Supplementation with flax oil and vitamin C improves the outcome of Attention Deficit Hyperactivity Disorder (ADHD)

Benefits versus risks associated with consumption of fish and other seafood

Fish provide nutrition for much of the world's population, and when not contaminated with chemicals, fish is a very good food. A major benefit of fish is that they are high in polyunsaturated fatty acids (PUFAs), low in saturated fat, and they contain other critical nutrients. Much of the benefit of fish consumption derives from their high levels of long chain omega-3 PUFAs, which are produced by aquatic microorganisms and bioconcentrate in the aquatic food supply. The PUFAs are essential, in that humans and other vertebrates are not able to synthesize them and therefore must obtain them from the diet. The PUFAs particularly concentrate in the nervous system, alter immune system function reduce serum triglyceride levels and have been reported to reduce the risk of sudden death after a myocardial infarction. But the problem is that most fish have at least some degree of chemical contamination with methylmercury, (which binds to muscle) and/or with persistent organic pollutants such as dioxins, polychlorinated biphenyls, polybrominated diphenyl ethers, chlorinated pesticides (which concentrate in fish fat). These chemicals have adverse effects on nervous system function, modulate the immune system, and are associated with elevations in risk of cardiovascular disease. Thus the question of benefits and risk from fish consumption is complex but very important.

Maternal caloric restriction spares fetal brain polyunsaturated fatty acids in Wistar rats

There is increasing interest in the role of developmental programming; however, the impact on fetal oxidative stress and brain fatty acid levels has been relatively unexplored. Recent reports have shown that caloric restriction regimens in adult animals reduce the occurrence of chronic diseases by reducing the oxidative stress and altering the long chain polyunsaturated fatty acids (LCPUFA). The present study examined whether caloric restriction during pregnancy alters oxidative stress and essential fatty acid metabolism in mother and offspring at birth. Pregnant female rats were fed either a standard chow (C, n=7) or were calorie restricted (CR, n=7) by feeding 60% of the intake of the control. Oxidative stress marker (malondialdehyde) and polyunsaturated fatty acid profiles in brain and liver were analyzed in both dams and offspring. Total weight gain during pregnancy was lower (p<0.01) in the CR group as compared to the control group but did not affect the litter size and weight. Brain malondialdehyde levels were lower (p<0.05) in dams from the CR group. There was no change in brain and liver LCPUFA levels in both male and female offspring in the CR group. Most of the polyunsaturated fatty acids were reduced (p<0.05) in plasma and brain in the CR dams. Caloric restriction during pregnancy did not alter LCPUFA metabolism in the offspring suggesting that during maternal caloric restriction mothers own stores are mobilized to provide docosahexaenoic acid and arachidonic acid for fetal brain development.

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.

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.

The role of fatty acids in the treatment of ADHD

Several arguments have been proposed to support the hypothesis that supplementation with essential fatty acids (EFAs) could be valuable in the treatment of attention deficit-hyperactivity disorder (ADHD). Indeed, this disorder seems to involve the monoaminergic systems which have been shown to be affected by polyunsaturated fatty acid (PUFA) status, at least in animal models. In addition, several studies have reported abnormal nutritional status with regard to EFAs in ADHD, indicating that lower levels of long-chain PUFAs occur more frequently in the plasma and/or red blood cells of ADHD subjects. Few nutritional EFA supplementation studies have been reported in ADHD to date, but several of them have shown increased blood EFA levels, although their effects on ADHD-related symptoms were not or were only partly successful. The current findings have not yet been clearly proved and require further investigation.

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.

The influence of short-chain essential fatty acids on children with attention-deficit/hyperactivity disorder: a double-blind placebo-controlled study

Essential fatty acids (EFA) are needed for normal sensory, cognitive, and motor function. The EFA blood profile seems to be different in children with attention-deficit/hyperactivity disorder (ADHD) as compared to matched controls. Previous open EFA supplementation trials were successful in demonstrating significant therapeutic effects in this population, whereas most of the randomized controlled trials failed to show any benefit over placebo. The current randomized, double-blind, placebo-controlled trial tested the influence of short-chain EFA supplementation on ADHD children, using parent and teacher questionnaires and a computerized continuous performance test. A total of 73 unmedicated children aged 7-13 years with a diagnosis of ADHD participated in the study; 63 children completed the study. The EFA supplement contained 480 mg of linoleic acid and 120 mg of alpha-linolenic acid, and the placebo contained 1000 mg of vitamin C (daily amounts); both were given for a 7-week supplementation period. Analysis of variance for repeated measures revealed that both treatments ameliorated some of the symptoms, but no significant differences were found between the groups in any of the treatment effects.

