d = 0.7) at 80 and 100% the MIT duration. These results showed that CAF and CAF-perceived PLA had the ability to improve motor performance, despite unchanged MC activation and greater PFC deoxygenation. The effectiveness of CAF as ergogenic aid to improve MIT performance was challenged.
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Affiliation(s)
- Flavio O Pires
- Exercise Psychophysiology Research Group, School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, Brazil
| | - Carlos A S Dos Anjos
- Neurophysics Group, Gleb Wataghin Physics Institute, University of Campinas, Campinas, Brazil
| | - Roberto J M Covolan
- Neurophysics Group, Gleb Wataghin Physics Institute, University of Campinas, Campinas, Brazil
| | - Eduardo B Fontes
- Research Group in Physical Activity, Cognition and Behavior, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Timothy D Noakes
- Sports Science Institute of South Africa, Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | | | - Fernando H Magalhães
- Exercise Psychophysiology Research Group, School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, Brazil
| | - Carlos Ugrinowitsch
- School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil
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14
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Brietzke C, Asano RY, De Russi de Lima F, Pinheiro FA, Franco-Alvarenga, Ugrinowitsch C, Pires FO. Caffeine effects on VO 2max test outcomes investigated by a placebo perceived-as-caffeine design. Nutr Health 2018; 23:231-238. [PMID: 29214920 DOI: 10.1177/0260106017723547] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
BACKGROUND Ergogenic effects of caffeine (CAF) ingestion have been observed in different cycling exercise modes, and have been associated with alterations in ratings of perceived exertion (RPE). However, there has been little investigation of maximal oxygen uptake (VO2MAX) test outcomes. AIM This study aimed to verify whether CAF may reduce RPE, thereby improving maximal incremental test (MIT) outcomes such as VO2MAX, time to exhaustion and peak power output (WPEAK). METHODS Nine healthy individuals performed three MITs (25 W/min until exhaustion) in a random, counterbalanced fashion after ingestion of CAF, placebo perceived as caffeine (PLA), and no supplementation (baseline control). VO2 was measured throughout the test, while RPE was rated according to overall and leg effort sensations. The power output corresponding to submaximal (RPE = 14 according to the 6-20 Borg scale) and maximal RPE was recorded for both overall (O-RPE14 and O-RPEMAX) and leg RPE (L-RPE14 and L-RPEMAX). RESULTS VO2MAX did not change significantly between MITs; however, CAF and PLA increased time to exhaustion (↑ ∼18.7% and ∼17.1%, respectively; p < .05) and WPEAK (↑ ∼13.0% and ∼11.8%, respectively; p < .05) when compared with control. When compared with control, CAF ingestion reduced submaximal and maximal overall and leg RPEs, the effect being greater in maximal (likely beneficial in O-RPEMAX and L-RPEMAX) than submaximal RPE (possibly beneficial in O-RPE14 and L-RPE14). Similar results were found when participants ingested PLA. CONCLUSIONS Compared with control, CAF and PLA improved MIT performance outcomes such as time to exhaustion and WPEAK, without altering VO2MAX values. CAF effects were attributed to placebo.
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Affiliation(s)
- Cayque Brietzke
- 1 Exercise Psychophysiology Research Group, School of Arts, Sciences and Humanities, University of São Paulo, Brazil
| | - Ricardo Yukio Asano
- 1 Exercise Psychophysiology Research Group, School of Arts, Sciences and Humanities, University of São Paulo, Brazil
| | - Felipe De Russi de Lima
- 1 Exercise Psychophysiology Research Group, School of Arts, Sciences and Humanities, University of São Paulo, Brazil
| | - Fabiano Aparecido Pinheiro
- 1 Exercise Psychophysiology Research Group, School of Arts, Sciences and Humanities, University of São Paulo, Brazil.,2 School of Physical Education and Sport, University of São Paulo, Brazil
| | - Franco-Alvarenga
- 1 Exercise Psychophysiology Research Group, School of Arts, Sciences and Humanities, University of São Paulo, Brazil
| | | | - Flávio Oliveira Pires
- 1 Exercise Psychophysiology Research Group, School of Arts, Sciences and Humanities, University of São Paulo, Brazil
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15
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Caffeine and cardiovascular health. Regul Toxicol Pharmacol 2017; 89:165-185. [DOI: 10.1016/j.yrtph.2017.07.025] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 07/21/2017] [Accepted: 07/23/2017] [Indexed: 02/07/2023]
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16
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Szemerszky R, Dömötör Z, Berkes T, Köteles F. Attribution-Based Nocebo Effects. Perceived Effects of a Placebo Pill and a Sham Magnetic Field on Cognitive Performance and Somatic Symptoms. Int J Behav Med 2016; 23:204-13. [PMID: 26420517 DOI: 10.1007/s12529-015-9511-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND Negative non-specific (nocebo-like) effects of medications and electromagnetic fields are often described as results of mistaken attribution. PURPOSE The current study aimed to find empirical evidence supporting this theory. METHOD Participants completed questionnaires assessing modern health worries, health anxiety, and somatosensory amplification, were assigned to one of three conditions (placebo pill with sedative information, sham magnetic field, or control), and completed a 14-min vigilance task. Changes in physiological arousal (heart rate, heart rate variability, and skin conductance) and reported symptoms were also measured. Finally, causal attributions concerning cognitive performance and reported symptoms were assessed. RESULTS No increase in symptom reports and physiological arousal was measured in the two intervention groups. A perceived negative effect on cognitive performance was attributed to both sham conditions, and attributions were connected to modern health worries. A proportion of reported symptoms was ascribed to the placebo pill but not to the sham magnetic field. Symptom attributions were not related to any assessed psychological variables. CONCLUSIONS An aroused physiological state is not necessary for the automatic causal attribution process. Negative effects attributed to medication and environmental factors can be regarded as unavoidable side effects of human cognitive-emotional functioning; they might be alleviated, but cannot be completely eradicated.
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Affiliation(s)
- Renáta Szemerszky
- Institute of Health Promotion and Sport Sciences, Eötvös Loránd University, Bogdánfy Ödön u. 10., Budapest, 1117, Hungary
| | - Zsuzsanna Dömötör
- Doctoral School of Psychology and Institute of Psychology, Eötvös Loránd University, Budapest, Hungary
| | - Tímea Berkes
- Institute of Health Promotion and Sport Sciences, Eötvös Loránd University, Bogdánfy Ödön u. 10., Budapest, 1117, Hungary
| | - Ferenc Köteles
- Institute of Health Promotion and Sport Sciences, Eötvös Loránd University, Bogdánfy Ödön u. 10., Budapest, 1117, Hungary.
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