Dietary patterns and blood fatty acid composition in children with attention-deficit hyperactivity disorder in Taiwan

Raising attention to attention deficit hyperactivity disorder in schizophrenia

Schizophrenia and attention deficit hyperactivity disorder (ADHD) are two psychiatric disorders with a negative impact on quality of life of individuals affected. Although they are classified into distinct disorders categories, attentional dysfunction is considered as a core feature in both conditions, either at the clinical then pathophysiological level. Beyond the obvious clinical overlap between these disorders, the Research Domain Criteria approach might offer an interesting perspective for disentangling common circuits underpinning both disorders. Hence, we review evidences regarding the overlap between schizophrenia and ADHD, at the clinical level, and at the level of underlying brain mechanisms. The evidence regarding the influence of environmental risk factors in the emergence of both disorders, and their developmental trajectories is also reviewed. Among these, we will try to elucidate the complex relationship between stimulants use and psychotic symptoms, discussing the potential role of ADHD medication in inducing psychosis or in exacerbating it. We aim that, taken together, these findings may promote further investigation with important implications both for clinicians and research. In fact, considering the amounting evidence on the overlap between schizophrenia and ADHD, the delineation of their boundaries might help in the decision for diagnosis and treatment. Moreover, it may help to promote interventions focused on the prevention of both schizophrenia and ADHD, by the reduction of recognized environmental risk factors.

Pathways of polyunsaturated fatty acid utilization: implications for brain function in neuropsychiatric health and disease

Essential polyunsaturated fatty acids (PUFAs) have profound effects on brain development and function. Abnormalities of PUFA status have been implicated in neuropsychiatric diseases such as major depression, bipolar disorder, schizophrenia, Alzheimer's disease, and attention deficit hyperactivity disorder. Pathophysiologic mechanisms could involve not only suboptimal PUFA intake, but also metabolic and genetic abnormalities, defective hepatic metabolism, and problems with diffusion and transport. This article provides an overview of physiologic factors regulating PUFA utilization, highlighting their relevance to neuropsychiatric disease.

Fatty acid status and its relationship to cognitive decline and homocysteine levels in the elderly

Polyunsaturated fatty acids (PUFAs), especially the n-3 series, are known for their protective effects. Considering that cardiovascular diseases are risk factors for dementia, which is common at aging, the aim of this study was to evaluate whether fatty acid status in the elderly was associated with cognitive function and cardiovascular risk. Forty-five elderly persons (age ≥60 years) were included and divided into two groups based on their Mini-Mental Status Examination score adjusted for educational level: the case group (n = 12) and the control group (n = 33). Serum fatty acid composition, homocysteine (Hcy), hs-CRP, lipid profile and different cognitive domains were evaluated. The case group, characterized by reduced cognitive performance, showed higher levels of 14:0, 16:0, 16:1n-7 fatty acids and lower levels of 22:0, 24:1n-9, 22:6n-3 (DHA) and total PUFAs compared to the control group (p < 0.05). The n-6/n-3 ratio was elevated in both study groups, whereas alterations in Hcy, hs-CRP and lipid profile were observed in the case group. Cognitive function was positively associated with the 24:1n-9, DHA and total n-3 PUFAs, while 14:0, 16:0 and 16:1n-7 fatty acids, the n-6/n-3 ratio and Hcy were inversely associated. In addition, n-3 PUFAs, particularly DHA, were inversely associated with cardiovascular risk, assessed by Hcy levels in the elderly.

Omega-3 fatty acid and nutrient deficits in adverse neurodevelopment and childhood behaviors

Nutritional insufficiencies of omega-3 highly unsaturated fatty acids (HUFAs) may have adverse effects on brain development and neurodevelopmental outcomes. A recent meta-analysis reported a small to modest effect size for the efficacy of omega-3 in youth. Several controlled trials of omega-3 HUFAs combined with micronutrients show sizable reductions in aggressive, antisocial, and violent behavior in youth and young adult prisoners. Studies of HUFAs in youth, however, remain lacking. As the evidence base for omega-3 HUFAs as potential psychiatric treatment develops, dietary adjustments to increase omega-3 and reduce omega-6 HUFA consumption are sensible recommendations based on general health considerations.

Omega-3 fatty acid and ADHD: blood level analysis and meta-analytic extension of supplementation trials

Interest in the value of omega-3 (n-3) fatty acid supplementation for treatment of ADHD remains high. No prior meta-analysis has examined whether ADHD is associated with alterations in blood lipid levels and meta-analyses of supplementation have reached conflicting conclusions.

METHODS

We report two new meta-analyses. Study 1 examined blood levels of omega-3 fatty acids in relation to ADHD. Study 2 examined a larger sample of randomized intervention trials than previously reported.

RESULTS

Study 1 included 9 studies (n=586) and found lower overall blood levels of n-3 in individuals with ADHD versus controls (g=0.42, 95% CI=0.26-0.59; p<.001). Study 2 included 16 studies (n=1408) and found that n-3 supplementation improved ADHD composite symptoms; using the best available rating and reporter (g=0.26, 95% CI=0.15-0.37; p<.001). Supplementation showed reliable effects on hyperactivity by parent and teacher report, but reliable effects for inattention only by parent report.

CONCLUSIONS

Omega-3 levels are reduced in children with ADHD. Dietary supplementation appears to create modest improvements in symptoms. There is sufficient evidence to consider omega-3 fatty acids as a possible supplement to established therapies. However it remains unclear whether such intervention should be confined to children with below normal blood levels.

Which polyunsaturated fatty acids are active in children with attention-deficit hyperactivity disorder receiving PUFA supplementation? A fatty acid validated meta-regression analysis of randomized controlled trials

Concerns about growth retardation and unknown effects on long-term brain development with stimulants have prompted interest in polyunsaturated fatty acid supplementation (PUFA) as an alternative treatment. However, randomized controlled trials (RCTs) and meta-analyses of PUFA supplementation in ADHD have shown marginal benefit, and uncertainty exists as to which, if any, PUFA might be effective in alleviating symptoms of ADHD. We conducted an updated meta-analysis of RCTs in ADHD together with multivariable meta-regression analyses using data on PUFA content obtained from independent fatty acid methyl ester analyses of each study PUFA regimen. The PubMed, Embase and PsycINFO databases were searched with no start date and up to 28th July 2013. Study inclusion criteria were: randomized design, placebo controlled, PUFA preparation as active intervention, reporting change scores on ADHD rating-scale measures. Rating-scale measures of inattention and hyperactive-impulsive symptoms were extracted, study authors were contacted to obtain missing data, studies not reporting negative findings had these data imputed, and study quality was assessed using the Jadad system plus other indicators. Random-effects models were used for pooled effects and for meta-regression analyses. Standardized mean differences (SMD) in inattention, hyperactive-impulsive and combined symptoms were assessed as rated by parents, teachers or all raters. The influence of study characteristics and PUFA regimen content was explored in multivariable meta-regression analyses. The overall pooled estimate from 18 studies showed that combined ADHD symptoms rated by all raters decreased with PUFA supplementation; SMD -0.192 (95% CI: -0.297, -0.086; P<0.001). However, when analyzed by rater, only parent-rated symptoms decreased significantly. Multivariable meta-regression showed that longer study duration, γ-linolenic acid (GLA), and the interaction between GLA and eicosapentaenoic acid (EPA) were associated with significant decreases in inattention; however, PUFA regimen content was unrelated to changes in hyperactive-impulsive symptoms. Certain fatty acids present in placebo preparations may potentially have been psychoactive. This meta-analysis provides modest evidence of PUFA effectiveness in ADHD, especially GLA and EPA for inattention symptoms; however, evidence of reporting bias, publication bias, variable methodological quality, and use of potentially psychoactive placebos limit the generalizability of these findings.