Is there a role for n-3 long-chain polyunsaturated fatty acids in the regulation of mood and behaviour? A review of the evidence to date from epidemiological studies, clinical studies and intervention trials

Selected biochemical evidence suggests a potential role for n-3 long-chain PUFA (n-3PUFA) in the regulation of mood and behaviour. The present paper reviews the relevant evidence, to date, from epidemiological studies, clinical studies and intervention trials. Most evidence is available investigating a role for n-3PUFA in depression, depressive illness and suicidal behaviour, but work is also available on anxiety and anxiety-related disorders, fatigue and fatigue-related disorders, aggression, hostility and anti-social behaviour, inattention, impulsivity and attention deficit hyperactivity disorder and schizophrenic disorders. For all these aspects of mood and behaviour, the evidence available is currently limited and highly inconsistent, both in terms of study methodology and study findings. There is a clear need for further work in this area.

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.

[Alternative agents used in ADHD]

Attention-deficit/hyperactivity disorder (ADHD) is, with a prevalence of 2% to 6%, one of the most common neurobehavioral disorder affecting children and adolescents, persisting into adulthood. Comorbidity and psychosocial circumstances enter into the choice of intervention strategies. Several agents have been demonstrated effective in treating individuals with ADHD. Direct or indirect attenuation of dopamine and norepinephrine neurotransmission appears closely related to both the stimulant and nonstimulant medications efficacious in ADHD. However, important differences concerning efficacy and side effects exist both between and with the specific classes of agents like neuroleptics, antidepressants, antiepileptics, alpha-agonists, beta-blockers, buspiron, l-dopa, melatonin, pycnogenol, zinc, magnesium, polyunsaturated fatty acids, and homeopathy. Elucidating the various mechanisms of action of ADHD medications may lead to better choices in matching potential responses to the characteristics of individuals. We review the purported mechanism of action and available evidence for selected complementary and alternative medicine therapies for ADHD in childhood and adolescence.

Docosahexaenoic acid and cognitive function: Is the link mediated by the autonomic nervous system?

Docosahexaenoic acid is a long-chain polyunsaturated fatty acid that is found in large quantity in the brain and which has repeatedly been observed to be related in positive ways to both cognitive function and cardiovascular health. The mechanisms through which docosahexaenoic acid affects cognition are not well understood, but in this article, we propose a hypothesis that integrates the positive effects of docosahexaenoic acid in the cognitive and cardiovascular realms through the autonomic nervous system. The autonomic nervous system is known to regulate vital functions such as heart rate and respiration, and has also been linked to basic cognitive components related to arousal and attention. We review the literature from this perspective, and delineate the predictions generated by the hypothesis. In addition, we provide new data showing a link between docosahexaenoic acid and fetal heart rate that is consistent with the hypothesis.

Update on alpha-linolenic acid

Consumption of omega 3 fatty acids is known to have health benefits. For many years, the importance of the only member of the omega 3 family considered to be essential, alpha-linolenic acid (ALA), has been overlooked. Current research indicates that ALA, along with its longer chain metabolites, may play an important role in many physiological functions. Potential benefits of ALA include cardioprotective effects, modulation of the inflammatory response, and a positive impact on both central nervous system function and behavior. Recommended levels for ALA intake have been set, yet the possible advantages of its consumption are just being revealed.

Nutritional and environmental approaches to preventing and treating autism and attention deficit hyperactivity disorder (ADHD): a review

OBJECTIVES

The purpose of this study was to concisely review the available literature of nutritional and environmental factors on autistic spectrum and attention deficit hyperactivity disorder (ADHD).

DESIGN AND METHODS

Review of journal articles found on the PubMed database and from information from several conference proceedings.

RESULTS

Many, but not all, studies link exposure to toxins such as mercury, lead, pesticides, and in utero smoking exposure to higher levels of autism and/or ADHD. Some studies have reported many nutritional deficiencies in autism/ADHD patients. Numerous studies have reported that supplemental nutrients such as omega-3 fatty acids, vitamins, zinc, magnesium, and phytochemicals may provide moderate benefits to autism/ADHD patients. Avoidance of food allergens, food chemicals, and chelation therapy may also provide some relief to autism/ADHD patients.

CONCLUSIONS

Autistic spectrum disorders and ADHD are complicated conditions in which nutritional and environmental factors play major roles. Larger studies are needed to determine optimum multifactorial treatment plans involving nutrition, environmental control,medication, and behavioral/education/speech/physical therapies.

Seizure resistance in fat-1 transgenic mice endogenously synthesizing high levels of omega-3 polyunsaturated fatty acids

N-3 polyunsaturated fatty acids (PUFA), derived from marine oils, have been shown to protect against various neurological diseases. However, very little is known about their potential anticonvulsant properties. The objective of the present study was to determine whether enrichment of brain lipids with n-3 PUFA inhibits seizures induced by pentylenetetrazol. We demonstrate that increased brain levels of n-3 PUFA in transgenic fat-1 male mice, which are capable of de novo synthesis of n-3 PUFA from n-6 PUFA, increases latency to seizure onset by 45%, relative to wildtype controls (p = 0.08). Compared with wildtype littermates, transgenic fat-1 mice have significantly (p < 0.05) higher levels of docosahexaenoic acid and total n-3 PUFA in brain total lipid extracts and phospholipids. Levels of brain docosahexaenoic acid were positively correlated to seizure latency (p < 0.05). These findings demonstrate that n-3 PUFA have anticonvulsant properties and suggest the possibility of a novel, non-drug dietary approach for the treatment of epilepsy.

