Greater fruit and vegetable intake is associated with increased bone mass among postmenopausal Chinese women

Although studies in Caucasian populations have reported the beneficial effects of intakes of fruit and vegetables on bone mass, limited data are available in the Asian populations. We examined the association of the intake of fruits and vegetables with bone mineral density (BMD) in a population-based cross-sectional study of 670 postmenopausal Chinese women aged 48-63 years. Habitual dietary intakes were assessed using a food frequency questionnaire. BMD at the whole body, lumbar spine and left hip were measured with dual-energy X-ray absorptiometry. Univariate regression analyses showed that the total intake of fruits and vegetables was significantly associated with greater BMD at the whole body, lumbar spine (L1-L4), total hip, trochanter and intertrochanter. An independently positive association between fruit and vegetable intake and BMD at the whole body (P = 0.005), lumbar spine (P < 0.001) and total hip (P = 0.024) remained even after adjusting for age, years since menopause, body weight and height, dietary energy, protein and Ca, and physical activities. A daily increase of 100 g fruit and vegetable intake was associated with 0.0062 (95 % CI 0.0019, 0.0105) g/cm2, 0.0098 (95 % CI 0.0041, 0.0155) g/cm2 and 0.0060 (95 % CI 0.0011, 0.0109) g/cm2 increases in BMD at the whole body, lumbar spine and total hip, respectively. In conclusion, greater fruit and vegetable intake is independently associated with better BMD among postmenopausal Chinese women.     

Alcohol intake and bone metabolism in elderly women

BACKGROUND: Published reports on the effect of alcohol consumption on bone mineral density (BMD) are inconsistent. OBJECTIVE: The objective of this study was to examine the relation between alcohol intake and BMD, calcitropic hormones, calcium absorption, and other biochemical indexes of bone and mineral metabolism in elderly women. DESIGN: The results presented are derived from baseline observations of 489 elderly women (aged 65-77 y) recruited for an osteoporosis study. The nondrinking group comprised 297 women and the drinking group comprised 148 women. Furthermore, the effect of different alcohol intakes (28.6 to 57.2 to 142.9 g/wk) was studied. RESULTS: Women who consumed alcohol had significantly higher spine (10%), total body (4.5%), and midradius (6%) BMD than did nondrinkers. An alcohol intake >28.6 g/wk was associated with higher BMD; maximum effect was seen with an intake of >28.6 to 相似文献   

Dietary carotenoid intake as a predictor of bone mineral density

Our understanding of the influence of nutrition on bone health is limited because most studies concentrate on the role of calcium and protein, while other nutrients receive less attention. Recent evidence shows a positive link between fruit and vegetable consumption and bone health. In the present study, the relationships of dietary intakes of preformed retinol and carotenoids, one group of phytonutrients abundant in fruit and vegetables, were examined in an Anglo-Celtic Australian population of 68 men and 137 women. Bone mass of total body and lumbar spine were positively related to lycopene intake in men, and to lycopene and lutein/zeaxanthin intake in premenopausal women. In addition, a positive association of lumbar spine bone mass with dietary beta-carotene intake was observed in postmenopausal women. No relationship was found between dietary retinol intake and bone mineral status. The finding of the present study suggests a beneficial effect of fruit and vegetable consumption, as indicated by dietary carotenoid intake, on bone health, possibly via an antioxidant mechanism.     

Usual dietary isoflavone intake, bone mineral density, and bone metabolism in postmenopausal women

