Weggemans R M, Trautwein E A
Unilever Health Institute, Unilever Research and Development Vlaardingen, Vlaardingen, The Netherlands.
Eur J Clin Nutr. 2003 Aug;57(8):940-6. doi: 10.1038/sj.ejcn.1601628.
Differences in isoflavone content of soy protein may explain the absence of a dose-response relation between soy protein intake and blood cholesterol concentrations.
To study specifically the effect of soy-associated isoflavones on cholesterol concentrations in well-controlled trials substituting soy protein with dairy or animal protein.
Studies were identified by MEDLINE searches (1995 - 6 June 2002) and reviewing reference lists. Studies were included if they had a control group or treatment, experimental diets only differed in the amounts of soy protein and isoflavones and were each fed for at least 14 days. A total of 10 studies met these criteria, providing 21 dietary comparisons.
: Studies comprised 959 subjects (336 men and 623 women), average age ranged from 41 to 67 y and baseline cholesterol concentration from 5.42 to 6.60 mmol/l.
The intake of soy-associated isoflavones increased by 1-95 mg/day and the intake of soy protein increased by 19-60 g/day.
Feeding daily 36 g soy protein with 52 mg soy-associated isoflavones on average decreased low-density lipoprotein (LDL) cholesterol by -0.17+/-0.04 mmol/l (mean+/-s.e.) and increased high-density lipoprotein (HDL) cholesterol by 0.03+/-0.01 mmol/l. There was no dose-response relation between soy-associated isoflavones and changes in LDL cholesterol (R=-0.33, P=0.14) (Pearson correlation coefficient) or HDL cholesterol (R=-0.07, P=0.76) or their ratio.
Consumption of soy-associated isoflavones is not related to changes in LDL or HDL cholesterol.
大豆蛋白中异黄酮含量的差异可能解释了大豆蛋白摄入量与血液胆固醇浓度之间不存在剂量反应关系的原因。
在以乳制品或动物蛋白替代大豆蛋白的严格对照试验中，专门研究大豆相关异黄酮对胆固醇浓度的影响。
通过医学文献数据库（MEDLINE）检索（1995年至2002年6月6日）并查阅参考文献列表来确定研究。如果研究有对照组或处理组，实验饮食仅在大豆蛋白和异黄酮的含量上有所不同，且每种饮食喂养至少14天，则纳入研究。共有10项研究符合这些标准，提供了21种饮食比较。
研究包括959名受试者（336名男性和623名女性），平均年龄在41至67岁之间，基线胆固醇浓度在5.42至6.60 mmol/L之间。
大豆相关异黄酮的摄入量每天增加1 - 95毫克，大豆蛋白的摄入量每天增加19 - 60克。
每天摄入平均含52毫克大豆相关异黄酮的36克大豆蛋白，可使低密度脂蛋白（LDL）胆固醇平均降低-0.17±0.04 mmol/L（均值±标准误），高密度脂蛋白（HDL）胆固醇升高0.03±0.01 mmol/L。大豆相关异黄酮与LDL胆固醇变化（R = -0.33，P = 0.14）（Pearson相关系数）、HDL胆固醇变化（R = -0.07，P = 0.76）或它们的比值之间不存在剂量反应关系。
食用大豆相关异黄酮与LDL或HDL胆固醇的变化无关。
