Anderson W, Hollins J G, Bond P S
J Hyg (Lond). 1971 Mar;69(1):1-15. doi: 10.1017/s0022172400021197.
Recent epidemiological studies have shown that death-rates from certain chronic diseases are higher in areas with soft than in areas with hard drinking-water. In the striking negative correlation found in the county boroughs of England and Wales between cardiovascular mortality and water hardness the important underlying factor is apparently the water calcium. Interest is therefore focused on the dietary significance of calcium present in drinking-water. In relation to that interest, the present report gives a quantitative account of the composition of tea infusions prepared with waters containing different amounts of calcium. It is shown that a substantial part of water calcium is taken up by the tea leaf during the preparation of infusions. The analysis of the infusions covers a wide range of individual components, including trace metals and polyphenolic substances. It appears that the principal change caused in infusion composition by the presence of calcium in the water is a substantial reduction in the relatively high oxalate content. The question is raised whether there may be some connexion between the ;water factor' in cardiovascular disease and the absorption of oxalates from foods.
最近的流行病学研究表明，某些慢性病的死亡率在饮用软水的地区高于饮用硬水的地区。在英格兰和威尔士的自治市中发现的心血管疾病死亡率与水硬度之间显著的负相关关系中，重要的潜在因素显然是水中的钙。因此，人们的兴趣集中在饮用水中钙的饮食意义上。关于这一兴趣点，本报告定量说明了用含钙量不同的水冲泡的茶的成分。结果表明，在泡茶过程中，水中相当一部分钙被茶叶吸收。对冲泡液的分析涵盖了广泛的单个成分，包括微量金属和多酚类物质。水中钙的存在似乎导致冲泡液成分发生的主要变化是相对较高的草酸盐含量大幅降低。有人提出疑问，心血管疾病中的 “水因素” 与食物中草酸盐的吸收之间是否可能存在某种联系。
