Literature on the relationship between ADHD and nutrition
Curtis, L. T., & Patel, K. (2008). Nutritional and environmental approaches to preventing and treating autism and attention deficit hyperactivity disorder (ADHD): a review. The Journal of Alternative and Complementary Medicine, 14(1), 79-85.
OBJECTIVES: The purpose of this study was to concisely review the available literature of nutritional and environmental factors on autistic spectrum and attention deficit hyperactivity disorder (ADHD). DESIGN AND METHODS: Review of journal articles found on the PubMed database and from information from several conference proceedings. RESULTS: Many, but not all, studies link exposure to toxins such as mercury, lead, pesticides, and in utero smoking exposure to higher levels of autism and/or ADHD. Some studies have reported many nutritional deficiencies in autism/ADHD patients. Numerous studies have reported that supplemental nutrients such as omega-3 fatty acids, vitamins, zinc, magnesium, and phytochemicals may provide moderate benefits to autism/ADHD patients. Avoidance of food allergens, food chemicals, and chelation therapy may also provide some relief to autism/ADHD patients. CONCLUSIONS: Autistic spectrum disorders and ADHD are complicated conditions in which nutritional and environmental factors play major roles. Larger studies are needed to determine optimum multifactorial treatment plans involving nutrition, environmental control,medication, and behavioral/education/speech/physical therapies.
Akhondzadeh, S., Mohammadi, M. R., & Khademi, M. (2004). Zinc sulfate as an adjunct to methylphenidate for the treatment of attention deficit hyperactivity disorder in children: a double blind and randomized trial [ISRCTN64132371]. BMC psychiatry, 4(1), 9.
Background: Attention-deficit hyperactivity disorder is an early-onset, clinically heterogenous disorder of inattention, hyperactivity, and impulsiveness. The diagnosis and treatment of attention-deficit hyperactivity disorder continues to raise controversy, and, there is also an increase in treatment options. In this 6-week double blind, placebo controlled-trial, we assessed the effects of zinc plus methylphenidate in the treatment of children with attention deficit hyperactivity disorder. To the best of our knowledge, this study is the first double blind and placebo controlled clinical trial assessing the adjunctive role of zinc in ADHD. Methods: Our subjects were 44 outpatient children (26 boys and 18 girls) between the ages of 5–11 (mean ± SD was 7.88 ± 1.67) who clearly met the DSM IV diagnostic criteria for attention-deficit hyperactivity disorder and they were randomized to methylphenidate 1 mg/kg/day + zinc sulfate 55 mg/day (with approximately 15 mg zinc element) (group 1) and methylphenidate 1 mg/kg/day + placebo (sucrose 55 mg) (group 2) for a 6 week double blind clinical trial. The principal measure of the outcome was the Teacher and Parent ADHD Rating Scale. Patients were assessed by a child psychiatrist at baseline, 14, 28 and 42 days after the medication started. Results: The present study shows the Parent and Teacher Rating Scale scores improved with zinc sulfate over this 6-week, double blind and placebo controlled trial. The behavior of the two treatments was not homogeneous across the time. The difference between the two protocols was significant as indicated by the effect on the group, the between-subjects factor (F = 4.15, d.f. = 1, P = 0.04; F = 4.50, d.f. = 1, P = 0.04 respectively). The difference between the two groups in the frequency of side effects was not significant. Conclusions: This double-blind, placebo-controlled study demonstrated that zinc as a supplementary medication might be beneficial in the treatment of children with attention-deficit hyperactivity disorder. However, further investigations and different doses of zinc are required to replicate these findings in children with ADHD.
Arnold, L. E., Bozzolo, H., Hollway, J., Cook, A., DiSilvestro, R. A., Bozzolo, D. R., … & Williams, C. (2005). Serum zinc correlates with parent-and teacher-rated inattention in children with attention-deficit/hyperactivity disorder. Journal of Child & Adolescent Psychopharmacology, 15(4), 628-636.
