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A combined DHA-rich fish oil and cocoa flavanols intervention does not improve cognition or brain structure in older adults with memory complaints: results from the CANN randomized, controlled parallel-design study.
Vauzour, D, Scholey, A, White, DJ, Cohen, NJ, Cassidy, A, Gillings, R, Irvine, MA, Kay, CD, Kim, M, King, R, et al
The American journal of clinical nutrition. 2023;118(2):369-381
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At a population level, interventions that delay the onset of dementia by 2 years are predicted to reduce the number of dementia patients by 20%. Prospective cohort studies have consistently reported cognitive and neurophysiological benefits of the fish-derived omega-3 long-chain polyunsaturated fatty acids (PUFAs), EPA, and DHA and plant-derived flavanols (FLAVs). This study hypothesised that 12-month administration of a combination of 500 mg cocoa FLAVs with 1.5g omega-3 long-chain PUFAs would improve cognitive function in a mixed subjective cognitive impairment and mild cognitive impairment cohort. This study is based on the results of the CANN randomised controlled trial. A total of 258 participants were recruited and randomised to control or test intervention. Following baseline measurements, 125 participants were randomised into the active OM3FLAV intervention group and 121 into the control group. Results showed that the 1-year intervention with EPA and DHA and cocoa FLAVs did not improve cognition or protect the brain against atrophy in older adults with evidence of memory deficits. Authors concluded that given the complexity of neuropathological processes underpinning cognitive decline and dementia risk, multidomain, multinutrient, or whole diet approaches may be needed to positively impact the cognitive trajectory in the medium term (months to 3 years).
Abstract
BACKGROUND There is evidence that both omega-3 long-chain polyunsaturated fatty acids (PUFAs) (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) and cocoa flavanols can improve cognitive performance in both healthy individuals and in those with memory complaints. However, their combined effect is unknown. OBJECTIVES To investigate the combined effect of EPA/DHA and cocoa flavanols (OM3FLAV) on cognitive performance and brain structures in older adults with memory complaints. METHODS A randomized placebo-controlled trial of DHA-rich fish oil (providing 1.1 g/d DHA and 0.4 g/d EPA) and a flavanol-rich dark chocolate (providing 500 mg/d flavan-3-ols) was conducted in 259 older adults with either subjective cognitive impairment or mild cognitive impairment. Participants underwent assessment at baseline, 3 mo, and 12 mo. The primary outcome was the number of false-positives on a picture recognition task from the Cognitive Drug Research computerized assessment battery. Secondary outcomes included other cognition and mood outcomes, plasma lipids, brain-derived neurotrophic factor (BDNF), and glucose levels. A subset of 110 participants underwent structural neuroimaging at baseline and at 12 mo. RESULTS 197 participants completed the study. The combined intervention had no significant effect on any cognitive outcomes, with the exception of reaction time variability (P = 0.007), alertness (P < 0.001), and executive function (P < 0.001), with a decline in function observed in the OM3FLAV group (118.6 [SD 25.3] at baseline versus 113.3 [SD 25.4] at 12 mo for executive function) relative to the control, and an associated decrease in cortical volume (P = 0.039). Compared with the control group, OM3FLAV increased plasma HDL, total cholesterol ratio (P < 0.001), and glucose (P = 0.008) and reduced TG concentrations (P < 0.001) by 3 mo, which were sustained to 12 mo, with no effect on BDNF. Changes in plasma EPA and DHA and urinary flavonoid metabolite concentrations confirmed compliance to the intervention. CONCLUSIONS These results suggest that cosupplementation with ω-3 PUFAs and cocoa flavanols for 12 mo does not improve cognitive outcomes in those with cognitive impairment. This trial was registered at clinicaltrials.gov as NCT02525198.
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Impulsiveness in children with attention-deficit/hyperactivity disorder after an 8-week intervention with the Mediterranean diet and/or omega-3 fatty acids: a randomised clinical trial.
San Mauro Martin, I, Sanz Rojo, S, González Cosano, L, Conty de la Campa, R, Garicano Vilar, E, Blumenfeld Olivares, JA
Neurologia. 2022;37(7):513-523
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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.
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A Mediterranean Diet with Fresh, Lean Pork Improves Processing Speed and Mood: Cognitive Findings from the MedPork Randomised Controlled Trial.
Wade, AT, Davis, CR, Dyer, KA, Hodgson, JM, Woodman, RJ, Keage, HAD, Murphy, KJ
Nutrients. 2019;11(7)
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Dementia is characterised by severe cognitive impairment and reduced quality of life. Observational studies have demonstrated that populations following a traditional Mediterranean diet experience less cognitive decline and a lowered risk of dementia. The aim of this study was to examine a Mediterranean diet modified to include 2–3 fresh servings of pork each week across measures of cognitive function and well-being. The study is a 24-week parallel randomised controlled crossover design to compare a Mediterranean diet with 2-3 weekly servings of fresh, lean pork (MedPork) and a low-fat control diet (LF). It recruited adults aged 45–80 years due to their increased risk of developing cardiovascular disease. Results indicate that compared with the LF control diet, the MedPork intervention led to higher performance in the cognitive domain of processing speed and higher scores for the SF-36 subscale emotional role functioning. No significant differences were observed for other domains of cognitive function, nor for additional measures of psychological well-being. Authors conclude that the MedPork intervention can improve processing speed and mood in a population at risk of cardiovascular disease and therefore dementia.
Abstract
BACKGROUND The Mediterranean diet may be capable of improving cognitive function. However, the red meat restrictions of the diet could impact long-term adherence in Western populations. The current study therefore examined the cognitive effects of a Mediterranean diet with additional red meat. METHODS A 24-week parallel crossover design compared a Mediterranean diet with 2-3 weekly servings of fresh, lean pork (MedPork) and a low-fat (LF) control diet. Thirty-five participants aged between 45 and 80 years and at risk of cardiovascular disease followed each intervention for 8 weeks, separated by an 8-week washout period. Cognitive function was assessed using the Cambridge Neuropsychological Test Automated Battery. Psychological well-being was measured through the SF-36 Health Survey and mood was measured using the Profile of Mood States (POMS). RESULTS During the MedPork intervention, participants consumed an average of 3 weekly servings of fresh pork. Compared to LF, the MedPork intervention led to higher processing speed performance (p = 0.01) and emotional role functioning (p = 0.03). No other significant differences were observed between diets. CONCLUSION Our findings indicate that a Mediterranean diet inclusive of fresh, lean pork can be adhered to by an older non-Mediterranean population while leading to positive cognitive outcomes.