• Journal of Nutrition and Health
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• v.36 no.5
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• pp.476-482
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• 2003

We studied the effects of soy isoflavone supplements on bone metabolism marker (serum osteocalcin, urinary deoxypyridinoline) and urinary mineral excretion (urinary Ca, Mg, Zn) in 47 postmenopausal women. There were 24 participants in the treatment group and 23 in the control group. The treatment group consumed isoflavone extract capsules daily (which contained 90 mg of soy isoflavones) for 12 weeks. The study compared before and after isoflavone intake in the following areas: Physical examination, diet survey, bone metabolism marker and urinary mineral excretion. The average age of the treatment group was 64.6 years and that of the control group was 66.5 years. There were no significant differences between the two groups in terms of height, weight and body mass index. Both groups maintained a regular diet pattern in terms of their average daily nutrient intake. There were no significant differences between the treatment group (23.9 mg) and the control group (25.4 mg) in terms of daily isoflavone intake based on diet. The analysis of bone metabolism marker changes in the treatment group after 12 weeks of taking the isoflavone supplements demonstrated significant differences in the following: Serum osteocalcin (13.7 ng/mL in befor versus 6.8 ng/mL in after) and urinary deoxypyridinoline (5.9 nmol/mmol Cr in befor versus 4.5 nmol/mmol Cr in after). The subjects in the treatment group showed no significant difference in urinary Ca excretion. But the subjects showed a significant difference in urinary Mg (131.9 mg/day in befor versus 115.6 mg/day in after) and Zn (400.5 $\mu\textrm{g}$/day in befor versus 310.2 $\mu\textrm{g}$/day in after) excretion in the isoflavone treatment group at the levels of p<0.001, p<0.01, respectively. No changes were made in the intake of minerals. The composition of serum osteocalcin and urinary deoxypyridinoline, and indicators of bone metabolism, including the excretion Mg and Zn, significantly decreased. As a result, bone mineral loss was lessened. (Korean J Nutrition 36(5): 476~482, 2003)

• Nutritional Sciences
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• v.7 no.1
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• pp.17-22
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• 2004

This study was undertaken to determine the bioavailability of isoflavones in weanling Sprague-Dawley rats by providing diets containing different levels of soy isoflavones for 6 weeks: 0.025% (low isoflavone intake; LI), 0.125% (medium isoflavone intake; MI), and 0.25% (high isoflavone intake; HI). The subsequent fecal and urinary excretion of daidzein and genistein was then measured. As the levels of dietary isoflavones increased, the amount of food intakes significantly decreased, and weight gain was slower in female rats. In male rats, there was no significant difference in weight gains related to dietary intakes. Urinary excretion of daidzein and genistein was significantly higher in the MI and HI groups in both male and female rats than the control and LI groups. The recovery % of daidzein and genistein in the urine was significantly lower in the MI and HI groups. Fecal daidzein increased as dietary isoflavone intakes increased in female rats; however, in male rats the increase was significant only in the HI group. The recovery % of daidzein and genistein in the feces of female rats was not significantly different among the four groups. When dietary isoflavones were increased from 0.025% to 0.25%, the amounts of daidzein and genistein excreted in the urine and feces increased; however, the low recovery rate of both daidzein and genistein in the urine implies an increased bioavailability of isoflavones. We also observed sex-related differences in the urinary and fecal recovery of isoflavone intakes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.6
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• pp.1043-1047
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• 2002

It is well known that soy isoflavones play beneficial roles in the prevention of chronic diseases such as breast cancer, cardiovascular disease and osteoporosis. However current data are not sufficient for estimating the level of isoflavone intake. To use the urinary isoflavone excretion as a maker of isoflavone intake,26 participants consumed the isoflavone extract capsule (90 mg soy isoplavones/capsule) daily for 3 months. The study compared effects of pre- and post-isoflavone supplement in the following parameters; physical examination, dietary recalls, and urinary isoflavon excretion. The average age, height and weight were 65.7 years, 149.4 cm, and 57.3 kg. Subjects maintained regular diet pattern, and average daily nutrient intakes between pre- and post- supplementation were not significantly different except vitamin A, carotene and vitamin C. There was no significant difference between pre- and post- supplementation in terms of daily isoflavone intake. The basal urinary isoflavone excretion was 8.37 mg/day (daidzein 6.23 mu genistein 2.14 mg), and average daily excretion rate was IS.8%. Urinary isoflavone excretion was significantly increased, after isoflavone supplementation for 3 months as compared the basal level (p<0.01). Our data suggest that urinary isoflavone level, especially daidzein and genistein, may be a useful maker to estimate isoflavone intake.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.4
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• pp.421-428
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• 2006

