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Fatty acid deficiency signs predict the severity of reading and related difficulties in dyslexic children

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Abstract

It has been proposed that developmental dyslexia may be associated with relative deficiencies in certain highly unsaturated fatty acids (HUFA). In children with attention-deficit/hyperactivity disorder, minor physical signs of fatty acid deficiency have been shown to correlate with blood biochemical measures of HUFA deficiency. These clinical signs of fatty acid deficiency were therefore examined in 97 dyslexic children in relation to reading and related skills, and possible sex differences were explored. Children with high fatty acid deficiency ratings showed poorer reading (P<0.02) and lower general ability (P<0.04) than children with few such clinical signs. Within males (n=72) these relationships were stronger, and fatty acid deficiency signs were also associated with poorer spelling and auditory working memory (P<0.05, P<0.005 respectively). Within females (n=25) no associations were significant. These results support the hypothesis that fatty acid deficiency may contribute to the severity of dyslexic problems, although sex differences merit further investigation.

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... Among the essential nutrients believed to be required for optimal neurological functioning, highly unsaturated fatty acids (HUFA; also known as long-chain polyunsaturated fatty acids or LCPUFA) from the omega-3 and omega-6 groups of polyunsaturated fatty acids have received increasing attention from researchers interested in a range of mental health conditions, including schizophrenia (Horrobin, 1997, 1998; Peet, 2003), bipolar disorder (Chiu et al., 2003; Stoll et al., 1999), and depression (Adams, Lawson, Sanigorski, & Sinclair, 1996; Hibbeln, 1998; Su, Huang, Chiu, & Shen, 2003; Tanskanen et al., 2001), as well as developmental disorders such as autistic spectrum disorder (Bell et al., 2004; Bell, Sargent, Tocher, & Dick, 2000), dyslexia (Baker, 1985; Richardson et al., 2000; Richardson, Cox, Sargentoni, & Puri, 1997; Stordy, 2000; Taylor et al., 2000; Taylor & Richardson, 2000) and ADHD (Richardson, 2003a). ...
... Research in the last decade has found a link between HUFA and central nervous system functioning (Leaf & Kang, 2001), pointing to their role in healthy brain functioning (Bell et al., 2000; Richardson, 2003a; Richardson & Puri, 2002), neural cell signalling (Haag, 2003; Hamilton et al., 2000; Horrobin, 1998; Richardson et al., 2000; Yehuda et al., 1998, 2002; Youdim et al., 2000), and neurotransmitter processes (Chalon, Vancassel, Zimmer, Guilloteau, & Durand, 2001; Youdim et al., 2000). ...
... In the following section, attention is turned to the role of HUFA in abnormal development, with a focus on the symptoms and behaviors implicated in, or existing comorbidly with, ADHD and/or mental retardation. Recent summaries suggest that there is growing evidence pointing to a biological basis for neurological disorders (Horrobin, 1998; Richardson & Ross, 2000), with many of these focusing on a critical role for neurotransmitters. The roles that HUFA are believed to play in the brain provide a theoretical connection to the current neurotransmitter theories for various mental illnesses, e.g. the role of serotonin in depression (Maes & Smith, 1998) and dopamine in schizophrenia (Horrobin, 1997) and ADHD (Biederman, 1997). ...
Article
Attention‐deficit/hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder of childhood with prevalence estimated at between 2% and 18% in the general population of children. This chapter discusses the possible role of highly unsaturated fatty acids (HUFAs), together with a brief description of research that has tried to explain the mechanism by which HUFAs impact brain development. The chapter reviews research that has linked various cognitive and behavioral outcomes, including ADHD, to HUFA intake and discusses a possible role for HUFA supplementation as a therapy for ADHD‐related behaviors specifically and for developmental disorders more generally. Children with a range of developmental disorders including mental retardation and ADHD display problems in attention and learning, may be hyperactive and distractible, and may have difficulty with impulse control and aggression that result in the production of maladaptive social behavior. The chapter proposes that consideration be given to further testing of dietary interventions, both as an approach to treatment and as a therapy for prevention in groups considered at high risk for the later display of developmental disorders.
... Defective PUFAs metabolism due to abnormally high seric concentration of phospholipase A2, reduced incorporation of docosahexaenoic acid, arachidonic acid, and, ultimately, phospholipids into cell membranes has been documented in disabled readers [8, [44][45][46]. Indeed, mild clinical signs of fatty acid deficiency, namely rough and dry skin and hair, weak and soft fingernails, dandruff, follicular keratosis, polydipsia, and pollakiuria, have been reported in these patients [47][48][49], and confirmed with biochemical testing in a dyslexic boy [47]. In turn, boys with lower plasma omega-3 polyunsaturated fatty acids showed more learning problems compared to those with higher concentrations [50], and the severity of these signs is found to correlate with the degree of reading and spelling disability [48,49]. ...
... Indeed, mild clinical signs of fatty acid deficiency, namely rough and dry skin and hair, weak and soft fingernails, dandruff, follicular keratosis, polydipsia, and pollakiuria, have been reported in these patients [47][48][49], and confirmed with biochemical testing in a dyslexic boy [47]. In turn, boys with lower plasma omega-3 polyunsaturated fatty acids showed more learning problems compared to those with higher concentrations [50], and the severity of these signs is found to correlate with the degree of reading and spelling disability [48,49]. Notably, the relationship between PUFAs deficiency and reading performance was evident in males but not in females: this is not unexpected, as fatty acids needs in males is higher compared to females, as suggested by studies with animal models [51,52]. ...
... Notably, the relationship between PUFAs deficiency and reading performance was evident in males but not in females: this is not unexpected, as fatty acids needs in males is higher compared to females, as suggested by studies with animal models [51,52]. This discrepancy could explain the higher prevalence of reading disability in males (1.69 to 1, according to Miles et al. [53]) and, as suggested by Richardson et al. [48], it could be accounted for by beneficial hormonal effects (oestrogen in particular) on both synthesis and retention of PUFAs in females [54] (see [55] for a review). ...
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In the last decades evidence has been collected that the depletion of the visual magnocellular population (a fast-conduction cellular system made of large ganglion neurons) plays a pathogenetical role in developmental dyslexia. Smaller size of the magnocells and reduction of their overall number in a proportion of disabled readers, in fact, are believed to hamper the visual processing of the written text. Polyunsaturated fatty acids (PUFAs) are important structural parts of the cellular membrane and of the cytoskeleton, and are pivotal for the correct development and functioning of neurons. Magnocells are thought to be particularly vulnerable to PUFAs deficiency, due to the large extent of their plasma membrane: so, reduced availability of polyunsaturated fatty acids is argued to selectively affect the magnocellular population. Indeed, PUFAs deficiency has been reported in a consistent proportion of disabled readers. This finding has led to hypothesize this deficiency may play a main role in the reading problems of patients by hindering the normal development of their magnocellular pathway. Based on these assumption there is some evidence that dietary supplementation with a predefined combination of omega-3 and omega-6 fatty acids has a beneficial effect on the reading performance and behavior of dyslexics. Here the rationale for this line of intervention is reported. The conclusion is that supplementation of dyslexic children with PUFAs is worth to be considered, despite its effectiveness in improving their academic skills needs further clarification.
... Essa hipótese é interessante, considerando-se o fato de as autópsias de disléxicos terem revelado uma maior proporção de células pequenas Disponível em <http://www.uepg.br/olhardeprofessor> Modelos teóricos atuais da dislexia no desenvolvimento do que as usuais no núcleo geniculado lateral e no núcleo geniculado medial (TAYLOR; RICHARDSON, 2000). ...
... Os disléxicos apresentam uma elevada freqüência de sinais de deficiência de ácidos graxos essenciais, tais como sede excessiva, urinação freqüente, pele seca, cabelo ressecado, caspa, unhas fracas ou quebradiças e ceratose folicular, os quais variam de acordo com a severidade da dislexia (RICHARDSON et al., 2000;TAYLOR et al, 2000). ...
... Some recent studies have suggested that fatty acid deficiency may be involved in autistic spectrum disorder (6). Also, there is growing evidence that fatty acid metabolism and abnormal membrane fatty acid composition may contribute to neurodevelopmental and psychiatric disorders (7). Reduced levels of polyunsaturated fatty acids have been associated with some childhood mental disorders, such as attention deficit hyperactivity disorder in boys (8,9), severe deficits in reading, spelling, and auditory memory (5,7), as well as dyslexia and developmental coordination disorder (10). ...
... Also, there is growing evidence that fatty acid metabolism and abnormal membrane fatty acid composition may contribute to neurodevelopmental and psychiatric disorders (7). Reduced levels of polyunsaturated fatty acids have been associated with some childhood mental disorders, such as attention deficit hyperactivity disorder in boys (8,9), severe deficits in reading, spelling, and auditory memory (5,7), as well as dyslexia and developmental coordination disorder (10). Also, children with ASD have been shown to present significantly higher phospholipase A2 activity (11). ...
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Background: Abnormalities in fatty acid metabolism and membrane fatty acid composition play a part in a wide range of neurodevelopmental and psychiatric disorders. Altered fatty acid homeostasis as a result of insufficient dietary supplementation, genetic defects, the function of enzymes involved in their metabolism, or mitochondrial dysfunction contributes to the development of autism. Objective: This study evaluates the association of altered brain lipid composition and neurotoxicity related to autism spectrum disorders in propionic acid (PA)-treated rats. Design: Forty-eight young male western albino rats were used in this study. They were grouped into six equal groups with eight rats in each. The first group received only phosphate buffered saline (control group). The second group received a neurotoxic dose of buffered PA (250 mg/kg body weight/day for 3 consecutive days). The third and fourth groups were intoxicated with PA as described above followed by treatment with either coenzyme Q (4.5 mg/kg body weight) or melatonin (10 mg/kg body weight) for 1 week (therapeutically treated groups). The fifth and sixth groups were administered both compounds for 1 week prior to PA (protected groups). Methyl esters of fatty acid were extracted with hexane, and the fatty acid composition of the extract was analyzed on a gas chromatography. Results: The obtained data proved that fatty acids are altered in brain tissue of PA-treated rats. All saturated fatty acids were increased while all unsaturated fatty acids were significantly decreased in the PA-treated group and relatively ameliorated in the pre-post melatonin and coenzyme Q groups. Conclusions: Melatonin and coenzyme Q were effective in restoring normal level of most of the impaired fatty acids in PA-intoxicated rats which could help suggest both as supplements to ameliorate the autistic features induced in rat pups.
... Furthermore, recent reports that many of dyslexics' problems may be exacerbated by modern diets that can contain dangerously low quantities of polyunsaturated fatty acids (PUFAs) can be fitted into this schema. Dyslexia in both children and adults is associated with clinical signs of essential fatty acid deficiency (Richardson et al., 2000; Taylor et al., 2000). As we have seen, magnocellular function is dependent upon the rapid dynamics of their membrane ionic channels. ...