Low docosahexaenoic acid status is associated with reduced indices in cortical integrity in the anterior cingulate of healthy male children: a 1H MRS Study

Docosahexaenoic acid (DHA, 22:6n-3) is the principal omega-3 fatty acid in mammalian brain gray matter, and emerging preclinical evidence suggests that DHA has neurotrophic and neuroprotective properties. This study investigated relationships among DHA status, neurocognitive performance, and cortical metabolism measured with proton magnetic resonance spectroscopy (1H MRS) in healthy developing male children (aged 8-10 years, n = 38). Subjects were segregated into low-DHA (n = 19) and high-DHA (n = 19) status groups by a median split of erythrocyte DHA levels. Group differences in 1H MRS indices of cortical metabolism, including choline (Cho), creatine (Cr), glutamine + glutamate + γ-aminobutyric acid (Glx), myo-inositol (mI), and n-acetyl aspartate (NAA), were determined in the right and left dorsolateral prefrontal cortex (R/L-DLPFC, BA9) and bilateral anterior cingulate cortex (ACC, BA32/33). Group differences in neurocognitive performance were evaluated with the Kaufman Brief Intelligence Test and identical-pairs version of the continuous performance task (CPT-IP). Subjects in the low-DHA group consumed fish less frequently (P = 0.02), had slower reaction times on the CPT-IP (P = 0.007), and exhibited lower mI (P = 0.007), NAA (P = 0.007), Cho (P = 0.009), and Cr (P = 0.01) concentrations in the ACC compared with the high-DHA group. There were no group differences in ACC Glx or any metabolite in the L-DLPFC and R-DLPFC. These data indicate that low-DHA status is associated with reduced indices of metabolic function in the ACC and slower reaction time during sustained attention in developing male children.

Lipid peroxidation markers in adult attention deficit hyperactivity disorder: new findings for oxidative stress

Malondialdehyde (MDA) is a reliable marker of lipid peroxidation where paraoxonase and arylesterase are two enzymes against it. Although increased MDA has been previously shown in adults with attention deficit/hyperactivity disorder (A-ADHD), levels of paraoxonase and arylesterase enzymes have not been studied yet. We aimed to determine the status of both MDA level and paraoxonase and arylesterase enzyme activities in A-ADHD patients. A total of 35 adults with ADHD diagnosis according to Diagnostic and Statistical Manual of Mental Disorders fourth edition (DSM-IV) criteria and 29 healthy volunteers were included in the study. Serum MDA, paraoxonase and arylesterase levels of the participants were measured. The disease severity of the patients was determined by using Turgay's Adult Attention Deficit Disorder/Attention Deficit Hyperactivity Disorder (ADD/ADHD) DSM IV Based Diagnostic Screening and Rating Scale. The serum MDA level of patients was significantly higher than that of healthy control subjects, whereas their paraoxonase and arylesterase levels were significantly lower. There was no correlation between the levels of biochemical parameters (MDA, paraoxonase and arylesterase) and the disease severity. Sub-types of A-ADHD were similar in terms of these biochemical parameters. Increased lipid peroxidation, a part of oxidative stress, in adults with ADHD appears to be unbuffered by antioxidant enzymes, namely paraoxonase and arylesterase.

Omega-6 to omega-3 fatty acid ratio and higher-order cognitive functions in 7- to 9-y-olds: a cross-sectional study

BACKGROUND

Biochemical and behavioral evidence has suggested that the ratio of n-6 (omega-6) to n-3 (omega-3) could be an important predictor of executive function abilities in children.

OBJECTIVE

We determined the relation between the ratio of n-6 to n-3 and cognitive function in children. We hypothesized that children with lower ratios of n-6 to n-3 fatty acids would perform better on tests of planning and working memory.

DESIGN

Seventy 7- to 9-y-old children completed three 24-h diet recalls and a subset of the Cambridge Neuropsychological Test Assessment Battery. Parents provided information on their demographics and children's diet histories.

RESULTS

Mean n-3 and mean n-6 intakes were related to the mean time spent on each action taken in the planning problem. The ratio of n-6 to n-3 significantly predicted performance on the working memory and planning problems. There was a significant interaction between the ratio and fatty acid intake; when children had high ratios, a higher intake of n-3 fatty acids predicted a better performance on the planning task than when children had lower n-3 intakes. When children had low ratios, a lower intake of n-3 and lower intake of n-6 predicted better performance than when intakes were higher.

CONCLUSIONS

The relation between cognitive abilities and the ratio of n-6 to n-3 may be mediated by an enzymatic affinity for n-3 fatty acids. The ratio of n-6 to n-3 should be considered an important factor in the study of fatty acids and cognitive development. This trial was registered at clinicaltrials.gov as NCT01823419.

Dietary fat in relation to erythrocyte fatty acid composition in men

Erythrocyte membrane fatty acid (EMFA) composition is used in the validation of food frequency questionnaires (FFQ) and the evaluation of dietary fat quality. In this cross-sectional study we aimed to investigate associations of diet with EMFA. Altogether, 1,033 randomly selected Finnish men, aged from 47 to 75 years filled in a FFQ and their EMFA composition was analyzed. Marine polyunsaturated fatty acid (PUFA) intake correlated positively with erythrocyte eicosapentaenoic and docosahexaenoic acids (r(s) = 0.415 and r(s) = 0.340, respectively, P < 0.001) and inversely with all n-6 PUFA analyzed (P < 0.001). PUFA intake from spreads and cooking fats correlated positively with alpha-linolenic (ALA), linoleic (LNA) and nervonic acids (r(s) = 0.229, r(s) = 0.160 and r(s) = 0.143, respectively, P < 0.001). Milk fat intake was associated with myristic and behenic acids (r(s) = 0.186 and r(s) = 0.132, respectively P < 0.001). Butter users had lower ALA and LNA proportions (mol%) than non-users (0.16 ± 0.04 vs. 0.19 ± 0.05, P < 0.001 and 7.77 ± 1.02 vs. 8.12 ± 1.11, P = 0.001). Higher PUFA intake from meat was related to decreased long-chain n-3 (P < 0.001) and increased n-6 PUFA (P < 0.001) proportions. In conclusion, EMFA composition reflects particularly well the intakes of n-3 PUFA, whereas other associations remained lower. Yet, all main sources of dietary fat were related with EMFA. The dietary effect on the nervonic acid proportion was confirmed.

[Dietary patterns in patients with attention deficit hyperactivity disorder]

OBJECTIVE

To evaluate the dietary patterns in a group of patients diagnosed with attention deficit hyperactivity disorder (ADHD) and under treatment with extended-release methylphenidate (MPH-ER).