This study assessed the effects of daily isoflavone intake on urinary excretion of deoxypyridinoline(DPD), Ca and Zn excretion as an index of bone resorption rates in 162 postmenopausal osteoporotic women. There were 87 participants in the osteoporosis group and 75 in the control group. The average age in the osteoporosis group was 62.97 years and that of the control group was 63.67 years. There were no significant differences between the two groups in height, weight and body mass index. The osteoporosis group consumed significantly lower amounts of soy foods compared to the control group(p<0.00l). Daily isoflavone intake was significantly different between the osteoporosis group(29.19 mg) and the control group(48.56 mg). The average urinary excretion of deoxypyridinoline in the osteoporosis and control groups were 5.71 nmol/mmol Cr and 5.15 nmol/mmol Cr, respectively and these values were significantly different(p<0.05). In addition, the subjects in the osteoporosis group and control group exhibited significant difference in urinary excretion of Ca(200.16 mg/day, 177.05 mg/day respectively) and Zn(333.32 $\mu$g/day, 303.68 $\mu$g/day respectively) at the levels of p<0.0l and p<0.05, respectively. There were no significant differences between the two groups in mineral intake. Thus, daily isoflavone intakes may contribute to decreases in the rates of urinary excretion of deoxypyridinoline, Ca and Zn in postmenopausal subjects.

• Journal of Nutrition and Health
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• v.37 no.4
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• pp.291-301
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• 2004

We studied the effects of soy isoflavones supplementation with exercise on bone mineral density and the urinary excretion of deoxypyridinoline as an index of bone resorption rates in postmenopausal women. A total of 67 postmen-opausal women were assigned to Isoflavone (90 mg/day) or placebo groups. These group were further divided into groups that undergone a regular exercise or a rather sedentary state performing daily activity only. Four groups were Placebo-control group (n = 16), Placebo-exercise group (n = 16), Isoflavone-sedentary group (n = 19) and Isofla-vone-exercise group (n = 16). After the intervention, we compared anthropometric mesurement, dietary recall, bone mineral density (femoral neck, lumbar spine), urinary deoxypyridinoline between the groups and between the pre and post studies. There were no significant differences between the four groups in terms of average age, height, weight, period after menopause at the baseline. The average age of the subjects were 55.2 yrs, average height, weight, period after menopause were 154.7 cm, 59.3 kg, 5.58 yrs, respectively. After eight week intervention period, there were no significant differences between the four groups in bone mineral density, but urinary deoxypyridinoline excretion was significantly decreased both in Isoflavone-sedentary and Isoflavone-Exercise groups. These results suggest that Isofla-vone supplementation alone or with exercise may be preventive measures through the decrease of bone reabsorption rate in post-menopausal subjects. Whereas exercise alone did not appear to be an effective measure in bone loss with these subjects.

• Korean Journal of Community Nutrition
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• v.5 no.1
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• pp.120-129
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• 2000

Very little is known about the relation between isoflavone intake and menopausal symptoms in Korean woman To find the effects and correlations between these factors, questionnaires(maternal factors, menopausal symptoms) anthropometric measurement, 24hr dietary recalls, and urinary isoflavones analysis were conducted in 100 postmenopausal women residing in the Kyunggi-do rural area. The average age hight and weight of the subject were 61.5 years, 153.6 cm and 56.2kg. The average age at menarche, menopause, and menstrual cycle were 16.7 years, 47.2 years, 29.8 years, respectively. Most of the postmenopausal women experienced mildly menopausal symptoms. The mean calorie, protein and calcium intake were 1417.6 kcal(74.7% of the Korean RDA) 53.2 g(88.6% of the Korean RDA) and 454.0mg(65.6% of the Korean RDA) respectively. The ration of energy from carbohydrate, protein, and fat was 68: 15: 17 The average isoflavone intake from soy foods was 27.27 mg. The major food source of the isoflavone were soybeans and soybean curd. The average urinary isoflavone excretion was 2. 78nmol/mg Cr and showed significant positive correlation with isoflavone intake. Isoflavone intake from soy foods had a negative correlation with the severity of menopausal symptoms. Therefore, soy foods which contain isoflavone may have a protective effect on menopausal symptoms of women in Korea.