Clinical trials of isoflavone supplementation and bone density have been of relatively short duration and yielded inconsistent results. Few studies examined the effects of usual dietary isoflavone intake on bone density, and none examined the effects on markers of bone turnover. This cross-sectional study examines the association of usual, unsupplemented dietary soy intake with bone density at the lumbar spine and hip and markers of bone turnover in postmenopausal women. Participants were 208 postmenopausal Southern California women aged 45-74 years. Information on behavioral and lifestyle factors was obtained, and dietary intake of isoflavones over the past year was assessed with a standardized questionnaire. Bone density was measured at the spine and hip with dual energy x-ray absorptiometry (DEXA). Urinary type I collagen cross-linked N-telopeptides (N-Tx) and pyridinium cross-links (PYR), both markers of bone resorption, and bone alkaline phosphatase (BAP), a marker of bone formation, were assayed. After adjustment for age and obesity, women with the highest daily intake of dietary genistein had N-Tx concentrations 18% lower than those of women who reported no daily genistein consumption (mean 37.29 vs. 45.44, respectively, p = 0.01). After adjustment for all covariates, there were trends toward significant differences in N-Tx (p = 0.09) and spine bone density (p = 0.07), whereby women with the highest level of isoflavone consumption had greater bone density at the spine. These results suggest that usual, unsupplemented dietary isoflavone consumption may be protective against bone loss in postmenopausal women through a reduction in bone resorption.     

Spinal bone density and calcium intake in healthy postmenopausal women

Dietary calcium intake and bone mineral density (BMD) of the lumbar spine (L2-L4) were determined in 131 healthy free-living postmenopausal women (aged 64.7 +/- 7.6 y, means +/- SD). The calcium consumption for the total population was 606 +/- 302 mg/d. Subjects consuming less than the population mean of dietary calcium had significantly lower BMDs than did subjects with intakes above the mean (P less than 0.009); these two groups did not differ in basic demographic characteristics. Additional analyses using a stepwise univariate regression model demonstrated that BMD was significantly associated with body weight (P less than 0.001) and dietary calcium intake (P less than 0.02). These data support the hypothesis that dietary calcium intake is a determinant of skeletal health in postmenopausal women.     

Effect of alcohol intake on bone mineral density in elderly women: The EPIDOS Study. Epidémiologie de l'Ostéoporose

To study potential associations between alcohol consumption and bone mineral density in women aged 75 years or older, the authors analyzed 7,598 ambulatory women (mean age, 79.9 years; standard deviation, 3.8 years) recruited at five centers in France between 1992 and 1994. The current alcohol intake was assessed using a self-questionnaire. Bone mineral density was measured by dual-photon X-ray absorptiometry of the proximal femur and total body and adjusted for age, weight, and height (Z score). Compared with nonusers, women who drank 11-29 g of alcohol per day (g/day) had higher bone mineral density values at the trochanteric site (p = 0.0017). Neither 1-10 g/day nor >30 g/day users had increased bone mineral density levels. These results were unrelated to estrogen replacement therapy use, dietary calcium intake, current smoking status, usual physical activity, educational attainment, household monthly income, and general health status. Alcohol intake was not associated with bone mineral density at the femoral neck. Total body bone mineral density was lower in subjects with alcohol intakes >30 g/day (p = 0.047). Our data suggest that moderate drinking (e.g., 1-3 glasses of wine per day) is associated with an increase in trochanteric bone mineral density in elderly ambulatory women. However, higher intakes may have detrimental effects on bone mass.     

Preventing Wintertime Bone Loss: Effects of Vitamin D Supplementation in Healthy Postmenopausal Women

A double-blind, placebo-controlled trial in healthy, postmenopausal women with low vitamin D intakes (100 IU/day) has shown that increasing daily vitamin D intake to 500 IU for one year can significantly reduce late wintertime bone loss and increase bone density in the spine.     

Soybean and soy isoflavone intake indicate a positive change in bone mineral density for 2 years in young Korean women