MATERIAL AND METHODS

A nutrition survey (food intake recall for three consecutive days) was carried out on 100 patients diagnosed with ADHD and under treatment with MPH-ER, and in 150 healthy children (control group). Calorie and nutrient intake, as well as nutrition status, were evaluated and compared in both groups.

RESULTS

The mean MPH-ER dose was 1.02 mg/kg/day. Nutritional status in the ADHD group was significantly lower (P < .05) than in control group. The consumption of cereals, meat, pulses and fruits in the control group was significantly higher (P < .05) than in ADHD group. Calorie intake in the mid-morning snack, lunch and afternoon snack was significantly higher (P < .05) in the control group. Calorie intake at supper was significantly higher (P < .05) in the ADHD group. Total calorie intake, as well as protein, carbohydrates, fat, fibre, calcium, iron, magnesium, zinc, selenium and phosphorous, thiamine, niacin, vitamin B6 and folate intake in the control group was significantly higher than in ADHD group.

CONCLUSIONS

Treatment with MPH-ER substantially modifies the percentage distribution of calorie intake of the different meals. The daily calorie and nutrients intake in patients under treatment with MPH-ER is, generally, lower than in the healthy population of a similar age. Nutrition education should be provided, along with multimodal treatment, to the patients and/or their families.

Low blood long chain omega-3 fatty acids in UK children are associated with poor cognitive performance and behavior: a cross-sectional analysis from the DOLAB study

Background

Omega-3 long-chain polyunsaturated fatty acids (LC-PUFA), especially DHA (docosahexaenonic acid) are essential for brain development and physical health. Low blood Omega-3 LC-PUFA have been reported in children with ADHD and related behavior/learning difficulties, as have benefits from dietary supplementation. Little is known, however, about blood fatty acid status in the general child population. We therefore investigated this in relation to age-standardized measures of behavior and cognition in a representative sample of children from mainstream schools.

Participants

493 schoolchildren aged 7–9 years from mainstream Oxfordshire schools, selected for below average reading performance in national assessments at age seven.

Method

Whole blood fatty acids were obtained via fingerstick samples. Reading and working memory were assessed using the British Ability Scales (II). Behaviour (ADHD-type symptoms) was rated using the revised Conners’ rating scales (long parent and teacher versions). Associations were examined and adjusted for relevant demographic variables.

Results

DHA and eicosapentaenoic acid (EPA), accounted for only 1.9% and 0.55% respectively of total blood fatty acids, with DHA showing more individual variation. Controlling for sex and socio-economic status, lower DHA concentrations were associated with poorer reading ability (std. OLS coeff. = 0.09, p = <.042) and working memory performance (0.14, p = <.001). Lower DHA was also associated with higher levels of parent rated oppositional behavior and emotional lability (−0.175, p = <.0001 and −0.178, p = <.0001).

Conclusions

In these healthy UK children with below average reading ability, concentrations of DHA and other Omega-3 LC-PUFA were low relative to adult cardiovascular health recommendations, and directly related to measures of cognition and behavior. These findings require confirmation, but suggest that the benefits from dietary supplementation with Omega-3 LC-PUFA found for ADHD, Dyspraxia, Dyslexia, and related conditions might extend to the general school population.

Omega-3 fatty acids are inversely related to callous and unemotional traits in adolescent boys with attention deficit hyperactivity disorder

A number of research studies have reported abnormal plasma fatty acid profiles in children with ADHD along with some benefit of n-3 to symptoms of ADHD. However, it is currently unclear whether (lower) long chain-polyunsaturated fatty acids (LC-PUFAs) are related to ADHD pathology or to associated behaviours. The aim of this study was to test whether (1) ADHD children have abnormal plasma LC-PUFA levels and (2) ADHD symptoms and associated behaviours are correlated with LC-PUFA levels. Seventy-two, male children with (n=29) and without a clinical diagnosis of ADHD (n=43) were compared in their plasma levels of LC-PUFA. Plasma DHA was higher in the control group prior to statistical correction. Callous-unemotional (CU) traits were found to be significantly negatively related to both eicosapentaenoic acid (EPA), and total omega-3 in the ADHD group. The findings unveil for the first time that CU and anti-social traits in ADHD are associated with lower omega-3 levels.

Fatty acid correlates of temperament in adolescent boys with attention deficit hyperactivity disorder

Atypical fatty acid metabolism has been reported in attention deficit hyperactivity disorder (ADHD), however, its relationship with temperament in this population is unclear. The current study investigated the association between blood levels of fatty acids implicated in brain structure and function (omega-3, omega-6, omega-9) and personality traits of stability (neuroticism, conscientiousness and agreeableness) and plasticity (extraversion and openness). Twenty right-handed adolescent boys with ADHD completed a self-report NEO-FFI personality questionnaire, and had fatty acid content assessed from red blood using gas chromatography. Pearson's correlations showed no significant associations between omega-3 levels and personality. After correction for multiple comparisons, Adrenic Acid (C22:4n6) was inversely associated with stability. Oleic acid (C18:1n9) was positively associated with plasticity. Results are in line with a role of fatty acids in brain function. They suggest that those fatty acids that are involved in myelination (Adrenic, Oleic) have the strongest associations with temperament in adolescents with ADHD.

Altered serum mono- and polyunsaturated fatty acid levels in adults with ADHD

Other than in children diagnosed with attention deficit hyperactivity disorder (ADHD), the connection between ADHD and lipids has not been sufficiently investigated so far in adults. Blood serum lipoproteins and fatty acids (FA) composition were measured and analyzed by colorimetry and gaschromatography in eight male and seven female adults diagnosed with ADHD as well as in 15 age- and gender-matched healthy control subjects. In ADHD patients, polyunsaturated FAs [docosahexaenoic, arachidonic and dihomogammalinolenic acid (p = 0.048; 0.003; 0.012)] showed lower concentrations, while monounsaturated acids (palmitoleic and oleic acid) as well as total and LDL cholesterol showed higher concentrations (p = 0.011; 0.005). ADHD scores positively correlated with palmitoleic (R = -0.56; p = 0.032), stearic (R = 0.53; p = 0.044), eicosapentaenoic (R = 0.62; p = 0.014), docosahexaenoic (R = 0.51; p = 0.050), gammalinolenic (R = 0.62; p = 0.018) and alphalinolenic acid (R = 0.56; p = 0.031) concentration. Even though the total and LDL cholesterol concentrations in blood serum were significantly higher among the ADHD patients than in controls, none of the ADHD symptom scores were significantly associated with any of the lipoproteine measures. We could demonstrate that a lack of polyunsaturated FAs in blood serum of subjects with ADHD persists into adulthood. Furthermore, we could show that adult ADHD symptomatology positively correlates with elevated levels of saturated stearic and monounsaturated FAs.

