Caffeine sobriety connected to sleep disturbances in older women, long-term study finds

05 Jan 2024 --- Researcher from the Vrije Universiteit (VU) Amsterdam, the Netherlands, worked on a long-term observational study of older Dutch adults and discovered that community-dwelling women — those who live independently — who do not consume caffeine had more sleep disturbances and shorter sleep duration than those who consume the stimulant.

No association was found between caffeine consumption and sleep health in older men. Sleep disturbances and disorders typically increase with age. The study indicates that one-fourth of adults over 65 do not reach the recommended eight hours of sleep. They exhibit insomnia symptoms such as difficulty with sleep onset, sleep maintenance and early morning awakening.

The researchers conducted cross-sectional analyses using data from 1,256 participants between 61–101 years from the Longitudinal Ageing Study Amsterdam, an ongoing cohort study focusing on the determinants, trajectories and consequences of physical, cognitive, emotional and social functioning.

Snoozing sleep health
Caffeine consumption was established by asking questions about the frequency, quantity and type of coffee and tea consumption. In Europe, including The Netherlands, coffee and tea are the primary sources of caffeine for adults.

Poor sleep health is associated with negative health outcomes. Still, the relationship between caffeine consumption and sleep health in older people needs to be better understood, according to the study published in Nutrients.

Poor sleep quality and inadequate sleep duration lead to impaired physical and mental health outcomes, including impaired cognitive function, reduced functional capacity, disability, reduced quality of life and a higher risk of all-cause mortality. Older adults experience this more often because of poor nutrition, medical conditions, medication use, loneliness and depression.The absence of caffeine has been linked to sleep disturbances in older Dutch women.

While the importance of gender differences in health research is gaining recognition, its association with caffeine consumption and sleep has received little attention, the VU researchers claim.

Furthermore, the researchers say the results of their study contradict results from controlled experiments in laboratories where the administration of 200 mg of caffeine prolonged sleep latency, reduced sleep efficiency and shorter sleep duration. 

They posit that the key difference between controlled experiments and the present study is that caffeine exposure in this study represents the participants’ habitual caffeine consumption, which could lead to caffeine tolerance and reduce its effects on sleep in a real-life setting.  

Data collection across decades
Researchers first collected data between 1992–1993 from a cohort of 3,107 participants aged 55–85. Follow-up measurements were conducted every three years. A nationally representative sample was created by recruiting participants from municipalities across three culturally distinct regions.

An additional second and third cohort of respondents aged 55–64 were added to the sample in 2002–2003 and 2012–2013. Data from 2018–2019 of 1,701 participants aged 61 to 101 years from the first, second and third cohorts were taken for this cross-sectional study.

The researchers recommend that further epidemiological studies could help to understand better the relationship between caffeine and sleep in real-life settings. These studies could consider using diaries to collect information on caffeine consumption and sleep health. They may benefit from investigating the timing of caffeine consumption and the motivations behind older adults’ decisions to limit or abstain from caffeine consumption. 

In addition, studies should consider the potential gender differences in the effects of caffeine on sleep and gender differences in caffeine-related behaviors.

In addition, Brazil-based researchers have made an association between poor sleep quality in overweight older adults and deterioration in health problems such as anxiety, depression, body fat gain and loss of muscle mass. The study indicates that sleep quality is an independent predictor of lower appendicular lean mass and health-related quality of life, anxiety and depression in older people with obesity.

Meanwhile, PharmaLinea has unveiled a new clinically supported food supplement to improve sleep quality and acute sleep latency issues. Based on melatonin and its patented ingredient, Qnight, the product addresses sleep quality holistically.

By Inga de Jong