Unité Maladies Métaboliques et Micronutriments, INRA de Clermont-Ferrand-Theix, CRNH d'Auvergne, 63122 St-Genés-Champanelle, France.
Nutr Res Rev. 2004 Dec;17(2):249-58. doi: 10.1079/NRR200485.
The present review examines the importance of dietary organic anions in preventive nutrition. Organic anions are chiefly supplied by plant foods, as partially neutralised K salts such as potassium citrate, potassium malate and, to a lesser extent, oxalate or tartrate salts. Animal products may also supply K anions, essentially as phosphate, but also as lactate as a result of fermentative or maturation processes, but these K salts have little alkalinising significance. Citrate and malate anions are absorbed in the upper digestive tract, while a substantial proportion is probably metabolised in the splanchnic area. Whatever their site of metabolism, these anions finally yield KHCO3 which is used by the kidneys to neutralise fixed acidity. This acidity essentially reflects the oxidation of excess S amino acids to sulfate ions, which is mainly related to the dietary protein level. Failure to neutralise acidity leads to low-grade metabolic acidosis, with possible long-term deleterious effects on bone Ca status and on protein status. Furthermore, low-grade acidosis is liable to affect other metabolic processes, such as peroxidation of biological structures. These metabolic disturbances could be connected with the relatively high incidence of osteoporosis and muscle-protein wasting problems observed in ageing individuals in Europe and Northern America. Providing a sufficient supply of K organic anions through fruit and vegetable intake should be recommended, fostering the actual motivational campaigns ('five (or ten) per d') already launched to promote the intake of plant foods rich in complex carbohydrates and various micronutrients.
本综述探讨了饮食有机阴离子在预防营养中的重要性。有机阴离子主要由植物性食物提供，如部分中和的 K 盐，如柠檬酸钾、苹果酸钾，以及在较小程度上的草酸盐或酒石酸盐。动物产品也可能提供 K 阴离子，主要作为磷酸盐，但也作为由于发酵或成熟过程中的乳酸盐，但这些 K 盐的碱化意义不大。柠檬酸盐和苹果酸盐阴离子在上消化道被吸收，而相当一部分可能在内脏区域被代谢。无论其代谢部位如何，这些阴离子最终都会产生 KHCO3，肾脏会用它来中和固定酸。这种酸度主要反映了过量 S 氨基酸氧化为硫酸盐离子，这主要与饮食蛋白质水平有关。如果不能中和酸度，就会导致低水平代谢性酸中毒，可能对骨钙状态和蛋白质状态产生长期的有害影响。此外，低水平酸中毒容易影响其他代谢过程，如生物结构的过氧化。这些代谢紊乱可能与欧洲和北美老年人群中观察到的相对较高的骨质疏松症和肌肉蛋白消耗问题有关。通过摄入水果和蔬菜提供足够的 K 有机阴离子应该是被推荐的，促进已经发起的实际激励运动（“每天五份（或十份）”），以促进摄入富含复杂碳水化合物和各种微量营养素的植物性食物。
