Abstract
The comparative effects of coffee robusta and coffee arabica (Qahwa) on different attention and memory related assignments were measured in a double-blind study of 300 healthy young adult women who were randomly assigned to one of three different drinks: Group I (coffee robusta sachet dissolved in 100 ml of hot water): Group II (coffee arabica): and group III (100 ml water only). Cognitive function was assessed by standardized tests. Several monitoring cognitive tests and tasks were specifically chosen and performed to investigate the comparative effects of coffee robusta (CR) and coffee arabica (Qahwa; AC) on sleepiness (sleep and clear headed scale), attention (trail A & B, symbol digit, letter cancellation), general cognitive ability (stroop test) and memory (card test). Data was interpreted by analysis of variance (ANOVA). The present study revealed that coffee robusta has beneficial effects on attention, general cognitive ability and memory. Higher though non-significant cognitive scores were associated with coffee robusta consumption. Although, consumption of coffee arabica (Qahwa) has significant effects (P < 0.05) on sleepiness, attention, general cognitive ability and memory and it significantly improve reaction time and correct responses. Since different tasks were related to the sustained attention and working memory processes, results would suggest that coffee arabica (qahwa) could increase the memory and efficiency of the attentional system might be due to the presence of chlorogenic acids (CGA) which are found in less quantity in coffee robusta. However, more studies using larger samples and different tasks are necessary to better understand the effects of coffee robusta and arabica (Qahwa) on attention and memory.