How does caffeine influence memory? Drug, experimental, and demographic factors

Abstract

Caffeine is a widely used nootropic drug, but its effects on memory in healthy participants have not been sufficiently evaluated. Here we review evidence of the effects of caffeine on different types of memory, and the associated drug, experimental, and demographical factors.There is limited evidence that caffeine affects performance in memory tasks beyond improved reaction times. For drug factors, a dose-response relationship may exist but findings are inconsistent. Moreover, there is evidence that the source of caffeine can modulate its effects on memory. For experimental factors, past studies often lacked a baseline control for diet and sleep and none discussed the possible reversal of withdrawal effect due to pre-experimental fasting. For demographic factors, caffeine may interact with sex and age, and the direction of the effect may depend on the dose, individual tolerance, and metabolism at baseline. Future studies should incorporate these considerations, as well as providing continued evidence on the effect of caffeine in visuospatial, prospective, and implicit memory measures.

Methylliberine Ingestion Improves Various Indices of Affect but Not Cognitive Function in Healthy Men and Women

“…Similarly, Taylor et al (2016) noted increased levels of vigor from week 4 to week 8 with daily TeaCrine ® ingestion that were unique to women. Previous observations on caffeine have observed sex-specific impacts in terms of physical performance [30] and memory [31], potentially mediated by sex hormones' influence on caffeine metabolism [32]. Meanwhile, there have not been any reported sex-specific differences with CMT consumption.…”

Effects of Acute Guarana (Paullinia cupana) Ingestion on Mental Performance and Vagal Modulation Compared to a Low Dose of Caffeine

“…Reported cognitive benefits due to caffeine are most frequently observed when taken in dosages > 200 mg [ 16 ]. Caffeine dosage at this minimum threshold or above has the potential to enhance memory consolidation [ 21 ], vigilance performance [ 22 ], ratings of alertness [ 22 ], and speed of encoding new information [ 22 ].…”

“…Despite the paucity of such research, claims have been made that lower doses of caffeine may also enhance performance, specifically on attention tasks compared to higher doses > 200 mg [ 17 ]. In summary, the dose–response effect on cognitive performance with caffeine remains uncertain [ 16 ]. Therefore, this study originally attempted to match the low caffeine dosage listed on the commercially available Guarana supplements at 100 mg to the same dose of caffeine alone.…”

“…Factors such as daily consumption habits, age, gender, body size, medical conditions, and genetics [13] all influence individual mood and cognitive responses to caffeine Nutrients 2024, 16, 1892 2 of 15 doses [14]. Habitual caffeine consumers often experience more significant cognitive improvements, especially in spatial memory and rapid visual information processing, than non-habitual drinkers [15].…”

“…Habitual caffeine consumers often experience more significant cognitive improvements, especially in spatial memory and rapid visual information processing, than non-habitual drinkers [ 15 ]. Moreover, the effective caffeine dosage for acute cognitive benefits is debated but also generally observed at 200 mg or higher [ 16 ], although smaller doses (below 3 mg per kilogram of body weight) may enhance performance in attention-related tasks [ 17 ]. While black coffee is the most common source of caffeine, Guarana, an Amazonian rainforest plant, has emerged with potential cognitive and mood benefits [ 18 ].…”