Effect of long-term intervention of soy isoflavones on bone mineral density in women: a meta-analysis of randomized controlled trials

Isoflavone intervention and its impact on bone mineral density in postmenopausal women: a systematic review and meta-analysis of randomized controlled trials

Due to estrogen deficiency, postmenopausal women may suffer from an imbalance in bone metabolism that leads to bone fractures. Isoflavones, a type of phytoestrogen, have been suggested to improve bone metabolism and increase bone mass. Therefore, isoflavones are increasingly recognized as a promising natural alternative to hormone replacement therapy for postmenopausal women who face a heightened risk of osteoporosis and are susceptible to bone fractures.

PURPOSE

This study aimed to evaluate the efficacy of isoflavone interventions on bone mineral density (BMD) in postmenopausal women by means of systematic review and meta-analysis.

METHODS

The electronic database searches were performed on PubMed, Embase, Scopus, and Cochrane Library databases, covering literature up to April 20, 2023. A random-effects model was used to obtain the main effect estimates, with a mean difference (MD) and its 95% confidence interval (CI) as the effect size summary. The risk of bias assessment was conducted using the Risk of Bias 2 (RoB2) tool.

RESULTS

A total of 63 randomized controlled trials comparing isoflavone interventions (n = 4,754) and placebo (n = 4,272) were included. The results indicated that isoflavone interventions significantly improved BMD at the lumbar spine (MD = 0.0175 g/cm2; 95% CI, 0.0088 to 0.0263, P < 0.0001), femoral neck (MD = 0.0172 g/cm2; 95% CI, 0.0046 to 0.0298, P = 0.0073), and distal radius (MD = 0.0138 g/cm2; 95% CI, 0.0077 to 0.0198, P < 0.0001) in postmenopausal women. Subgroup analysis showed that the isoflavone intervention was effective for improving BMD when the duration was ≥ 12 months and when the intervention contained genistein of at least 50 mg/day.

CONCLUSION

This systematic review and meta-analysis suggests that isoflavone interventions, especially those containing genistein of at least 50 mg/day, can effectively enhance BMD in postmenopausal women.

Phytoestrogens and Health Effects

Phytoestrogens are literally estrogenic substances of plant origin. Although these substances are useful for plants in many aspects, their estrogenic properties are essentially relevant to their predators. As such, phytoestrogens can be considered to be substances potentially dedicated to plant-predator interaction. Therefore, it is not surprising to note that the word phytoestrogen comes from the early discovery of estrogenic effects in grazing animals and humans. Here, several compounds whose activities have been discovered at nutritional concentrations in animals and humans are examined. The substances analyzed belong to several chemical families, i.e., the flavanones, the coumestans, the resorcylic acid lactones, the isoflavones, and the enterolignans. Following their definition and the evocation of their role in plants, their metabolic transformations and bioavailabilities are discussed. A point is then made regarding their health effects, which can either be beneficial or adverse depending on the subject studied, the sex, the age, and the physiological status. Toxicological information is given based on official data. The effects are first presented in humans. Animal models are evoked when no data are available in humans. The effects are presented with a constant reference to doses and plausible exposure.

Fracture Risk in Vegetarians and Vegans: the Role of Diet and Metabolic Factors

PURPOSE OF REVIEW

There is strong evidence that poor dietary intake of certain micro- and macro-nutrients can negatively affect bone health. It is unclear if diet is the primary culprit for poor bone health in the vegan population.

RECENT FINDINGS

Plant-based diets are gaining public interest since they may improve metabolic health. Studies that examine vegetarians and vegans together show a lower bone mineral density (BMD), but not always increased fracture risk compared to omnivores. However, vegans consistently have higher risk of fracture at multiple bone sites, especially at the hip. There is higher fracture risk in vegans which may be due to calcium and vitamin D intake, as well as amount of dietary protein and quality. Other nutrients (B vitamins, Se, Zn, Fe, iodine) or physiological factors (lower body mass index, microbiome, or endocrine profile) may also play a role but have not been examined and require further study.

The Role of Soy Isoflavones in the Prevention of Bone Loss in Postmenopausal Women: A Systematic Review with Meta-Analysis of Randomized Controlled Trials

The aim of the report was to determine the effects of soy isoflavones on lumbar spine, femoral neck, and total hip bone mineral density (BMD) in menopausal women. MEDLINE (PubMed), EMBASE, and Cochrane Library databases were searched for articles published in English during 1995–2019. Studies were identified and reviewed for inclusion and exclusion eligibility. Weighted mean differences (WMD) were calculated for each study and were pooled by using the random effects model. Eighteen randomized controlled trials were selected for meta-analysis. Different types of soy phytoestrogens, i.e., genistein extracts, soy isoflavones extracts, soy protein isolate, and foods containing diverse amounts of isoflavones were used in the studies. The analysis showed that daily intake of 106 (range, 40–300) mg of isoflavones for 6–24 months moderately but statistically significantly positively affects BMD, compared with controls: lumbar spine WMD = 1.63 (95% CI: 0.51 to 2.75)%, p = 0004; femoral neck WMD = 1.87 (95% CI: 0.14 to 3.60)%, p = 0.034; and total hip WMD = 0.39 (95% CI: 0.08 to 0.69)%, p = 0.013. Subgroups analyses indicated that the varying effects of isoflavones on BMD across the trials might be associated with intervention duration, racial diversity (Caucasian, Asian), time after menopause, form of supplements (especially genistein), and dose of isoflavones. Our review and meta-analysis suggest that soy isoflavones are effective in slowing down bone loss after menopause.

A novel extraction method enhanced the osteogenic and anti-osteoporosis effect of tea extract without any hepatotoxicity in ovariectomized rats

Tea (Camellia sinensis) has several reported health benefits, including that on bone health attributed to catechins of which the most abundant is epigallocatechin-3-gallate (EGCG). However, several preclinical and clinical studies raise safety concerns about EGCG in tea extract causing acute liver failure. Tea also contains kaempferol, albeit scanty, and it has hepatoprotective and osteogenic effects. Here, we utilized a novel extraction procedure of acid hydrolysis to enhance the osteogenic effect of tea extract while reducing its hepatotoxicity. The resultant extract (USKECSE) has a ~40-fold increase in kaempferol and a 2.5-fold reduction in EGCG content compared with the hydroethanolic extract (USCSE). In a female Sprague Dawley (SD) rat femur osteotomy model, USKECSE (100 mg/kg) but not USCSE promoted bone regeneration. In a rat postmenopausal osteoporosis model induced by bilateral ovariectomy (OVX), USKECSE through an osteogenic mechanism maintained bone mass, strength, and microarchitecture to the levels of ovary-intact rats with no hepatotoxic effect. After a single oral dose (100 mg/kg) of USKECSE to adult rats, kaempferol was detectable for 48 hours, suggesting its significant absorption and distribution in plasma. Peak kaempferol concentration in plasma (C_max) was 483 ng/ml (2 μM), and at this concentration, kaempferol induces osteoblast differentiation. USKECSE had no genotoxicity, and its safety index assessed by preclinical toxicity studies, including safety pharmacology, was >20-fold. Taken together, we report a novel extraction process that enhanced the osteogenicity and concomitantly reduced hepatotoxicity of tea extract with significant kaempferol bioavailability and a favorable systemic safety profile. Based on these data, we propose assessing the USKECSE effect for postmenopausal osteoporosis treatment.

