Age and IQ Explained Working Memory Performance in a RCT with Fatty Fish in a Group of Forensic Inpatients.

OBJECTIVES: To investigate the effect of a long-term fatty fish intervention on a pure cognitive mechanism important for self-regulation and mental health, i.e. working memory (WM), controlling for age and IQ.

DESIGN: A randomized controlled trial.

SETTING: A forensic facility.

PARTICIPANTS: Eighty-four young to middle aged male forensic inpatients with psychiatric disorders.

INTERVENTION: Consumption of farmed salmon or control meal (meat) three times a week during 23 weeks.

MEASUREMENT: Performance on WM tasks, both accuracy and mean reaction time, were recorded pre and post intervention.

RESULTS: Performance on a cognitive functioning tasks taxing WM seemed to be explained by age and IQ.

CONCLUSION: Fatty fish consumption did not improve WM performance in a group of young to middle aged adults with mental health problems, as less impressionable factors such as aging and intelligence seemed to be the key components. The present study improves the knowledge concerning the interaction among nutrition, health and the aging process.