Abstract

There is some evidence that phytostrogen plays an important role in bone metabolism in postmenopausal women. In this study, we investigated the phytoestrogen intake levels and the relation between dietary phytoestrogens intake and bone mineral density of vegetarian (n = 77) and omnivore postmenopausal women (n = 122). Vegetarian women, all of them were seven day adventists, who had been on vegetarian diet (almost lacto-ovo vegetarians;a few vegans) over 20 yrs. The average age of vegetarians and omnivores were 62.3 yrs and 60.2 yrs, respectively and, there was no significant difference. However, body weight (p < 0.001), body mass index (p < 0.001) of vegetarians were significantly lower than those of omnivores. The mean daily energy intake of vegetarians and omnivores were 1386.1 kcal (76.3% of RDA) and 1424.5 kcal (76.9% of RDA), respectively. The mean calcium intake of vegetarians (456.7 mg, 66.3 % of RDA) was not significantly different from that of omnivores (453.5 mg, 65.2 % of RDA). The mean daily isoflavones (daidzein + genistein) intake of vegetarians and omnivore were 33.9 mg and 23.9 mg, respectively. The vegetarians consumed significantly greater quantities of isoflavones (p < 0.05) and lignans precursor (p < 0.05). In the vegetarians, intake of isoflavones was significantly positively correlated with BMD of femoral neck, after adjusted for age and BMI. Also lignan precursor intake of vegetarians was significantly positively correlated with BMD of spine, after adjusted for age and BMI. In conclusion, in omnivore post menopausal women, intake of phytoestrogen such as isoflavones and lignans was little low, and it is not clear that positive association with bone mineral density. But in vegetarian postmenopausal women, phytoestrogen intakes be important factors related to bone mineral density.

• Keywords: phytostrogens; vegetarians; bone mineral density