Associations of Dietary Intakes of Calcium, Magnesium, and Soy Isoflavones With Bone Fracture Risk in Men: A Prospective Study

The role of dietary factors in osteoporotic fractures in men is underinvestigated. We examined the associations of dietary intakes of calcium, magnesium, and soy isoflavones with risk of osteoporotic fractures in the Shanghai Men's Health Study. Included in this prospective study were 61,025 men aged 40 to 74 years at study enrollment (2002–2006). The cohort was followed up via in‐person surveys for occurrence of bone fractures, major diseases, and survival status. Multivariable Cox regression was applied to evaluate the associations of variables under study (ie, dietary intakes of calcium, magnesium, and soy isoflavones) with incidence of osteoporotic and non‐osteoporotic fractures, measured by hazard ratio (HR) and 95% confidence interval (CI). During a median follow‐up of 9.5 years, 1.2% and 3.4% of participants experienced osteoporotic or non‐osteoporotic fractures, respectively. Dietary calcium intake was inversely associated with risk of osteoporotic fractures with adjusted HRs of 0.78 (95% CI 0.60–1.02) and 0.27 (95% CI 0.13–0.56), respectively, for intake levels of 401 mg/d and >1000 mg/d versus ≤400 mg/d. Higher magnesium intake was associated with increased risk of osteoporotic fractures after adjusting for dietary calcium intake, with HRs of 1.27 (95% CI 0.97–1.66) and 2.21 (95% CI 1.08–4.50), respectively, for intakes of 251 mg/d and >450 mg/d versus intake ≤250 mg/d. High soy isoflavone intake was associated with a 25% reduction of osteoporotic fracture risk (HR = 0.73, 95% CI 0.56–0.97 for soy isoflavone intake >45.2 mg/d versus <21.7 mg/d). Dietary intakes of calcium, magnesium, or soy isoflavones were unrelated to the risk of non‐osteoporotic fractures. Our study added to the evidence that dietary calcium intake was inversely associated with a reduced risk of osteoporotic fractures in a dose–response fashion, while high magnesium intake was associated with an increased risk. Our study also revealed a novel association between higher soy isoflavone consumption and osteoporotic fractures in men. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Role of diet in osteoporosis incidence: Umbrella review of meta-analyses of prospective observational studies

An umbrella review and meta-analysis were conducted to summarize evidence for the association between dietary factors and the incidence of osteoporosis in adults. Only systematic reviews or meta-analyses were eligible for this study. Two researchers independently performed reading, data extraction, and quality evaluation of the included literature. The outcomes included in this study were all associated with osteoporosis, including osteoporotic fractures and low bone density. A total of 54 studies were included in this study, with 83 adjusted hazard ratios on diet, dairy group (n = 13), alcohol (n = 2), tea (n = 6), coffee (n = 3), micronutrient (n = 31), dietary pattern (n = 21), and foods (n = 7) regarding the incidence of osteoporosis. Grades of Recommendations, Assessment, Development, and Evaluation (GRADE) quality assessment method was used in this study. The high, medium, low and very low quality studies accounted for 27.7, 41, 21.7 and 9.6% of this study, respectively. Based on the included literature studies in this umbrella review, it was found that dietary factors have a relevant impact on the incidences of human osteoporosis, appropriate consumption of dairy products, vegetables, fruits, and micronutrients, as well as reduced intake of alcohol and coffee, can reduce the risk of osteoporosis.

Urinary Isoflavones Levels in Relation to Serum Thyroid Hormone Concentrations in Female and Male Adults in the U.S. General Population

Isoflavones are phytoestrogens found in plant-based foods and nutritional supplements. Experimental studies show a positive association between isoflavones and hypothyroidism, but epidemiological findings are conflicting. We used multivariable linear regression to examine the association between urinary isoflavone concentrations and serum thyroid hormone concentrations in the National Health and Nutrition Examination Survey (2007-2010). In this study, we found that Daidzein and O-DMA associations with free T4 were stronger among women: a 10-fold increase in daidzein was associated with a 3.2% (95% CI: 1.9%, 4.5%) increase in women and a 0.6% (95% CI: -1.7%, 0.6%) decrease in men and a 10-fold increase in O-DMA was related to a 2.0% (95% CI: 1.1%, 2.9%) increase in women and a 0.3% (95% CI: -1.2%, 0.5%) decrease in men. In this study, selected urinary isoflavone concentrations were associated with serum thyroid hormone concentration in a sex-dependent fashion.

Botanicals in Postmenopausal Osteoporosis

Osteoporosis is a systemic bone disease characterized by reduced bone mass and the deterioration of bone microarchitecture leading to bone fragility and an increased risk of fractures. Conventional anti-osteoporotic pharmaceutics are effective in the treatment and prophylaxis of osteoporosis, however they are associated with various side effects that push many women into seeking botanicals as an alternative therapy. Traditional folk medicine is a rich source of bioactive compounds waiting for discovery and investigation that might be used in those patients, and therefore botanicals have recently received increasing attention. The aim of this review of literature is to present the comprehensive information about plant-derived compounds that might be used to maintain bone health in perimenopausal and postmenopausal females.

The effects of phytoestrogens on postmenopausal health

Phytoestrogens are a group of non-steroidal polyphenolic plant-based substances, commonly used for the treatment of menopause-related conditions. They have both genomic and non-genomic effects, displaying weak affinity for estrogen receptors (ER) and preferentially binding to ER-B over ER-A. However, evidence for the benefits of phytoestrogen consumption has been limited. We conducted a review of recent literature, focusing on systematic reviews and meta-analyses reporting on postreproductive health effects of phytoestrogens. While many trials concerning dietary and supplementary phytoestrogens have been conducted, evidence of clinical efficacy is heterogeneous and inconclusive. There appears to be reduction in the vasomotor symptoms of menopause with phytoestrogen intake; however, it is likely small and slow in onset. Phytoestrogens also appear to improve bone mineral density and markers of cardiovascular risk; however, there is inadequate research regarding long-term outcomes. There appear to be no harmful effects of phytoestrogens on breast, endometrial cancer or colorectal cancer and phytoestrogens intake may in fact be protective. Research regarding the effect of phytoestrogens on cognition is mixed, with most studies reporting no significant association. Overall, individual variations in the metabolism of phytoestrogens and age-related genomic effects may account for the considerable variability in the measured effects of phytoestrogens.