Many studies have shown that soybean and isoflavones have a favorable effect on bone mass for postmenopausal women, but few data are available on young Asian women. To investigate the effect of soybean and isoflavone intake on bone mineral density (BMD) and its change among young Korean women over 2 years, we conducted a longitudinal study for 34 women. The BMD was measured 3 times with 1-year intervals by dual x-ray absorptiometry at the lumbar spine and femur (neck, Ward's triangle [WT], and trochanter). Dietary intake was assessed up to 8 times by 24-hour recall with average 4-month interval. During the study period, BMD increased significantly for lumber spine and WT (2.5% and 5.2%). The average daily intake of soybeans and isoflavones was 39 g and 8 mg, respectively. Soybean intake and total isoflavone intake had positive correlation on femoral neck (FN) and WT. By longitudinal mixed-model regression analysis, BMD increased 0.26% per 1 mg of isoflavone intake per year in the FN and 0.31% for WT (P = .05 and .008). In conclusion, soybean and isoflavone intake have a positive effect on the change of BMD on the FN and WT among young Korean women. Because soybean and isoflavone intakes could be confounded by other nutrients, the positive effects of isoflavones on bone should be further investigated.     

Nutritional associations with bone loss during the menopausal transition: evidence of a beneficial effect of calcium, alcohol, and fruit and vegetable nutrients and of a detrimental effect of fatty acids

BACKGROUND: The menopausal transition is characterized by rapid bone loss. Few data exist on the role of nutrition. OBJECTIVE: The objective of the study was to ascertain which dietary factors influence perimenopausal skeletal loss. DESIGN: A longitudinal study was conducted of 891 women aged 45-55 y at baseline and 50-59 y at follow-up 5-7 y later. Bone mineral density (BMD) was measured by using dual-energy X-ray absorptiometry at the lumbar spine and femoral neck (FN). Nutrient intakes were assessed after the baseline visit and 5 y later, by using the same food-frequency questionnaire. RESULTS: After adjustment for energy intake and other confounders, higher intakes of calcium were correlated with change in FN BMD (ie, reduced loss) (r = 0.073, P < 0.05), and the intake of modest amounts of alcohol was associated with less lumbar spine bone loss (P < 0.01 for quartile of alcohol intake). Greater FN BMD loss was associated with increased intake of polyunsaturated fatty acids (r = -0.110, P < 0.01), monounsaturated fatty acids (r = -0.069, P < 0.05), retinol (r = -0.067; P < 0.05), and vitamin E (r = -0.110; P < 0.01). The latter 2 nutrients were highly correlated with polyunsaturated fatty acids. For premenopausal women, calcium and nutrients found in fruit and vegetables (vitamin C, magnesium, and potassium) were associated with FN BMD, and calcium, vitamin C, and magnesium were associated with change in FN BMD. CONCLUSIONS: Although menopausal status and hormone replacement therapy use dominate women's bone health, diet may influence early postmenopausal bone loss. Fruit and vegetable intake may protect against premenopausal bone loss.     

Is caffeine associated with bone mineral density in young adult women?

BACKGROUND: By increasing the urinary excretion of calcium, caffeine consumption may reduce bone mineral density (BMD) and subsequently increase the risk for osteoporotic fracture. Although negative associations between caffeine consumption and BMD have been reported for postmenopausal women, in particular for those who consume low amounts of dietary calcium, the relation between caffeine and BMD in younger women is unclear. Therefore, we evaluated the association between caffeine consumption and BMD in a cross-sectional study of 177 healthy white women, age 19-26 years, who attended a Midwestern university. METHODS: Average caffeine intake (milligrams per day) was calculated from self-reports of the consumption of coffee, decaffeinated coffee, tea, colas, chocolate products, and select medications during the previous 12 months (mean caffeine intake = 99. 9 mg/day). BMD (grams per square centimeter) at the femoral neck and the lumbar spine was measured by dual-energy X-ray absorptiometry. RESULTS: After adjusting in linear regression models for potential confounders, including height, body mass index, age at menarche, calcium intake, protein consumption, alcohol consumption, and tobacco use, caffeine consumption was not a significant predictor of BMD. For every 100 mg of caffeine consumed, femoral neck BMD decreased 0.0069 g/cm(2) (95% confidence in terval [CI] = -0.0215, 0. 0076) and lumbar spine BMD decreased 0.0119 g/cm(2) (95% CI = -0. 0271, 0.0033). No single source of caffeine was significantly associated with a decrease in BMD. Furthermore, the association between caffeine consumption and BMD at either site did not differ significantly between those who consumed low levels of calcium (< or =836 mg/day) and those who consumed high levels of calcium (>836 mg/day). CONCLUSIONS: Caffeine intake in the range consumed by young adult women is not an important risk factor for low BMD.     

