Birlouez-Aragon I, Ravelontseheno L, Villate-Cathelineau B, Cathelineau G, Abitbol G
Analytical Chemistry Laboratory, Institut National Agronomique, Paris, France.
J Nutr. 1993 Aug;123(8):1370-6. doi: 10.1093/jn/123.8.1370.
Lactose consumption has been associated with a high incidence of cataract in northern Indian and southern Italian populations. Galactose absorbed after hydrolysis of lactose from milk in individuals with normal lactase activity is considered responsible. However, lactase-deficient subjects who often avoid drinking milk are able to digest lactose and absorb free galactose in fermented milk and yogurt. This study was conducted to evaluate the relationships between milk and yogurt consumption, galactose metabolism and cataract risk. Milk ingestion was dose-related with cataract risk in lactose digesters (particularly in diabetics) but not in lactose maldigesters. Conversely, yogurt intake had a protective dose-effect on cataract formation for the whole population. Maximal galactose concentrations after an oral galactose test increased exponentially with age. Red blood cell galactokinase activity was significantly lower in elderly subjects (> 60 y) than in young individuals (P < 0.05), and galactose-1-phosphate uridyl-transferase activity was significantly lower in institutionalized subjects and in home-living elderly with cataract than in healthy elderly subjects (P < 0.05). We conclude that the cataractogenic action of milk lactose is dependent on the disturbance of galactose metabolism in elderly subjects and that yogurt is not cataractogenic, although the mechanism of the protective effect of yogurt remains unknown.
在印度北部和意大利南部人群中，乳糖摄入与白内障的高发病率有关。在乳糖酶活性正常的个体中，牛奶中的乳糖水解后吸收的半乳糖被认为是罪魁祸首。然而，经常避免饮用牛奶的乳糖酶缺乏者能够消化发酵乳和酸奶中的乳糖并吸收游离半乳糖。本研究旨在评估牛奶和酸奶摄入量、半乳糖代谢与白内障风险之间的关系。在乳糖消化者（尤其是糖尿病患者）中，牛奶摄入与白内障风险呈剂量相关，但在乳糖消化不良者中并非如此。相反，酸奶摄入对整个人群的白内障形成具有保护剂量效应。口服半乳糖试验后的最大半乳糖浓度随年龄呈指数增加。老年受试者（>60岁）的红细胞半乳糖激酶活性显著低于年轻人（P<0.05），而机构化受试者以及患有白内障的居家老年人的半乳糖-1-磷酸尿苷转移酶活性显著低于健康老年受试者（P<0.05）。我们得出结论，牛奶乳糖的致白内障作用取决于老年受试者半乳糖代谢的紊乱，并且酸奶不具有致白内障性，尽管酸奶保护作用的机制尚不清楚。