The Diverse Efficacy of Food-Derived Proanthocyanidins for Middle-Aged and Elderly Women

Middle-aged and elderly women are affected by various symptoms and diseases induced by estrogen deficiency. Proanthocyanidins, widely present in many kinds of fruits and berries, have many beneficial effects, such as antioxidative, anti-inflammatory, and antimicrobial activities. We researched the effects of proanthocyanidins for middle-aged and elderly women, finding that it has been revealed in many clinical trials and cohort studies that proanthocyanidins contribute to the prevention of cardiovascular disease, hypertension, obesity, cancer, osteoporosis, and urinary tract infection, as well as the improvement of menopausal symptoms, renal function, and skin damage. Thus, proanthocyanidins can be considered one of the potent representatives of complementary alternative therapy.

Dietary protein and bone health: towards a synthesised view

The present paper reviews published literature on the relationship between dietary protein and bone health. It will include arguments both for and against the anabolic and catabolic effects of dietary protein on bone health. Adequate protein intake provides the amino acids used in building and maintaining bone tissue, as well as stimulating the action of insulin-like growth factor 1, which in turn promotes bone growth and increases calcium absorption. However, the metabolism of dietary sulphur amino acids, mainly from animal protein, can lead to increased physiological acidity, which may be detrimental for bone health in the long term. Similarly, cereal foods contain dietary phytate, which in turn contains phosphate. It is known that phosphate consumption can also lead to increased physiological acidity. Therefore, cereal products may produce as much acid as do animal proteins that contain sulphur amino acids. The overall effect of dietary protein on physiological acidity, and its consequent impact on bone health, is extremely complex and somewhat controversial. The consensus is now moving towards a synthesised approach. Particularly, how anabolic and catabolic mechanisms interact; as well as how the context of the whole diet and the type of protein consumed is important.

Effects of isoflavone interventions on bone mineral density in postmenopausal women: a systematic review and meta-analysis of randomized controlled trials

Isoflavones have a structure similar to 17β-estradiol, so they may be useful to postmenopausal women in preventing bone loss related to estrogen deficiency. The present study integrated the findings from 63 randomized controlled trials and found that isoflavone interventions may have benefits in the prevention and treatment of menopause-related osteoporosis.

PURPOSE

This study aimed to determine the efficacy of isoflavone interventions on bone density outcomes and the safety of isoflavone interventions in postmenopausal women by means of systematic review and meta-analysis.

METHODS

A systematic search was performed on three databases (PubMed, Scopus, and Cochrane Library). Included studies were limited to randomized controlled trials (RCTs) assessing the effects of isoflavone intervention on bone mineral density (BMD) in postmenopausal women. Mean difference (MD) in BMD or relative risk for adverse outcomes was used as a summary effect measure; pooled-effect estimates were calculated using a random-effects model.

RESULTS

A total of 63 RCTs, involving 6427 postmenopausal women, were included in the meta-analysis. Statistically significant differences in BMD at the last follow-up visit between the two groups (isoflavones vs. control) were found at the lumbar spine (MD = 21.34 mg/cm², 95% CI = 8.21 to 34.47 mg/cm², p = 0.001), the femoral neck (MD = 28.88 mg/cm², 95% CI = 15.05 to 42.71 mg/cm², p < 0.0001), and the distal radius (MD = 19.27 mg/cm², 95% CI = 5.65 to 32.89 mg/cm², p = 0.006). The positive effects in improved BMD were primarily associated with two formulations, i.e., genistein 54 mg/day and ipriflavone 600 mg/day. Isoflavone interventions were generally safe and well tolerated.

CONCLUSION

Isoflavone interventions, genistein (54 mg/day) and ipriflavone (600 mg/day) in particular, have beneficial effects on BMD outcomes and are safe in postmenopausal women. They may be considered as a complementary or alternative option in the prevention and treatment of menopause-related osteoporosis.

Isoflavone combined with exercise on bone mineral density in postmenopausal women: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

This meta-analysis of randomized control trials (RCTs) aimed to evaluate the effects of isoflavones supplementation combined with exercise training on bone mineral density (BMD) in postmenopausal women.

METHODS

Two reviewers did a complete search of two electronic database (Medline, PubMed) records up to January 31, 2019. Risk of bias was classified based on the Cochrane Collaboration tool. The pooled standard mean difference (SMD) combined with 95% confidence interval (CI) was used as the effect size of BMD values.

RESULTS

A total of four RCTs with 609 participants were included for meta-analysis. The BMD did not differ significantly between isoflavone supplementation combined with exercise training group and placebo group (sub-whole body: SMD = 0.00, 95% CI, -0.23 to 0.24; lumbar spine: SMD = 0.15, 95% CI, -0.30 to 0.60; total hip: SMD = 0.05, 95% CI, -0.18 to 0.298; femoral neck: SMD = 0.10, 95% CI, -0.23 to 0.43; trochanter: SMD = 0.09, 95% CI, -0.14 to 0.33; ward's triangle: SMD = -0.03, 95% CI, -0.24 to 0.30). In addition, combined intervention did not provide additive effects on BMD improvements compared with exercise or isoflavone supplementation alone. The trials included in this meta-analysis were small and some had methodological limitations.

CONCLUSION

The present meta-analysis reveals that isoflavone supplements combined with exercise training do not significantly increase BMD in postmenopausal women. In addition, combined intervention does not provide additive effects on BMD improvements compared with exercise or isoflavone supplementation alone.

Osteoporosis and the Potential of Cell-Based Therapeutic Strategies

Osteoporosis, the most common chronic metabolic bone disease, is characterized by low bone mass and increased bone fragility. Nowadays more than 200 million individuals are suffering from osteoporosis and still the number of affected people is dramatically increasing due to an aging population and longer life, representing a major public health problem. Current osteoporosis treatments are mainly designed to decrease bone resorption, presenting serious adverse effects that limit their safety for long-term use. Numerous studies with mesenchymal stem cells (MSCs) have helped to increase the knowledge regarding the mechanisms that underlie the progression of osteoporosis. Emerging clinical and molecular evidence suggests that inflammation exerts a significant influence on bone turnover, thereby on osteoporosis. In this regard, MSCs have proven to possess broad immunoregulatory capabilities, modulating both adaptive and innate immunity. Here, we will discuss the role that MSCs play in the etiopathology of osteoporosis and their potential use for the treatment of this disease.