Familial resemblance of bone mineralization, calcium intake, and physical activity in early-adolescent daughters, their mothers, and maternal grandmothers

OBJECTIVE: To describe familial relationships among bone mineral density (BMD), calcium intake, and physical activity in early-adolescent daughters, their premenopausal mothers, and postmenopausal maternal grandmothers. SUBJECTS: Healthy, early-adolescent daughter and premenopausal mother pairs (n=72) were enrolled in the study. In addition, a cohort of 22 postmenopausal maternal grandmothers were measured for comparison of related triads (n=22). DESIGN: Cross-sectional measurements of hip (three sites) and lumbar spine BMD by dual energy x-ray absorptiometry (DXA), body height and weight, menstrual function, current calcium intake, and current and past physical activity patterns were assessed using recalls and questionnaires. STATISTICAL ANALYSIS: Correlational analysis was used to establish relationships between bone characteristics and body size, menstrual function, calcium intake, and physical activity. Multiple regression analyses with backward elimination were used to examine heritability of bone characteristics in daughter-mother and mother-grandmother pairs and daughter-mother-grandmother triads. Quick cluster analysis and cross-tabulation with Pearson's chi(2) were used to evaluate familial patterns for bone characteristics and lifestyle practices. RESULTS: Height, weight, and lumbar spine BMD were significantly correlated within mother-daughter pairs. Current and past calcium intakes were not related within pairs or triads or to BMD in the daughters or the grandmothers. A weak inverse relationship between calcium intake and the hip trochanter and lumbar spine BMD was observed in the mothers (R(2)=-0.25; P=.05). Physical activity, independent of calcium intake, was strong predictor of BMD for daughters and mothers. Among the daughters, the hertiability estimates for trochanter and lumbar spine BMD were 0.56 and 0.70, respectively (P<.01). The heritability estimate for premenopausal mothers were significant for lumbar spine BMD (h(2)=0.66; P<.01). Daughter-mother-grandmother triads with low physical activity had low femoral neck BMD whereas those with high physical activity had high femoral neck BMD (P<.001). APPLICATIONS: Making physical activity a part of the daily routine, in addition to an adequate intake of calcium and bone-related nutrients, is an important goal for maintaining or improving bone health for women of all ages.     

Longitudinal Impact of Substance Use and Depressive Symptoms on Bone Accrual Among Girls Aged 11–19 Years

PurposeOsteoporosis is primarily evident in postmenopausal women, but its roots are traceable to periods of growth, including during adolescence. Depression, anxiety, and smoking are associated with lower bone mineral density (BMD) in adults. These associations have not been studied longitudinally across adolescence, when more than 50% of bone accrual occurs.MethodsTo determine the impact of depressive and anxiety symptoms, smoking, and alcohol use on bone accrual in girls 11–19 years, 262 healthy girls were enrolled in age cohorts of 11, 13, 15, and 17 years. Using a cross-sequential design, girls were seen for three annual visits. Outcome measures included total body bone mineral content and BMD of the total hip and lumbar spine using dual energy x-ray absorptiometry. Depressive and anxiety symptoms and smoking and alcohol use were by self-report.ResultsHigher-frequency smoking was associated with a lower rate of lumbar spine and total hip BMD accrual from ages 13–19. Higher depressive symptoms were associated with lower lumbar spine BMD across 11–19 years of age. There was no effect of depressive symptoms on total body bone mineral content, and there was no effect of alcohol intake on any bone outcome.ConclusionAdolescent smokers are at higher risk for less than optimal bone accrual. Even in the absence of diagnosable depression, depressive symptoms may influence adolescent bone accrual. These findings have import for prevention of later osteoporosis and fractures.     

