Effects of nutrients (in food) on the structure and function of the nervous system: update on dietary requirements for brain. Part 1: micronutrients.
Effects of nutrients (in food) on the structure and function of the nervous system: update on dietary requirements for brain. Part 1: micronutrients.
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发表时间：
2006-09
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通讯作者：
J. Bourre
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作者：
J. Bourre
本次更新的目的是概述膳食营养素对大脑结构和某些功能的影响。和其他器官一样，大脑是由饮食中的物质形成的（有时只包括维生素、矿物质、必需氨基酸和必需脂肪酸，包括omega- 3多不饱和脂肪酸）。然而，长期以来，人们并没有完全接受食物可以影响大脑结构，从而影响其功能，包括认知和知识。事实上，大多数微量营养素（维生素和微量元素）已经在大脑功能的背景下直接进行了评估。例如，为了产生能量，神经组织对葡萄糖的使用意味着维生素B1的存在；这种维生素可以调节认知能力，尤其是老年人。维生素B9在大脑发育和衰老时保持记忆。维生素B6可能对治疗经前抑郁症有益。维生素B6和B12等直接参与一些神经递质的合成。维生素B12可以延缓痴呆症状（和血液异常）的出现，前提是在最初症状出现之前，在一个精确的临床时间窗口内服用。补充钴胺素可改善老年人的大脑和认知功能；它经常改善与额叶有关的因素的功能，以及那些有认知障碍的人的语言功能。维生素B12水平处于临界水平的青少年会出现认知变化的迹象。在大脑中，神经末梢是人体中维生素C含量最高的部位（仅次于肾上腺上腺）。维生素D（或其某些类似物）可能对预防神经退行性或神经免疫疾病的各个方面感兴趣。在多种维生素E成分（生育酚和生育三烯酚）中，只有α -生育酚被大脑积极吸收，并直接参与神经膜保护。甚至维生素K也参与了神经组织的生物化学。铁是保证脑实质氧合和产生能量（通过细胞色素氧化酶）以及合成神经递质和髓磷脂所必需的；缺铁见于有注意力缺陷/多动障碍的儿童。脐带动脉中的铁浓度在胎儿发育过程中至关重要，并与儿童的智商有关；婴儿贫血及其相关的缺铁与认知功能发育的紊乱有关。缺铁性贫血很常见，尤其是在女性中，与运动时的冷漠、抑郁和快速疲劳等症状有关。锂的重要性，至少在精神病学上，早已为人所知。镁在所有主要代谢中都起着重要的作用：在氧化还原和离子调节等方面。锌和其他元素一起参与味觉的感知。不平衡的铜代谢稳态（由于饮食缺乏）可能与阿尔茨海默病有关。甲状腺激素提供的碘保证了脑细胞的能量代谢；怀孕期间饮食中碘的减少会导致严重的脑功能障碍，实际上会导致克汀病。在许多机制中，锰、铜和锌参与酶的机制，以防止自由基，有毒的氧衍生物。更具体地说，由于微量营养素的缺乏（甚至亚临床），儿童身体生长和智力发育的全部遗传潜力可能受到损害。营养状况不良的儿童和青少年可能会出现精神和行为功能的改变，这些改变可以通过饮食措施加以纠正，但只能在一定程度上加以纠正。事实上，营养成分和膳食模式可以产生即时或长期的影响，有益或有害。衰老期间的脑部疾病也可能是由于保护机制失效，由于饮食缺乏，例如抗氧化剂和与防止自由基有关的营养素（微量元素、维生素、非必需微量营养素，如多酚）的缺乏。宏量营养素在随附的论文中介绍。
The objective of this update is to give an overview of the effects of dietary nutrients on the structure and certain functions of the brain. As any other organ, the brain is elaborated from substances present in the diet (sometimes exclusively, for vitamins, minerals, essential amino-acids and essential fatty acids, including omega- 3 polyunsaturated fatty acids). However, for long it was not fully accepted that food can have an influence on brain structure, and thus on its function, including cognitive and intellectuals. In fact, most micronutrients (vitamins and trace-elements) have been directly evaluated in the setting of cerebral functioning. For instance, to produce energy, the use of glucose by nervous tissue implies the presence of vitamin B1; this vitamin modulates cognitive performance, especially in the elderly. Vitamin B9 preserves brain during its development and memory during ageing. Vitamin B6 is likely to benefit in treating premenstrual depression. Vitamins B6 and B12, among others, are directly involved in the synthesis of some neurotransmitters. Vitamin B12 delays the onset of signs of dementia (and blood abnormalities), provided it is administered in a precise clinical timing window, before the onset of the first symptoms. Supplementation with cobalamin improves cerebral and cognitive functions in the elderly; it frequently improves the functioning of factors related to the frontal lobe, as well as the language function of those with cognitive disorders. Adolescents who have a borderline level of vitamin B12 develop signs of cognitive changes. In the brain, the nerve endings contain the highest concentrations of vitamin C in the human body (after the suprarenal glands). Vitamin D (or certain of its analogues) could be of interest in the prevention of various aspects of neurodegenerative or neuroimmune diseases. Among the various vitamin E components (tocopherols and tocotrienols), only alpha-tocopherol is actively uptaken by the brain and is directly involved in nervous membranes protection. Even vitamin K has been involved in nervous tissue biochemistry. Iron is necessary to ensure oxygenation and to produce energy in the cerebral parenchyma (via cytochrome oxidase), and for the synthesis of neurotransmitters and myelin; iron deficiency is found in children with attention-deficit/hyperactivity disorder. Iron concentrations in the umbilical artery are critical during the development of the foetus, and in relation with the IQ in the child; infantile anaemia with its associated iron deficiency is linked to perturbation of the development of cognitive functions. Iron deficiency anaemia is common, particularly in women, and is associated, for instance, with apathy, depression and rapid fatigue when exercising. Lithium importance, at least in psychiatry, is known for a long time. Magnesium plays important roles in all the major metabolisms: in oxidation-reduction and in ionic regulation, among others. Zinc participates among others in the perception of taste. An unbalanced copper metabolism homeostasis (due to dietary deficiency) could be linked to Alzheimer disease. The iodine provided by the thyroid hormone ensures the energy metabolism of the cerebral cells; the dietary reduction of iodine during pregnancy induces severe cerebral dysfunction, actually leading to cretinism. Among many mechanisms, manganese, copper, and zinc participate in enzymatic mechanisms that protect against free radicals, toxic derivatives of oxygen. More specifically, the full genetic potential of the child for physical growth ad mental development may be compromised due to deficiency (even subclinical) of micronutrients. Children and adolescents with poor nutritional status are exposed to alterations of mental and behavioural functions that can be corrected by dietary measures, but only to certain extend. Indeed, nutrient composition and meal pattern can exert either immediate or long-term effects, beneficial or adverse. Brain diseases during aging can also be due to failure for protective mechanism, due to dietary deficiencies, for instance in anti-oxidants and nutrients (trace elements, vitamins, non essential micronutrients such as polyphenols) related with protection against free radicals. Macronutrients are presented in the accompanying paper.