... With the decline of eating fish, modern diets tend to be dangerously low in PUFAs, hence magnocellular function may be particularly compromised. Therefore supplementing dyslexics' diets with PUFAs may relieve their fatty acid deficiency and help them to learn to read (Richardson et al., 2000). In summary, therefore, it is possible that the impaired magnocellular function found in dyslexics results from genetically directed antibody attack on their development in the foetus in utero, coupled with vulnerability resulting from diets low in essential fatty acids. ...
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Background / Purpose: Of the 10% of children who find it unexpectedly difficult to learn to read fluently despite normal intelligence, health and education (developmental dyslexia), many have impaired development of visual magnocellular neurons. This impairs their ability to visually process letters properly. Magnocellular neurons are responsible for directing visual attention and eye movements during reading, hence for accurately sequencing letters. Main conclusion: Accumulating evidence suggests that many dyslexics have visual magnocellular deficits, as well as auditory and cerebellar magnocellular deficits due to genetic effects on neural migration during brain development, immune anomalies, lack of omega 3 docosahexaenoic (DHA) acid and eicosapentaenoic acid (EPA). These can be helped by blue or yellow filters and omega-3 supplements.
... Les acides gras polyinsaturés, dont les acides gras oméga-3, seraient impliqués dans les maladies du développement cérébral, les déficits d'attention et les hyperactivités, les dyslexies et même l'autisme [97]. Chez l'enfant dyslexique, la sévérité des signes est en proportion du déficit en acides gras polyinsaturés, mais chez les garçons seulement [98]. Dans un groupe de 135 adultes (74 hommes et 61 femmes), la dyslexie est accompagnée de signes de déficience en acides gras polyinsaturés [99]. ...
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Omega-3 fatty acids participated in the first coherent experimental demonstration of the effect of dietary substances (nutrients) on the structure and function of the brain. Experiments were first of all carried out on ex-vivo cultured brain cells, then on in vivo brain cells, finally on physiochemical, biochemical, physiological, neurosensory, and behavioural parameters. These findings indicated that the nature of polyunsaturated fatty acids (in particular omega-3) present in formula milks for infants (both premature and term) determines the visual, cerebral, and intellectual abilities, as described in a recent review in OCL [1]. In view of the high omega-3 polyunsaturated fatty acid content of the brain, it is evident that these fats are involved in brain biochemistry, physiology and functionning; and thus in some neuropsychiatric diseases and in the cognitive decline of ageing. Though omega-3 fatty acids appear effective in the prevention of stress, their role as regulator of mood and libido is a matter for discussion pending experimental proof in animal and human models. Dietary omega-3 fatty acids could play a role in the prevention of some disorders including depression, as well as in dementia, particularly Alzheimer's disease. Their direct role in major depression and bipolar disorder (manic-depressive disease) and schizophrenia is not yet established. Their deficiency can prevent the renewal of membranes, and thus accelerate cerebral ageing; nonetheless, the respective roles of the vascular component on one hand (where the omega-3's are active) and the cerebral parenchyma itself on the other, have not yet been clearly resolved. The role of omega-3 in certain diseases such as dyslexia and autism is suggested. The role of omega-3 in certain diseases such as dyslexia, autism, and schizophrenia seems to suggest a problem of diet. Indeed, the insufficient dietary supply of omega-3 fatty acids in today's French diet raises the problem of how to correct dietary habits so that the consumer will select foods that are genuinely rich in omega-3/the omega-3 family; mainly rapeseed and walnut oils on one hand and fatty fish on the other.
... The cortical dorsal "where" pathway is dominated by the M input, and abnormalities have been found in subjects with DD in this pathway as well. Specifically, anomalies have been reported in the primary visual cortex-V1 (Lovegrove et al. 1980;Chase and Jenner 1993;Mason et al. 1993;Cornelissen et al. 1995;Felmingham and Jakobson 1995;Talcott et al. 1998;Bednarek and Grabowska 2002;Edwards et al. 2004), in the extrastriate visual motion area-V5/MT (Cornelissen et al. 1995;Richardson et al. 2000;Talcott et al. 2000;Hill and Raymond 2002;Downie et al. 2003;Samar and Parasnis 2005), in the posterior parietal cortex and in the prefrontal cortex (Rao 1997). ...
Article
Developmental dyslexia (DD) is a heritable neurodevelopmental reading disorder that could arise from auditory, visual, and cross-modal integration deficits. A deletion in intron 2 of the DCDC2 gene (hereafter DCDC2d) increases the risk for DD and related phenotypes. In this study, first we report that illusory visual motion perception—specifically processed by the magnocellular-dorsal (M-D) stream—is impaired in children with DD compared with age-matched and reading-level controls. Second, we test for the specificity of the DCDC2d effects on the M-D stream. Children with DD and DCDC2d need significantly more contrast to process illusory motion relative to their counterpart without DCDC2d and to age-matched and reading-level controls. Irrespective of the genetic variant, children with DD perform normally in the parvocellular-ventral task. Finally, we find that DCDC2d is associated with the illusory motion perception also in adult normal readers, showing that the M-D deficit is a potential neurobiological risk factor of DD rather than a simple effect of reading disorder. Our findings demonstrate, for the first time, that a specific neurocognitive dysfunction tapping the M-D stream is linked with a well-defined genetic susceptibility.
... Linkage analysis could ascertain whether there is a specific set of genes controlling the phenotype (Grigorenko, Wood, Meyer, Hart, Speed, Shuster et al., 1997), while biochemical analysis could ascertain whether there is a distinct pattern of related biochemical anomalies. Preliminary biochemical analyses have been based on the suggestion that visual processing problems in people with dyslexia might be linked to an abnormality in the metabolism of fatty acids (Richardson, Calvin, Clisby, Schoenheimer, Montgomery, Hall et al., 2000). Robinson et al. (2001) identified biochemical markers related to the incidence of symptoms of IS. ...
... There is evidence of an association between dyslexia and abnormal fatty acid metabolism (MacDonnell, Skinner, Ward, Glen, Glen, McDonald at al., 2000;Rae, Lee, Dixon, Blamire, Thompson, Styles et al., 1998;Richardson, Cox, Sargentoni, & Puri, 1997), in particular for visual symptoms when reading (Richardson, Easton, McDaid, Hall, Montgomery, Clisby, & Puri, 1999;Richardson, Calvin, Clisby, Schoenheimer, Montgomery, Hall et al., 2000;Wilmer & Richardson, 2001). found that high signs of EFA deficiency were significantly correlated with visual symptoms when reading and the checklist used to identify visual symptoms had many indicators of IS, including headaches, eye strain, blurring, movement and pulsation of print, light sensitivity and a haloing effect around words (Irlen, 1991a). ...
... Several studies investigated the levels of blood fatty acids in children with DD, and it was found that children with the most severe fatty acid deficiencies had poorer reading, spelling and auditory working memory than children with milder PUFA deficiency [39]. Moreover, omega-3 appears to be associated with reading and spelling ability, regardless of the diagnosis of DD [25]. ...
Article
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The purpose of the present study was to investigate whether there are associations between polyunsaturated fatty acid (PUFA) blood levels, reading/writing performance and performance in neuropsychological tasks. Moderate to strong correlations were found between PUFA levels (specific omega-6/omega-3 ratios) and reading/writing abilities, and the former and neuropsychological test scores. Mediation models analyzing the direct and indirect effects of PUFA on reading and writing scores showed that the effects of fatty acids on learning measures appear to be direct rather than mediated by the investigated visual and auditory neuropsychological mechanisms. The only significant indirect effect was found for the difference in accuracy between the left and right visual fields in visual-spatial cueing tasks, acting as a mediator for the effect of PUFA ratios on writing accuracy. Regression analyses, by contrast, confirmed the roles of phonological awareness and other visual attentional factors as predictors of reading and writing skills. Such results confirm the crucial role of visual-spatial attention mechanisms in reading and writing, and suggest that visual low-level mechanisms may be more sensitive to the effects of favorable conditions related to the presence of higher omega-3 blood levels.
... Dysfunction of the dorsal stream has been reported in association with dyslexia, 52 and n-3 PUFA deficiency has been detected in children and adults with dyslexia. 53,54 Although indirect, this finding supports a relationship between DHA and dorsal stream processing. Moreover, a clinical trial has revealed improved reading abilities in dyslexic children following DHA intake for 5 months. ...
Chapter
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Omega-3 (n-3) fatty acids are highly concentrated in neuronal membranes and retina photoreceptors, where they accumulate from midpregnancy until the first years of life. A growing body of evidence links n-3 fatty acids with visual and cognitive functions. Because the fetus and breastfed infants depend on their mother's dietary intake for n-3 fatty acid supply, prenatal and perinatal exposure to essential fatty acids is crucial for their normal development. This chapter discusses human and animal studies suggesting a role for n-3 fatty acids in visual processes and reviews the current knowledge of n-3 fatty acid benefits for retina development and function and for visual acuity. Long-term effects of prenatal exposure to n-3 fatty acids on brain visual processing in children are discussed, as well as mechanisms that may underlie the benefit of n-3 fatty acids. Sufficient prenatal and perinatal n-3 fatty acid intake is needed to ensure adequate visual development. The neural substrates underlying the beneficial effects of docosahexaenoic acid exposure may preferentially involve the parvocellular visual pathway and the dorsal stream at a cortical level.
... Dysfunction of the dorsal stream has been reported in association with dyslexia, 52 and n-3 PUFA deficiency has been detected in children and adults with dyslexia. 53,54 Although indirect, this finding supports a relationship between DHA and dorsal stream processing. Moreover, a clinical trial has revealed improved reading abilities in dyslexic children following DHA intake for 5 months. ...
Chapter
To develop and function optimally, the brain requires a balanced environment of electrolytes, amino acids, neurotransmitters, and metabolic substrates. As a consequence, organ dysfunction has the potential to induce brain disorders and toxic-metabolic encephalopathies, particularly when occurring during early stages of cerebral maturation. Induced toxicity of three different organ systems that are commonly associated with brain complications are discussed. First, thyroid hormone deficiency caused by intrinsic or extrinsic factors (e.g., environmental toxins) may induce severe adverse effects on child neurological development from reversible impairments to permanent mental retardation. Second, inadequate removal of wastes due to chronic renal failure leads to the accumulation of endogenous toxins that are harmful to brain function. In uremic pediatric patients, the brain becomes more vulnerable to exogenous substances such as aluminum, which can induce aluminum encephalopathy. Following surgical procedures, neurological troubles including focal defects and severe epileptic seizures may result from hypertensive encephalopathy combined with toxicity of immunomodulating substances, or from the delayed consequences of cardiovascular defect. Taken together, this illustrates that organ disorders clearly have an impact on child brain function in various ways.