Role of Long-Chain Omega-3 Fatty Acids in Psychiatric Practice

Nutrition plays a minor role in psychiatric practice which is currently dominated by a pharmacological treatment algorithm. An accumulating body of evidence has implicated deficits in the dietary essential long-chain omega-3 (LCn-3) fatty acids, eicosapenaenoic acid (EPA) and docosahexaenoic acid (DHA), in the pathophysiology of several major psychiatric disorders. LCn-3 fatty acids have an established long-term safety record in the general population, and existing evidence suggests that increasing LCn-3 fatty acid status may reduce the risk for cardiovascular disease morbidity and mortality. LCn-3 fatty acid supplementation has been shown to augment the therapeutic efficacy of antidepressant, mood-stabilizer, and second generation antipsychotic medications, and may additionally mitigate adverse cardiometabolic side-effects. Preliminary evidence also suggests that LCn-3 fatty acid supplementation may be efficacious as monotherapy for primary and early secondary prevention and for perinatal symptoms. The overall cost-benefit ratio endorses the incorporation of LCn-3 fatty acids into psychiatric treatment algorithms. The recent availability of laboratory facilities that specialize in determining blood LCn-3 fatty acid status and emerging evidence-based consensus guidelines regarding safe and efficacious LCn-3 fatty acid dose ranges provide the infrastructure necessary for implementation. This article outlines the rationale for incorporating LCn-3 fatty acid treatment into psychiatric practice.

Deciphering the role of docosahexaenoic acid in brain maturation and pathology with magnetic resonance imaging

Animal studies have found that deficits in brain docosahexaenoic acid (DHA, 22:6n-3) accrual during perinatal development leads to transient and enduring abnormalities in brain development and function. Determining the relevance of this evidence to brain disorders in humans has been hampered by an inability to determine antimortem brain DHA levels and limitations associated with a postmortem approach. Accordingly, there is a need for alternate or complementary approaches to better understand the role of DHA in cortical function and pathology, and conventional magnetic resonance imaging (MRI) techniques may be ideally suited for this application. A major advantage of neuroimaging is that it permits prospective evaluation of the effects of manipulating DHA status on both clinical and neuroimaging variables. Emerging evidence from MRI studies suggest that greater DHA status is associated with cortical structural and functional integrity, and suggest that reduced DHA status and abnormalities in cortical function observed in psychiatric disorders may be interrelated phenomenon. Preliminary evidence from animal MRI studies support a critical role of DHA in normal brain development. Neuroimaging research in both human and animals therefore holds tremendous promise for developing a better understanding of the role of DHA status in cortical function, as well as for elucidating the impact of DHA deficiency on neuropathological processes implicated in the etiology and progression of neurodevelopmental and psychiatric disorders.

Biomarkers and attention-deficit/hyperactivity disorder: a systematic review and meta-analyses

OBJECTIVE

To determine whether peripheral biochemical markers (biomarkers) might differentiate patients with attention-deficit/hyperactivity disorder (ADHD) from non-ADHD individuals.

METHOD

We conducted a systematic search and a series of meta-analyses of case-control studies comprising studies from 1969 to 2011.

RESULTS

We identified 210 studies in the following categories: 71 studies of the main metabolites and metabolism enzymes of monoaminergic neurotransmission pathway; 87 studies of environmental risk factors divided into heavy metals (18 studies), substance/chemical exposures (16 studies), and nutritional factors (trace elements: 29 studies; essential fatty acids: 24 studies); 22 studies of the hypothalamic-pituitary-adrenal axis (HPA) pathway; 31 studies indicated with "other". After screening for the availability for meta-analyses of drug naïve/free case-control studies and Bonferroni correction, five comparisons were statistically significant (Norepinephrine [NE], 3-Methoxy-4-hydroxyphenylethylene glycol [MHPG], monoamine oxidase [MAO], Zinc [Zn], cortisol), five of the significant findings found support in studies of response to ADHD medications (NE, MHPG, MAO, b-phenylethylamine [PEA], cortisol), six in studies of symptoms severity (NE, MHPG, MAO, ferritin, Zn, cortisol) and three in studies of neurophysiological or cognitive functioning (lead-ferritin-Zn). No evidence of publication bias was found, whereas significant heterogeneity of effect sizes across studies was found for three of the five biomarkers that differentiated ADHD from control subjects. Suggestive associations were evidenced for neuropeptide Y (NPY), manganese, and dehydroepiandrosterone (DHEA).

CONCLUSIONS

This study provides evidence for several peripheral biomarkers as being associated with ADHD both in diagnosis and in treatment efficacy. Further studies are warranted to replicate these findings, to assess their specificity for ADHD, and to quantify the degree to which they are sufficiently precise to be useful in clinical settings.

Polyunsaturated fatty acids (PUFA) for attention deficit hyperactivity disorder (ADHD) in children and adolescents

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a major problem in children and adolescents, characterised by age-inappropriate levels of inattention, hyperactivity and impulsivity, and is associated with long-term social, academic and mental health problems. The stimulant medications methylphenidate and amphetamine are the most frequently used treatments for ADHD, but these are not always effective and can be associated with side effects. Clinical and biochemical evidence suggests that deficiencies of polyunsaturated fatty acids (PUFA) could be related to ADHD. Children and adolescents with ADHD have been shown to have significantly lower plasma and blood concentrations of PUFA and, in particular, lower levels of omega-3 PUFA. These findings suggest that PUFA supplementation may reduce the attention and behaviour problems associated with ADHD.

OBJECTIVES

To compare the efficacy of PUFA to other forms of treatment or placebo in treating the symptoms of ADHD in children and adolescents.

SEARCH METHODS

We searched the following databases in August 2011: CENTRAL (The Cochrane Library 2011, Issue 2), MEDLINE (1948 to July Week 3, 2011), EMBASE (1980 to 2011 Week 29), PsycINFO (1806 to current), CINAHL (1937 to current), BIOSIS (1969 to 30 July 2011), Science Citation Index (1970 to 30 July 2011), Social Science Citation Index (1970 to 30 July 2011), Conference Proceedings Citation Index - Science (1990 to 30 July 2011), Conference Proceedings Citation Index - Social Science and Humanities (1990 to 30 July 2011), Cochrane Database of Systematic Reviews (2011, Issue 7), DARE (2011 Issue 2), Dissertation Abstracts (via Dissertation Express) and the metaRegister of Controlled Trials (mRCT). In addition, we searched the following repositories for theses on 2 August 2011: DART, NTLTD and TROVE. We also checked reference lists of relevant studies and reviews for additional references.

SELECTION CRITERIA

Two review authors independently assessed the results of the database searches. We resolved any disagreements regarding the selection of studies through consensus or, if necessary, by consultation with a third member of the review team.

DATA COLLECTION AND ANALYSIS

Two members of the review team independently extracted details of participants and setting, interventions, methodology and outcome data. If differences were identified, we resolved them by consensus or referral to a third member of the team. We made all reasonable attempts to contact the authors where further clarification or missing data were needed.

