Park et al. recently published an article in the Journal of sleep looking at the impact of long term coffee consumption on sleep quality later in life. Previous studies have shown that coffee consumption may suppress the production of melatonin in pinealocytes through competitive inhibition of adenosine A2 receptors by caffeine. They investigated the impact of lifetime coffee consumption on pineal gland volume and the resulting effects on sleep quality.
They found that smaller VPP was associated with higher cumulative lifetime coffee consumption. Participants who consumed more than 60 cup-years of coffee had VPPs that were smaller by about 20% than individuals who consumed less than 60 cup-years of coffee. The VPP mediated the association between lifetime coffee consumption and sleep efficiency and quality.
Conclusions: These findings suggest that high lifetime coffee consumption may reduce VPP, and that this reduction in VPP may impair the quality of sleep in late life.
Statement of Significance: Increasing evidence supports a link between coffee consumption and the circadian system and sleep. This study adds new information showing that the pineal gland volume decreased as the amount of lifetime coffee consumption increased in humans. The decrease of pineal volume due to high lifetime coffee consumption was associated with poor sleep efficiency and quality. These findings improve our understanding of the impact of coffee consumption on the human pineal gland and provide insight into the relationship between pineal gland volume and sleep.
Note: 1 cup year of coffee = 365 cups of coffee consumed over a lifetime.
Citation:
Jeongbin Park, Ji Won Han, Ju Ri Lee, Seonjeong Byun, Seung Wan Suh, Tae Kim, In Young Yoon, Ki Woong Kim; Lifetime coffee consumption, pineal gland volume, and sleep quality in late life, Sleep, , zsy127, https://doi.org/10.1093/sleep/zsy127