Impact of calcium, vitamin D, vitamin K, oestrogen, isoflavone and exercise on bone mineral density for osteoporosis prevention in postmenopausal women: a network meta-analysis

The aim of this network meta-analysis is to compare bone mineral density (BMD) changes among different osteoporosis prevention interventions in postmenopausal women. We searched MEDLINE, Embase and Cochrane Library from inception to 24 February 2019. Included studies were randomised controlled trials (RCT) comparing the effects of different treatments on BMD in postmenopausal women. Studies were independently screened by six authors in three pairs. Data were extracted independently by two authors and synthesised using Bayesian random-effects network meta-analysis. The results were summarised as mean difference in BMD and surface under the cumulative ranking (SUCRA) of different interventions. A total of ninety RCT (10 777 participants) were included. Ca, vitamin D, vitamin K, oestrogen, exercise, Ca + vitamin D, vitamin D + vitamin K and vitamin D + oestrogen were associated with significantly beneficial effects relative to no treatment or placebo for lumbar spine (LS). For femoral neck (FN), Ca, exercise and vitamin D + oestrogen were associated with significantly beneficial intervention effects relative to no treatment. Ranking probabilities indicated that oestrogen + vitamin D is the best strategy in LS, with a SUCRA of 97·29 % (mean difference: +0·072 g/cm2 compared with no treatment, 95 % credible interval (CrI) 0·045, 0·100 g/cm2), and Ca + exercise is the best strategy in FN, with a SUCRA of 79·71 % (mean difference: +0·029 g/cm2 compared with placebo, 95 % CrI –0·00093, 0·060 g/cm2). In conclusion, in postmenopausal women, many interventions are valuable for improving BMD in LS and FN. Different intervention combinations can affect BMD at different sites diversely.

Effect of whole soy and isoflavones daidzein on bone turnover and inflammatory markers: a 6-month double-blind, randomized controlled trial in Chinese postmenopausal women who are equol producers

BACKGROUND

Human studies have demonstrated the beneficial effects of soy or isoflavones on bone metabolism. However, conflicting data remain. Equol is the intestinal metabolite of the isoflavone daidzein. The health benefits of soy are more pronounced in equol producers than those not producing equol. This 6-month randomized controlled trial aimed to examine the effect of whole soy (soy flour) and purified daidzein on bone turnover markers (BTMs) in Chinese postmenopausal women who are equol producers.

METHODS

A total of 270 eligible women were randomized to either one of the three isocaloric supplements as follows: 40 g soy flour (whole soy group), 40 g low-fat milk powder + 63 mg daidzein (daidzein group), or 40 g low-fat milk powder (placebo group) given as a solid beverage daily for 6 months. The following fasting venous samples were collected at the baseline and end of the trial to analyze BTMs: serum cross-linked C-telopeptides of type I collagen, bone-specific alkaline phosphatase, osteocalcin, procollagen type I N-terminal propeptide, and 25(OH)D₃. Inflammation-related biomarkers, such as serum interleukin-6, tumor necrosis factor-alpha, C-reactive protein, transferrin, and homocysteine, were also tested to explore potential mechanisms.

RESULTS

A total of 253 subjects validly completed the study protocol. Urinary isoflavones suggested a good compliance to the treatments. Intention-to-treat and per-protocol analyses indicated no significant difference in the 6-month or percentage changes in the parameters of bone metabolism and inflammatory markers among the three treatment groups.

CONCLUSIONS

Whole soy and purified daidzein at provided dosages exhibited no significant effect on the bone metabolism and inflammation levels among Chinese equol-producing postmenopausal women.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT01270737.

Soy isoflavones prevent bone resorption and loss, a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Osteoporosis is a common bone disease characterized by reduced bone mass resulting from continuous bone resorption.

METHODS

PubMed, Scopus, and Embase were searched to find published trials on the effect of soy isoflavones on bone mineral density (BMD) and bone turnover markers (bone-specific alkaline phosphatase, osteocalcin, osteoprotegerin, pyridinoline, deoxypyridinoline, C-telopeptide, and N-telopeptide). Random-effects inverse-variance model was used to calculate the pooled effects.

RESULTS

A total of 5313 articles were found, screened, and assessed for eligibility, and finally 52 trials were included in the meta-analysis. Consumption of soy isoflavones caused significant improvement in BMD of lumbar spine (mean difference (MD) = 0.76%; 95% CI: 0.09, 1.42%; p = 0.03), hip (MD = 0.22%; 95% CI: 0.02, 0.42%; p = 0.04), and femoral neck (MD = 2.27%; 95% CI: 1.22, 3.31%; p < 0.001). Subgroup analysis showed that in all 3 sites, the improvement was significant in normal weight subjects and interventions longer than a year, although trial location and dosage were also factors influencing isoflavones' impact on BMD. Among markers of bone turnover, osteoprotegerin (MD = 5.79; 95% CI: 3.08, 8.51 pg/ml; p < 0.001), pyridinoline (MD = -5.13; 95% CI: -7.76, -2.50 nmol/mmol; p < 0.001), and C-telopeptides (MD = -0.08; 95% CI: -0.16, -0.00 ng/ml; p = 0.04) were favorably affected by isoflavones while osteocalcin and bone alkaline phosphatase did not change. Subgroup analysis of bone markers showed that in overweight/obese individuals and dosages <90 mg/day, isoflavones are more effective.

CONCLUSIONS

Soy isoflavones prevent osteoporosis-related bone loss in any weight status or treatment duration. They increase BMD in normal weight subjects and diminish bone resorption in overweight/obese individuals. Although bone resorption may be decelerated over short-term isoflavone consumption, periods longer than a year are probably needed to affect BMD. Isoflavones also appear benefits on bone in any dose or subjects' ethnicity.

Soy Food Consumption, Exercise, and Body Mass Index and Osteoporotic Fracture Risk Among Breast Cancer Survivors: The Shanghai Breast Cancer Survival Study

Background

Breast cancer survivors have a high incidence of osteoporosis-related fractures; the associated factors are understudied. We investigated incidence of bone fracture and its associations with soy food consumption, exercise, and body mass index among breast cancer survivors.

Methods

This prospective study included 4139 stage 0–III breast cancer patients and 1987 pre-/perimenopausal and 2152 postmenopausal patients. Fractures were assessed at 18 months and at 3, 5, and 10 years after cancer diagnosis. Osteoporotic fractures were defined as fractures caused by falls from standing height and at sites associated with osteoporosis. Exercise and soy isoflavone intake were assessed at 6 and 18 months postdiagnosis. Weight and height were measured at baseline. Lifetable and Cox regression analyses were employed. All statistical tests were two sided.

Results

The 10-year incidence for osteoporotic fractures was 2.9% and 4.4% for pre-/perimenopausal and postmenopausal patients, respectively. High soy isoflavone intake was associated with reduced risk among pre-/perimenopausal patients (hazard ratio [HR] = 0.22, 95% confidence interval [CI] = 0.09 to 0.53, for soy isoflavone mg/d ≥56.06 vs <31.31; P_trend < .001) but not among postmenopausal patients (P_interaction < .01). Overweight (vs normal weight) was a risk factor for pre-/perimenopausal patients (HR = 1.81, 95% CI = 1.04 to 3.14) but not for postmenopausal patients (HR = 0.67, 95% CI = 0.43 to 1.03; P_interaction = .01). Exercise was inversely associated with osteoporotic fractures in postmenopausal patients (HR = 0.56, 95% CI = 0.33 to 0.97, for metabolic equivalents hours ≥12.6 vs <4.5) following a dose-response pattern (P_trend = .035), an association not modified by menopausal status.