MAIN RESULTS

We included 13 trials with 1011 participants in the review. After screening 366 references, we considered 23 relevant and obtained the full text for consideration. We excluded five papers and included 18 papers describing the 13 trials. Eight of the included trials had a parallel design: five compared an omega-3 PUFA supplement to placebo; two compared a combined omega-3 and omega-6 supplement to placebo, and one compared an omega-3 PUFA to a dietary supplement. Five of the included trials had a cross-over design: two compared combined omega-3/6 PUFA to placebo; two compared omega-6 PUFA with placebo; one compared omega-3 to omega-6 PUFA, and one compared omega-6 PUFA to dexamphetamine. Supplements were given for a period of between four and 16 weeks.There was a significantly higher likelihood of improvement in the group receiving omega-3/6 PUFA compared to placebo (two trials, 97 participants; risk ratio (RR) 2.19, 95% confidence interval (CI) 1.04 to 4.62). However, there were no statistically significant differences in parent-rated ADHD symptoms (five trials, 413 participants; standardised mean difference (SMD) -0.17, 95% CI -0.38 to 0.03); inattention (six trials, 469 participants; SMD -0.04, 95% CI -0.29 to 0.21) or hyperactivity/impulsivity (five trials, 416 participants; SMD -0.04, 95% CI -0.25 to 0.16) when all participants receiving PUFA supplements were compared to those receiving placebo.There were no statistically significant differences in teacher ratings of overall ADHD symptoms (four trials, 324 participants; SMD 0.05, 95% CI -0.18 to 0.27); inattention (three trials, 260 participants; SMD 0.26, 95% CI -0.22 to 0.74) or hyperactivity/impulsivity (three trials, 259 participants; SMD 0.10, 95% CI -0.16 to 0.35).There were also no differences between groups in behaviour, side effects or loss to follow-up.Overall, there were no other differences between groups for any other comparison.

AUTHORS' CONCLUSIONS

Overall, there is little evidence that PUFA supplementation provides any benefit for the symptoms of ADHD in children and adolescents. The majority of data showed no benefit of PUFA supplementation, although there were some limited data that did show an improvement with combined omega-3 and omega-6 supplementation.It is important that future research addresses current weaknesses in this area, which include small sample sizes, variability of selection criteria, variability of the type and dosage of supplementation, short follow-up times and other methodological weaknesses.

Fatty acids in ADHD: plasma profiles in a placebo-controlled study of Omega 3/6 fatty acids in children and adolescents

The aim of this study was to assess baseline levels and changes in plasma fatty acid profiles in children and adolescents with ADHD, in a placebo-controlled study with Omega 3/6 supplementation, and to compare with treatment response. Seventy-five children and adolescents aged 8-18 years with DSM-IV ADHD were randomized to 3 months of Omega 3/6 (Equazen eye q) or placebo, followed by 3 months of open phase Omega 3/6 for all. n-3, n-6, n-6/n-3 ratio, EPA and DHA in plasma were measured at baseline, 3 and 6 months. Subjects with more than 25 % reduction in ADHD symptoms were classified as responders. At baseline, no significant differences in mean fatty acid levels were seen across active/placebo groups or responder/non-responder groups. The 0-3 month changes in all parameters were significantly greater in the active group (p < 0.01). Compared to non-responders, the 6-month responders had significantly greater n-3 increase at 3 months and decrease in n-6/n-3 ratio at 3 and 6 months (p < 0.05). Omega 3/6 supplementation had a clear impact on fatty acid composition of plasma phosphatidyl choline in active versus placebo group, and the fatty acid changes appear to be associated with treatment response. The most pronounced and long-lasting changes for treatment responders compared to non-responders were in the n-6/n-3 ratio.

Effects of omega 3 fatty acids supplementation in behavior and non-neurodegenerative neuropsychiatric disorders

This work provides a systematic review of all published randomised, controlled clinical trials (RCT) investigating the effects ofn-3 PUFA intake on the prevention and treatment of non-neurodegenerative neuropsychiatric disorders. Five databases (PubMed, EMBASE, LILACS, CINAHL and The Cochrane Database) were searched for RCT in this area published up to April 2011. The selected studies all involved human participants and included a comparison group. Thirty eight studies were identified, which examined the influence ofn-3 PUFA supplementation on the prevention/treatment of depression (non-perinatal) (n23), perinatal depression (n6) and attention deficit hyperactivity disorder (ADHD) (n9). Great heterogeneity was noticed in terms of study design, the doses ofn-3 PUFA administered, and study duration. Some benefit was noted with respect to the treatment of hyperactivity and depression in over half the examined studies, although the evidence was not conclusive. For any firm conclusions to be drawn, further studies will be needed that take into account the initialn-3 PUFA status of the subjects. Excessiven-3 PUFA intakes might be associated with a greater risk of peroxidation events and therefore neuropsychiatric deterioration. Indeed, some studies only recorded benefits when lower doses were administered. It is therefore important that the dose required to achieve any potential benefit be determined.

(N-3) Fatty acids: molecular role and clinical uses in psychiatric disorders

New discoveries in the field of neurophysiology and neuropharmacology have revealed the role of (n-3) fatty acids in controlling inflammation and protecting neuron cells from oxidative damage, preserving their function. It has also been thought that their psychoactive properties could be beneficial in certain psychiatric illnesses. This article discusses the newest discoveries of the affected activities by these fats in the cerebral cortex and the efforts that have been made to put them in practice in clinical trials in humans. In general, we were able to detect certain discord in the scientific community when designing placebo-based studies (mainly in establishing the appropriate therapeutic dose of (n-3) fatty acids, varying from the recommended dietary dose to an amount that may be 3 or 4 times higher), and in interpreting results. Although many studies have had the validity of their results questioned because of their small sample size, several studies seem to indicate that the (n-3) fatty acids are useful therapeutic tools in treating psychiatric conditions such as major depression, bipolar disorder, and several other disorders. Larger sample size studies are still required to better analyze the treatment potential of these agents.

Polyunsaturated fatty acids, cognition and literacy in children with ADHD with and without learning difficulties

Suboptimal omega-3 polyunsaturated fatty acid (n-3 PUFA) levels may contribute to attention deficit hyperactivity disorder (ADHD) and related developmental problems. Associations between n-3 and omega-6 (n-6) PUFA levels in red blood cells (erythrocytes) and learning and behaviour were investigated in 75 children aged 7-12 with ADHD. Children provided blood samples and underwent cognitive assessments. Parents completed questionnaires and Conners' Rating Scales. Controlling for covariates, higher n-3 PUFA predicted lower anxiety/shyness (β = -.27), higher docosahexaenoic acid (DHA) better word reading (β = .22), and higher n-6 PUFA poorer reading (β = -.34), vocabulary (β = .-.26), spelling (β = -.30) and attention (β = -.30). Thirty-six per cent of the sample with learning difficulties had lower DHA than those without (M = 3.26 ± 0.54 vs M = 3.68 ± 0.76, p = .02). This study is the first to compare erythrocyte PUFAs (a measure of PUFA status) in children who have ADHD with and without learning difficulties, and supports emerging indications that the former may be more likely responders to n-3 PUFAs.

Update on environmental risk factors for attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent neurobehavioral disorder affecting 5% to 10% of children. Although considered to be a highly familial disorder, ADHD heritability estimates of 60% to 80% highlight the considerable role that environmental factors may still play in disorder susceptibility. Proposed ADHD environmental risk factors include prenatal substance exposures, heavy metal and chemical exposures, nutritional factors, and lifestyle/psychosocial factors. This paper reviews the literature published in 2010 investigating the association between environmental risk factors and ADHD or related symptomatology. Sources of risk factor exposure and the proposed mechanism by which each exposure is linked to ADHD-related neurobehavioral changes are also reported. Methodologic limitations of the current literature are discussed, and guidelines for future study are proposed. An improved understanding of the role that environmental factors play in ADHD etiology is critical to future ADHD prevention efforts.

