Soy Isoflavones Have a Favorable Effect on Bone Loss in Chinese Postmenopausal Women with Lower Bone Mass: A Double-Blind, Randomized, Controlled Trial

Abstract

Animal studies have shown that soy isoflavones have an effect in preventing estrogen-related bone loss, but few data are available in humans, especially in the Asian populations. This double-blind, placebo-controlled, randomized trial examines the effects of soy isoflavones on bone loss in postmenopausal Chinese women, aged 48-62 yr. Two hundred and three eligible subjects were randomly assigned to three treatment groups with daily doses of placebo (1 g starch; n = 67), mid-dose (0.5 g starch, 0.5 g soy extracts, and approximately 40 mg isoflavones; n = 68), and high dose (1.0 g soy extracts and approximately 80 mg isoflavones; n = 68). All were given 12.5 mmol (500 mg) calcium and 125 IU vitamin D(3). Bone mineral density (BMD) and bone mineral content (BMC) of the whole body, spine, and hip were measured using dual energy x-ray absorptiometry at baseline and 1 yr post treatment. Both univariate and multivariate analyses showed that women in the high dose group had mild, but statistically significantly, higher favorable change rate in BMC at the total hip and trochanter (P < 0.05) compared with the placebo and mid-dose groups, even after further adjustments for the potential confounding factors. Further stratified analyses revealed that the positive effects of soy isoflavone supplementation were observed only among women with lower initial baseline BMC (median or less). In conclusion, soy isoflavones have a mild, but significant, independent effect on the maintenance of hip BMC in postmenopausal women with low initial bone mass.

Soy isoflavone intake inhibits bone resorption and stimulates bone formation in menopausal women: meta-analysis of randomized controlled trials

“…Our literature search identified 31 RCTs. Twenty-two studies were excluded because of lack of indices of interest (Agnusdei et al, 1997a, b;Gambacciani et al, 1997a, b;Potter et al, 1998;Alekel et al, 2000;Wangen et al, 2000;Clifton-Bligh et al, 2001;Katase et al, 2001;Anderson et al, 2002;Chiechi et al, 2002;Lucas et al, 2002;Chen et al, 2003Chen et al, , 2004Jones et al, 2003;Schult et al, 2003;Atkinson et al, 2004;Harkness et al, 2004;Olsen et al, 2004;Mori et al, 2004a, b), non-randomization (Dalais et al, 1998), lack of a control group (Agnusdei et al, 1997a, b), insufficient original data or baseline values (Gambacciani et al, 1997a, b;Khalil et al, 2002). Thus, nine studies with a total of 432 subjects were included in this meta-analysis, in which five studies had quality score of five; three studies had quality score of four and one study had quality score of three (Morabito et al, 2002;Uesugi et al, 2002;Yamori et al, 2002;Arjmandi et al, 2003Arjmandi et al, , 2005Dalais et al, 2003;Brooks et al, 2004;Mori et al, 2004a, b;Nikander et al, 2004) (Table 1).…”

A randomized, placebo-controlled trial on the effects of soy protein containing isoflavones on quality of life in postmenopausal women

“…Some trials have shown effects of intervention with isoflavones on bone mineral density. 11,[42][43][44] However, there are also studies that showed no significant effects of isoflavone interventions on bones. 45,46 For hot flushes, data are also confusing, although a recent meta-analysis suggests that there might be an effect of isoflavones that is restricted to women whose initial hot flush frequency was five or more per day.…”

Validity of body mass index and waist circumference in the classification of obesity as compared to percent body fat in Chinese middle-aged women

“…They were recruited from the local community-based population during 1996 17 and 1999-2000. [18][19][20] Inclusion in the study required that subjects be ambulatory with no medical conditions known to affect bone health. For the first cohort, 2125 women were identified and interviewed through telephone dialing of a random sample of the numbers listed in the Hong Kong residents' telephone directory (whole region).…”

“…Subject recruitment was described in detail in previous reports, [18][19][20] In brief, the study participants were community subjects residing in housing estates in Shatin (a town district with a total population of B630 000), Hong Kong SAR. Stratified-cluster sampling method was used to select the housing estates in the Shatin district.…”

“…Individual information was collected by trained interviewers with face-to-face interviews based on a structured questionnaire on sociodemographic data. [18][19][20][21] Height was measured to the nearest 0.5 cm, and weight to the nearest 0.1 kg in light clothing and without shoes. BMI was calculated as weight (kg)/height (m) 2 .…”