Conclusions

Our findings, especially the novel association of soy food intake with osteoporotic fractures in breast cancer survivors, if confirmed, can help guide future strategies for fracture risk reduction in this vulnerable population.

Phytoestrogens and Their Health Effect

Phytoestrogens have structures that are very similar to endogen estradiol derived from plants. Phytoestrogens sources are widespread in Asian regions including in Indonesia. Its have health benefits including reproductive health, heart health, a role in weight loss, hormone-dependent tumours, bone and skin health, and the immune system. This review aimed to provide information on phytoestrogens' effect on human health.

Phytoestrogens and Their Health Effect

Phytoestrogens have structures that are very similar to endogen estradiol derived from plants. Phytoestrogens sources are widespread in Asian regions including in Indonesia. Its have health benefits including reproductive health, heart health, a role in weight loss, hormone-dependent tumours, bone and skin health, and the immune system. This review aimed to provide information on phytoestrogens' effect on human health.

A systematic review and meta-analysis of the effects of isoflavone formulations against estrogen-deficient bone resorption in peri- and postmenopausal women

Background: Age-related estrogen deficiency leads to accelerated bone resorption. There is evidence that, through selective estrogen receptor modulation, isoflavones may exert beneficial effects against estrogen-deficient bone loss. Isoflavone aglycones show higher bioavailability than their glycosidic counterparts and thus may have greater potency.Objective: To summarize evidence, we executed a systematic review and meta-analysis examining isoflavone therapies and bone mineral density (BMD) loss in peri- and postmenopausal women.Design: We systematically searched EMBASE and PubMed for randomized controlled trials (RCTs) evaluating isoflavone therapies for treating BMD loss at the lumbar spine and femoral neck in estrogen-deficient women. Separate meta-analyses were carried out with the use of random-effects models for the lumbar spine and femoral neck for all studies providing isoflavones as aglycones.Results: Twenty-six RCTs (n = 2652) were included in the meta-analysis. At the lumbar spine, isoflavone treatment was associated with a significantly (P < 0.00001) higher weighted mean difference (WMD) of BMD change of 0.01 (95% CI: 0.01, 0.02) than the control. For the femoral neck (18 RCTs, n = 1604), isoflavone treatment showed a significantly (P < 0.01) higher WMD of BMD change of 0.01 (95% CI: 0.00, 0.02) compared with the control. When isolating studies that provide isoflavone aglycones in their treatment arm, the average effect was further significantly increased at the spine (5 RCTs, n = 682) to 0.04 (P < 0.00001; 95% CI: 0.02, 0.05) and femoral neck (4 RCTs, n = 524) to 0.03 (P < 0.05; 95% CI: 0.00, 0.06) compared with the control. This protective effect against bone loss disappeared when only studies with formulations comprising predominantly isoflavone glycosides were included.Conclusions: Isoflavone treatments exert a moderately beneficial effect against estrogen-deficient bone loss in women. The effect appears dependent on whether isoflavone treatments are in aglycone form; we conclude that beneficial effects against bone loss may be enhanced for isoflavone aglycones.

New horizons in treatment of osteoporosis

BACKGROUND

Prevalence of osteoporosis is increasing both in developed and developing countries. Due to rapid growth in the burden and cost of osteoporosis, worldwide, it seems reasonable to focus on the reduction of fractures as the main goal of treatment. Although, efficient pharmacological agents are available for the treatment of osteoporosis, there still remains a need to more specific drugs with less adverse effects.

MAIN BODY

This review article provides a brief update on the pathogenesis, presenting current pharmacological products approved by the US Food and Drug Administration (FDA) or Europe, and also newer therapeutic agents to treat osteoporosis according to the clinical trial data available at PubMed, UpToDate, International Osteoporosis Foundation (IOF), and clinical practice guidelines. As well, the effect of combination therapy and recommendations for future research will be further discussed.

SHORT CONCLUSION

The use of current antiresorptive and anabolic agents alone or in combinations for the treatment of osteoporosis entails several limitations. Mainly, their efficacy on non-vertebral fracture reduction is lower than that observed on vertebral fracture. In addition, they have potential adverse events on long time usage. Development of newer agents such as cathepsin k inhibitor and strontium ranelate not only have increased the available options for treating osteoporosis, but also have opened doors of opportunity to improvements in the effective treatment. However, the high cost of new agents have restricted their usage in selective patients who are at high risk of fracture or whom failed response to first line treatment options. Thus, personalized medicine should be considered for future evaluation of genetic risk score and also for environmental exposure assessment. In addition to permanent attention to early diagnosis of osteoporosis and understanding of the pathophysiology of osteoporosis for novel approach in drug discovery, there seems a need to more well-designed clinical trials with larger sample sizes and longer duration on current as well as on newer agents. Also, continuous research on plant-derived components as the source of discovering new agents, and conducting more clinical trials with combination of two or more synthetic drugs, plants, or drug-plant for the treatment of osteoporosis are recommended. Summary of treatment modalities for osteoporosis.

Short-Term Isoflavone Intervention in the Treatment of Severe Vasomotor Symptoms after Surgical Menopause: A Case Report and Literature Review

Isoflavones are soy phytoestrogens that potentially exert various favorable effects in postmenopausal women, for example, alleviating vasomotor episodes, attenuating bone loss, and stimulating vaginal epithelial maturation. There has, however, been lack of consensus regarding those therapeutic effects. Most clinical studies of isoflavones have been conducted with women who had undergone natural menopause, but not those who had undergone surgical menopause. This study reports on a 51-year-old woman who presented with severe vasomotor episodes after undergoing a hysterectomy and a bilateral oophorectomy due to hypermenorrhea secondary to myoma uteri. She refused hormone therapy due to fear of adverse drug reactions so was treated with oral soy isoflavones (two capsules twice daily, equivalent to at least 100 mg daily dose) for 8 weeks. The number and severity of hot flushes and her menopause-specific quality of life dramatically improved from baseline values. The serum bone resorption marker (beta C-telopeptide) decreased markedly, while vaginal epithelial maturation improved slightly, suggesting the potential of isoflavones in attenuating bone loss and stimulating vaginal maturation. The intervention did not adversely affect the hormonal profile (FSH, LH, and estradiol) and liver or renal functions. Thus, isoflavones could be an option for women experiencing severe vasomotor episodes after surgical menopause.

Association between dietary intake of flavonoid and bone mineral density in middle aged and elderly Chinese women and men

SUMMARY

This large cross-sectional study examined the associations of dietary intakes of total flavonoids and their subtypes with bone density in women and men. We found that greater flavonoid intake was associated with higher bone density in women but not in men.