Omega-3 fatty acids as treatments for mental illness: which disorder and which fatty acid?

BACKGROUND

A growing number of observational and epidemiological studies have suggested that mental illness, in particular mood disorders, is associated with reduced dietary intake and/or cellular abundance of omega-3 polyunsaturated fatty acids (PUFA). This has prompted researchers to test the efficacy of omega-3 PUFA in a range of different psychiatric disorders. We have critically reviewed the double blind placebo controlled clinical trials published prior to April 2007 to determine whether omega-3 PUFA are likely to be efficacious in these disorders.

RESULTS

Most trials involved a small number of participants but were largely well designed. Omega-3 PUFA were well tolerated by both children and adults with mild gastrointestinal effects being the only consistently reported adverse event. For schizophrenia and borderline personality disorder we found little evidence of a robust clinically relevant effect. In the case of attention deficit hyperactivity disorder and related disorders, most trials showed at most small benefits over placebo. A limited meta-analysis of these trials suggested that benefits of omega-3 PUFA supplementation may be greater in a classroom setting than at home. Some evidence indicates that omega-3 PUFA may reduce symptoms of anxiety although the data is preliminary and inconclusive. The most convincing evidence for beneficial effects of omega-3 PUFA is to be found in mood disorders. A meta-analysis of trials involving patients with major depressive disorder and bipolar disorder provided evidence that omega-3 PUFA supplementation reduces symptoms of depression. Furthermore, meta-regression analysis suggests that supplementation with eicosapentaenoic acid may be more beneficial in mood disorders than with docosahexaenoic acid, although several confounding factors prevented a definitive conclusion being made regarding which species of omega-3 PUFA is most beneficial. The mechanisms underlying the apparent efficacy of omega-3 PUFA in mood disorders compared to schizophrenia are discussed as is a rational for the possibly greater efficacy of EPA compared to DHA.

CONCLUSION

While it is not currently possible to recommend omega-3 PUFA as either a mono- or adjunctive-therapy in any mental illness, the available evidence is strong enough to justify continued study, especially with regard to attentional, anxiety and mood disorders.

The impact of diet on anti-social, violent and criminal behaviour

The role of diet in anti-social behaviour was considered, paying particular attention to double-blind placebo-controlled trials. Meta-analysis of five well-designed studies found that elimination diets reduced hyperactivity-related symptoms, producing a summary standardized mean difference (SSMD) of 0.80 (95% CI 0.41-1.19). The picture was of children potentially responding to a wide range of food items although the pattern was individual to the child. Supplementation with poly-unsaturated fatty acids decreased violence (SSMD -0.61, 95% CI -0.83 to -0.39) although there was no evidence of an influence on hyperactivity. Three well-designed studies have reported that vitamin/mineral supplementation reduced anti-social behaviour. There are also findings of an association between a tendency to develop low blood glucose and aggression. Many responses to diet were idiosyncratic and involved a wide range of foods interacting with individual differences in physiology. Reactions were not observed in all members of groups chosen because they share a common behavioural designation or diagnosis.

Role of omega-3 fatty acids in brain development and function: potential implications for the pathogenesis and prevention of psychopathology

The principle omega-3 fatty acid in brain, docosahexaenoic acid (DHA), accumulates in the brain during perinatal cortical expansion and maturation. Animal studies have demonstrated that reductions in perinatal brain DHA accrual are associated with deficits in neuronal arborization, multiple indices of synaptic pathology including deficits in serotonin and mesocorticolimbic dopamine neurotransmission, neurocognitive deficits, and elevated behavioral indices of anxiety, aggression, and depression. In primates and humans, preterm delivery is associated with deficits in fetal cortical DHA accrual, and children/adolescents born preterm exhibit deficits in cortical gray matter maturation, neurocognitive deficits particularly in the realm of attention, and increased risk for attention-deficit/hyperactivity disorder (ADHD) and schizophrenia. Individuals diagnosed with ADHD or schizophrenia exhibit deficits in cortical gray matter maturation, and medications found to be efficacious in the treatment of these disorders increase cortical and striatal dopamine neurotransmission. These associations in conjunction with intervention trials showing enhanced cortical visual acuity and cognitive outcomes in preterm and term infants fed DHA, suggest that perinatal deficits in brain DHA accrual may represent a preventable neurodevelopmental risk factor for the subsequent emergence of psychopathology.