• Journal of Nutrition and Health
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• v.38 no.1
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• pp.40-47
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• 2005

This study was performed to determine the effect of three different concentrations of soy-isoflavones on calcium and phosphorus balance in either sham-operated or ovariectomized female rats. Seventy-two 16-week old Sprague-Dawley rats underwent sham operation or bilateral ovariectomy. They were provided diets containing different levels of soy iso-flavones for 6 weeks: 50 ppm (Jow isoflavone intake; LI) , 250 ppm (medium isoflavone intake; MI) and 500 ppm (high isoflavone intake; HI). The subsequent fecal and urinary excretions of calcium and phosphorus were then measured. In the sham-operated rats, body weight gains and food efficiency ratio of the MI and HI groups were significantly lower than the control group while food intake was not different. However, there was no significant difference in the ovariectomized rats. The fecal excretion of calcium was significantly lower in the LI, MI and HI groups than the control group in sham operated rats, and significantly lower in the HI group than the control group in ovariectomized rats. Also, apparent ab-sorption rate of calcium and phosphorus did not show any significant difference among groups. Urinary excretion of calcium and phosphorus was significantly lower in the HI group than the LI group in the sham-operated rats. Urinary excretion of calcium was significantly higher in the control ovariectomized rats than in the control sham-operated rats. Retention of calcium and phosphorus did not show any significant difference in both groups. From the above result, we see that isoflavone intake increases calcium retention through an increase in calcium absorption and also suppresses the increase of calcium excretion in urine in ovariectomy. Therefore, it is suggested that isoflavone intake is recommended for menopausal women who experience sharp bone loss due to the decrease in estrogen honnone.

• Journal of Nutrition and Health
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• v.41 no.7
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• pp.612-620
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• 2008

This study assessed the effects of soy isoflavones supplementation with exercise on urinary mineral (calcium, magnesium, copper, zinc) excretion as an index of bone resorption rates in 67 postmenopausal women. A total subjects were assigned to Isoflavone (90 mg/day) or placebo groups. These groups were further divided into groups that undergone a regular exercise or a rather sedentary state performing daily activity only. We conducted study eight week period. Result showed urinary zinc excretion was more significantly decreased in the isoflavone-sedentary group ($-180.76\;{\pm}\;171.30\;ug/day$) than in the placebo-sedentary group ($-31.23\;{\pm}\;146.60\;ug/day$), placebo-exercise group ($40.93\;{\pm}\;193.44\;ug/day$) and isoflavione-exercise group ($-1.21\;{\pm}\;160.61\;ug/day$) (p < 0.05), but no significant changes in the differences between the values of the pre and post study values in urinary calcium, magnesium and copper excretion. These results suggest that Isoflavone supplementation decrease urinary zinc excretion rate in postmenopausal subjects.

• Proceedings of the Korean Nutrition Society Conference
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• 2003.10a
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• pp.100-100
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• 2003

• Nutrition Research and Practice
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• v.7 no.5
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• pp.393-399
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• 2013

Asian populations are thought to receive significant health benefits from traditional diets rich in soybeans due to high isoflavone contents. However, available epidemiologic data only weakly support this hypothesis. The present study was carried out to assess the pharmacokinetics of isoflavones in South Korean women after ingestion of soy-based foods. Twenty-six healthy female volunteers (20-30 y old) consumed three different soy products (i.e., isogen, soymilk, and fermented soybeans) with different aglycone/glucoside ratios. Plasma and urine isoflavone concentrations were measured by high-performance liquid chromatography (HPLC) after ingestion of one of the soy products. Pharmacokinetic parameters were determined using the WinNonlin program. The area under the curve (AUC) for plasma daidzein levels of the soymilk group ($2,101{\pm}352ng{\cdot}h/mL$) was significantly smaller than those of the isogen ($2,628{\pm}573ng{\cdot}h/mL$) and fermented soybean ($2,593{\pm}465ng{\cdot}h/mL$) groups. The maximum plasma concentration ($C_{max}$) of daidzein for the soymilk group ($231{\pm}44$ ng/mL) was significantly higher than those of the isogen ($160{\pm}32$ ng/mL) and fermented soybean ($195{\pm}35$ ng/mL) groups. The half-lives of daidzein and genistein in the soymilk group (5.9 and 5.6 h, respectively) were significantly shorter than those in the individuals given isogen (9.6 and 8.5 h, respectively) or fermented soybean (9.5 and 8.2 h, respectively). The urinary recovery rates of daidzein and genistein were 42% and 17% for the isogen group, 46% and 23% for the fermented soybean group, and 33% and 22% for the soymilk group. In conclusion, our data indicated that soy products containing high levels of isoflavone aglycone are more effective for maintaining plasma isoflavone concentrations. Additional dose-response, durational, and interventional studies are required to evaluate the ability of soy-based foods to increase the bioavailability of isoflavones that positively affect human health.