... The notion that dorsal stream processing may be related to DHA deficiency is supported by dyslexia research. Numerous studies report that dyslexics who have clinical signs of essential fatty acid deficiency (Richardson et al. 2000;Taylor et al. 2000), demonstrate a specific vulnerability to magnocellular dysfunction. This has been consistently shown by testing sensitivity to moving stimuli. ...
Article
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Preterm children are at risk for a number of visual impairments which can be important for a range of other more complex visuocognitive tasks reliant on visual information. Despite the relatively high incidence of visual impairments in this group there are no good predictors that would allow early identification of those at risk for adverse outcomes. Several lines of evidence suggest that docosahexaenoic acid (DHA) supplementation for preterm infants may improve outcomes in this area. For example, diets deficient in the long-chain polyunsaturated fatty acid DHA have been shown to reduce its concentration in the cerebral cortex and retina, which interferes with physiological processes important for cognition and visual functioning. Further, various studies with pregnant and lactating women, as well as formula-fed infants, have demonstrated a general trend that supplementation with dietary DHA is associated with better childhood outcomes on tests of visual and cognitive development over the first year of life. However, research to date has several methodological limitations, including concentrations of DHA supplementation that have been too low to emulate the in utero accretion of DHA, using single measures of visual acuity to make generalised assumptions about the entire visual system, and little attempt to match what we know about inadequate DHA and structural ramifications with how specific functions may be affected. The objective of this review is to consider the role of DHA in the context of visual processing with a specific emphasis on preterm infants and to illustrate how future research may benefit from marrying what we know about structural consequences to inadequate DHA with functional outcomes that likely have far-reaching ramifications. Factors worth considering for clinical neuropsychological evaluation are also discussed.
... These signs were assessed using the same scale as was used in recent studies of ADHD (Stevens et al., 1995), where fatty acid deficiency scores were also related to blood biochemical measures of fatty acid deficiency. Within dyslexic children, those with more clinical signs of fatty acid deficiency had more severe difficulties in reading, spelling and working memory (Richardson et al, 2000a). However, there was no evidence that fatty acid deficiency was confined to any particular subgroup as defined by psychometric tests. ...
Article
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Dyslexia alone affects at least 5% of the general population in a severe form, as does ADHD, although estimates rise when milder forms are included. Dyspraxia remains less well-known, but prevalence appears to be similar. There is considerable overlap between dyslexia, dyspraxia and ADHD as well as autistic spectrum disorders, and each of these syndromes can occur with differing degrees of severity. Current evidence suggests that up to 20% of the population may be affected to at least some degree by one or more of these conditions. The associated difficulties usually persist into adulthood, causing serious problems not only for those affected, but also for society as a whole.
... Subsequent studies showed these clinical signs of fatty acid deficiency to be elevated in both ADHD children (22,23) and dyslexic adults (24) compared with appropriately matched controls. They also related to visual symptoms in both dyslexic and non-dyslexic adults, and to the severity of reading, spelling and working memory deficits in dyslexic children (25). ...
... Abnormalities in the fatty acid compositions of phospholipids, the major constituents of cell membranes , have been implicated in several neurodevelopmental disorders that manifest with psychiatric symptoms. For example, in schizophrenia, changes of red blood cell (RBC) membrane phospholipids such as deficiencies in n-3 PUFAs have been reported13141516. Indeed, supplementing diets with fish oil was shown to correct these deficiencies and lead to improvements in the symptom scores of schizophrenic patients [17]. ...
Article
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Autism is a developmental disorder characterized by social and emotional deficits, language impairments and stereotyped behaviors that manifest in early postnatal life. This study aims to compare the relative concentrations of essential fatty acids (Linoleic and α- linolenic), their long chain polyunsaturated fatty acids and phospholipids in plasma of autistic patients from Saudi Arabia with age-matching controls. 25 autistic children aged 3-15 years and 16 healthy children as control group were included in this study. Relative concentration of essential fatty acids/long chain polyunsaturated fatty acids and omega-3/omega-6 fatty acid series together with phosphatidylethanolamine, phosphatidylserine and phosphatidylcholine were measured in plasma of both groups. Remarkable alteration of essential fatty acids/long chain polyunsaturated fatty acids, omeg-3/omega-6 and significant lower levels of phospholipids were reported. Reciever Operating characteristics (ROC) analysis of the measured parameters revealed a satisfactory level of sensitivity and specificity. Essential fatty acids/long chain polyunsaturated fatty acids and omeg-3/omega-6 ratios, phosphatidylethanolamine, phosphatidylserine and phosphatidylcholine could be used as potential biomarkers that point to specific mechanisms in the development of autism and may help tailor treatment or prevention strategies.
... Ultra pure ethyl-eicosapentaenoate (E-EPA) diminished aggression and depressive symptoms in women with untreated borderline per- sonality disorder (Zanarini & Frankenburg, 2003). Essential fatty acid deficiencies (with improvements after supplementation) have been found to be implicated in three developmental disorders which are frequently co-morbid: dyslexia Richardson & Ross, 2000;Richardson et al., 1999;Richardson et al., 2000aRichardson et al., , 2000bStordy, 1995;Stordy, 1997;Taylor & Richardson, 2000;), dyspraxia (Richardson & Ross, 2000;Stordy, 1997) and ADHD Stevens et al., 1995;Stevens, Zentall, Abate, Kuczek, and Burgess, 1996). In a review, Garland and Hallahan (2006) concluded that decreased levels of essential fatty acids are implicated in psychiatric conditions charac- terized by disordered impulsivity (ADHD; borderline personality disorder; suicide, deliberate self-harm, aggression and homicide) and that improvement occurred when deficiencies were corrected. ...
... Finding at-risk participants based on phenotype rather than genotype means that one has to define other risk factors besides the genetic factor. The " grand " theories of dyslexia advocate a diversity of etiologies pointing to assessable risk factors: auditory, visual, audiovisual modalities (Boder, 1968; Gjessing, 1977 Gjessing, , 1986); autoimmune deficits (Geschwind & Galaburda, 1985a, 1985b, 1985c Richardson et al., 2000); deficits within the magno-cellular system (Stein & Walsh, 1997); genetics (Annett, 1985; McManus, 1991; Pennington, 1990); impaired phonological awareness (Vellutino, 1979; Vellutino, Fletcher, Snowling, & Scanlon, 2004); impaired motor control (Nicolson & Fawcett, 1999); and auditory processing impairment (Tallal, 1984Tallal, , 2006 ). To our knowledge no longitudinal study of preschool children at risk has used phenotype criteria rather than genotype criteria for participant selection. ...
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This longitudinal study focused on the effects of two different principles of intervention in children at risk of developing dyslexia from 5 to 8 years old. The children were selected on the basis of a background questionnaire given to parents and preschool teachers, with cognitive and functional magnetic resonance imaging results substantiating group differences in neuropsychological processes associated with phonology, orthography, and phoneme-grapheme correspondence (i.e., alphabetic principle). The two principles of intervention were bottom-up (BU), "from sound to meaning", and top-down (TD), "from meaning to sound." Thus, four subgroups were established: risk/BU, risk/TD, control/BU, and control/TD. Computer-based training took place for 2 months every spring, and cognitive assessments were performed each fall of the project period. Measures of preliteracy skills for reading and spelling were phonological awareness, working memory, verbal learning, and letter knowledge. Literacy skills were assessed by word reading and spelling. At project end the control group scored significantly above age norm, whereas the risk group scored within the norm. In the at-risk group, training based on the BU principle had the strongest effects on phonological awareness and working memory scores, whereas training based on the TD principle had the strongest effects on verbal learning, letter knowledge, and literacy scores. It was concluded that appropriate, specific, data-based intervention starting in preschool can mitigate literacy impairment and that interventions should contain BU training for preliteracy skills and TD training for literacy training.
... Recent investigations of causal factors for dyslexia have implicated the abnormal metabolism of fatty acids (MacDonnell, Skinner, Ward, Glen, Glen, McDonald et al., 2000;Richardson, Cox, Sargentoni, & Puri, 1997), with visual processing in particular likely to be affected (Richardson, Calvin, Clisby, Schoenheimer, Montgomery, Hall et al., 2000;Richardson, Easton, McDaid, Hall, Montgomery, Clisby et al., 1999;Wilmer & Richardson, 2001). found that high signs of EFA deficiency were significantly correlated with visual symptoms when reading and the checklist used to identify visual symptoms had many indicators of IS, including headaches, eye strain, blurring, movement and pulsation of print, light sensitivity and a haloing effect around words (Irlen, 1991a). ...
... This threshold therefore defines that individual's motion (visual dorsal stream) sensitivity. Several researchers have shown that this is reduced in many dyslexic individuals [23,[49][50][51][52][53]. Other work has similarly shown reduced velocity discrimination [54][55][56] and elevated speed thresholds for motion-defined form [32,57]. ...
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Dyslexia is more than just difficulty with translating letters into sounds. Many dyslexics have problems with clearly seeing letters and their order. These difficulties may be caused by abnormal development of their visual “magnocellular” (M) nerve cells; these mediate the ability to rapidly identify letters and their order because they control visual guidance of attention and of eye fixations. Evidence for M cell impairment has been demonstrated at all levels of the visual system: in the retina, in the lateral geniculate nucleus, in the primary visual cortex and throughout the dorsal visuomotor “where” pathway forward from the visual cortex to the posterior parietal and prefrontal cortices. This abnormality destabilises visual perception; hence, its severity in individuals correlates with their reading deficit. Treatments that facilitate M function, such as viewing text through yellow or blue filters, can greatly increase reading progress in children with visual reading problems. M weakness may be caused by genetic vulnerability, which can disturb orderly migration of cortical neurones during development or possibly reduce uptake of omega-3 fatty acids, which are usually obtained from fish oils in the diet. For example, M cell membranes require replenishment of the omega-3 docosahexaenoic acid to maintain their rapid responses. Hence, supplementing some dyslexics’ diets with DHA can greatly improve their M function and their reading.
... Reduced levels of polyunsaturated fatty acids have been associated with some childhood mental disorders such as attention deficit hyperactivity disorder (ADHD) in boys, 1,2 severe deficits in reading, spelling, and auditory memory, 3 as well as dyslexia and developmental coordination disorder (DCD). 4 Autism spectrum disorders (ASD) also seem to be associated with altered lipid metabolism in their pathogenesis. ...
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Objective: To evaluate fatty acid plasma levels, phospholipase A2 activity, and the developmental profiles of children with autism vs. control subjects. Methods: Twenty four children with autism underwent laboratory analysis for fatty acid quantification using gas chromatography and PLA2 activity determination by fluorometric assay. Results: No correlation was observed between the developmental quotient and fatty acid plasma levels. Phospholipase A2 activity was significantly higher among autistic children compared with controls. Conclusion: The study did not show a correlation between fatty acid and phospholipase A2 plasma levels and the developmental profile of children with autism.
