In a recent study published in the Nutrients journal, researchers from The Netherlands investigated whether coffee consumption was associated with low sleep quality, shorter sleep durations, and sleep disturbances among the older population.
Study: The Association between Caffeine Consumption from Coffee and Tea and Sleep Health in Male and Female Older Adults: A Cross-Sectional Study. Image Credit: portumen/Shutterstock.com
Background
Well-being and health are intricately linked to sleep health, with the importance of this association becoming more apparent with age as the prevalence of sleep disorders and disturbances increases.
Studies show that close to 25% of adults above the age of 65 years do not attain optimal sleep in either quality or duration, which subsequently impacts various aspects of mental and physical health, such as cognitive function and overall quality of life.
While numerous age-related factors, such as an increased incidence of psychiatric and physical health conditions, behavioral factors, such as depression and loneliness, as well as the use of medications, can impact sleep quality, modifiable risk factors, such as nutrition, can also play an important role in sleep health.
One of the most common psychoactive substances in food is caffeine, and beverages such as tea and coffee are common sources of caffeine.
Furthermore, while research indicates that caffeine is beneficial in reducing the risk of type 2 diabetes, cardiovascular disease, and all-cause mortality, its action on the brain's adenosine receptors also results in wakefulness. Therefore, it is essential to understand whether caffeine contributes to disrupted sleep and low sleep quality in older adults.
About the study
In the present study, the researchers used data from a longitudinal study on aging among the population of Amsterdam to investigate whether caffeine intake through tea and coffee consumption was associated with sleep health.
They also examined whether these associations varied based on sex. The study, known as Longitudinal Ageing Study Amsterdam, was commenced between 1992 and 1993 among Dutch adults between the ages of 55 and 85 years, with follow-ups being conducted every three years to examine the trajectories and determinants of cognitive, physical, social, and emotional functioning.
The current study used data collected between 2018 and 2019, which also consisted of data from participants included in the study in subsequent cohorts after the first intake. The information was collected from the participants through two structured interviews — one main and one medical, which also involved clinical measurements and a questionnaire.
The questionnaire was self-administered and assessed various parameters associated with sleep health, such as whether and how frequently the participants experienced sleep disturbances. The questions regarding sleep disturbances pertained to three broad sleep categories: onset, continuity, and waking up early.
The sleep duration was assessed based on an open-ended question about how long each participant slept each night, which was then classified as recommended, long, or short based on the recommended hours of sleep for each age group.
The average consumption of tea or coffee over a month was also assessed through the questionnaire based on the quantity and frequency of consumption. Additionally, the cup size was determined in milliliters, and questions about whether the coffee was decaffeinated or caffeinated and the type of tea were also included in the questionnaire.
Based on this information, the average daily consumption of caffeine was calculated for each participant. Information on sociodemographic factors such as sex, age, educational level, partner or marital status, medical history, substance use history, and various other confounders was also collected.
Results
The results indicated that the association between caffeine consumption and sleep quality among older adults varied significantly based on sex. Surprisingly, older women who did not consume caffeine had a higher probability of shorter durations of sleep and sleep disturbances than those who reported consuming caffeine.
No such associations were observed in older males and similar associations were also not found between caffeine consumption and longer-than-recommended sleep durations.
Although the study found no link between increased caffeine consumption and poor sleep quality, the results from various other studies have conflicted.
While some studies have reported similar results, other observational studies among the European population have found that high coffee consumption has been linked to shorter durations of sleep.
The authors believe that the difference might lie in how these studies assess caffeine intake and whether it is calculated based on coffee consumption alone or based on the intake of various other caffeinated beverages.
Conclusions
Overall, the findings suggested that sleep quality and caffeine intake were linked in a sex-specific manner, with older women who abstained from consuming caffeine experiencing shorter and more disturbed sleep than those who did not abstain. These associations were not observed in older men or linked to longer sleep durations.
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