Wednesday March 4 2009
Students watching films portraying alcohol drank more alcohol themselves
“People are more likely to turn to alcohol while watching TV if they see drinking being portrayed in films or adverts,” BBC News has reported. The news is based on research which observed 80 male students, who watched films containing either high or low levels of alcohol consumption, interspersed with adverts featuring either alcohol or other products. On average, students watching the ‘alcoholic’ film and commercials drank 1.5 more glasses than those watching the ‘non-alcoholic’ content.
Care must be taken when saying that viewing ‘causes’ alcohol drinking because many factors may influence an individual’s alcohol consumption in real life. The study in question also had limitations, such as differences in typical alcohol consumption between groups, a lack of information on longer-term drinking behaviour, and the study of only male students, who are more likely to drink compared with the general population.
Nevertheless, smoking advertisement and the portrayal of smoking on television is increasingly being limited due to the possibility that it may encourage smoking. Whether alcohol use in the media should be viewed similarly is an important question.
Where did the story come from?
This research was carried out by Rutger Engels and colleagues at the Radboud University Nijmegen, Utrecht University in The Netherlands, and Queen’s University in Ontario, Canada. The study was funded by Netherlands Organisation for Scientific Research and published in the peer-reviewed medical journal Alcohol and Alchoholism.
What kind of scientific study was this?
This was an experimental study designed to investigate whether alcohol portrayal in films and commercial breaks prompts people to drink alcohol. Although many countries limit or prohibit advertising and portrayal of smoking, the same restrictions may not apply to alcohol. To date, little research has been done on whether alcohol portrayal on television affects drinking behaviour.
The researchers recruited 80 male students (40 pairs of friends) aged between 18 and 29. These students were not told of the aim of the study, they only knew that the study was assessing “general TV viewing behaviour in daily life”. The volunteers were randomly assigned to four exposure groups of 20 students each. Pairs of friends were assigned to the same group rather than split into different exposure groups.
The first exposure group watched American Pie 2 – a film containing scenes of alcohol consumption – interspersed with commercials that contained alcohol. The second group watched the same film with neutral, non-alcoholic commercials. The third group watched 40 Days and 40 Nights – a film without alcohol – interspersed with alcohol commercials. The final group watched the same ‘non-alcohol’ film with non-alcohol commercials.
The groups watched the films in the late afternoon in a home cinema setting, where they had access to a refrigerator containing both alcoholic and non-alcoholic beverages. Snacks were available, and the students were allowed to smoke. During the film, the researchers took audio and visual recordings of the two groups.
After the film, each student completed a questionnaire about the film, advertisements, alcohol drinking, his personality and his relationship with the friend he watched the film with. The researchers also assessed movie appreciation (using a 5-point scale), familiarity with the movie from previous viewing, self-reported typical alcohol consumption, self-reported alcohol consumption during the film, and researcher-observed alcohol consumption during the film.
What were the results of the study?
During the films, students drank an average of two alcoholic beverages. Within experience groups this represented an average of:
• 2.98 drinks in the group watching American Pie with alcohol commercials.
• 1.86 drinks in the group watching American Pie with non-alcohol commercials.
• 1.95 drinks in the group watching 40 Days and 40 Nights with alcohol commercials.
• 1.51 drinks in the group watching 40 Days and 40 Nights with non-alcohol commercials.
After correcting analyses for the students’ reported weekly alcohol consumption, the portrayal of alcohol in the film and in the commercials was found to have a significant effect upon alcohol consumption.
All of the group reported relatively high previous drinking exposure, with 36.3% reporting drinking heavily once or twice a week, and 17.5% more than twice a week, and weekly intake averaging 21 ‘glasses’. Seventy-four percent of students had previously seen the movie that they were watching. There was no difference in appreciation scores between the two films.
What interpretations did the researchers draw from these results?
The researchers say that “this study – for the first time – shows a causal link between exposure to drinking models and alcohol commercials on acute alcohol consumption”.
What does the NHS Knowledge Service make of this study?
This study has demonstrated an association between exposure to alcohol in films and commercials and drinking alcohol while viewing. However, care must be taken with the researchers’ conclusion that this study “shows a causal link”.
There are many factors that may influence a person in their drinking habits and their decision to start drinking alcohol. These include peer group, social events, family and personal relationships, life situations, and medical and psychological health. It is not possible to say from a single observation during a short viewing session that this exposure would influence longer-term drinking patterns and therefore TV exposure to drinking causes drinking in real-life situations.
There are other possible limitations that must be considered when interpreting this study:
- The method of allocating the participants to the four exposure groups was not truly randomised, given that the 80 students were made up of 40 friend pairs, who were then randomised as a pair rather than individually. Therefore, the groups may not have had a balanced number of tee-totallers or heavier drinkers for example, which may have affected their choice of drink more strongly than the television they were watching.
- The researchers found that estimated alcohol consumption in the week prior to the study had been significantly higher among the ‘alcohol movie/alcohol commercials’ group than in the ‘non-alcohol movie/non-alcohol commercials’ group.
- Additionally, the setting may have affected drinking habits, as students were each with a friend and part of a larger group of similar-aged students. This situation may not be representative of other situations, for example, the students viewing the films alone, in a much smaller family group, or paying for the alcohol themselves.
- The study sample size of only 20 in each group was relatively small. This small size may have made it harder for the randomisation to balance the groups for important confounding factors.
- The study involved only young male students, and therefore results cannot be generalised to females or to other population groups. The study was also carried out in the Netherlands, and patterns of drinking may vary across different countries.
- In the study, alcohol consumption was recorded in terms of number of ‘drinks’ or ‘glasses’. With no information on unit size and alcoholic content of drinks, one cannot calculate the exact amount of alcoholic units actually consumed.
Smoking advertisements or portrayal of smoking in television programmes is now either prohibited or very limited due to the possibility that it may encourage smoking. While this study had limitations, it does raise important questions about whether alcohol consumption in the media should be treated similarly. This research is likely to prompt further investigation using larger samples and other population groups.