Department of Public Health, Kinki University Faculty of Medicine, 377-2 Oono-higashi, Osaka-Sayama, Osaka 589-8511, Japan.
Osteoporos Int. 2012 Feb;23(2):705-14. doi: 10.1007/s00198-011-1594-1. Epub 2011 Mar 11.
A cross-sectional analysis of 1,662 community dwelling elderly Japanese men suggested that habitual natto intake was significantly associated with higher bone mineral density (BMD). When adjustment was made for undercarboxylated osteocalcin levels, this association was insignificant, showing the natto-bone association to be primarily mediated by vitamin K.
Low vitamin K intake is associated with an increased risk of hip fracture, but reports have been inconsistent on its effect on BMD. Our first aim was to examine the association between BMD and intake of fermented soybeans, natto, which contain vitamin K1 (20 μg/pack) and K2 (380 μg/pack). Our second aim was to examine the association between undercarboxylated osteocalcin (ucOC), a biomarker of vitamin K intake, and BMD to evaluate the role of vitamin K in this association.
Of the Japanese men aged ≥65 years who participated in the baseline survey of the Fujiwara-kyo Osteoporosis Risk in Men study, 1,662 men without diseases or medications known to affect bone metabolism were examined for associations between self-reported natto intake or serum ucOC levels with lumbar spine or hip BMD.
The subjects with greater intake of natto showed significantly lower level of serum ucOC. Analysis after adjustment for confounding variables showed an association of greater intake of natto with both significantly higher BMD and lower risk of low BMD (T-score < -1 SD) at the total hip and femoral neck. This association became insignificant after further adjustment for ucOC level.
Habitual intake of natto was associated with a beneficial effect on bone health in elderly men, and this association is primarily due to vitamin K content of natto, although the lack of information on dietary nutrient intake, including vitamin K1 and K2, prevented us from further examining the association.
一项对 1662 名居住在社区的日本老年男性的横断面分析表明，习惯性食用纳豆与更高的骨密度（BMD）显著相关。当调整未羧化骨钙素水平后，这种关联变得不显著，表明纳豆与骨骼的关联主要是由维生素 K 介导的。
维生素 K 摄入不足与髋部骨折风险增加有关，但关于其对 BMD 的影响的报告结果并不一致。我们的首要目的是研究食用纳豆（一种含有维生素 K1（20μg/包）和 K2（380μg/包）的发酵大豆）与 BMD 之间的关系。我们的第二个目的是研究未羧化骨钙蛋白（ucOC），一种维生素 K 摄入的生物标志物，与 BMD 之间的关系，以评估维生素 K 在这种关联中的作用。
在富山男性骨质疏松风险研究的基线调查中，我们对年龄≥65 岁且无已知影响骨代谢疾病或药物的日本男性进行了检查，研究了自我报告的纳豆摄入量或血清 ucOC 水平与腰椎或髋部 BMD 之间的关系。
纳豆摄入量较大的受试者血清 ucOC 水平显著较低。在调整混杂变量后分析显示，纳豆摄入量较大与全髋和股骨颈的 BMD 显著升高以及低 BMD（T 评分<-1 SD）的风险降低相关。进一步调整 ucOC 水平后，这种关联变得不显著。
习惯性食用纳豆与老年男性的骨骼健康有益相关，这种关联主要归因于纳豆的维生素 K 含量，尽管缺乏关于膳食营养素摄入（包括维生素 K1 和 K2）的信息，使我们无法进一步研究这种关联。