Omega-3 fatty acid supplementation for the treatment of children with attention-deficit/hyperactivity disorder symptomatology: systematic review and meta-analysis

OBJECTIVE

Several studies have demonstrated differences in omega-3 fatty acid composition in plasma and in erythrocyte membranes in patients with attention-deficit/hyperactivity disorder (ADHD) compared with unaffected controls. Omega-3 fatty acids have anti-inflammatory properties and can alter central nervous system cell membrane fluidity and phospholipid composition. Cell membrane fluidity can alter serotonin and dopamine neurotransmission. The goal of this meta-analysis was to examine the efficacy of omega-3 fatty acid supplementation in children with ADHD.

METHOD

PubMed was searched for randomized placebo-controlled trials examining omega-3 fatty acid supplementation in children with ADHD symptomatology. The primary outcome measurement was standardized mean difference in rating scales of ADHD severity. Secondary analyses were conducted to determine the effects of dosing of different omega-3 fatty acids in supplements.

RESULTS

Ten trials involving 699 children were included in this meta-analysis. Omega-3 fatty acid supplementation demonstrated a small but significant effect in improving ADHD symptoms. Eicosapentaenoic acid dose within supplements was significantly correlated with supplement efficacy. No evidence of publication bias or heterogeneity between trials was found.

CONCLUSION

Omega-3 fatty acid supplementation, particularly with higher doses of eicosapentaenoic acid, was modestly effective in the treatment of ADHD. The relative efficacy of omega-3 fatty acid supplementation was modest compared with currently available pharmacotherapies for ADHD such as psychostimulants, atomoxetine, or α(2) agonists. However, given its relatively benign side-effect profile and evidence of modest efficacy, it may be reasonable to use omega-3 fatty supplementation to augment traditional pharmacologic interventions or for families who decline other psychopharmacologic options.

Complementary medicine for children and young people who have attention deficit hyperactivity disorder

PURPOSE OF REVIEW

Despite effectiveness of medication in treating children and young people who have attention deficit hyperactivity disorder (ADHD), concerns about the effects of medication on children's developing brains, adverse side-effects, possibility of long-term use, and compliance issues have all contributed to the continuing search for alternative therapies. This article reviews the latest scientific evidence of the effectiveness and safety of these treatments in ADHD.

RECENT FINDINGS

Although there is evidence from a large randomized controlled study that neurofeedback has positive effects on reducing children's symptoms of ADHD, most recent randomized controlled trials have generally yielded negative results. Some positive results exist from a pilot study of repetitive transcranial magnetic stimulation. However, the sample size was far too small to enable any conclusions to be drawn about the evidence. Findings from the recent randomized controlled trials of supplements of essential fatty acids in children who have ADHD clearly demonstrated lack of superiority compared with placebo.

SUMMARY

Notwithstanding efforts made to increase the scientific rigor of previous studies, more recent studies have generally been unsuccessful in demonstrating adequate treatment effects of complementary medicine on children who have ADHD. Currently, there is no proof that complementary medicine provides a better alternative for children who have ADHD than treatments that are currently available within multimodal therapy.

The impact of polyunsaturated fatty acids in reducing child attention deficit and hyperactivity disorders

OBJECTIVES

To review the impact of polyunsaturated fatty acids (PUFA) in reducing ADHD symptoms in children.

METHODS

Peer-reviewed experimental literature published from 1980 to Mai 2009 is consulted (Psychinfo, Medline, and resulting reference lists).

RESULTS

Placebo-controlled studies with ADHD or hyperactive children show no effects on behaviors or cognition when only n-6 (omega-6) PUFA, only docosahexaenoic acid (DHA), or n-6 and n-3 (omega-3) short-chain PUFA are supplemented. Yet three out of four studies suggest that a combination of long-chain n-3 and n-6 fatty acids (DHA, eicosapentaenoic acid [EPA], and gamma-linolenic acid [GLA]) supplemented daily for 3 to 4 months could lead to a reduction in ADHD symptomatology. Results on cognitive outcomes are inconsistent.

CONCLUSIONS

Evidence is too limited to reach definitive conclusions but suggests that research on the impact of long-chain PUFA (n-3 and n-6) should continue with special focus on individual differences (genetic and fatty acid markers), mechanisms (brain imaging), and new enhanced methods of systematic observations of behaviors.

The association of fatty acid deficiency symptoms (FADS) with actual essential fatty acid status in cheek cells

Seven clinical symptoms have been utilised in several studies as a means of potentially identifying children with a deficiency in essential polyunsaturated fatty acids (PUFAs). The purpose of this study was to investigate whether there was any correlation between parental reports of the frequency of these seven 'fatty acid deficiency symptoms' (FADS) with actual levels of fatty acids in buccal cell samples of 450 children aged 8-10 years old. Additionally, the relationship between FADS and cognitive test performance, ratings of attention and behaviour and other somatic complaints were explored. The severity of reported FADS was not related to the levels of omega-6 or omega-3 in buccal cell samples. There was a relationship between parental reports of child behaviour and reported FADS; with high FADS being related to higher ratings of behaviour problems. Using FADS as a marker of PUFA deficiency may not be appropriate especially when assessing typically developing children.

Nutritional status of children with attention deficit hyperactivity disorder: a pilot study

Objectives. This is a pilot study of the dietary intake and nutrient status of children with Attention Deficit Hyperactivity Disorder (ADHD). Method. Nutritional assessment of 43 children aged 6–12 with ADHD was performed using a 3-day food record, 24-hour recall, and serum assessors. Results. Macronutrient intake and consumption of Low-Nutrient Foods were comparable to population norms; however, 66% were found to be deficient in zinc and 23% in copper. Conclusions. This pilot study reports the food intake and nutrient status of children with ADHD and shows a predisposition for low zinc and copper status in ADHD.

Docosahexaenoic acid supplementation increases prefrontal cortex activation during sustained attention in healthy boys: a placebo-controlled, dose-ranging, functional magnetic resonance imaging study

BACKGROUND

Emerging evidence suggests that docosahexaenoic acid (DHA, 22:6n-3), the principal omega-3 (n-3) fatty acid in brain gray matter, positively regulates cortical metabolic function and cognitive development. However, the effects of DHA supplementation on functional cortical activity in human subjects are unknown.

OBJECTIVE

The objective was to determine the effects of DHA supplementation on functional cortical activity during sustained attention in human subjects.

DESIGN

Healthy boys aged 8-10 y (n = 33) were randomly assigned to receive placebo or 1 of 2 doses of DHA (400 or 1200 mg/d) for 8 wk. Relative changes in cortical activation patterns during sustained attention at baseline and endpoint were determined by functional magnetic resonance imaging.

RESULTS

At 8 wk, erythrocyte membrane DHA composition increased significantly from baseline in subjects who received low-dose (by 47%) or high-dose (by 70%) DHA but not in those who received placebo (-11%). During sustained attention, both DHA dose groups had significantly greater changes from baseline in activation of the dorsolateral prefrontal cortex than did the placebo group, and the low-dose and high-dose DHA groups had greater decreases in the occipital cortex and cerebellar cortex, respectively. Relative to low-dose DHA, high-dose DHA resulted in greater decreases in activation of bilateral cerebellum. The erythrocyte DHA composition was positively correlated with dorsolateral prefrontal cortex activation and was inversely correlated with reaction time, at baseline and endpoint.