... Parents were required to complete a health questionnaire about their child, which included questions about the existence and severity of each of the FADS items: excessive thirst, frequent urination, dry hair, dry skin, dandruff, brittle nails, and small bumps on the skin (Richardson et al., 2000). Parents were required to rate the degree of each of the seven possible FAD symptoms on a scale of 0 to 3 (0 = not at all, 1 = just a little, 2 = somewhat, 3 = very much). ...
Article
This study investigates the association between polyunsaturated fatty acid (PUFA) intake and neurocognitive functions in children with attention-deficit/hyperactivity disorder (ADHD). We recruited 21 drug-naïve children diagnosed with ADHD according to the Diagnostic and Statistical Manual of Mental Disorders and 21 non-ADHD controls. The n-3 intake and essential fatty acid (EFA) deficiency severity were recorded while the children were assessed for inhibitory control, delay aversion, and temporal processing with the Go/No Go Task, Delayed Reaction Time Task, and Finger Tapping Task, respectively. The ADHD group had more EFA deficiency symptoms (p =.02) and poorer performance in delay aversion (p =.02) and temporal processing (p <.001). Moreover, ADHD symptoms correlated negatively with n-3 intake and positively with EFA deficiency. In addition, EFA deficiency was associated with higher delay aversion (p <.001). Children with ADHD had a higher deficiency of EFA, and EFA deficiency had a positive association with ADHD severity and delay aversion.
... In addition, seven questions (of which three were selected from the recent specialist medical history and focused on the characteristics proper of dyslexic subjects and four formulated to investigate signs of polyunsaturated fatty acids (PUFA) and especially omega 3 fatty acid deficiency) were included ("developmental dyslexia section," DD section). As a matter of fact, omega 3 fatty acid deficiency seems a distinctive trait of disabled readers [21][22][23][24]. ...
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Introduction: Early diagnosis is a main requisite when dealing with subjects suspected to suffer from neuro-developmental disorders, and especially reading disability. In this respect, self-reports are a promising tool and could prove to be as reliable as ordinary screenings, with the advantage of low cost and low time consumption. Since the last decades, the perceptual and visuo-motor function is believed to be involved in the pathogenesis of developmental dyslexia, so that specific elements related to an alteration of the sensorial and visuo-motor domain in the familiar and personal medical history could reveal a risk to develop this condition at a pre-examination phase. Yet, rather than evaluating the perceptual and motor function, the self-reports presented so far investigate the presence of dyslexic traits and co-morbidities in parents, relatives, and in the sons. In a previous study, the Analytic Anamnestic Protocol (AAP), specifically devised to assess the perceptual and visuo-motor function in children, revealed higher visuo-motor and sensorial scores in samples suffering from congenital cerebral lesions, Down syndrome, and reading disability compared to a control group. Sensibility and specificity were acceptable, as shown by the ROC curves. In this paper a modified version of the AAP (the AAP2) targeting more specifically developmental dyslexics is presented, along with the preliminary results obtained in a group of school-age disabled readers. Methods: The AAP2 is made of twenty-five questions divided into four sections (family, general, past and recent specialist medical history). In addition, seven questions inquiring about aspects related to the lexical difficulties (DD section) have been included. Like the previous version, each answer is assigned a perceptive and visuo-motor score. The self-report has been administered to thirty-seven normal subjects (median age nine years), and 34 dyslexic children (median age eight and a half years). Results: Visuo-motor and sensory scores in the dyslexic sample was consistently higher than in controls in the recent specialist medical history and in the DD section (Welch test: VM: t= 7.02, p <.0001; VS: t= 7.39, p <.0001) with the visuosensory domain more involved than the visual-motor function (t-test: t=4.70, p<.0001, and t=7.06, p<.0001, respectively). The sensibility and specificity of the recent specialist medical history of the AAP was 94.12% and 77.78%. Sensibility and specificity of the DD section DD were 100 and 80%, respectively. Conclusion: The AAP2 is a promising tool to screen subjects at risk for developmental dyslexia at the beginning of primary school. Like the previous version, also in this modified questionnaire the main weakness remains the heuristic criterion adopted for the assignment of the scores.
... FADS is a health questionnaire including the existence and severity of the FADS items: excessive thirst, frequent urination, dry hair, dry skin, dandruff, brittle nails, and small bumps on the skin (Richardson et al., 2000). The higher score indicates a greater fatty acid deficiency severity. ...
Article
Introduction: Cardiovascular diseases (CVDs) and major depressive disorder (MDD) will be the two most disabling diseases by 2030. Patients with CVDs comorbid depression had lower levels of total omega-3 polyunsaturated fatty acids (n-3 PUFAs), docosahexaenoic acid (DHA), and a higher omega-6 to omega-3 ratio. However, there have been limited studies on the effects n-3 PUFAs on MDD in patients with CVDs. Method: We have enrolled a total of 59 patients (64% males, mean age of 61.5 ± 9.0 years and mean education of 10.2 ± 4.2 years) with CVDs comorbid MDD. They were randomized into either receiving n-3 PUFAs (2 g per day of eicosapentaenoic acid (EPA) and 1 g of DHA) or placebo for 12 weeks. We assessed depression symptom severity with Hamilton Depression Rating Scale (HAMD) and Beck Depression Inventory (BDI), as well as blood fatty acid levels, electrocardiogram and blood biochemistry, at the baseline and at the endpoint. Results: There were no differences between the n-3 PUFAs and placebo group in the changes of HAMD and BDI total scores, while PUFAs group had a greater reduction in HAMD Cognition subscale scores than the placebo group at week 8 (p < 0.05). Moreover, subgroup analyses found that the n-3 group had a greater reduction of HAMD Core subscale scores than the placebo group at the end of week 12 (p < 0.05) for the very severe DEP group (HAMD ≥ 23). Conclusion: Overall, n-3 PUFAs did not show a beneficial effect on depressive symptoms when compared with placebo. However, when stratified with depression severity, n-3 PUFAs supplementation improved core depression symptoms in the very severe MDD group. N-3 PUFAs supplementation may provide a treatment option for a subpopulation of patients with CVDs comorbid MDD.
... Speech problems (p = 0.000), feeding problems (p = 0.017) and lack of imaginative play (p = 0.000). (14) also maintains that many features associated with dyspraxia are consistent with HUFA deficiencies or imbalances. ...
Article
The objectives of the study is to determine the epidemiology of dyspraxia among preschool children in Alexandria. Method of the study: a case control study was designed. The sample of the study was 33 children (26 ♂ and 7 ♀) with dyspraxia and 33 normal children as a control. Both groups were subjected to the followings a) screening phase, b) developmental assessment and, c) clinical assessment. The results: Males are significantly affected more than females (p= 0.037). Prematurity (p= 0.012), allergic disease (p= 0.004), and positive family history (p= 0.000) are significant factors for dyspraxia. Dyspraxic children have significantly behavior problems (p=0.008), speech disturbance (p=0.000), and lack of imaginative play (p
... Physical activity that improves cardiorespiratory fitness has been shown to improve working memory performance in pre-adolescents [28]. The impact of breakfast and diet have also been the subject of attention, and although the findings are clear in respect the negative impact of poor diet [29] [30], the identification of the best breakfast to enhance performance has proven more difficult [31] [32] [33]. A recent review of micronutrient supplementation studies concluded that positive effects were only to be found for children deficient as a consequence of diet, with no overall enhancement effects observed [34]. ...
... Parents were required to complete a health questionnaire about their child, which included questions about the existence and severity of each of the FADS items: excessive thirst, frequent urination, dry hair, dry skin, dandruff, brittle nails, and small bumps on the skin (Richardson et al., 2000). Parents were required to rate the degree of each of the seven possible FAD symptoms on a scale of 0 to 3 (0 = not at all, 1 = just a little, 2 = somewhat, 3 = very much). ...
Article
The aim of the study is to investigate the association between intake of fatty acids, or omega-3 polyunsaturated fatty acids (n3-PUFAs), and cognitive functions in children with attention deficit hyperactivity disorder (ADHD). Twenty-one drug-naïve children diagnosed with DSM-IV ADHD, and 21 non-ADHD controls were enrolled in the study. The parents were asked to record the n3-PUFAs diet intake of their children by using the Food Frequency Questionnaire. Essential fatty acid (EFA) deficiency severity of the children was defined by the EFA deficiency scale scores. The children were also assessed by cognitive tasks, including Go-No-Go Task, Delayed Reaction Time Task, and Finger Tapping Task for inhibitory control, delay aversion, and temporal processing. The findings showed that the ADHD group had a greater severity in EFA deficiency (7.24+4.56, p = .02), and poorer performance in delay aversion (−177.88+280.40, p = .02) and temporal processing (85.34+10.96, p < .001). Moreover, ADHD symptom severity was negatively correlated with EFA deficiency. EFA deficiency was also associated with a higher delay aversion (p < .001) in this study. In conclusion, children with ADHD had a higher deficiency of EFA, and EFA deficiency had a positive association with ADHD severity and delay aversion.
... Several epidemiological studies have shown that individuals with learning disorders including attention deficit hyperactivity disorder (ADHD), dyslexia, and autism have signs of EFA deficiency or have lower than normal blood levels of DHA and ARA [286][287][288][289]. A meta-analysis of pooled data from RBC and plasma/serum samples indicated that ARA and DHA concentrations were significantly lower than normal in individuals with learning/developmental disorders [290]. ...
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Arachidonic acid (ARA, 20:4n-6) is an n-6 polyunsaturated 20-carbon fatty acid formed by the biosynthesis from linoleic acid (LA, 18:2n-6). This review considers the essential role that ARA plays in infant development. ARA is always present in human milk at a relatively fixed level and is accumulated in tissues throughout the body where it serves several important functions. Without the provision of preformed ARA in human milk or infant formula the growing infant cannot maintain ARA levels from synthetic pathways alone that are sufficient to meet metabolic demand. During late infancy and early childhood the amount of dietary ARA provided by solid foods is low. ARA serves as a precursor to leukotrienes, prostaglandins, and thromboxanes, collectively known as eicosanoids which are important for immunity and immune response. There is strong evidence based on animal and human studies that ARA is critical for infant growth, brain development, and health. These studies also demonstrate the importance of balancing the amounts of ARA and DHA as too much DHA may suppress the benefits provided by ARA. Both ARA and DHA have been added to infant formulas and follow-on formulas for more than two decades. The amounts and ratios of ARA and DHA needed in infant formula are discussed based on an in depth review of the available scientific evidence.