Dietary iron is associated with bone mineral density in healthy postmenopausal women

Healthy nonsmoking postmenopausal women (n = 242; ages 40-66 y) were included in the Bone, Estrogen, and Strength Training (BEST) Study. Bone mineral density (BMD) was measured at five sites (lumbar spine L2-L4, trochanter, femur neck, Ward's triangle and total body) using dual energy X-ray absorptiometry (DXA). Mean nutrient intakes were assessed using a 3-d diet record. Regression models were calculated using each BMD site as the dependent variable and iron as the independent variable. Covariates included in the models were years past menopause, fat-free mass, fat mass, use of hormone replacement therapy, total energy intake and dietary intake of protein and calcium. Using linear models, iron was associated with greater BMD at all sites (P < or = 0.01), even after adjusting for protein and/or calcium. Increasing levels of iron intake (>20 mg) were associated with greater BMD at several bone sites among women with a mean calcium intake of 800-1200 mg/d. Elevated iron intake was not associated with greater BMD among women with higher (>1200 mg/d) or lower calcium intakes (<800 mg/d). Dietary iron may be a more important factor in bone mineralization than originally thought and, its combined effect with calcium on BMD warrants exploration in future studies.     

Effects of dietary calcium intake on body weight and prevalence of osteoporosis in early postmenopausal women

BACKGROUND: High calcium intakes seem to be ineffective at reducing bone loss in early postmenopausal women. However, the inverse relation between calcium intake and body weight can attenuate the negative effect of a low dietary calcium intake. OBJECTIVE: The objective was to assess the role of dietary calcium and body mass index (BMI) on osteoporosis, defined according to World Health Organization criteria as a lumbar bone density >2.5 SD below the T score. DESIGN: This was a cross-sectional, retrospective, observational study conducted in 1771 healthy, early postmenopausal women, who were not taking calcium supplements at the first densitometric evaluation. Weekly frequency of dairy food consumption was used to estimate the relative intake of dietary calcium. Total dairy intake was classified into 4 categories by quartile cutoffs. Multiple logistic regression analyses were used to study this sample. RESULTS: BMI and prevalence of overweight showed significant inverse trends with increasing dairy intake. Calcium intake was not associated with osteoporosis when overweight was not considered. However, when overweight was considered in the analysis, women with the lowest calcium intake were more likely to have osteoporosis (odds ratio: 1.46; 95% CI: 1.12, 1.89; P = 0.008) than were women with the highest calcium intake. CONCLUSIONS: In early postmenopausal women, a low dietary calcium intake may increase the risk of osteoporosis, but its negative effect can be offset by the greater BMI found in women with a low calcium intake.     

膳食钙、磷以及奶制品对绝经后妇女骨密度的影响

目的探讨膳食中钙、磷以及奶制品的摄入量对骨密度及骨盐含量的影响,为研究骨质疏松的预防提供相关线索和依据。方法在广州市越秀区农林街社区发放传单招募调查对象,并采用自编的结构化标准问卷,对320名广州绝经后妇女的膳食习惯进行调查,并测量其全身、股骨全身、股骨颈、股骨干、大粗隆、Ward’s三角以及腰锥1～4的骨密度和骨量,采用多因素逐步回归分析探讨膳食钙、磷及奶制品对骨盐含量及骨密度的影响。结果 320名调查对象平均57.1岁,平均绝经年限7.3年,平均每天摄入钙、磷及奶制品分别为822 mg、949 mg和126 g,平均全身骨密度为1.054 g/cm2,磷与7个部位的骨密度及骨盐含量呈正相关关系（P〈0.05）。随着磷摄入量增加,全身及腰锥1～4骨密度增加,偏回归系数值分别为0.121和0.184 g.（cm2）-1.g-1.d-1。随着奶制品摄入量增加,股骨全身、股骨干骨密度也相应增加,骨密度偏回归系数值分别为0.686、0.841mg.（cm2）-1.g-1.d-1。钙与全身、股骨全身、股骨颈、大粗隆、股骨干和Ward’s三角的BMC具有正相关性,而在钙与BMD关系中,钙只与股骨全身、大粗隆和股骨干呈正相关性,且每日膳食中每增加100 g钙的摄入量,则股骨全身、大粗隆、股骨干的骨密度相应增加5.3、4.8和7.6 g/cm2。结论增加膳食中钙、磷以及奶制品的摄入量有利于绝经后妇女的骨盐含量及骨密度的提高。     

