Objectives: The aim of this study was to examine effects of the observation of video-recorded chewing in a daily setting on mixing ability, cognition, activities of daily living, depressive symptoms and quality of life of older adults with dementia.

Methods: A clustered randomised controlled trial was carried out with residents from 14 residential care facilities. n = 56 participants' data were analysed. An experimental group watched videos of people chewing, displayed on tablet-PCs during lunch, while a control group watched videos of nature and buildings. This was scheduled to take place 5 days a week for 12 weeks. A two-colour chewing gum test was used to measure mixing ability, neuropsychological tests for cognition and questionnaires for the other outcomes. Effects were examined via hierarchical linear mixed model analyses for T1-T3 (i.e. pre-, halfway and post-intervention). When a significant interaction effect was found, T4 (follow-up) was also included.

Results: The experimental (n = 27) and control (n = 28) groups differed on a few variables at baseline. A significant Time*Group interaction effect was found for the Mini-Mental State Examination only (b = 1.18, t(48.35) = 2.53, p = .015), in favour of the experimental group. A significant effect was also found, albeit smaller, when T4 was included.

Conclusion: One potential reason for the intervention effect on cognition is activation of specific brain areas. Some challenges associated with conducting this intervention in a daily setting are presented. Further research is required before a well-considered decision can be made regarding any potential implementation.

Trial registration: Number: NTR5124. Date of registration: 30 March 2015, retrospectively registered (during participant inclusion).