Sleep, alcohol, and caffeine in financial traders

In a study published in journal PLOS One, scientists looked at the combined impact of alcohol and caffeine on nightly sleep.
Using a six-week micro-longitudinal study, the researchers examined the real-world impact of alcohol, caffeine, and their combined consumption in a cohort of financial traders. They found that alcohol consumption significantly degrades the subjective quality of sleep. Caffeine consumption led to a different phenotype of sleep impairment, resulting in a detrimental reduction in sleep quantity, rather than a marked alteration in sleep quality. Contrary to the researchers’ hypothesis, when consumed in combination, evening alcohol consumption interacted with ongoing caffeine consumption such that alcohol partially mitigated the impairments in sleep quantity associated with caffeine. This finding suggests the sedating effects of alcohol and the psychoactive stimulant effects of caffeine obscure each other’s impact on sleep quantity and sleep quality, respectively–potentially explaining their interdependent use in this cohort (i.e., “self-medication” of evening sedation with alcohol to combat the prior daytime ingestion of caffeine and vice versa). More generally, these results contribute to a unique understanding of the singular and combinatory impacts of two of the most commonly used substances for augmenting human consciousness under free-living, real-world conditions, the performance-impairing (and thus economic-cost) consequences of which may be important to the business sector and the society, the researchers say.
Source: Song F, Walker MP (2023) Sleep, alcohol, and caffeine in financial traders. PLOS ONE 18(11): e0291675.