INTRODUCTION

Studies in vitro and in animal models suggest a potential effect of flavonoids on bone health. Few studies have examined the association between the habitual intake of flavonoids and bone mineral density (BMD) in humans.

METHODS

The cross-sectional study recruited 2,239 women and 1,078 men. A semiquantitative food frequency questionnaire was administered in face-to-face interviews to assess habitual dietary flavonoid intake using food composition databases. BMD was measured over the whole body (WB) and in the femoral neck (FN) and lumbar spine (LS) by dual-energy X-ray absorptiometry (DXA).

RESULTS

After adjusting for covariates, women who consumed higher total flavonoids, and the subtypes of flavonols, flavan-3-ols, flavones, and proanthocyanidins tended to have greater BMD at the WB, LS, and FN (all P-trend < 0.05). Women in the highest (vs. the lowest) quartile of total flavonoids intake had 0.020 (1.91 %), 0.021 (2.51 %), and 0.013 (1.99 %) g/cm(2) greater BMD at the whole body, LS, and FN, respectively. For the subtypes of flavonoids, the corresponding differences in BMD (in g/cm(2)) were 0.012-0.021 (flavan-3-ols), 0.013-0.020 (flavonols), 0.016-0.019 (flavones), and 0.014-0.016 (proanthocyanidins), respectively. A higher intake of flavonones was associated with a greater BMD at the whole body (P-trend 0.041) and the FN (P-trend 0.022). In men, there were no significant positive associations between the consumption of total flavonoids and the subclasses and BMD at any sites.

CONCLUSION

Dietary flavonoids intake was positively associated with BMD in women. Further large studies are needed to clarify this issue in men.

Therapeutic effects of isoflavones on impaired salivary secretion

Dry mouth, which is characterized by decreased salivation, has a number of causes; the involvement of estrogen has been suggested as symptoms typically develop in middle-aged females. However, there is a lack of consensus regarding the treatment of this condition. Soy isoflavones, a subgroup of flavonoids, are abundantly found in the soy germ. They are thought to exert a number of effects by specifically binding to estrogen receptors due to their structural similarity to estrogen. Recently, soy isoflavones have been found to exert antioxidant effects, ameliorating disorders caused by reactive oxygen/free radicals. Based on these observations, the effects of soybean isoflavones on impaired salivary secretion were studied in patients with dry mouth. Soy isoflavone aglycones were administered at 25 mg per day to 15 subjects with an average age of 67.9 ± 8.0 years for 2 months, and salivary secretion was analyzed. The results showed a significant improvement based on the saliva flow rate and self-completed questionnaire, thus suggesting the usefulness of isoflavones in improving the symptoms of salivary gland hypofunction.

Medicinal herbs in the prevention and treatment of osteoporosis

Osteoporosis is a common disease with wide prevalence, especially in the elderly population. Osteoporosis induced fractures not only decrease the patient's life quality, but also cause heavy financial burden to the society. Although current medications for osteoporosis are effective, numerous adverse effects have been observed accompanying their clinical applications. Effective prevention and therapy strategies with high safety are critical, which benefit both individual patients and the whole society. Traditional Chinese medicines have been used for thousands of years to treat bone related diseases in China and a number of modern preparations have been developed that are currently commercially available. In addition, several medicinal herbs demonstrated therapeutic effects against osteoporosis in animal models. This paper reviewed the anti-osteoporotic effects of traditional Chinese formulas, medicinal herbs and bioactive constituents based on clinical trials and in vivo animal studies. Due to the lack of rigorous studies to compare the effectiveness with conventional interventions, traditional formulas are recommended as alternative medications or supplements to treat osteoporosis at the current stage. Although there are abundant natural resources with anti-osteoporotic effects, either in the form of medicinal herbs or bioactive components, much work need to be accomplished before they are developed into potential drugs.

Protein intake and lumbar bone density: the Multi-Ethnic Study of Atherosclerosis (MESA)

Dietary protein has been shown to increase urinary Ca excretion in randomised controlled trials, and diets high in protein may have detrimental effects on bone health; however, studies examining the relationship between dietary protein and bone health have conflicting results. In the present study, we examined the relationship between dietary protein (total, animal and vegetable protein) and lumbar spine trabecular volumetric bone mineral density (vBMD) among participants enrolled in the Multi-Ethnic Study of Atherosclerosis (n 1658). Protein intake was assessed using a FFQ obtained at baseline examination (2000-2). Lumbar spine vBMD was measured using quantitative computed tomography (2002-5), on average 3 years later. Multivariable linear and robust regression techniques were used to examine the associations between dietary protein and vBMD. Sex and race/ethnicity jointly modified the association of dietary protein with vBMD (P for interaction = 0·03). Among white women, higher vegetable protein intake was associated with higher vBMD (P for trend = 0·03), after adjustment for age, BMI, physical activity, alcohol consumption, current smoking, educational level, hormone therapy use, menopause and additional dietary factors. There were no consistently significant associations for total and animal protein intakes among white women or other sex and racial/ethnic groups. In conclusion, data from the present large, multi-ethnic, population-based study suggest that a higher level of protein intake, when substituted for fat, is not associated with poor bone health. Differences in the relationship between protein source and race/ethnicity of study populations may in part explain the inconsistent findings reported previously.

Lifestyle modifications to improve musculoskeletal and bone health and reduce disability--a life-course approach

This review covers the evidence relating to lifestye modification in the big three musculoskeletal conditions: osteoarthritis, osteoporosis and rheumatoid arthritis. Lifestyle is of considerable importance in the first two and there is emerging evidence for rheumatoid arthritis despite it not traditionally being considered a lifestyle disease.

Legumes and meat analogues consumption are associated with hip fracture risk independently of meat intake among Caucasian men and women: the Adventist Health Study-2

OBJECTIVE

In contrast to non-vegetarians, vegetarians consume more legumes and meat analogues as sources of protein to substitute for meat intake. The present study aimed to assess the association between foods with high protein content (legumes, meat, meat analogues) by dietary pattern (vegetarians, non-vegetarians) and hip fracture incidence, adjusted for selected lifestyle factors.

DESIGN

A prospective cohort of Adventist Health Study-2 (AHS-2) enrollees who completed a comprehensive lifestyle and dietary questionnaire between 2002 and 2007.

SETTING

Every two years after enrolment, a short questionnaire on hospitalizations and selected disease outcomes including hip fractures was sent to these members.

SUBJECTS

Respondents (n 33,208) to a baseline and a follow-up questionnaire.

RESULTS

In a multivariable model, legumes intake of once daily or more reduced the risk of hip fracture by 64% (hazard ratio = 0·36, 95% CI 0·21, 0·61) compared with those with legumes intake of less than once weekly. Similarly, meat intake of four or more times weekly was associated with a 40% reduced risk of hip fracture (hazard ratio = 0·60, 95% CI 0·41, 0·87) compared with those whose meat intake was less than once weekly. Furthermore, consumption of meat analogues once daily or more was associated with a 49 % reduced risk of hip fracture (hazard ratio = 0·51, 95% CI 0·27, 0·98) compared with an intake of less than once weekly.