OBJECTIVE: The aim of this study was to explore the relationship of zinc nutrition to the severity of attention-deficit/hyperactivity disorder (ADHD) symptoms in a middle-class American sample with well-diagnosed ADHD. Previous reports of zinc in ADHD, including two positive clinical trials of supplementation, have come mainly from countries and cultures with different diets and/or socioeconomic realities. METHOD: Children 5-10 years of age with DISC- and clinician-diagnosed ADHD had serum zinc determinations and parent and teacher ratings of ADHD symptoms. Zinc levels were correlated (Pearson’s and multiple regression) with ADHD symptom ratings. RESULTS: Forty-eight children (37 boys, 11 girls; 33 combined type, 15 inattentive) had serum zinc levels with a median/mode at the lowest 30% of the laboratory reference range; 44 children also had parent/teacher ratings. Serum magnesium levels were normal. Nutritional intake by a parent-answered food frequency questionnaire was unremarkable. Serum zinc correlated at r = -0.45 (p = 0.004) with parent-teacher-rated inattention, even after controlling for gender, age, income, and diagnostic subtype, but only at r = -0.20 (p = 0.22) with CPT omission errors. In contrast, correlation with parent-teacher-rated hyperactivity-impulsivity was nonsignificant in the opposite direction. CONCLUSION: These findings add to accumulating evidence for a possible role of zinc in ADHD, even for middle-class Americans, and, for the first time, suggest a special relationship to inattentive symptoms. They do not establish either that zinc deficiency causes ADHD nor that ADHD should be treated with zinc. Hypothesis-testing clinical trials are needed.
Konikowska, K., Regulska-Ilow, B., & Rozanska, D. (2012). The influence of components of diet on the symptoms of ADHD in children. Roczniki Państwowego Zakładu Higieny, 63(2).
In most children with ADHD the cause of the disease is not exactly known, and its etiology is multifactorial. The conventional treatment is based on the combination of behavioral and psychological therapy and the pharmacotherapy. The pharmacotherapy has a high effectiveness in ADHD treatment, but it is often associated with undesirable side effects, such as: loss of appetite and weight, growth inhibition, abdominal pain, headaches, sleeping problems and increased blood pressure. In the recent years, much attention was devoted to the issue of an appropriate diet in this disease, especially when the standard pharmacotherapy is not effective. The diet of pregnant and lactating woman, and child may have an impact on the development and deepening of the hyperkinetic syndrome. There is much evidence to indicate that it is linked to nutritional factors. Chronic deficiencies of certain minerals such as zinc, iron, magnesium and iodine and insufficient dietary intake of long-chain polyunsaturated fatty acids may have a significant impact on the development and deepening of the symptoms of ADHD in children. A crucial role in the diet of pregnant and lactating women, and child plays also polyunsaturated omega-3 fatty acids, mainly DHA, which are necessary for proper development and function of brain. Their chronic deficiency may contribute to increase risk of ADHD in children. The authors of several studies also demonstrated the positive impact of the elimination food products containing synthetic food additives, like artificial food dyes and preservatives on the behavior of children with ADHD. The beneficial effects brought also the elimination of food products, that are rich in salicylates. It was found that the intake of food products with a low glycemic index helps to reduce symptoms in some hyperactive children. Providing an appropriate supply of nutrients and minerals and elimination of certain food products from diet is especially important during intensive growth and development of the child. In this article the issues concerning the role of the diet in treatment of the children with diagnosed ADHD and the importance of deficiency of certain minerals and long-chain polyunsaturated fatty acids in pregnancy and child growth was discussed. There is a need for further studies in this area to evaluate the potential effectiveness of the diet in treating the symptoms of ADHD.
Konofal, E., Lecendreux, M., Deron, J., Marchand, M., Cortese, S., Zaïm, M., … & Arnulf, I. (2008). Effects of iron supplementation on attention deficit hyperactivity disorder in children. Pediatric neurology, 38(1), 20-26.
Iron deficiency has been suggested as a possible contributing cause of attention deficit hyperactivity disorder (ADHD) in children. This present study examined the effects of iron supplementation on ADHD in children. Twenty-three nonanemic children (aged 5-8 years) with serum ferritin levels <30 ng/mL who met DSM-IV criteria for ADHD were randomized (3:1 ratio) to either oral iron (ferrous sulfate, 80 mg/day, n = 18) or placebo (n = 5) for 12 weeks. There was a progressive significant decrease in the ADHD Rating Scale after 12 weeks on iron (−11.0 ± 13.9; P < 0.008), but not on placebo (3.0 ± 5.7; P = 0.308). Improvement on Conners’ Parent Rating Scale (P = 0.055) and Conners’ Teacher Rating Scale (P = 0.076) with iron supplementation therapy failed to reach significance. The mean Clinical Global Impression-Severity significantly decreased at 12 weeks (P < 0.01) with iron, without change in the placebo group. Iron supplementation (80 mg/day) appeared to improve ADHD symptoms in children with low serum ferritin levels suggesting a need for future investigations with larger controlled trials. Iron therapy was well tolerated and effectiveness is comparable to stimulants.