CONCLUSION

Dietary DHA intake and associated elevations in erythrocyte DHA composition are associated with alterations in functional activity in cortical attention networks during sustained attention in healthy boys. This trial was registered at clinicaltrials.gov as NCT00662142.

Oiling the brain: a review of randomized controlled trials of omega-3 fatty acids in psychopathology across the lifespan

Around one in four people suffer from mental illness at some stage in their lifetime. There is increasing awareness of the importance of nutrition, particularly omega-3 polyunsaturated fatty acids (n-3 PUFA), for optimal brain development and function. Hence in recent decades, researchers have explored effects of n-3 PUFA on mental health problems over the lifespan, from developmental disorders in childhood, to depression, aggression, and schizophrenia in adulthood, and cognitive decline, dementia and Alzheimer's disease in late adulthood. This review provides an updated overview of the published and the registered clinical trials that investigate effects of n-3 PUFA supplementation on mental health and behavior, highlighting methodological differences and issues.

Significance of long-chain polyunsaturated fatty acids (PUFAs) for the development and behaviour of children

omega-6 and omega-3 polyunsaturated fatty acids (PUFAs) play a central role in the normal development and functioning of the brain and central nervous system. Long-chain PUFAs (LC-PUFAs) such as eicosapentaenoic acid (EPA, C20:5omega-3), docosahexaenoic acid (DHA, C22:6omega-3) and arachidonic acid (AA, C20:4omega-6), in particular, are involved in numerous neuronal processes, ranging from effects on membrane fluidity to gene expression regulation. Deficiencies and imbalances of these nutrients, not only during the developmental phase but throughout the whole life span, have significant effects on brain function. Numerous observational studies have shown a link between childhood developmental disorders and omega-6:omega-3 fatty acid imbalances. For instance, neurocognitive disorders such as attention-deficit hyperactivity disorder (ADHD), dyslexia, dyspraxia and autism spectrum disorders are often associated with a relative lack of omega-3 fatty acids. In addition to a high omega-6 fatty acid intake and, in many cases, an insufficient supply of omega-3 fatty acids among the population, evidence is increasing to suggest that PUFA metabolism can be impaired in individuals with ADHD. In this context, PUFA imbalances are being discussed as potential risk factors for neurodevelopmental disorders. Another focus is whether the nutritive PUFA requirements-especially long-chain omega-3 fatty acid requirements-are higher among some individuals. Meanwhile, several controlled studies investigated the clinical benefits of LC-PUFA supplementation in affected children and adolescents, with occasionally conflicting results.

Undernutrition, fatty acid and micronutrient status in relation to cognitive performance in Indian school children: a cross-sectional study

While undernutrition and anaemia have previously been linked to poor development of children, relatively little is known about the role of B-vitamins and fatty acids on cognition. The present study aims to explore the associations between indicators of body size, fatty acid and micronutrient status on cognitive performance in 598 Indian school children aged 6-10 years. Baseline data of a clinical study were used to assess these associations by analyses of variance adjusting for age, sex, school, maternal education and cognitive tester. The Kaufman Assessment Battery for Children II was used to measure four cognitive domains, including fluid reasoning, short-term memory, retrieval ability and cognitive speediness. Scores were combined into an overall measure, named mental processing index (MPI). Body size indicators and Hb concentrations were significantly positively related to cognitive domains and MPI, such that increases of 1 sd in height-for-age and weight-for-age z-scores would each translate into a 0.09 sd increase in MPI, P = 0.0006 and 0.002, respectively. A 10 g/l increase in Hb concentrations would translate into a 0.08 sd increase in MPI, P = 0.0008. Log-transformed vitamin B12 concentrations were significantly inversely associated with short-term memory, retrieval ability and MPI (beta (95 % CI) = - 0.124 (- 0.224, - 0.023), P = 0.02). Other indicators of Fe, iodine, folate and fatty acid status were not significantly related to cognition. Our findings for body size, fatty acids and micronutrients were in agreement with previous observational studies. The inverse association of vitamin B12 with mental development was unexpected and needed further study.

Molecular cloning and characterization of a KCS gene from Cardamine graeca and its heterologous expression in Brassica oilseeds to engineer high nervonic acid oils for potential medical and industrial use

Nervonic acid 24:1 Delta15 (cis-tetracos-15-enoic acid) is a very long-chain monounsaturated fatty acid and exists in nature as an elongation product of oleic acid. There is an increasing interest in production of high nervonic acid oils for pharmaceutical, nutraceutical and industrial applications. Using a polymerase chain reaction approach, we have isolated a gene from Cardamine graeca L., which encodes a 3-ketoacyl-CoA synthase (KCS), the first component of the elongation complex involved in synthesis of nervonic acid. Expression of the Cardamine KCS in yeast resulted in biosynthesis of nervonic acid, which is not normally present in yeast cells. We transformed Arabidopsis and Brassica carinata with the Cardamine KCS under the control of the seed-specific promoter, napin. The T(3) generations of transgenic Arabidopsis and B. carinata plants expressing the Cardamine KCS showed that seed-specific expression resulted in relatively large comparative increases in nervonic acid proportions in Arabidopsis seed oil, and 15-fold increase in nervonic acid proportions in B. carinata seed oil. The highest nervonic acid level in transgenic B. carinata lines reached 44%, with only 6% of residual erucic acid. In contrast, similar transgenic expression of the Cardamine KCS in high erucic B. napus resulted in 30% nervonic acid but with 20% residual erucic acid. Experiments using the Lunaria KCS gene gave results similar to the latter. In both cases, the erucic acid content is too high for human or animal consumption. Thus, the Cardamine KCS: B. carinata high nervonic/highly reduced erucic transgenic seed oils will be the most suitable for testing in pharmaceutical/nutraceutical applications to improve human and animal health.

Do FADS genotypes enhance our knowledge about fatty acid related phenotypes?

Several physiological processes, such as visual and cognitive development in early life, are dependent on the availability of long-chain polyunsaturated fatty acids (LC-PUFAs). Furthermore, the concentration of LC-PUFAs in phospholipids has been associated with numerous complex diseases like cardiovascular disease, atopic disease and metabolic syndrome. The level and composition of LC-PUFAs in the human body is mainly dependent on their dietary intake or on the intake of fatty acid precursors, which are endogenously elongated and desaturated to physiologically active LC-PUFAs. The delta-5 and delta-6 desaturase are the most important enzymes in this reaction cascade. In the last few years, several studies have reported an association between single nucleotide polymorphisms (SNPs) in the two desaturase encoding genes (FADS1 and FADS2) and the concentration of omega-6 and omega-3 fatty acids. This shows that beside nutrition, genetic factors play an important role in the regulation of LC-PUFAs as well. This review focuses on current knowledge of the impact of FADS genotypes on LC-PUFA and lipid metabolism and discusses their influence on infant intellectual development, neurological conditions, metabolic disease as well as cardiovascular disease.