Article
About 5% of schoolchildren have a specific learning disorder, defined as an unexpected failure to acquire adequate abilities in reading, writing or mathematic skills not as a result of reduced intellectual ability, inadequate teaching or social deprivation. Of these, 80% are reading disorders. Polyunsaturated fatty acids (PUFAs), in particular omega-3 and omega-6 fatty acids, which are found abundantly in the brain and retina are important for learning. Some children with specific learning disorders have been found to be deficient in these PUFAs, and it is argued that supplementation of PUFAs may help these children improve their learning abilities. To assess the effects of polyunsaturated fatty acids (PUFAs) supplementation for children with specific learning disorders, on learning outcomes. We searched the following databases in April 2012: CENTRAL (2012, Issue 4), MEDLINE (1948 to April Week 2 2012), EMBASE (1980 to 2012 Week 16), PsycINFO (1806 to April 2012), ERIC (1966 to April 2012), Science Citation Index (1970 to 20 April 2012), Social Science Citation Index (1970 to 20 April 2012), Conference Proceedings Citation Index-Science (1970 to 20 April 2012), Conference Proceedings Citation Index-Social Sciences and Humanites (1970 to 20 April 2012), Cochrane Database of Systematic Reviews (2012, Issue 4), DARE (2012, Issue 2) , ZETOC (24 April 2012) and WorldCat (24 April 2012). We searched the WHO International Clinical Trials Registry Platform and ClinicalTrials.gov on 24 April 2012. We also searched the reference lists of relevant articles identified by the searches. Randomised or quasi-randomised controlled trials comparing polyunsaturated fatty acids (PUFAs) with placebo or no treatment in children aged below 18 years with specific learning disabilities diagnosed using DSM-IV, ICD-10 or equivalent criteria. We intended to include participants with co-existing developmental disorders such as attention deficit hyperactivity disorder (ADHD) or autism. Two authors (ML and KH) independently screened the titles and abstracts of the search results and eliminated all studies that did not meet the inclusion criteria. Authors were contacted for missing information and clarifications when needed. We did not find any studies suitable for inclusion in the review. One study is awaiting classification as we were unable to get any information from the study author. There is insufficient evidence to draw any conclusion about the use of PUFAs for children with specific learning disorders. There is a need for well designed randomised studies to support or refute the use of PUFAs in this group of children.
Article
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.
Article
Lay abstract: Prior studies suggest that maternal polyunsaturated fatty acids intake during pregnancy may have protective effects on autism spectrum disorder in their children. However, they did not examine detailed timing of maternal polyunsaturated fatty acid intake during pregnancy, nor did they evaluate plasma concentrations. This study investigates whether maternal polyunsaturated fatty acids in defined time windows of pregnancy, assessed by both questionnaires and biomarkers, are associated with risk of autism spectrum disorder and other non-typical development in the children. Food frequency questionnaires were used to estimate maternal polyunsaturated fatty acid intake during the first and second half of pregnancy. Gas chromatography measured maternal plasma polyunsaturated fatty acid concentrations in the third trimester. In all, 258 mother-child pairs from a prospective cohort were included. All mothers already had a child with autism spectrum disorder and were planning a pregnancy or pregnant with another child. Children were clinically assessed longitudinally and diagnosed at 36 months. For polyunsaturated fatty acid intake from questionnaires, we only found mothers consuming more omega-3 in the second half of pregnancy were 40% less likely to have children with autism spectrum disorder. For polyunsaturated fatty acid concentrations in the third-trimester plasma, we did not observe any statistical significance in relation to the risk of autism spectrum disorder. However, our study confirmed associations from previous studies between higher maternal docosahexaenoic acid and eicosapentaenoic acid plasma concentrations in the late pregnancy and reduced risk for non-typical development. This study markedly advanced understandings of whether and when maternal polyunsaturated fatty acid intake influences risk for autism spectrum disorder and sets the stage for prevention at the behavioral and educational level.
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Dyslexie, dyspraxie, ADHD en het autistische spectrum Het is de gewoonte binnen ons opvoedings-en gezondheidszorgsysteem om verschillende diagnosecriteria te gebruiken voor dyslexie, dyspraxie, hyperactief gedrag met aandachtsstoornissen (attention deficit/hyperactivity disorder, ADHD) en autismespectrumstoornissen (autistic spectrum disorders, ASD). Elk van hen verwijst naar een specifiek gedragspatroon en leermoeilijkheden waarbij de centrale definitiecriteria vrij verschillend zijn. Voor dyslexie gaat het om specifieke leermoeilijkheden bij lezen en schrijven. Dyspraxie verwijst naar specifieke moeilijkheden in het plannen en coördineren van bewegingen. Bij ADHD zijn er blijvende en niet bij de leeftijd passende aandachtsproblemen, hyperactief en impulsief gedrag, of beide. In geval van ASD zijn er uitgesproken sociale en communicatiestoornissen en bestaat er een restrictief en stereotiep gedragspatroon. Deze ontwikkelingsstoornissen zijn vrij frequent, en treffen in meer of mindere mate tot 20% van de kinderen op schoolleeftijd. Ze vertegenwoordigen de grote meerderheid van de kinderen met bijzondere onderwijsbehoeften. De geassocieerde moeilijkheden blijven doorgaans bestaan op volwassen leeftijd, met enorme gevolgen voor de getroffen individuen, hun familie en de samenleving in haar geheel. Gezien de uiteenlopende manieren waarop de aandoeningen gedefinieerd zijn, gebeurt de diagnose en de aanpak van elk van hen gewoonlijk door verschillende specialismen. Dyslexie valt ongetwijfeld binnen het bestek van de opvoedkundige psycholoog, en de interventies spitsen zich doorgaans toe op speciaal onderwijs rond lezen, spellen en aanverwante vaardigheden. Dyspraxie wordt doorgaans aangepakt via een gedragsmatige benadering met het doel de fysieke coördinatie te verbeteren, zoals fysiotherapie en ergotherapie. De diagnose van ADHD valt in het domein van de psychiatrie, met toediening van stimulantia als standaardbehandeling. De diagnose van autismespectrumstoornissen heeft eveneens een medische oriëntatie, hoewel de aanpak een combinatie van farmacologische, gedragsmatige en psychologische behandelingen kan omvatten.
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Dyslexia is one of the most common learning disability. Though dyslexia is a major educational problem, studies on biological aspects of dyslexia are very limited in India. Here we report prevalence, inheritance patterns and biological markers of dyslexia in 179 selected families from South India. Families were ascertained through probands attending special schools for dyslexic students as well as from regular schools from Karnataka state, South India. Prevalence and types of inheritance patterns were recorded. A questionnaire concerning allergies, asthma, arthritis, migraine etc. was used to assess the prevalence of immune disorders. Occurrence of chicken pox, measles, mumps, delayed milestones, birth complications, motor coordination problems, short sight and left handedness, fatty acid deficiency signs were recorded in the dyslexic probands. Among school children, prevalence of dyslexia is found to be 9.87% and in the selected families the prevalence is 28.32%. Based on the affectedness, dyslexia phenotypes were classified as severe and mild deficits. Mild deficits were better compensated than the severe deficits. Among the selected families autosomal dominant mode of inheritance was found to be more prevalent. Consanguinity plays a major role in familial aggregation of dyslexia. Allergy, migraine, delayed milestones, low level of blood cholesterol and certain fatty acid deficiency signs were found to be associated with dyslexia. Since complex array of symptoms are associated with dyslexia an integrated research approach is needed for effective diagnosis and remediation of dyslexia.
Chapter
Fatty acids control the structure and function of biological membranes, including membranes in the nervous system. The brain has higher lipid content than any other of the bodys organs, except adipose tissue itself. All its lipids, which are mostly phospholipids, are found in cell membranes, and they are almost never sources of energy. Position 2 of the glycerol molecules in phospholipids generally bears a polyunsaturated fatty acid such as docosahexanoic acid (DHA; 22:6(n-3), 22:6ω3, cervonic acid), or arachidonic acid (ARA; 20:4(n-6), 20:4ω6). There may well be smaller amounts of adrenic acid (22:4ω6) and eicosapentanoic acid (EPA; 20:5(n-3), 20:5ω3) or docosapentaenoic acid (22:5ω3). The brain contains very little alpha-linolenic acid (ALA; 18:3(n-3), 18:3ω3) although this fatty acid is the precursor of all the other omega-3 fatty acids. The families of fatty acids are shown in Figure 39.1. A major component of brain membrane phospholipids is the omega-3 fatty acid DHA, and high concentrations of this fatty acid are found in the more metabolically active area of the brain, including the frontal cerebral cortex, which is involved in cognition, mitochondria, nerve endings, and synaptic vesicles. Most studies on cognition have focused on omega-3 fatty acids, or the balance between these fatty acids and omega-6 fatty acids. However, one review has examined the role of the ARA cascade in affective disorders (Sublette and Trappler, 2000).
Article
Lay summary: This Keynote Lecture, delivered at the 2016 meeting of the International Society for Autism Research, discusses evidence from human epidemiologic studies of prenatal factors contributing to autism, such as pesticides, maternal nutrition and her health. There is no single cause for autism. Examples highlight the features of a high-quality epidemiology study, and what comprises a compelling case for causation. Emergent research directions hold promise for identifying potential interventions to reduce disabilities, enhance giftedness, and improve lives of those with ASD.
Article
Despite the potential impact nutrition may have on learning, there have been surprisingly few papers published directed towards the educational research community. In contrast, omega-3 supplementation studies are being frequently cited in the media, leading to parents asking for advice and guidance. The purpose of this article is to review the evidence to date for any effect of using omega-3 supplementation in school-aged children. This article focuses on the research that has been undertaken, particularly in relation to behaviour, education and cognitive development, in both typically developing populations as well as in children with specific learning difficulties and developmental disorders. Recommendations for future studies in this area have been highlighted in view of current knowledge. In conclusion, it was found that there is a shortage of properly controlled omega-3 supplementation trials, particularly with typically developing children, to advocate the supplementation of all children with omega-3 fatty acids, but due to the known importance of omega-3 fatty acids in the brain and early development, further research is required.
