J Endocrinol Metab

Journal of Endocrinology and Metabolism, ISSN 1923-2861 print, 1923-287X online, Open Access

Article copyright, the authors; Journal compilation copyright, J Endocrinol Metab and Elmer Press Inc

Journal website http://www.jofem.org

Review

Volume 4, Number 3, June 2014, pages 51-55

Effects of Soy Protein and Isoflavones Intake on HDL Metabolism in Asian Populations

**Table 1.** Meta-Analyses to Evaluate Effects of Soy Protein and Isoflavones on High-Density Lipoprotein Cholesterol (HDL-C)
Authors	Aim of study	Subjects studied	Results/conclusions
Taku et al [8]	The meta-analysis to evaluate the precise effects of soy isoflavones on lipid profiles	PubMed was searched for randomized controlled trials published from 1990 to 2006 that described the effects of soy protein intake in humans. Eleven studies were selected for the meta-analysis.	Soy isoflavones did not change HDL-C, and soy protein with enriched isoflavones significantly increased HDL-C by 3.0%.
Reynolds et al [9]	The meta-analysis to examine the effect of soy protein supplementation on serum lipid levels in adults	A total of 41 randomized controlled trials in which isolated soy protein supplementation was the only intervention and the net changes in serum lipids during intervention were reported.	Soy protein supplementation was associated with a significant increase in HDL-C (0.77 mg/dL, 95% CI: 0.20 - 1.34).
Zhan et al [10]	To identify and quantify the effects of soy protein containing isoflavones on lipid profiles	Twenty-three eligible randomized controlled trials published from 1995 to 2002 were identified from the PubMed database.	Soy protein with isoflavones intact was associated with significant increases in serum HDL-C (3.03%).
Weggemans et al [11]	To study specifically the effect of soy-associated isoflavones on cholesterol concentrations in well-controlled trials substituting soy protein with dairy or animal protein	Studies comprised 959 subjects (336 men and 623 women), average age ranged from 41 to 67 years old and baseline cholesterol concentration ranged from 5.42 to 6.60 mmol/L.	Feeding daily 36 g soy protein with 52 mg soy-associated isoflavones on average increased HDL-C by 0.03 ± 0.01 mmol/L.

Table 1. Meta-Analyses to Evaluate Effects of Soy Protein and Isoflavones on High-Density Lipoprotein Cholesterol (HDL-C)

Authors

Aim of study

Subjects studied

Results/conclusions

Taku et al [8]

The meta-analysis to evaluate the precise effects of soy isoflavones on lipid profiles

PubMed was searched for randomized controlled trials published from 1990 to 2006 that described the effects of soy protein intake in humans. Eleven studies were selected for the meta-analysis.

Soy isoflavones did not change HDL-C, and soy protein with enriched isoflavones significantly increased HDL-C by 3.0%.

Reynolds et al [9]

The meta-analysis to examine the effect of soy protein supplementation on serum lipid levels in adults

A total of 41 randomized controlled trials in which isolated soy protein supplementation was the only intervention and the net changes in serum lipids during intervention were reported.

Soy protein supplementation was associated with a significant increase in HDL-C (0.77 mg/dL, 95% CI: 0.20 - 1.34).

Zhan et al [10]

To identify and quantify the effects of soy protein containing isoflavones on lipid profiles

Twenty-three eligible randomized controlled trials published from 1995 to 2002 were identified from the PubMed database.

Soy protein with isoflavones intact was associated with significant increases in serum HDL-C (3.03%).

Weggemans et al [11]

To study specifically the effect of soy-associated isoflavones on cholesterol concentrations in well-controlled trials substituting soy protein with dairy or animal protein

Studies comprised 959 subjects (336 men and 623 women), average age ranged from 41 to 67 years old and baseline cholesterol concentration ranged from 5.42 to 6.60 mmol/L.

Feeding daily 36 g soy protein with 52 mg soy-associated isoflavones on average increased HDL-C by 0.03 ± 0.01 mmol/L.