A meta-analysis of blood fatty acids in people with learning disorders with particular interest in arachidonic acid

Small individual studies report that people with learning disorders have lower than normal blood concentrations of docosahexaenoic acid and arachidonic acid. The origin and consequence of the subnormal docosahexaenoic acid have been much speculated. However, relatively little attention has been paid to the significance of the low arachidonic acid concentration. Studies were identified through a literature search including subjects with various learning disorders or symptoms thereof and age-matched controls. A meta-analysis of pooled data from the red blood cell and plasma/serum showed that red blood cell arachidonic acid and docosahexanoic acid concentrations were significantly lower than normal [-3.93 and -18.92, respectively (weighted mean difference as a % of weighted mean control)]. Plasma/serum arachidonic acid and docosahexaenoic acid concentrations were also significantly lower than normal [-6.99 and -15.66, respectively (weighted mean difference as a % of weighted mean control)]. However, in absolute amounts the arachidonic acid was as severely depressed as docosahexanoic acid within red blood cells 0.57mg/100mg of fatty acid below normal verses 0.59mg/100mg for docosahexaenoic acid. Plasma/serum arachidonic acid was even lower; 0.71mg/100mg of fatty acid below normal verses 0.34mg/100mg for docosahexaenoic acid. The origin, consequences and relative importance of subnormal arachidonic acid to brain function bears further investigation.

Nutrition, mood and behaviour: a review

OBJECTIVE

To conduct a critical review of recent empirical research regarding mood, behaviour and nutrition factors including essential fatty acids, macronutrients, micronutrients and food additives.

METHOD

A literature search of databases Medline, PsycInfo, CINAHL and Embase up to October 2008. The search emphasised empirical research published in the last 10 years and also included older literature. Studies in both adults and children were addressed.

RESULTS

Research into omega-3 fatty acids has been substantial but evidence for their potential in treating mood and behaviour is modest. In comparison, there has been much less research into carbohydrate and protein intakes and little evidence for their ability to influence mood and behaviour. Recent trials with food additives suggest their removal from the diet may benefit susceptible children with hyperactivity disorders. Micronutrient supplementation appears to improve mood only in those who were initially deficient in micronutrients.

CONCLUSIONS

More stringent research designs such as longitudinal studies and the use of biologically inert placebos within randomised controlled trials are needed before supplemental use of omega-3 fatty acids to treat disorders of mood and behaviour can be recommended. Caution is advised regarding the indiscriminate use of diets free of artificial food additives in managing hyperactivity disorders, as they may place an undue burden on individuals and their families. Should omega-3 fatty acid supplementation or the elimination of certain food additives be established as effective, they may provide cost-effective, accessible and well-tolerated adjuncts to standard psychiatric treatments for mood and behavioural disturbances.

Essential fatty acids and attention-deficit-hyperactivity disorder: a systematic review

AIM

Essential fatty acids (EFAs), also known as omega-3 and omega-6 fatty acids, have been claimed to have beneficial effects as a treatment for attention-deficit-hyperactivity disorder (ADHD). Animal experiments have provided information about the role of EFA in the brain, and several mechanisms of EFA activity are well known. The current review provides an updated, systematic overview of the theory and use of EFA in ADHD.

METHOD

Clinical studies and review papers of EFA blood levels and EFA supplementation trials in children with ADHD were researched in the Medline PubMed database. Additional studies were found from the references of these reports.

RESULTS

Children with ADHD present lower levels of blood EFAs, and open-label EFA supplementation trials in ADHD raise EFA blood levels and improve symptoms of ADHD. Randomized controlled trials, however, have generally been unsuccessful in demonstrating any behavioural treatment effects.

INTERPRETATION

Current findings do not support the use of EFA supplements as a primary or supplementary treatment for children with ADHD.

Resting state electroencephalographic correlates with red cell long-chain fatty acids, memory performance and age in adolescent boys with attention deficit hyperactivity disorder

Abnormal fatty acid status has been implicated in the aetiology of attention deficit hyperactivity disorder (ADHD). Delayed maturation in ADHD may result in raised frontal low frequency (theta) electroencephalographic activity (EEG) and a reduction in posterior high frequency (beta, alpha) activity. The current study used sequential linear regression to investigate the association between age, resting-state EEG and levels of long-chain polyunsaturated omega-3 and omega-6 fatty acids in red blood cells in 46 adolescent boys with ADHD symptoms. Docosahexaenoic acid (DHA) levels were positively associated with fast frequency activity: alpha during eyes-open and beta during eyes-closed conditions. Frontal theta activity during both eyes-open and eyes-closed conditions was inversely associated with age and positively associated with eicosapentaenoic acid (EPA) levels. Alpha activity correlated positively with performance on fluency for categories (semantic memory). Theta activity correlated inversely with performance on delayed (25 min) verbal memory (recall + recognition/2). No associations were observed between long-chain omega-6 and EEG measures. Results support differential associations for DHA and EPA with fast and slow EEG activity respectively. Results support EEG activity as an objective biomarker of neural function associated with long-chain omega-3 fatty acids in ADHD.

Project DyAdd: Fatty acids in adult dyslexia, ADHD, and their comorbid combination

In project DyAdd, we compared the fatty acid (FA) profiles of serum phospholipids in adults with attention deficit hyperactivity disorder (ADHD) (n=26), dyslexia (n=36), their comorbid combination (n=9), and healthy controls (n=36). FA proportions were analyzed in a 2x2 design with Bonferroni corrected post hoc comparisons. A questionnaire was used to assess dietary fat quality and use of supplements. Results showed that ADHD and dyslexia were not associated with total saturated FAs, monounsaturated FAs, or n-3 polyunsaturated FAs (PUFAs). However, those with ADHD had elevated proportions of total n-6 PUFAs (including gamma-linolenic and adrenic acids) as compared to those without ADHD. Dyslexia was related to a higher proportion of monounsaturated nervonic acid and a higher ratio of n-6/n-3 PUFAs. Among females none of the associations were significant. However in males, all the original associations observed in all subjects remained and ADHD was associated with elevated nervonic acid and n-6/n-3 PUFA ratio like dyslexia. Controlling for poorly diagnosed reading difficulties, education, dietary fat quality, or use of FA supplements did not generally remove the originally observed associations.

Role of docosahexaenoic acid in maternal and child mental health

Mental health problems in women and children represent a significant public health problem worldwide, especially in developing countries. The role of nutrition as a cost-effective approach in the prevention and management of these conditions has received recent attention, particularly nutrients such as iron, zinc, and n-3 (omega-3) fatty acids, which play a role in brain structure and function. The objective of this article was to review current evidence on the relation between n-3 fatty acids, especially docosahexaenoic acid (DHA), and maternal and child mental health disorders. Human studies published in English were identified from Medline databases (1966 to June 2008) by using key search terms and review articles. A summary of the role of DHA in the human brain is followed by a review of human studies, both observational and intervention trials, that examine the relation between n-3 fatty acids such as DHA and depression and child mental health disorders. Observational studies support a direct association between poor n-3 fatty acid status and increased risk of maternal depression and childhood behavioral disorders such as attention-deficit hyperactivity disorder (ADHD). However, evidence from intervention trials is weak. Most of the studies reviewed had small sample sizes and were conducted in clinically diagnosed samples, with no placebo-controlled groups. Little is known about the benefits of DHA in the prevention of maternal depression and ADHD. Large, well-designed, community-based prevention trials are needed.