Plain language summary
From a clinical perspective, impulsiveness is an important diagnostic characteristic of several psychiatric disorders, including attention-deficit/hyperactivity disorder (ADHD). ADHD is a neurodevelopmental disorder characterised by a persistent pattern of lack of attention and/or hyperactivity and impulsiveness. Dietary approaches to the treatment of ADHD include fatty acid supplementation, particularly with omega-3 polyunsaturated fatty acids (n-3 PUFA) The aim of this study was to analyse changes in the Barratt Impulsiveness Scale (BIS-11c) scores in children with ADHD after an 8-week intervention with the Mediterranean diet, omega-3 fatty acid supplementation, or Mediterranean diet plus omega-3 fatty acid supplementation, as compared to a control group. This study is a cross-sectional, observational cohort study of an 8-week dietary intervention in children with ADHD. Participants (n= 60) were divided into 4 groups, with a control group and 3 intervention groups. Results show that participants with ADHD taking n-3 PUFA supplements (550 mg EPA and 225 mg DHA daily) showed significantly lower levels of impulsiveness than those adopting a Mediterranean diet and controls. These participants also scored lower on all subscales of the BIS (cognitive, motor, and lack of planning). However, there weren’t any differences in impulsive behaviour between patients taking n-3 PUFA supplements and those taking supplements and adhering to the Mediterranean diet. Authors conclude that omega-3 rich (EPA/DHA) supplements should be considered for paediatric patients with ADHD, particularly those with the predominantly hyperactive-impulsive subtype.
Expert Review
Conflicts of interest:
None
Take Home Message:
- The results from this study show no statistically significant differences between groups, except for the group of children receiving omega-3 supplementation.
- Patients with ADHD receiving omega 3 fatty acids (550 mg eicosatetraenoic acid [EPA] and 225 mg docosahexaenoic acid [DHA]) daily presented with less impulsive behaviour than controls with ADHD and patients who adopted a Mediterranean diet.
- EPA/DHA supplements may be considered for paediatric patients with ADHD, particularly those with the predominantly hyperactive-impulsive subtype.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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X
B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
A randomized, cross-sectional study was conducted to investigate the effects of a Mediterranean diet and Omega-3 supplementation on the impulsiveness in children with attention-deficit/hyperactivity disorder (ADHD).
Methods
76 Children ages 6-16 years of either sex, with a diagnosis of ADHD, were divided into 4 groups, with a control group and 3 intervention groups. Group 1 (controls) followed their usual diet. Group 2 (Mediterranean diet) adopted a Mediterranean diet according to a series of recommendations. Group 3 (omega-3) received omega-3 fatty acid supplements. Group 4 (Mediterranean diet + omega-3) adopted the same diet as group 2 and also received omega 3 fatty acid supplements.
Dieticians provided a tailored Mediterranean diet for each participant. The Omega-3 supplement comprised of 550mg EPA and 225mg of DHA sourced from deep-sea sardines and anchovies.
The Barratt Impulsiveness Scale (BIS-11c) was administered to every child individually to evaluate impulsiveness. The KIDMED questionnaire was administered to evaluate the participant’s adherence to the Mediterranean diet. The study was conducted over 8 weeks. At the endpoint, 60/76 subjects completed the study.
Results
Primary clinical outcomes were:
- Children in the omega-3 supplement group showed a significant drop in the Barratt Impulsiveness Scale score after the intervention (from 49 to 45.10; p =.049).
- Children in the Mediterranean diet and supplement group showed higher cognitive scores (from 2.758 to 2.631).
Limitation
There was a statistically significant difference between groups for the KIDMED score (a measure of adherence to a Mediterranean diet), reflecting a higher adherence to the Mediterranean diet by the control group.
Clinical practice applications:
- Approximately 20%-40% of patients with ADHD do not respond to pharmacological treatment therefore there is a need for alternative options.
- Based on these findings, a practitioner could therefore consider recommending 550mg of eicosatetraenoic acid (EPA) and 225mg of docosahexaenoic acid (DHA) sourced from deep-sea sardines and anchovies for at least 8 weeks to help reduce impulsiveness and improve cognitive function in patients with a hyperactive-impulsive subtype of ADHD.
Considerations for future research:
- This study included combined types of ADHD therefore further investigations are needed on each type of ADHD using different interventions to establish which intervention works best.
- Assessment of diet and omega status before intervention was not conducted, which may have affected outcomes in this study. Further research could consider gathering this data at baseline.
- Larger studies are also needed to determine the relationship between BIS scores and treatments to deepen our understanding of this topic.
- Conflict of interest statement: This study was fully funded by the manufacturer of the provided Omega 3 supplement.
Abstract
INTRODUCTION The Barratt Impulsiveness Scale (BIS) is a self-administered instrument designed to assess the personality/behavioural construct of impulsiveness. Impulsiveness has been associated with several psychiatric disorders, including attention-deficit/hyperactivity disorder (ADHD). This study assesses the progression of impulsive behaviour in children with ADHD after an 8-week dietary intervention with the Mediterranean diet and/or omega-3 fatty acid supplementation, by using a version of the 11-item BIS adapted for children (BIS-11c). METHODS This cross-sectional study includes 60 children with ADHD from the region of Madrid, Spain. Participants were divided into 4 groups, with one control group and 3 intervention groups (Mediterranean diet; omega-3 supplementation; and Mediterranean diet plus omega-3 supplementation). A personalised Mediterranean diet was designed for members of groups 2 and 4. The BIS-11c was administered to determine the level of impulsiveness, and the KIDMED test was used to assess adherence to the Mediterranean diet. RESULTS The supplementation group showed a fairly significant decrease in the total BIS-11c (P = .049). Total cognitive score slightly decreased in the diet and supplementation groups. Only the control group showed a considerable decrease in the total motor score. Total nonplanning scores were lower in all groups after the intervention. Baseline and final BIS-11c scores were positively correlated with treatments (r > 0.9). CONCLUSION An intake of 550 mg EPA fatty acid and 225 mg DHA fatty acid per day for 8 weeks is associated with less marked impulsive behaviour in children with ADHD. A Mediterranean diet may improve BIS scores, although our results are not conclusive in this population.
Methodological quality
Jadad score
:
3
Allocation concealment
:
Yes
