Regular Caffeine Consumption & Subjective Sleep Quality: A Systematic Review

This systematic review analyzed 10 studies out of 6,908 screened to evaluate the effects of regular caffeine consumption on subjective sleep quality. The findings were inconsistent—some studies reported poorer sleep with caffeine intake, while others found no significant effect. The research had limitations, including high study variability, selection bias, and inconsistent caffeine measurement methods. The sample sizes varied, and most studies used self-reported sleep assessments, increasing recall bias. The review highlights the need for standardized methodologies and future research into genetic and lifestyle factors that may mediate caffeine’s impact on sleep.

To improve sleep quality, individuals sensitive to caffeine should monitor their intake and avoid consumption close to bedtime. Maintaining a consistent sleep schedule, reducing screen exposure before sleep, and increasing exposure to natural light during the day may also enhance sleep. While this review found mixed results on caffeine’s impact, individual differences in metabolism and tolerance suggest a personalized approach is best. Future studies should refine measurement methods for more conclusive findings.