Chapter
Background: About 5% of school children have a specific learning disorder, defined as unexpected failure to acquire adequate abilities in reading, writing or mathematics that is not a result of reduced intellectual ability, inadequate teaching or social deprivation. Of these events, 80% are reading disorders. Polyunsaturated fatty acids (PUFAs), in particular, omega-3 and omega-6 fatty acids, which normally are abundant in the brain and in the retina, are important for learning. Some children with specific learning disorders have been found to be deficient in these PUFAs, and it is argued that supplementation of PUFAs may help these children improve their learning abilities. Objectives: 1. To assess effects on learning outcomes of supplementation of polyunsaturated fatty acids (PUFAs) for children with specific learning disorders.2. To determine whether adverse effects of supplementation of PUFAs are reported in these children. Search methods: In November 2015, we searched CENTRAL, Ovid MEDLINE, Embase, PsycINFO, 10 other databases and two trials registers. We also searched the reference lists of relevant articles. Selection criteria: Randomised controlled trials (RCTs) or quasi-RCTs comparing PUFAs with placebo or no treatment in children younger than 18 years with specific learning disabilities, as diagnosed in accordance with the fifth (or earlier) edition of theDiagnostic and Statistical Manual of Mental Disorders (DSM-5), or the 10th (or earlier) revision of the International Classification of Diseases (ICD-10) or equivalent criteria. We included children with coexisting developmental disorders such as attention deficit hyperactivity disorder (ADHD) or autism. Data collection and analysis: Two review authors (MLT and KHT) independently screened the titles and abstracts of articles identified by the search and eliminated all studies that did not meet the inclusion criteria. We contacted study authors to ask for missing information and clarification, when needed. We used the GRADE approach to assess the quality of evidence. Main results: Two small studies involving 116 children, mainly boys between 10 and 18 years of age, met the inclusion criteria. One study was conducted in a school setting, the other at a specialised clinic. Both studies used three months of a combination of omega-3 and omega-6 supplements as the intervention compared with placebo. Although both studies had generally low risk of bias, we judged the risk of reporting bias as unclear in one study, and as high in the other study. In addition, one of the studies was funded by industry and reported active company involvement in the study.None of the studies reported data on the primary outcomes of reading, writing, spelling and mathematics scores, as assessed by standardised tests.Evidence of low quality indicates that supplementation of PUFAs did not increase the risk of gastrointestinal disturbances (risk ratio 1.43, 95% confidence interval 0.25 to 8.15; two studies, 116 children). Investigators reported no other adverse effects.Both studies reported attention deficit hyperactivity disorder (ADHD)-related behaviour outcomes. We were unable to combine the results in a meta-analysis because one study reported findings as a continuous outcome, and the other as a dichotomous outcome. No other secondary outcomes were reported.We excluded one study because it used a cointervention (carnosine), and five other studies because they did not provide a robust diagnosis of a specific learning disorder. We identified one ongoing study and found three studies awaiting classification. Authors' conclusions: Evidence is insufficient to permit any conclusions about the effect of PUFAs on the learning abilities of children with specific learning disorders. Well-designed RCTs with clearly defined populations of children with specific learning disorders who have been diagnosed by standardised diagnostic criteria are needed.
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Objective The impact of lifetime dietary habits and their role in physical, mental, and social well-being has been the focus of considerable recent research. Omega-3 polyunsaturated fatty acids (n-3 PUFAs) as a dietary constituent have been under the spotlight for decades. n-3 PUFAs constitute key regulating factors of neurotransmission, neurogenesis, and neuroinflammation and are thereby fundamental for development, functioning and ageing of the CNS. Of note is the fact that these processes are altered in various psychiatric disorders, including attention deficit hyperactivity disorder (ADHD), depression and Alzheimer. Design Relevant literature was identified through a search of MEDLINE via PubMed using the following words, “n-3 PUFAs”, “EPA”, and “DHA” in combination with “stress”, “cognition”, “ADHD”, “anxiety”, “depression”, “bipolar disorder”, “schizophrenia”, and “Alzheimer”. The principal focus was on the role of n-3 PUFAs throughout the lifespan and their implication for psychopathologies. Recommendations for future investigation on the potential clinical value of n-3 PUFAs was examined. Results The inconsistent and inconclusive results from randomised clinical trials limits the usage of n-3 PUFAs in clinical practice. However, a body of literature demonstrates an inverse correlation between n-3 PUFAs levels and quality of life/ psychiatric diseases. Specifically, older healthy adults showing low habitual intake of n-3 PUFAs benefit most from consuming n-3 PUFAs, showing improved age related cognitive decline. Conclusions Although further studies are required, there is an exciting and growing body of research suggesting that n-3 PUFAs may have a potential clinical value in the prevention and treatment of psychopathologies.
Chapter
Fatty acids are directly involved in the structure of most lipids, including those in the nervous system, providing their chemical and biological characteristics. Besides saturated and monounsaturated fatty acids, two families of polyunsaturated fatty acids, the omega-6 fatty acids, such as linoleic acid (LA), and the omega-3 fatty acids, such as alpha linolenic acid (ALA), are most important. LA and ALA are essential nutrients, as the human body cannot synthesize them or convert one to the other. They were formerly called vitamin F, before their chemical structures were determined. The term “omega-3 fatty acids” is plural as there are four main ones that have increasing numbers of double bonds and carbon atoms. ALA (18:3 ω3) is the precursor of stearidonic acid (18:4 ω3, SA), which gives rise to eicosapentaenoic acid (EPA, 20:5 ω3) and docosapentaenoic acid (DHA, 22:6 ω3). The omega-3 polyunsaturated fatty acid content of the brain is extremely high, indicating that these fats are involved in brain physic chemistry, biochemistry, physiology and function; and, consequently, in brain development, in some neuropsychiatric diseases and in the cognitive decline of aging. This review examines all three aspects Some studies on perinatal cerebral development have focused on ALA, whereas others have examined long-chain derivatives, DHA and, to a lesser extent EPA. A third group of studies has examined the influence of ALA and DHA, sometimes with the omega-6 fatty acid, arachidonic acid (ARA). The studies on ALA provided the first demonstration of the effect of a dietary component on the structure and function of the brain that involved several scientific disciplines. These included cultures of dissociated brain cells; analyses of the fatty acids and lipids and cell types in the brain; regions and classes of phospholipids; physicochemical studies on brain membrane fluidity; biochemical and enzymological studies on enzymes such as ATPase; physiological studies on dopaminergic, serotoninergic, and cholinergic neurotransmission; toxicology of heavy metals and trans fatty acids; studies on vision, hearing, and taste; electrophysiological studies (ERG and EEG); and cognitive and behavioral studies, memory and habituation being specifically affected. The accumulation of considerable experimental evidence led to the inclusion of ALA in baby formulas. This decision has been confirmed by many studies on newborns. The nature of the polyunsaturated fatty acids (particularly the omega-3 fatty acids) in baby formulas for both full term and premature infants influences the infant's visual, neurological, cerebral, and intellectual capacities. Enrichment with long-chain fatty acids such as DHA (and EPA) is based on the fact that human milk contains them, unlike animal milks, that the brain is extremely rich in these fatty acids, and there is little desaturase activity (which, together with elongases, transforms ALA to DHA). Clinical studies on EPA and DHA, both found in fish oils, preceded or paralleled those on animals, in contrast to the work on ALA. Despite a lack of exhaustive experiments, DHA and EPA were added to baby formulas, which may well have a limited or even negative effect because of competition with omega-6 fatty acids. Formula supplemented with DHA and ARA has a positive effect on membranes, including nerve membranes, on physiological, electrophysiological, and sensory parameters, particularly vision and, most recently, on hearing. However, there is still debate about their influence on motor function, neurological capacity, behavior, and cognition. In fact, both DHA and ALA are essential fatty acids because of the low desaturase activities in the brain and liver. Dietary omega-3 fatty acids from oily fish in the human diet (the efficiency of fish oil in capsule has not yet been clearly demonstrated) may help prevent some psychiatric disorders, mainly depression and dementia, particularly Alzheimer's disease. The direct role of omega-3 fatty acids in bipolar disorder (manic-depressive disease) and schizophrenia has not yet been clearly established, although suspected in some aspects of these diseases. Omega-3 fatty acids may also be involved in dyslexia and autism, but there is evidence that they appear to help prevent stress. Finally, their influence on mood and libido is a matter for discussion pending experimental proof in animals and humans. A lack of dietary omega-3 fatty acid can prevent the renewal of membranes, and thus accelerate cerebral aging, but the roles of the vascular system (where the omega-3 fatty acids are active) and the cerebral parenchyma itself have not yet been clearly resolved. The insufficient dietary supply of omega-3 fatty acids (mainly ALA) in today's occidental diet (and in a number of diets throughout the world) raises the problem of how to correct dietary habits so that the consumer selects foods that are rich in omega-3 fatty acids; mainly rapeseed (canola) and walnut oils, oily fish, and certain eggs. Alpha tocopherol protects the omega-3 fatty acids in the nervous system membranes and not other components of vitamin E.
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Aim: Breastfeeding seems to be favorable for cognitive development. Could levels of polyunsaturated fatty acids (PUFA) explain this? Methods: Pregnant mothers were recruited consecutively at maternity care centres. PUFA were analysed in colostrum and breast milk at 1 and 3 mo. The product-precursor ratios of n-6+n-3 PUFA were examined as measures of activity in respective steps in the fatty acid metabolic chain. Also, the quotient between DHA and AA was analysed. The children were tested with the full WISC-III at 6.5 y. Results: First, the influence of length of breastfeeding was analysed by multiple regression together with relevant cofactors (except for PUFA). In the best models, 46% of the variation in total IQ was explained. Length of breastfeeding contributed significantly to total IQ (beta = 0.228, p=0.021), verbal IQ (beta = 0.204, p=0.040) and performance IQ (beta = 0.210, p=0.056). There were no significant single correlations between PUFA and measures of cognitive development. However, in multiple regression analysis of colostrum, significant beta-coefficients were found for steps 4+5 in the fatty acid metabolic chain (beta = 0.559, p=0.002). If length of breastfeeding and gestation week were added to steps 4+5, this three-factor model could explain 67% of the variation of total IQ. Introducing length of breastfeeding and gestation week together with the quotient DHA/AA (beta = 0.510, p<0.001) yielded a three-factor model, which explained 76% of the variation in total IQ. Conclusion: Our findings could be interpreted as supporting the importance of high levels of PUFA for cognitive development. However, the sample is small and the results must be interpreted with caution.
Article
Aim: Breastfeeding seems to be favorable for cognitive development. Could levels of polyunsaturated fatty acids (PUFA) explain this?Methods: Pregnant mothers were recruited consecutively at maternity care centres. PUFA were analysed in colostrum and breast milk at 1 and 3 mo. The product-precursor ratios of n-6+n-3 PUFA were examined as measures of activity in respective steps in the fatty acid metabolic chain. Also, the quotient between DHA and AA was analysed. The children were tested with the full WISC-III at 6.5 y. Results: First, the influence of length of breastfeeding was analysed by multiple regression together with relevant cofactors (except for PUFA). In the best models, 46% of the variation in total IQ was explained. Length of breastfeeding contributed significantly to total IQ (beta = 0.228, p= 0.021), verbal IQ (beta = 0.204, p= 0.040) and performance IQ (beta = 0.210, p= 0.056). There were no significant single correlations between PUFA and measures of cognitive development. However, in multiple regression analysis of colostrum, significant beta-coefficients were found for steps 4+5 in the fatty acid metabolic chain (beta = 0.559, p= 0.002). If length of breastfeeding and gestation week were added to steps 4+5, this three-factor model could explain 67% of the variation of total IQ. Introducing length of breastfeeding and gestation week together with the quotient DHA/AA (beta = 0.510, p > 0.001) yielded a three-factor model, which explained 76% of the variation in total IQ. Conclusion: Our findings could be interpreted as supporting the importance of high levels of PUFA for cognitive development. However, the sample is small and the results must be interpreted with caution.
