ABSTRACT
Energy drinks are thought to improve certain aspects of athletic and cognitive performances. Moreover, less is understood about physiological mechanisms that might underlie these effects. The aim of this study was to examine the influence of sugar-free energy drink (SFED) ingestion on corticomotor excitability and plasticity. Fourteen college students consumed a commercially available SFED or a "dummy" drink. By using Transcranial magnetic Stimulation (TMS) we investigated resting motor threshold (RMT), motor evoked potential (MEP) amplitude and cortical silent period (CSP). Paired-pulse stimulation was used to assess short interval intracortical inhibition (SICI) and intracortical facilitation (ICF). Sensorimotor integration was investigated with the short- and long-afferent inhibition paradigms (SAI and LAI). Cortical plasticity was studied with the paired associative stimulation (PAS) paradigm. In addition, we examined the effect of SFED on simple reaction time (RT), pre-movement facilitation and post-exercise facilitation (PEF). SFED consumption decreased ICF, shortened RT, increased pre-movement facilitation and PEF of the motor evoked potentials. These results demonstrate that SFED consumption induced a shorter RT that is paralleled by changes in cortical excitability at rest, prior and after a non-fatiguing muscle contraction. These acute changes in brain function might be of relevance in understanding the mechanisms underlying the enhancement of psychomotor performance.
Subject(s)
Caffeine/administration & dosage , Central Nervous System Stimulants/administration & dosage , Energy Drinks , Motor Activity/drug effects , Motor Cortex/drug effects , Adult , Cross-Over Studies , Double-Blind Method , Evoked Potentials, Motor/drug effects , Evoked Potentials, Motor/physiology , Female , Hand/physiology , Humans , Male , Motor Activity/physiology , Motor Cortex/physiology , Muscle, Skeletal/drug effects , Muscle, Skeletal/physiology , Neural Inhibition/drug effects , Neural Inhibition/physiology , Neural Pathways/drug effects , Neural Pathways/physiology , Neuronal Plasticity/drug effects , Neuronal Plasticity/physiology , Reaction Time/drug effects , Reaction Time/physiology , Rest , Transcranial Magnetic StimulationABSTRACT
BACKGROUND: Epstein-Barr virus (EBV) has become a common medical condition in adolescents and young children. The objective of this study was to examine the association of low dietary intake and food insecurity with EBV infection. METHODS: Cross-sectional data were analyzed using the National Health and Nutrition Examination Survey 2009-2010 sample population (n = 1550) aged 6 to 15 years. Self-report data on dietary intake and food security were abstracted from data files. The outcome variable was measured using EBV index from the laboratory data. Multivariable logistic regression analysis was used to determine the association between exposure and outcome variables. RESULTS: The prevalence of EBV in this population was 56.4%. In the unadjusted analyses, adolescents who consumed 100% fruit juice (OR = 1.49, 95% CI = 1.09-2.05), beans (OR = 2.35, 95% CI = 1.12-4.94), and red meat (OR = 1.57, 95% CI = 1.09-2.24) daily had statistically significant elevated odds of EBV as compared to adolescents who consumed them monthly. Furthermore, adolescents who sometimes did not get fed a balanced meal and had to rely on low-cost food had statistically significant increased odds of EBV. However, after adjusting for potential confounders the results for both dietary factors and food insecurity were no longer statistically significant. CONCLUSIONS: Certain dietary factors and food insecurity may predispose children to EBV infection.
