Department of Psychobiology and Methodology, Autonomous University of Barcelona, 08193 Barcelona, Spain.
Ciber Fisiopatología Obesidad y Nutrición (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain.
Nutrients. 2021 Nov 13;13(11):4059. doi: 10.3390/nu13114059.
Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder common from childhood to adulthood, affecting 5% to 12% among the general population in developed countries. Potential etiological factors have been identified, including genetic causes, environmental elements and epigenetic components. Nutrition is currently considered an influencing factor, and several studies have explored the contribution of restriction and dietary supplements in ADHD treatments. Iron is an essential cofactor required for a number of functions, such as transport of oxygen, immune function, cellular respiration, neurotransmitter metabolism (dopamine production), and DNA synthesis. Zinc is also an essential trace element, required for cellular functions related to the metabolism of neurotransmitters, melatonin, and prostaglandins. Epidemiological studies have found that iron and zinc deficiencies are common nutritional deficits worldwide, with important roles on neurologic functions (poor memory, inattentiveness, and impulsiveness), finicky appetite, and mood changes (sadness and irritability). Altered levels of iron and zinc have been related with the aggravation and progression of ADHD.
This is a systematic review focused on the contribution of iron and zinc in the progression of ADHD among children and adolescents, and how therapies including these elements are tolerated along with its effectiveness (according to PRISMA guidelines).
The scientific literature was screened for randomized controlled trials published between January 2000 to July 2021. The databases consulted were Medline, PsycINFO, Web of Science, and Google Scholar. Two independent reviewers screened studies, extracted data, and assessed quality and risk of bias (CONSORT, NICE, and Cochrane checklists used).
Nine studies met the eligibility criteria and were selected. Evidence was obtained regarding the contribution of iron-zinc supplementation in the treatment of ADHD among young individuals. The discussion was focused on how the deficits of these elements contribute to affectation on multiple ADHD correlates, and potential mechanisms explaining the mediational pathways. Evidence also suggested that treating ADHD with diet interventions might be particularly useful for specific subgroups of children and adolescents, but further investigations of the effects of these diet interventions are needed.
本系统评价聚焦于铁和锌在儿童和青少年 ADHD 进展中的作用，以及包含这些元素的疗法的耐受性及其有效性（根据 PRISMA 指南）。
筛选了 2000 年 1 月至 2021 年 7 月期间发表的随机对照试验。检索的数据库包括 Medline、PsycINFO、Web of Science 和 Google Scholar。两名独立评审员筛选研究、提取数据并评估质量和偏倚风险（使用 CONSORT、NICE 和 Cochrane 清单）。
符合入选标准并被选中的有 9 项研究。这些研究提供了关于铁-锌补充治疗年轻人 ADHD 的证据。讨论集中在这些元素的缺乏如何影响 ADHD 的多个相关因素，以及解释中介途径的潜在机制。证据还表明，针对特定亚组的儿童和青少年进行饮食干预治疗 ADHD 可能特别有用，但需要进一步研究这些饮食干预的效果。