CONCLUSIONS

Hip fracture incidence was inversely associated with legumes intake and, to a lesser extent, meat intake, after accounting for other food groups and important covariates. Similarly, a high intake of meat analogues was associated with a significantly reduced risk of hip fracture.

Phytoestrogens and bone health at different reproductive stages

BACKGROUND

Isoflavones are an alternative to hormonal therapy for the relief of menopausal symptoms. Since isoflavones interact with estrogen receptors it has been hypothesized that such substances may have an effect on bone health.

OBJECTIVE

To clarify the effect of isoflavones on bone at experimental and clinical level, and to identify areas that require further clarification and research.

METHOD

A systematic review of studies involving isoflavones and bone health was performed, and a specific search on isoflavone's mechanism of action and the importance of equol production was made based on Internet search engines, MEDLINE (1966-October 2012) and the Cochrane Controlled Clinical Trials Register. This search was supplemented by a handsearch of reference lists of selected papers.

RESULTS

In vitro and animal studies show a positive effect of isoflavones on bone which has not been clearly confirmed by long-term human trials. Equol producers seem to present a more positive response to isoflavone intervention. Isoflavone rich diets could help maintain peak bone mass in premenopausal women. The effect of isoflavones in perimenopausal women is insufficiently studied but it seems to attenuate bone loss in the menopausal transition. In postmenopause, isoflavones may present a modest benefit but its clinical relevance in preventing osteoporotic fractures remains to be determined.

CONCLUSIONS

The present review suggests that isoflavone increase bone mineral density and decrease the bone turnover resorption markers. The effect of soy isoflavones on BMD is mediated by equol production, reproductive status, supplement type, isoflavone dose and intervention duration.

Effect of a combination of genistein, polyunsaturated fatty acids and vitamins D3 and K1 on bone mineral density in postmenopausal women: a randomized, placebo-controlled, double-blind pilot study

Purpose

Many postmenopausal women desire non-pharmaceutical alternatives to hormone therapy for protection against osteoporosis. Soybean isoflavones, especially genistein, are being studied for this purpose. This study examined the effects of synthetic genistein in combination with other potential bone-protective dietary molecules on bone mineral density (BMD) in early postmenopausal women.

Methods

In this 6-month double-blind pilot study, 70 subjects were randomized to receive daily either calcium only or the geniVida™ bone blend (GBB), which consisted of genistein (30 mg/days), vitamin D3 (800 IU/days), vitamin K1 (150 μg/days) and polyunsaturated fatty acids (1 g polyunsaturated fatty acids as ethyl ester: eicosapentaenoic acid/docosahexaenoic acid ratio = ~2/1). Markers of bone resorption and formation and BMD at the femoral neck, lumbar spine, Ward’s triangle, trochanter and intertrochanter, total hip and whole body were assessed.

Results

Subjects supplemented with the GBB (n = 30) maintained femoral neck BMD, whereas in the placebo group (n = 28), BMD significantly decreased (p = 0.007). There was also a significant difference (p < 0.05) in BMD between the groups at Ward’s triangle in favor of the GBB group. Bone-specific alkaline phosphatase and N-telopeptide significantly increased in the GBB group in comparison with those in baseline and in the placebo group. The GBB was well tolerated, and there were no significant differences in adverse events between groups.

Conclusions

The GBB may help to prevent osteoporosis and reduce fracture risk, at least at the hip, in postmenopausal women. Larger and longer-term clinical trials are warranted.

Factors associated with osteoporosis in Brazilian women: a population-based household survey

The aging of Brazilian population has been well-documented. A longer time since menopause, poor self-perception of health, and having arthrosis and balance problems are factors associated with postmenopausal osteoporosis. Poor self-perception of health, menopausal treatment with natural remedies, smoking, and decreased functional capacity are associated with early onset of the disease.

PURPOSE

This study aims to evaluate the prevalence of osteoporosis and its associated factors in Brazilian women over 50 years of age and to obtain information on factors related to the early onset of the disease.

METHODS

A cross-sectional study with 622 women over 50 years of age residing in Campinas/Brazil was conducted between May 10 and October 31, 2011 in the form of a population survey. A questionnaire was applied by trained interviewers. Osteoporosis was classified either as self-reported or as osteoporosis diagnosed by bone densitometry. Statistical analysis was carried out by chi-square test, Poisson regression analysis, and Cox multiple regression model.

RESULTS

The mean age of the women was 64.1 years. The prevalence of self-reported osteoporosis was 21.3 %. A longer time since menopause (prevalence ratios (PR), 1.04; 95 % CI, 1.03-1.05; p < 0.001); self-perception of health as fair/poor/very poor (PR, 1.73; 95 % CI, 1.29-2.33; p < 0.001); having arthrosis (PR, 1.83; 95 % CI, 1.30-2.59; p < 0.002) and having problems maintaining balance when taking a bath or going down stairs (PR, 1.52; 95 % CI, 1.07-2.14; p = 0.020) were associated with osteoporosis. The variables associated with early onset of the disease were: self-perception of health as fair/poor/very poor (coefficient, 0.77; p < 0.001), menopausal treatment with natural remedies (coefficient, 1.01; p < 0.001), smoking or having smoked >20 cigarettes/day (coefficient, 1.02; p = 0.003), and problems in running/lifting something heavy/practicing sports/doing heavy work (coefficient, 0.60; p = 0.029).

CONCLUSIONS

The results of this study have improved understanding of the factors associated with osteoporosis in the Brazilian population and may help identify those women who should undergo bone densitometry.

Mechanisms underlying the dualistic mode of action of major soy isoflavones in relation to cell proliferation and cancer risks

Isoflavones are phytoestrogens that have been linked to both beneficial as well as adverse effects in relation to cell proliferation and cancer risks. The present article presents an overview of these seemingly contradicting health effects and of mechanisms that could be involved in this dualistic mode of action. One mechanism relates to the different ultimate cellular effects of activation of estrogen receptor (ER) α, promoting cell proliferation, and of ERβ, promoting apoptosis, with the major soy isoflavones genistein and daidzein activating especially ERβ. A second mode of action includes the role of epigenetics, including effects of isoflavones on DNA methylation, histone modification and miRNA expression patterns. The overview presented reveals that we are only at the start of unraveling the complex underlying mode of action for effects of isoflavones, both beneficial or adverse, on cell proliferation and cancer risks. It is evident that whatever model system will be applied, its relevance to human tissues with respect to ERα and ERβ levels, co-repressor and co-activator characteristics as well as its relevance to human exposure regimens, needs to be considered and defined.

