Leigh Gibson E, Green Michael W
Cancer Research UK Health Behaviour Unit, Department of Epidemiology and Public Health, Royal Free and University College Medical School, University College London, 2-16 Torrington Place, London WC1E 6BT, UK.
Nutr Res Rev. 2002 Jun;15(1):169-206. doi: 10.1079/NRR200131.
The impact of nutritional variation, within populations not overtly malnourished, on cognitive function and arousal is considered. The emphasis is on susceptibility to acute effects of meals and glucose loads, and chronic effects of dieting, on mental performance, and effects of cholesterol and vitamin levels on cognitive impairment. New developments in understanding dietary influences on neurohormonal systems, and their implications for cognition and affect, allow reinterpretation of both earlier and recent findings. Evidence for a detrimental effect of omitting a meal on cognitive performance remains equivocal: from the outset, idiosyncrasy has prevailed. Yet, for young and nutritionally vulnerable children, breakfast is more likely to benefit than hinder performance. For nutrient composition, despite inconsistencies, some cautious predictions can be made. Acutely, carbohydrate-rich-protein-poor meals can be sedating and anxiolytic; by comparison, protein-rich meals may be arousing, improving reaction time but also increasing unfocused vigilance. Fat-rich meals can lead to a decline in alertness, especially where they differ from habitual fat intake. These acute effects may vary with time of day and nutritional status. Chronically, protein-rich diets have been associated with decreased positive and increased negative affect relative to carbohydrate-rich diets. Probable mechanisms include diet-induced changes in monoamine, especially serotoninergic neurotransmitter activity, and functioning of the hypothalamic pituitary adrenal axis. Effects are interpreted in the context of individual traits and susceptibility to challenging, even stressful, tests of performance. Preoccupation with dieting may impair cognition by interfering with working memory capacity, independently of nutritional status. The change in cognitive performance after administration of glucose, and other foods, may depend on the level of sympathetic activation, glucocorticoid secretion, and pancreatic beta-cell function, rather than simple fuelling of neural activity. Thus, outcomes can be predicted by vulnerability in coping with stressful challenges, interacting with nutritional history and neuroendocrine status. Functioning of such systems may be susceptible to dietary influences on neural membrane fluidity, and vitamin-dependent cerebrovascular health, with cognitive vulnerability increasing with age.
本文探讨了在没有明显营养不良的人群中，营养变化对认知功能和唤醒水平的影响。重点关注饮食和葡萄糖负荷的急性影响、节食的慢性影响对心理表现的作用，以及胆固醇和维生素水平对认知障碍的影响。在理解饮食对神经激素系统的影响及其对认知和情感的意义方面的新进展，使得我们能够重新解读早期和近期的研究结果。关于不吃一顿饭对认知表现产生有害影响的证据仍然不明确：从一开始，个体差异就占了上风。然而，对于年幼且营养易损的儿童来说，早餐更有可能对其表现有益而非有害。就营养成分而言，尽管存在不一致之处，但仍可做出一些谨慎的预测。短期内，富含碳水化合物而蛋白质含量低的餐食可能具有镇静和抗焦虑作用；相比之下，富含蛋白质的餐食可能会使人兴奋，改善反应时间，但也会增加注意力不集中的警觉性。高脂肪餐食可能导致警觉性下降，尤其是当它们与习惯性脂肪摄入量不同时。这些急性影响可能会因一天中的时间和营养状况而有所不同。长期来看，相对于富含碳水化合物的饮食，富含蛋白质的饮食与积极情绪减少和消极情绪增加有关。可能的机制包括饮食引起的单胺变化，尤其是血清素能神经递质活性的变化，以及下丘脑 - 垂体 - 肾上腺轴的功能。这些影响是在个体特征以及对具有挑战性甚至压力性的表现测试的易感性背景下进行解读的。过度关注节食可能会干扰工作记忆能力，从而损害认知，而与营养状况无关。服用葡萄糖和其他食物后认知表现的变化可能取决于交感神经激活水平、糖皮质激素分泌和胰腺β细胞功能，而不仅仅是神经活动的简单供能。因此，通过应对压力挑战的易感性、与营养史和神经内分泌状态的相互作用，可以预测结果。这些系统的功能可能易受饮食对神经膜流动性以及维生素依赖性脑血管健康的影响，认知易感性会随着年龄的增长而增加。