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The Declaration of Nutrition, Health, and Intelligence for the Child-to-be is an urgent cry from the unborn child for a life-span of nutrients for physical and mental wellness. It is a proclamation of paramount importance for everyone involved in child development: parents, health professionals, teachers, government agencies, all producers of food – and children, so they may learn how to feed themselves well. The Declaration of Olympia on Nutrition and Fitness, 1996, came from a group of nutritional scientists and medical doctors to commemorate the Olympic Games' 100th anniversary. They based it on the health principles of Hippocrates: genetics, the age of the individual, the powers of various foods, and exercise. Following today's vast wealth of nutritional research and expressing it with my teaching experience, I have revitalized the Declaration of Olympia by writing from the heart of the little learner and the hope of the child-to-be. The nutrients implicated in healthy reproduction and lifelong health include B vitamins, particularly B1, B6, folate, B12; antioxidants, particularly vitamins C and E; minerals such as iron, zinc, magnesium, selenium, iodine, and copper; and essential fatty acids, particularly DHA. These nutrients also lower the risk of neural tube defects; autism, dyslexia, Down's syndrome; childhood cancers, obesity, and defective fetal cell membranes associated with maternal diabetes. Our metabolism is hugely influenced also by activity and by affection. Today's foods are often processed beyond the cells' recognition and can result in neurological and physical morbidity and mortality. A diet of unprocessed free-range animals and seafood; legumes, deep-colored vegetables and fruits; nuts, seeds, and whole grains, germ and bran, reinstates nutritional potency.
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Currently, only one medication (risperidone) is FDA-approved for the treatment of autism spectrum disorders (ASD). Perhaps for this reason, the use of novel, unconventional, and off-label treatments for ASD is common, with up to 74% of children with ASD using these treatments; however, treating physicians are often unaware of this usage. A systematic literature search of electronic scientific databases was performed to identify studies of novel and emerging treatments for ASD, including nutritional supplements, diets, medications, and nonbiological treatments. A grade of recommendation ("Grade") was then assigned to each treatment using a validated evidence-based guideline as outlined in this review: A: Supported by at least 2 prospective randomized controlled trials (RCTs) or 1 systematic review. B: Supported by at least 1 prospective RCT or 2 nonrandomized controlled trials. C: Supported by at least 1 nonrandomized controlled trial or 2 case series. D: Troublingly inconsistent or inconclusive studies or studies reporting no improvements. Potential adverse effects for each treatment were also reviewed. Grade A treatments for ASD include melatonin, acetylcholinesterase inhibitors, naltrexone, and music therapy. Grade B treatments include carnitine, tetrahydrobiopterin, vitamin C, alpha-2 adrenergic agonists, hyperbaric oxygen treatment, immunomodulation and anti-inflammatory treatments, oxytocin, and vision therapy. Grade C treatments for ASD include carnosine, multivitamin/mineral complex, piracetam, polyunsaturated fatty acids, vitamin B6/magnesium, elimination diets, chelation, cyproheptadine, famotidine, glutamate antagonists, acupuncture, auditory integration training, massage, and neurofeedback. The reviewed treatments for ASD are commonly used, and some are supported by prospective RCTs. Promising treatments include melatonin, antioxidants, acetylcholinesterase inhibitors, naltrexone, and music therapy. All of the reviewed treatments are currently considered off-label for ASD (ie, not FDA-approved) and some have adverse effects. Further studies exploring these treatments are needed. Physicians treating children with an ASD should make it standard practice to inquire about each child's possible use of these types of treatments.
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Attention-deficit hyperactivity disorder (ADHD) is the term used to describe children who are inattentive, impulsive, and hyperactive. The cause is unknown and is thought to be multifactorial. Based on the work of others, we hypothesized that some children with ADHD have altered fatty acid metabolism. The present study found that 53 subjects with ADHD had significantly lower concentrations of key fatty acids in the plasma polar lipids (20:4n-6, 20:5n-3, and 22:6n-3) and in red blood cell total lipids (20:4n-6 and 22:4n-6) than did the 43 control subjects. Also, a subgroup of 21 subjects with ADHD exhibiting many symptoms of essential fatty acid (EFA) deficiency had significantly lower plasma concentrations of 20:4n-6 and 22:6n-3 than did 32 subjects with ADHD with few EFA-deficiency symptoms. The data are discussed with respect to cause, but the precise reason for lower fatty acid concentrations in some children with ADHD is not clear.
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The purpose of the study reported here was to compare behavior, learning, and health problems in boys ages 6 to 12 with lower plasma phospholipid total omega-3 or total omega-6 fatty acid levels with those boys with higher levels of these fatty acids. A greater frequency of symptoms indicative of essential fatty acid deficiency was reported by the parents of subjects with lower plasma omega-3 or omega-6 fatty acid concentrations than those with higher levels. A greater number of behavior problems, assessed by the Conners' Rating Scale, temper tantrums, and sleep problems were reported in subjects with lower total omega-3 fatty acid concentrations. Additionally, more learning and health problems were found in subjects with lower total omega-3 fatty acid concentrations. (Only more colds and more antibiotic use were reported by those subjects with lower total omega-6 fatty acids). These findings are discussed in relation to recent findings for omega-3 experimentally deprived animals.
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Induction of microgyria by freezing injury to the developing somatosensory cortex of neonatal rats causes a defect in fast auditory processing in males, but not in females. It was speculated that early damage to the cortex has sexually dimorphic cascading effects on other brain regions mediating auditory processing, which can lead to the observed behavioral deficits. In the current series of experiments, bilateral microgyri were induced by placement of a freezing probe on the skulls of newborn male and female rats, and these animals were tested in adulthood for auditory temporal processing. Control animals received sham surgery. The brains from these animals were embedded in celloidin, cut in the coronal plane and the following morphometric measures assessed: microgyric volume, medial geniculate nucleus (MGN) volume, cell number, and cell size, and, as a control, dorsal lateral geniculate nucleus (dLGN) volume, cell number and cell size. There were no sex differences in the cortical pathology of lesioned animals. However, microgyric males had more small and fewer large neurons in the MGN than their sham-operated counterparts, whereas there was no difference between lesioned and sham-operated females. There was no effect on dLGN cell size distribution in either sex. Microgyric males were significantly impaired in fast auditory temporal processing when compared to control males, whereas lesioned females exhibited no behavioral deficits. These results suggest that early injury to the cerebral cortex may have different effects on specific thalamic nuclei in males and females, with corresponding differences in behavioral effects.
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Freezing injury to the cortical plate of rats induces cerebrocortical microgyria and, in males but not females, a shift toward greater numbers of small neurons in the medial geniculate nucleus (MGN). The purpose of the current study was to examine a hormonal basis for this sex difference. Cross-sectional neuronal areas of the MGN were measured in male rats, untreated female rats and female rats treated perinatally with testosterone propionate, all of which had received either neonatal cortical freezing or sham injury. Both male and androgenized female rats with microgyria had significantly smaller MGN neurons when compared to their sham-operated counterparts, whereas untreated females with microgyria did not. These differences were also reflected in MGN neuronal size distribution: both male and androgenized female rats with microgyria had more small and fewer large neurons in their MGN in comparison to shams, while there was no difference in MGN neuronal size distribution between lesioned and sham females. These findings suggest that perinatal gonadal steroids mediate the sex difference in thalamic response to induction of microgyria in the rat cortex.
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Edward Conze once observed of the thirty‐eight books constituting the Prajñāpāramitā Sūtras that their central message could be summed up in two sentences:(1) One should become a Bodhisattva (or Buddha‐to‐be), i.e. one who is content with nothing less than all‐knowledge attained through the perfection of wisdom for the sake of all beings. (2) There is no such thing as a Bodhisattva or as all‐knowledge or as a being or as the perfection of wisdom or as an attainment. [1]It seems to me that Conze was profoundly correct, as far as he went, and that what he said of the Prajñāpāramitā literary corpus might apply to other Mahāyāna Sūtras, as well.One test of this broad application of Conze's observation to the whole of the Mahāyāna scriptural tradition lies in a close reading of one of the Mahāyāna Sūtras from that tradition, the Saddharmapundarika Sūtra, “the scripture of the lotus blossom of the wonderful law”, or the Lotus Sūutra. The Lotus Sūtra not only makes Conze's point, as I shall try to show, but it goes further in offering a new middle path between the two summary sentences above. In doing this it brings forth a practical ethical‐religious way for Buddhists and others to follow who will be caught in the sufferings and terrors of the 21st century. We shall refer to this way as “the way of the Lotus” or “the Lotus way”.In what follows I want to attempt three things. First, using Edward Conze's summary sentences above, I identify and explicate three ways to liberation in the Lotus Sutra, viz. the way of ethics and attachment, i.e. “the Bodhisattva way” ("One should become a Bodhisattva...”); next, the way of emptiness and unattachment, i.e. “the Buddha way” ("There is no such thing as a Bodhisattva...”); and, finally, the Lotus way wherein the Bodhisattva way and the Buddha way combine to form a single and powerful new way of liberation. This third way is indirectly referred to in the remark which Edward Conze makes in his summary of the Prajñāpāramitā immediately following his previous two sentences: “To accept both of these contradictory facts is to be perfect”. [2] To accept the Bodhisattva way together with the Buddha way yields the Lotus way. Second, I demonstrate the significance of the Lotus way as a practical way of solving moral problems for Buddhists and others in the 21st century. Third, and finally, I raise and attempt to answer and solve several questions and puzzles about the Lotus way as a way to peace and liberation for Buddhists and others in the 21st century.
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This paper is based on a study carried out in Great Britain on a national sample of 11,804 ten-year olds. The first section describes an attempt to pick out cases of “specific developmental dyslexia” (Critchley 1970), a constellation or syndrome of difficulties which some believe to be recognizable clinically. When specified criteria for dyslexia were used, 269 children qualified as dyslexic (2.28 percent of the sample). These included 223 boys and 46 girls, for a ratio of 4.51 to 1. Two possible difficulties in interpreting these data are discussed, and a defense is offered of the criteria used. Since some recent research papers report a gender ratio much nearer 1:1 (Shaywitz et al. 1990; Wadsworth et al. 1992; Lubs et al. 1993), those papers were examined for possible differences in procedure; it was found that the definition of dyslexia they used was “poor reading in relation to intelligence.” We carried out a further analysis on our own data using the same criterion. Of the 494 children who qualified as dyslexic on the basis of discrepancy criteria alone (4.19 percent of the sample), 314 were boys and 180 were girls for a ratio of 1.69 to 1. It seems, therefore, that the apparent differences in gender ratio reported in the literature have arisen because different criteria for dyslexia have been used. We argue that the definition based on clinical criteria leads to a more powerful taxonomy and that the widespread equation of “dyslexia” with “poor reading” is a hindrance to progress.
