Habitual coffee drinkers display a distinct pattern of brain functional connectivity

Abstract

Coffee is the most widely consumed source of caffeine worldwide, partly due to the psychoactive effects of this methylxanthine. Interestingly, the effects of its chronic consumption on the brain’s intrinsic functional networks are still largely unknown. This study provides the first extended characterization of the effects of chronic coffee consumption on human brain networks. Subjects were recruited and divided into two groups: habitual coffee drinkers (CD) and non-coffee drinkers (NCD). Resting-state functional magnetic resonance imaging (fMRI) was acquired in these volunteers who were also assessed regarding stress, anxiety, and depression scores. In the neuroimaging evaluation, the CD group showed decreased functional connectivity in the somatosensory and limbic networks during resting state as assessed with independent component analysis. The CD group also showed decreased functional connectivity in a network comprising subcortical and posterior brain regions associated with somatosensory, motor, and emotional processing as assessed with network-based statistics; moreover, CD displayed longer lifetime of a functional network involving subcortical regions, the visual network and the cerebellum. Importantly, all these differences were dependent on the frequency of caffeine consumption, and were reproduced after NCD drank coffee. CD showed higher stress levels than NCD, and although no other group effects were observed in this psychological assessment, increased frequency of caffeine consumption was also associated with increased anxiety in males. In conclusion, higher consumption of coffee and caffeinated products has an impact in brain functional connectivity at rest with implications in emotionality, alertness, and readiness to action.

Drinking coffee enhances neurocognitive function by reorganizing brain functional connectivity

“…Based on the actions of caffeine, it is plausible that the stimulatory effects of caffeine might directly lead to the reorganization of network properties toward a state of increased efficiency. A recent fMRI study showed that habitual coffee drinkers had distinct brain FC properties from non-coffee drinkers, which could support our speculation 33 . Further studies are needed to unveil the mechanisms underlying the changes in network properties after coffee consumption.…”

Coffee in the Workplace: A Social Break or a Performance Enhancer?

“…Despite the known potential side effects of coffee, where high doses (more than 400mg, cf. EFSA [4]) not only exceed the beneficial ceiling that has been reported as effective for certain performance purposes but may also negatively affect the very concerns caffeine is aimed to address (e.g., increasing anxiety [3]), there is a general reliance on drinking coffee, more than, for instance, on using medicines or food supplements for similar purposes. Among other aspects, the broad acceptance of such a daily consumption practice is linked to its ambivalent social status, as both a substance with pharmacological properties and a common beverage both inside and outside work.…”

“…Besides being a socially rooted drink, coffee's main bioactive compound (caffeine) is claimed to have cognitive enhancing properties associated with fatigue reduction and improvement of mental alertness, concentration, and short-term memory, amongst other performative effects and benefits [2]. Yet, the effect of chronic coffee consumption on the brain is currently starting to be studied [3]. In a context of increasingly competitive economies, where the work rhythms and performance demands are extremely high in many professional environments, what is the role of coffee in managing everyday imperatives at work?…”

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

“…Particularly relevant to this study is the finding that females were more susceptible to the anxiogenic effects of caffeine under the same dose than males (Domschke et al, 2012;Gajewska et al, 2013). In comparison, a study examining the resting functional connectivity between habitual and non-coffee drinkers found an association between the increased frequency of caffeine consumption and anxiety in males only (Magalhães et al, 2021).…”

“…Although we did not focus on neuroimaging findings, in studies reviewed there is also evidence that an acute dose of caffeine is related to activation of attentional networks, such as bilateral medial frontopolar cortex extending to anterior cingulate gyrus (Koppelstaetter et al, 2008), bilateral dorsolateral prefrontal cortex (PFC), and the left thalamus (Haller et al, 2017(Haller et al, , 2013Klaassen et al, 2013). Furthermore, lifelong habitual caffeine consumers compared to non-coffee drinkers showed increased functional connectivity between cerebellar and several subcortical areas known to be involved in attention, arousal, and memory acquisition, including the thalamus, lingual and inferior occipital gyrus, and parahippocampus (Magalhães et al, 2021). In electroencephalography studies, caffeine is associated with increased prestimulus alpha amplitude (Trunk et al, 2015), and an increase in the theta activity in the right PFC, central, and temporal areas (Ueda and Nakao, 2019).…”