What do we want to know?
Energy drinks containing caffeine are increasingly part of everyday life. There is concern in the UK about the consumption of caffeinated energy drinks (CEDs) among young people under age 18. As no upper limit of caffeine intake has been established for young people, calls have been made to regulate energy drink sales to those under 18 years.
Understanding the patterns of energy drink consumption amongst different sociodemographic groups of youth across the UK can help determine how best to address the issue. We reviewed research evidence on patterns of CED consumption in young people and associations between consumption and their physical, mental and social health and wellbeing. We conducted two interconnected pieces of research: an overview of international systematic reviews and an analysis of UK population-level survey data to address key questions about:
- the frequency of and context of caffeinated energy drink consumption in UK youth under 18 years;
- how caffeinated energy drink consumption varies by youth and family socio-demographics; and
- caffeinated energy drink consumption and physical/psychological symptoms, education/social behaviours and health consequences.
Who wants to know?
The findings will be of interest to national and local policy-makers, young people and their parents, educators, and researchers and members of the public interested in the use and impact of CEDs in young people.
What did we find?
Internationally, nearly one-third of young people frequently consume CEDs, and between 10% and 36% report mixing these with alcohol. Consumption varies by age group and country. Some evidence suggests males consume more CEDs than females, and that they start to consume CEDs at a slightly younger age. The international evidence suggests associations between CED consumption and: physical symptoms (e.g. headaches, sleep-related issues); behavioural effects such as alcohol, smoking and substance use; behaviour disorders; and poorer psychological well-being (e.g. irritation, anger).
Evidence is less-clear or limited with regard to associations between CED consumption and mental health problems (e.g. depression, suicide), risky behaviours and education. The reviews reporting international evidence were rated as low or critically low quality, due to methodological limitations in their design and execution.
Evidence from the UK suggests that the proportion of children consuming one or more CEDs per week is similar across different regions of the UK. Consumption in the UK increases with age; up to a quarter of children aged 11-12 years consume one or more CEDs per week compared to between a quarter and a third of those aged 13-14 years and those aged 15-16 years. Boys consistently report higher use than girls; children in Northern England regions report higher use than those in the Southern England regions; and consumption is slightly more common among those eligible for free school meals than among those not eligible. The UK evidence shows associations with adverse health symptoms and unhealthy or risky behaviours including smoking and drinking, exclusion from school and truanting, self-reported well-being, headaches, sleep problems and stomach problems.
Statistical modelling of the UK findings suggests that children who consume CEDs on a weekly basis are twice as likely to experience low psychological wellbeing and four-times as likely to have low educational wellbeing than those who consume them less frequently. It is important to note that because of the cross-sectional nature of the data, these associations do not imply that weekly caffeinated energy drink consumption is a trigger of low wellbeing.
What are the conclusions?
International systematic review evidence indicates an association of caffeinated energy drink use with physical symptoms and lifestyle but is unclear about associations with mental health and behavioural outcomes. The design of studies included in the reviews and the quality of the systematic reviews themselves limits the strength of the conclusions. The lack of UK research in the reviews prompted our analysis of UK population-level data.
Our analysis of UK data suggests that many children in the UK consume CEDs with higher consumption reported by older children, by boys, and by those living in northern areas or in more deprived regions. Findings also suggest associations between consumption and physical, psychological, social and educational symptoms, behaviours and wellbeing. A lack of studies that measure these variables over time meant we were unable to determine whether CED consumption is the cause of associated symptoms, behaviours and wellbeing.
Future research on this topic should employ longitudinal methods to examine whether CED consumption is responsible for poorer health and wellbeing. Research should also examine the influence of geographic region and deprivation on children’s caffeinated energy drink consumption. The measurement of caffeinated energy drink consumption in the future needs to be consistent across surveys, so that a clearer picture of the frequency, timing and dosage can be established. UK-wide exploration of the context and reasons for caffeinated energy drink consumption is needed and should include examining consumption of CEDs with alcohol in older children aged 16 to 17 years.
How did we get these results?
This project contained two stages. First, we conducted an overview of systematic reviews published between 2013 and 2018, identified from database and citation searching. Descriptive data on review characteristics and effects were extracted and synthesised narratively and in tables. Review quality was evaluated using AMSTAR2 criteria and overall strength of evidence was assessed. The overview protocol was registered in PROSPERO (CRD42018096292). Second, we conducted a systematic review and secondary analysis of five UK population-level surveys of children and young people that measured their consumption of caffeinated energy drinks and related physical, psychological, social and behavioural effects. The secondary analysis protocol was registered in PROSPERO (CRD42018096292).
This report should be cited as:
Brunton G, Kneale D, Sowden A, Sutcliffe K, Thomas J (2019) Caffeinated energy drinks and effects in UK young people: A secondary analysis of population-level datasets. London: EPPI-Centre, Social Science Research Unit, UCL Institute of Education.