Kozielec, T., & Starobrat-Hermelin, B. (1997). Assessment of magnesium levels in children with attention deficit hyperactivity disorder (ADHD). Magnesium Research, 10(2), 143-148.
A positive influence of magnesium in the prevention and treatment of hyperactivity in children is more and more frequently raised in the literature. The aim of our work was to estimate magnesium contents in children with attention deficit hyperactivity disorder, (ADHD). The investigations comprised 116 children (94 boys and 20 girls), aged 9-12 years, with recognized ADHD. In 68 out of 116 patients examined ADHD occurred with other coexisting disorders specific to the developmental age and in the remaining 48 patients it occurred together with disruptive behaviour. Magnesium levels have been determined in blood serum, red blood cells and in hair with the aid of atomic absorption spectroscopy. Magnesium deficiency was found in 95 per cent of those examined, most frequently in hair (77.6 per cent), in red blood cells (58.6 per cent) and in blood serum (33.6 per cent) of children with ADHD. The conclusion from the investigations is that magnesium deficiency in children with ADHD occurs more frequently than in healthy children. Analysis of the material indicated the correlation between levels of magnesium and the quotient of development to freedom from distractibility.
Starobrat-Hermelin, B. (1998). The effect of deficiency of selected bioelements on hyperactivity in children with certain specified mental disorders. In Annales Academiae Medicae Stetinensis (Vol. 44, pp. 297-314).
The aim of my work was the answer to the following questions: how often does the deficiency of magnesium, copper, zinc, calcium, iron occur among hyperactive children in comparison with healthy children, deficiency of which of the considered bioelements is the most frequent, what is the effect of supplementation of deficit element on hyperactivity and does it depend on other certain disorders that coexist with hyperactivity? In a process of establishing the subject diagnosis I have followed the DSM IV criteria recognizing ADHD among examined ones. I have determined the deficiency of magnesium, copper, zinc, calcium, iron in the group of 116 children with diagnosed ADHD. Consequently, as a result, I have found out that shortage of above-mentioned bioelements occurs more often among hyperactive children than among those being healthy, and deficiency of magnesium is the most frequent in this respect. Further, I have divided the group of 110 children with magnesium deficiency into two groups according to the other mental disorders that coexist with ADHD: 1) the group where hyperactivity coexists with disorders typical for developmental age such as enuresis, tics, separation anxiety, stuttering, selective mutism (63 children); 2) the group where hyperactivity coexists with disruptive behaviour disorders: conduct disorder and oppositional defiant disorder (47 children). The content of magnesium, copper, zinc, calcium, iron has been determined respectively in blood (serum and red cells) and in hair by atomic absorption spectroscopy method in both groups accordingly. At the same time, the hyperactivity tests were carried out using Conner’s Rating Scales for Parents and Teachers, Wender’s Scale as well as Quotient of Development to Freedom from Distractibility. During the statistical analysis the inparametric tests have been used taking as a significance level p < 0.05. On the ground of obtained findings I have not stated any significant differences in bioelements content among hyperactive children in relation to other coexisting disorders, except for zinc. The zinc content in hair was higher among children with ADHD and disruptive behaviour disorder. The assessment of hyperactivity indicated the remarkably higher coefficient among children with coexisting behaviour disorders as compared to hyperactive children among whom, additionally, disorders typical for developmental age have occurred. The analysis of influence exerted by magnesium supplementation on hyperactivity has been carried out in the group of total 75 children with ADHD jointly with magnesium deficiency. The group of 50 children actually tested, apart from standard treatment have received the specified doses of magnesium preparations for 6 months on regular basis. The group of 25 children was left with standard treatment without additional magnesium. In both above-mentioned groups the content of bioelements and respectively ADHD level have been determined just before and after the test. The obtained results have clearly disclosed significant increase of magnesium, zinc, calcium content (Tab. 1) and respectively essential decrease of hyperactivity in the group of children treated with magnesium. At the same time, however, among the children given standard treatment without magnesium, hyperactivity has intensified (Tab. 3, 4). The findings herein presented indicate that it is necessary to take into consideration a possible bioelements deficiency among children with ADHD. Consequently, the accomplished study proves that there is a need of magnesium supplementation in ADHD children irrespectively of other mental disorders. The supplementation of that kind of magnesium supplementation together with standard traditional mode of treatment gives us the opportunity to extend the methods of therapy of ADHD children who are the “children of the risk” in connection with their educational, emotional and social problems.