Lifetime milk consumption and bone mineral density in older women.

This study examined the relationship between lifetime milk consumption both axial and appendicular bone mineral density in 581 postmenopausal White women. Positive significant, graded associations between milk consumption in adulthood and bone mineral density at the spine, total hip, trochanter, intertrochanter, and midradius, but not the ultradistal wrist or femoral neck, were observed. Adolescent milk consumption showed similar, statistically significant associations (spine and midradius). Associations were independent of age, body mass index, years postmenopausal, thiazide, estrogen and alcohol use, smoking, and exercise. Regular milk consumption in youth and adulthood is associated with better bone mineral density at cortical and trabecular sites in elderly women.     

Dietary influences on bone mass and bone metabolism: further evidence of a positive link between fruit and vegetable consumption and bone health?

BACKGROUND: The role of nutritional influences on bone health remains largely undefined because most studies have focused attention on calcium intake. OBJECTIVE: We reported previously that intakes of nutrients found in abundance in fruit and vegetables are positively associated with bone health. We examined this finding further by considering axial and peripheral bone mass and markers of bone metabolism. DESIGN: This was a cross-sectional study of 62 healthy women aged 45-55 y. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry at the lumbar spine and femoral neck and by peripheral quantitative computed tomography at the ultradistal radial total, trabecular, and cortical sites. Bone resorption was calculated by measuring urinary excretion of pyridinoline and deoxypyridinoline and bone formation by measuring serum osteocalcin. Nutrient intakes were assessed by using a validated food-frequency questionnaire; other lifestyle factors were assessed by additional questions. RESULTS: After present energy intake was controlled for, higher intakes of magnesium, potassium, and alcohol were associated with higher total bone mass by Pearson correlation (P < 0.05 to P < 0.005). Femoral neck BMD was higher in women who had consumed high amounts of fruit in their childhood than in women who had consumed medium or low amounts (P < 0.01). In a regression analysis with age, weight, height, menstrual status, and dietary intake entered into the model, magnesium intake accounted for 12.3% of the variation in pyridinoline excretion and 12% of the variation in deoxypyridinoline excretion. Alcohol and potassium intakes accounted for 18.1% of the variation in total forearm bone mass. CONCLUSION: The BMD results confirm our previous work (but at peripheral bone mass sites), and our findings associating bone resorption with dietary factors provide further evidence of a positive link between fruit and vegetable consumption and bone health.     

Relation of ascorbic acid to bone mineral density and self-reported fractures among US adults

Ascorbic acid is an essential nutrient involved in collagen formation, and its deficiency is associated with abnormal bone development. To examine the relation of ascorbic acid to bone mineral density and the prevalence of self-reported fractures, the authors analyzed data collected from 13,080 adults enrolled in the Third National Health and Nutrition Examination Survey (NHANES III) during 1988-1994. Because they identified three-way interactions among smoking, history of estrogen use, and dietary and serum ascorbic acid in postmenopausal women, they analyzed these relations stratified by smoking and estrogen use. Dietary ascorbic acid intake was independently associated with bone mineral density among premenopausal women (p = 0.002). Among men, serum ascorbic acid was associated in a nonlinear fashion with bone mineral density (p < 0.05), and dietary ascorbic acid intake was associated in a nonlinear fashion with self-reported fracture (p = 0.05). Among postmenopausal women without a history of smoking or estrogen use, serum ascorbic acid was unexpectedly associated with lower bone mineral density (p = 0.01). However, among postmenopausal women with a history of smoking and estrogen use, a standard deviation increase in serum ascorbic acid was associated with a 49% decrease in fracture prevalence (p = 0.001). Dietary and serum ascorbic acid measures were associated inconsistently with bone mineral density and self-reported fracture among adult participants in NHANES III.     

