van der Velpen V, Hollman P C, van Nielen M, Schouten E G, Mensink M, Van't Veer P, Geelen A
Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.
1] Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands [2] RIKILT, Wageningen University & Research Centre, Wageningen, The Netherlands.
Eur J Clin Nutr. 2014 Oct;68(10):1141-7. doi: 10.1038/ejcn.2014.108. Epub 2014 Jun 18.
BACKGROUND/OBJECTIVES: Isoflavones are present in soy foods and soy-based supplements. Despite low plasma isoflavone concentrations in the general Western population, concentrations in supplement users exceed those suggested to be beneficial for health in Asian populations, raising concerns for adverse effects. To aid risk assessment, quantification of the relation between isoflavone intake and plasma concentrations is essential.
SUBJECTS/METHODS: Plasma samples were collected from postmenopausal women in three placebo-controlled crossover studies with 8-week periods for supplements (two studies, ~100 mg isoflavones/day, n=88) or 4-week periods for soy foods (one study, ~48 mg isoflavones/day, n=15). Plasma isoflavone concentrations (daidzein, equol, genistein and glycitein) were quantified using high-performance liquid chromatography and electrochemical detection. The association between plasma concentrations and isoflavone intake, equol producer status, intake-producer interaction and background dietary intake was assessed based on the assumption of a log-linear relation.
Median plasma total isoflavone concentrations after the soy food and supplement interventions were respectively 2.16 and 3.47 μmol/l for equol producers and 1.30 and 2.39 μmol/l for non-producers. Regression analysis showed that doubling isoflavone intake increased plasma concentrations by 55-62% (±s.e. 1-2%, R(2)>0.87) for daidzein, genistein, equol (only for producers) and total isoflavones; for glycitein the association was weaker (15±1%, R(2)=0.48). Adjustments for energy, carbohydrate and fat intake did not affect these estimates. Inter-individual variation, estimated based on repeated measures in one of the studies, was 30-96%.
Although the relation between isoflavone intake and plasma concentrations was adequately quantified, the use of isoflavone intake data for risk assessment needs caution due to large inter-individual variation in plasma concentrations.
背景/目的：异黄酮存在于大豆食品和大豆基补充剂中。尽管西方普通人群血浆异黄酮浓度较低，但补充剂使用者的浓度超过了亚洲人群中被认为对健康有益的浓度，这引发了对不良反应的担忧。为了辅助风险评估，量化异黄酮摄入量与血浆浓度之间的关系至关重要。
受试者/方法：在三项安慰剂对照的交叉研究中，从绝经后女性中采集血浆样本。补充剂组的研究为期8周（两项研究，约100毫克异黄酮/天，n = 88），大豆食品组的研究为期4周（一项研究，约48毫克异黄酮/天，n = 15）。使用高效液相色谱和电化学检测法定量血浆异黄酮浓度（大豆苷元、雌马酚、染料木黄酮和黄豆黄素）。基于对数线性关系的假设，评估血浆浓度与异黄酮摄入量、雌马酚产生者状态、摄入量 - 产生者相互作用以及背景饮食摄入量之间的关联。
对于雌马酚产生者，大豆食品和补充剂干预后的血浆总异黄酮浓度中位数分别为2.16和3.47微摩尔/升，对于非产生者分别为1.30和2.39微摩尔/升。回归分析表明，大豆苷元、染料木黄酮、雌马酚（仅针对产生者）和总异黄酮的异黄酮摄入量翻倍会使血浆浓度增加55 - 62%（±标准误1 - 2%，R²>0.87）；对于黄豆黄素，这种关联较弱（15±1%，R² = 0.48）。对能量、碳水化合物和脂肪摄入量的调整不影响这些估计值。基于其中一项研究的重复测量估计的个体间变异为30 - 96%。
尽管异黄酮摄入量与血浆浓度之间的关系已得到充分量化，但由于血浆浓度存在较大的个体间变异，在风险评估中使用异黄酮摄入量数据时需谨慎。