**Table 2.** Randomized, Placebo-Controlled Trials to Evaluate Effects of Soy Protein and Isoflavones on High-Density Lipoprotein Cholesterol (HDL-C), Performed in Asian Populations
Authors	Nationality of subjects	Subjects studied	Study design	Results/conclusions
Liu et al [12]	Hong Kong	180 postmenopausal Chinese women with prediabetes or early untreated diabetes, aged 46-70 years and, on average, 6.0 years since menopause	Participants were randomly assigned to one of the three arms to receive 15 g soy protein and 100 mg isoflavone, or 15 g milk protein and 100 mg isoflavone or 15 g milk protein on a daily basis for 6 months.	No significant difference was observed in serum HDL-C between the three groups at both 3 and 6 months.
Ye et al [13]	China	Ninety early postmenopausal Chinese women, aged 45 to 60 years	Subjects were randomly assigned to three treatment groups (30 each) receiving daily doses of 0 (placebo), 84, and 126 mg of soy germ isoflavones.	No significant differences were observed in serum lipids.
Ho et al [14]	Hong Kong	203 postmenopausal Chinese women aged 48 to 62 years	Subjects were randomly assigned to receive daily doses of 500 mg calcium, and 0 mg isoflavones (placebo, n = 67), 40 mg isoflavones (n = 68) and 80 mg isoflavones (n = 68).	Little effect of soy isoflavones on changes in serum lipids was observed among the treatment groups.
Wu et al [15]	Japan	A total of 136 postmenopausal women at < 5 years after the onset of menopause	Subjects were randomly assigned to four groups: placebo, walking (45 min/day, 3 days/week) with placebo, isoflavone intake (75 mg of isoflavone/day) and combination of isoflavone plus walking.	Serum HDL-C significantly increased by 12 months after the walking and the combined intervention.
Wu et al [15]	Japan	128 postmenopausal women	Subjects were randomly assigned to 4 groups: placebo; placebo combined with walking (3 times/week); isoflavone intake (75 mg of isoflavones/day); and isoflavone combined with walking.	Serum HDL-C significantly increased (6.1%, P = 0.03) from the baseline in the combined intervention group.

Table 2. Randomized, Placebo-Controlled Trials to Evaluate Effects of Soy Protein and Isoflavones on High-Density Lipoprotein Cholesterol (HDL-C), Performed in Asian Populations

Authors

Nationality of subjects

Subjects studied

Study design

Results/conclusions

Liu et al [12]

Hong Kong

180 postmenopausal Chinese women with prediabetes or early untreated diabetes, aged 46-70 years and, on average, 6.0 years since menopause

Participants were randomly assigned to one of the three arms to receive 15 g soy protein and 100 mg isoflavone, or 15 g milk protein and 100 mg isoflavone or 15 g milk protein on a daily basis for 6 months.

No significant difference was observed in serum HDL-C between the three groups at both 3 and 6 months.

Ye et al [13]

China

Ninety early postmenopausal Chinese women, aged 45 to 60 years

Subjects were randomly assigned to three treatment groups (30 each) receiving daily doses of 0 (placebo), 84, and 126 mg of soy germ isoflavones.

No significant differences were observed in serum lipids.

Ho et al [14]

Hong Kong

203 postmenopausal Chinese women aged 48 to 62 years

Subjects were randomly assigned to receive daily doses of 500 mg calcium, and 0 mg isoflavones (placebo, n = 67), 40 mg isoflavones (n = 68) and 80 mg isoflavones (n = 68).

Little effect of soy isoflavones on changes in serum lipids was observed among the treatment groups.

Wu et al [15]

Japan

A total of 136 postmenopausal women at < 5 years after the onset of menopause

Subjects were randomly assigned to four groups: placebo, walking (45 min/day, 3 days/week) with placebo, isoflavone intake (75 mg of isoflavone/day) and combination of isoflavone plus walking.

Serum HDL-C significantly increased by 12 months after the walking and the combined intervention.

Wu et al [15]

Japan

128 postmenopausal women

Subjects were randomly assigned to 4 groups: placebo; placebo combined with walking (3 times/week); isoflavone intake (75 mg of isoflavones/day); and isoflavone combined with walking.

Serum HDL-C significantly increased (6.1%, P = 0.03) from the baseline in the combined intervention group.