Caffeine intake increases the rate of bone loss in elderly women and interacts with vitamin D receptor genotypes.

BACKGROUND: The role of caffeine as a risk factor for bone loss is controversial. OBJECTIVE: Our goals were 1) to compare in both a cross-sectional study and a 3-y longitudinal study the bone mineral density (BMD) of postmenopausal women consuming high or low amounts of caffeine and 2) to study the interaction between caffeine intake, vitamin D receptor (VDR) polymorphism, and BMD in the longitudinal study. DESIGN: The results are derived from cross-sectional measurements of BMD in 489 elderly women (aged 65-77 y) and from longitudinal measurements made in 96 of these women who were treated with a placebo for 3 y. Changes in BMD were adjusted for confounding factors and were compared between groups with either low (< or =300 mg/d) or high (>300 mg/d) caffeine intakes and between the VDR genotype subgroups of the low- and high-caffeine groups. RESULTS: Women with high caffeine intakes had significantly higher rates of bone loss at the spine than did those with low intakes (-1.90 +/- 0.97% compared with 1.19 +/- 1.08%; P = 0.038). When the data were analyzed according to VDR genotype and caffeine intake, women with the tt genotype had significantly (P = 0.054) higher rates of bone loss at the spine (-8.14 +/- 2.62%) than did women with the TT genotype (-0.34 +/- 1.42%) when their caffeine intake was >300 mg/d. CONCLUSIONS: Intakes of caffeine in amounts >300 mg/d ( approximately 514 g, or 18 oz, brewed coffee) accelerate bone loss at the spine in elderly postmenopausal women. Furthermore, women with the tt genetic variant of VDR appear to be at a greater risk for this deleterious effect of caffeine on bone.     

Long-term consumption of isoflavone-enriched foods does not affect bone mineral density, bone metabolism, or hormonal status in early postmenopausal women: a randomized, double-blind, placebo controlled study

BACKGROUND: Osteoporosis is a major health problem. It was hypothesized that isoflavone-containing products may be a potential alternative to hormone replacement therapy for preventing bone loss during the menopausal transition. OBJECTIVE: The objective was to investigate whether the consumption of isoflavone-enriched foods for 1 y affects bone mineral density, bone metabolism, and hormonal status in early postmenopausal women. DESIGN: This was a randomized, double-blind, placebo-controlled, parallel, multicenter trial. Two hundred thirty-seven healthy early postmenopausal women [mean (+/-SD) age of 53 +/- 3 y and time since last menses of 33 +/- 15 mo] consumed isoflavone-enriched foods providing a mean daily intake of 110 mg isoflavone aglycones or control products for 1 y while continuing their habitual diet and lifestyle. Outcome measures included bone mineral density of the lumbar spine and total body, markers of bone formation and bone resorption, hormones, isoflavones in plasma and urine, safety variables, and adverse events. RESULTS: Consumption of isoflavone-enriched products did not alter bone mineral density of the lumbar spine and total body or markers of bone formation and bone resorption. Hormone concentrations did not differ between the isoflavone and control groups. Consumption of isoflavone-enriched products resulted in increased isoflavone concentrations in plasma and urine, whereas control products did not. This finding indicated good compliance with treatment. Subgroup analysis did not support an effect of equol phenotype on bone density. The intervention had no effect on a range of safety variables and reported adverse events. CONCLUSION: Consumption of foods containing 110 mg/d of soy isoflavone aglycone equivalents for 1 y did not prevent postmenopausal bone loss and did not affect bone turnover in apparently healthy early postmenopausal white women. This trial was registered at clinicaltrials.gov as NCT00301353.