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Omega-3 fatty acids are a major component of neural membranes. They are essential nutrients for normal biochemical development of the brain and retina and may affect behavior. In our studies of long-term dietary omega-3 fatty acid deficiency, we have found a new effect of this deficiency in rhesus monkeys. Deficient monkeys visited the home cage drinking spout more frequently than controls (Experiment 1), and drank more water over 24 hours (Experiment 3), ahe increase in intake was mirrored by increased combined output of urine + feces over 24 hours (Experiment 3), and was not due to spillage (Experiment 4). The dietary deficiency greatly reduced omega-3 fatty acids in red blood cells but did not affect serum electrolyte levels. The changes in fluid intake and output may be related to direct or indirect effects on central or peripheral control mechanisms for drinking or excretion, which may be mediated by altered composition of neural or other membranes or changes in eicosanoid metabolism.
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We previously reported that long-term omega-3 fatty acid deficiency is associated with increased water intake in rhesus monkeys. To determine whether the increase was specific to water, intakes of salt solutions were measured in 15-minute single-bottle tests. Deficient monkeys drank at least twice as much of all NaCl concentrations as controls. Overall intake decreased as salt concentration increased. In 2-bottle preference tests, deficient monkeys again drank more total fluid but neither preferred nor avoided normal saline compared to controls. When deprived of water, deficient monkeys concentrated urine as well as controls, demonstrating that the increased intake was not a result of renal failure or diabetes insipidus. Omega-3 fatty acids have roles both in neural membrane function and in metabolism of prostaglandins and other eicosanoids. Omega-3 fatty acid deficiency may affect drinking through changes in one or both of these functions.
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There is a male excess in many samples of patients with dyslexia and related conditions. Various suggestions have been made to account for this, including: (1) ascertainment bias, in that boys are more likely to be referred than girls; (2) a biological propensity of parents of dyslexic children to produce a high proportion of boys (compared with parents of controls); and (3) greater susceptibility among boys than girls to these conditions. These explanations are not mutually exclusive, and the first undoubtedly applies to some clinic samples. This paper offers equivocal evidence for the second explanation, and introduces new evidence for the third.
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Brains from male cases with dyslexia show symmetry of the planum temporale and predominantly left-sided cerebrocortical microdysgenesis. We now report on three women with dyslexia. In all brains, the planum temporale was again symmetrical. Also, in two of the brains, multiple foci of cerebrocortical glial scarring were present. In both women, many of the scars were myelinated, suggesting origination during late intrauterine or early postnatal life. In one, scars were mainly left perisylvian and involved portions of the vascular border zone of the temporal cortex. In the other, scars were more numerous and occurred in the border zone of the anterior, middle, and posterior cerebral arteries symmetrically. All three cases showed to a variable extent brain warts, molecular layer ectopias, and focal architectonic dysplasia identical to those seen in the male cases. Two women had primary brain neoplasms, an oligodendroglioma and a low-grade astrocytoma, respectively, and two women showed small angiomas. Reexamination of previously reported male cases disclosed one with myelinated glial scars. Two control brains with asymmetrical plana temporale showed myelinated glial scars as well. The significance of the anatomical findings is discussed, and possible etiological factors are considered with known effects of autoimmune diseases on the nervous system.
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The in vivo effect of testosterone administration to male or female rats on the biosynthesis of unsaturated fatty acids of liver was studied. Twenty-four hours after injection of testosterone (260 micrograms/kg), delta 9 desaturase activity increased significantly, whereas the activities of delta 5 and delta 6 desaturases were strongly depressed. These effects were more pronounced in female than in male animals. The fatty acid composition of plasma and liver (homogenates, crude microsomes and cytosol) showed differences between the sexes. In males, the percentage of palmitic acid and the 18:1/18:0 ratio were higher whereas the 20:4(n-6)/18:2(n-6) ratio was lower than in female rats. The administration of testosterone significantly modified the fatty acid pattern in all fractions studied. Analytical data correlated with alterations in the fatty acid desaturase activities caused by the hormone. It is suggested that the mechanism by which testosterone exerts its effect on unsaturated fatty acid biosynthesis is different that that previously demonstrated by glucocorticoid action. The effects produced by testosterone may be of biological significance in atherosclerosis pathogenesis.
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We studied the effect of sex on the distribution of long-chain n-3 and n-6 fatty acids in essential fatty acid-deficient rats fed gamma-linolenate (GLA) concentrate and/or eicosapentaenoate and docosahexaenoate-rich fish oil (FO). Male and female weanling rats were rendered essential fatty acid deficient by maintaining them on a fat-free semisynthetic diet for 8 weeks. Thereafter, animals of each sex were separated into three groups (n = 6) and given, for 2 consecutive days by gastric intubation, 4 g/kg body wt per day of GLA concentrate (containing 84% 18:2n-6), n-3 fatty acid-rich FO (containing 18% 20:5n-3 and 52% 22:6n-3), or an equal mixture of the two oil preparations (GLA + FO). The fatty acid distributions in plasma and liver lipids were then examined. GLA treatment increased the levels of C-20 and C-22 n-6 fatty acids in all lipid fractions indicating that GLA was rapidly metabolized. However, the increases in 20:3n-6 were less in females than those in males, while those in 20:4n-6 were greater, suggesting that the conversion of 20:3n-6 to 20:4n-6 was more active in female than in male rats. FO treatment increased the levels of 20:5n-3 and 22:6n-3 and reduced those of 20:4n-6. The increase in n-3 fatty acids was greater in females than that in males and the reduction in 20:4n-6 was smaller. Consequently, the sum of total long-chain EFAs incorporated was greater in females than that in males. The administration of n-3 fatty acids also reduced the ratio of 20:4n-6 to 20:3n-6 in GLA + FO-treated rats indicating that n-3 fatty acids inhibited the activity of delta-5-desaturase. However, this effect was not affected by the sex difference.
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This paper discusses the importance, in cases of dyslexia as in the case of other difficulties, of treating the child with the problem rather than the problem as such. It presents the case of a boy, labelled dyslexic, who responded positively to a biochemical approach which checked both what necessary substances he could be lacking and what substances, if any, he might be getting too much of. Iron and zinc as well as Vitamin B-6 deficiencies were found, as well as an imbalance of fatty acids. When these imbalances were remedied, not only the quality of his hair and skin improved but also his reading. Further improvement followed reduction in intake of milk and dairy products. A biochemical approach to the solution of behavior problems is proposed.
Article
To determine the requirement of the female rat for essential fatty acids, weanlings were fed a fat-free diet supplemented with highly purified ethyl linoleate or ethyl linolenate at several levels. Weight gain, food efficiency, dermal symptoms of deficiency, and fatty acid composition of liver, heart, erythrocyte, and plasma lipids were determined and comparisons made with male rats from earlier experiments. Minimum linoleate requirement of the female rat was estimated as 0.5% of calories, of male rats, as 1.3%. The requirement for linolenate was estimated to be 0.5% of calories for both males and females. The degree of unsaturation of tissues was found to be different for the 2 sexes. Female tissues had lower propor tions of total saturated and monoenoic fatty acids and higher proportions of the more unsaturated, long-chain metabolites of oleic, linoleic and linolenic acids. Calculations of the number of double bonds per fatty acid showed that the fatty acids of female tissues contained 1.3 to 1.6 times more double bonds than those of male rats.
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The Hyperactive Children's Support Group (HCSG) in an organisation with over 70 branches in Britain devoted to helping such children and their families. We have carried out a detailed survey of the characteristics of many of our children and their families and have studied the literature in detail. We have come to the conclusion that many of these children have a deficiency of essential fatty acids (EFAs) either because they cannot metabolise linoleic acid normally, or because they cannot absorb EFAs normally from the gut, or because their EFA requirements are higher than normal. The main pieces of evidence are: 1. Most of the food constituents which cause trouble in these children are weak inhibitors of the conversion of EFAs to prostaglandins (PGs). 2. Boys are much more commonly effected than girls and males are known to have much higher requirements for EFAs than females. 3. A high proportion of our children have abnormal thirst and thirst is one of the cardinal signs of EFA deficiency. 4. Many of our children have eczema, allergies and asthma which some reports suggest can be alleviated by EFAs. 5. Many of our children are deficient in zinc which is required for conversion of EFAs to PGs. 6. Some of of our children are badly affected by wheat and milk which are known to give rise to exorphins in the gut which can block conversion of EFAs to PGE1. A preliminary study of EFA supplementation in a number of our children has given promising results. We hope that others with better facilities will be encouraged to test out this hypothesis.
Article
It has recently been suggested that many of the features of dyslexia may be explicable in terms of an abnormality of membrane phospholipid metabolism. To investigate this we studied 12 dyslexic and 10 non-dyslexic adults using in vivo cerebral phosphorus-31 magnetic resonance spectroscopy (31P MRS), as the phosphomonoester (PME) and phosphodiester (PDE) peaks include indices of membrane phospholipid turnover. Spectral localization was achieved using four-dimensional chemical shift imaging methods. The PME peak area was significantly elevated in the dyslexic group, as evidenced by higher ratios of PME/total phosphorus (F = 9.5, p < 0.006), PME/beta NTP (F = 17.5, p < 0.001) and PME/PDE (F = 6.9, p < 0.02). No other spectral measurements differed significantly between the groups. These findings are consistent with the hypothesis that membrane phospholipid metabolism is abnormal in dyslexia. The PME peak is multicomponent, but predominantly consists of phosphoethanolamine (PE) and phosphocholine (PC), which are precursors of membrane phospholipids. Our finding of raised PME in dyslexia could therefore reflect reduced incorporation of phospholipids into cell membranes, although definitive interpretation must await further evidence.
Essential fatty acids in dyslexia: theory, evidence and clinical trials
  • Richardson A J Easton
  • T Mcdaid
  • A M Hall
  • J A Montgomery
  • P Clisby
  • C Puri
Richardson A. J., Easton T., McDaid A. M., Hall J. A., Montgomery P., Clisby C., Puri B. K. Essential fatty acids in dyslexia: theory, evidence and clinical trials. In: Peet M., Glen I., Horrobin D. F., eds. Phospholipid spectrum disorder in psychiatry. Carnforth: Marius Press, 1999; 225±241.
Essential fatty acids in dyslexia: theory, evidence and clinical trials
  • Richardson