Beneficial effect of soy isoflavones on bone mineral content was modified by years since menopause, body weight, and calcium intake: a double-blind, randomized, controlled trial

Author: Chen, Yu-ming et al
Publication: Menopause. 11(3):246-254, 2004

Global interest in soy based products is rising because of higher level of consumer awareness of the potential health benefits of soy. A new study by Chinese scientists from the University of Hong Kong suggests that postmenopausal women, who take 80 mg of soy isoflavones daily, have an increased bone mineral content (BMC).

There are more studies about the influence of soy isoflavones on bone loss, but there’s not much data on the influence of other factors which could affect bone loss. The aim of this study was to investigate how the relation between isoflavones consumption and bone loss was influenced by factors such as body weight, years of menopause and calcium intake. The study was carried out on 203 women aged between 48 and 62 years.

The women were divided in 3 experimental groups, each group received 500 mg calcium:

  • Group 1: placebo, received no isoflavones
  • Group 2: received 40 mg isoflavones
  • Group 3: received 80 mg isoflavones

At the start of the study and after 1 year the following measurement were made: bone mineral density, bone mineral content (BMC) of the whole body, spine and hip.

The following results were obtained. There was a significant favourable effect of isoflavones intake on the bone mineral content (BMC) for the following women: those with more than 4 years of menopause, women with a lower than median body mass and women with lower than median level of calcium intake.