Effects of Extracts from Trifolium medium L. and Trifolium pratense L. on Development of Estrogen Deficiency-Induced Osteoporosis in Rats

Some plant species belonging to Trifolium L. genus are a source of isoflavones considered to exert phytoestrogenic activities. The aim of the present study was to examine the effects of standardized extract obtained from aerial parts of Trifolium medium L., in comparison with the extract of Trifolium pratense L., on the development of estrogen deficiency-induced osteoporosis in rats. Both Trifolium extracts, at doses corresponding to 10 and 20 mg/kg of isoflavone aglycones daily, or estradiol (0.2 mg/kg daily), were administered orally to ovariectomized (OVX) rats for 4 weeks. Serum bone turnover markers, bone mass, mineralization, and mechanical properties were studied. In OVX control rats, mechanical properties of the tibial metaphysis and femoral neck were strongly worsened in comparison with sham-operated control rats, and those of femoral diaphysis were unaffected. Estradiol counteracted the worsening of the tibial strength and increases in bone turnover markers. Both extracts significantly increased the strength of the femoral diaphysis and calcium and phosphorus content in the bone mineral, but only T. pratense extract increased the strength of the tibial metaphysis. In conclusion, effects of both Trifolium extracts differed from those of estradiol. It is possible that other than isoflavone extract constituents contributed to their skeletal effects.

Habitual flavonoid intakes are positively associated with bone mineral density in women

Dietary flavonoids exert bone-protective effects in animal models, but there is limited information on the effect of different flavonoid subclasses on bone health in humans. The aim of this observational study was to examine the association between habitual intake of flavonoid subclasses with bone mineral density (BMD) in a cohort of female twins. A total of 3160 women from the TwinsUK adult twin registry participated in the study. Habitual intakes of flavonoids and subclasses (flavanones, anthocyanins, flavan-3-ols, polymers, flavonols, and flavones) were calculated from semiquantitative food frequency questionnaires using an updated and extended U.S. Department of Agriculture (USDA) database. Bone density was measured using dual-energy X-ray absorptiometry. In multivariate analyses, total flavonoid intake was positively associated with higher BMD at the spine but not at the hip. For the subclasses, the magnitude of effect was greatest for anthocyanins, with a 0.034 g/cm(2) (3.4%) and 0.029 g/cm(2) (3.1%) higher BMD at the spine and hip, respectively, for women in the highest intake quintile compared to those in the lowest. Participants in the top quintile of flavone intake had a higher BMD at both sites; 0.021 g/cm(2) (spine) and 0.026 g/cm(2) (hip). At the spine, a greater intake of flavonols and polymers was associated with a higher BMD (0.021 and 0.024 g/cm(2) , respectively), whereas a higher flavanone intake was positively associated with hip BMD (0.008 g/cm(2) ). In conclusion, total flavonoid intake was positively associated with BMD, with effects observed for anthocyanins and flavones at both the hip and spine, supporting a role for flavonoids present in plant-based foods on bone health. .

Soy foods: are they useful for optimal bone health?

Numerous studies have investigated the relationship between soy foods, soy protein, or isoflavone extracts and markers of bone health and osteoporosis prevention, and have come to conflicting conclusions. Research on dietary patterns, rather than on specific food ingredients or individual foods, may offer an opportunity for better understanding the role of soy foods in bone health. Evidence is reviewed regarding the question of whether soy foods contribute to a dietary pattern in humans that supports and promotes bone health. Soy foods are associated with improved markers of bone health and improved outcomes, especially among Asian women. Although the optimal amounts and types of soy foods needed to support bone health are not yet clear, dietary pattern evidence suggests that regular consumption of soy foods is likely to be useful for optimal bone health as an integral part of a dietary pattern that is built largely from whole plant foods.

Soy milk and dairy consumption is independently associated with ultrasound attenuation of the heel bone among postmenopausal women: the Adventist Health Study-2

Soy milk has become a popular substitute for dairy milk with important health claims. We hypothesized that soy milk, based on its nutrient composition, is comparable to dairy products and, therefore, beneficial for bone health. To test this hypothesis, we examined the benefit of soy milk and dairy products intake on bone health using broadband ultrasound attenuation of the calcaneus. Postmenopausal white women (n = 337) who had completed a lifestyle and dietary questionnaire at enrollment into the Adventist Health Study-2 had their calcaneal broadband ultrasound attenuation measured 2 years later. The association between osteoporosis (defined as a T-score <-1.8) and some dietary factors (soy milk, dairy) and selected lifestyle factors was assessed using logistic regression. In a multivariable model adjusted for demographics, hormone use, and other dietary factors, osteoporosis was positively associated with age (odds ratio [OR] = 1.08; 95% confidence interval [CI], 1.06-1.12) and inversely associated with body mass index (OR = 0.91; 95% CI, 0.86-0.97) and current estrogen use (OR = 0.27; 95% CI, 0.13-0.56). Compared with women who did not drink soy milk, women drinking soy milk once a day or more had 56% lower odds of osteoporosis (OR = 0.44; 95% CI, 0.20-0.98; P(trend) = .04). Women whose dairy intake was once a day or more had a 62% reduction in the likelihood of having osteoporosis (OR = 0.38; 95% CI, 0.17-0.86; P(trend) = .02) compared with women whose dairy intake was less than twice a week. Among individual dairy products, only cheese showed an independent and significant protection (OR = 0.28; 95% CI, 0.12-0.66; P(trend) = .004) for women eating cheese more than once per week vs those who ate cheese less than once a week. We concluded that osteoporosis is inversely associated with soy milk intake to a similar degree as dairy intake after accounting for age, body mass index, and estrogen use.

In utero and postnatal exposure to isoflavones results in a reduced responsivity of the mammary gland towards estradiol

SCOPE

Exposure scenarios during different stages of development of an organism are discussed to trigger adverse and beneficial effects of isoflavones (ISO). The aim of this study was to investigate how in utero and postnatal ISO exposure modulates the estrogen sensitivity of the mammary gland and to identify the underlying molecular mechanisms.

METHODS AND RESULTS

Therefore, rats were exposed to either ISO-free (IDD), ISO-rich (IRD) or genistein-rich diet (GRD), up to young adulthood. Proliferative activity (PCNA expression) in the mammary gland at different ages and the estrogen sensitivity of the mammary gland to estradiol (E₂) or genistein (GEN) in adult ovariectomized animals was determined and compared with different treatments. Treatment with E₂ resulted in a significant lower proliferative and estrogenic response of the mammary gland in IRD and GRD compared with IDD. This correlates to a change in the gene expression pattern and a decrease in the ratio of estrogen receptor alpha (ERα) beta (ERβ

CONCLUSIONS

Our results provide evidence that in utero and postnatal exposure to a diet rich in ISO but also to GEN reduces the sensitivity of the mammary gland toward estrogens and support the hypothesis that in utero and postnatal ISO exposure reduces the risk to develop breast cancer.

Soy isoflavones for osteoporosis: an evidence-based approach

Effects of soy isoflavones on osteoporosis remain unclear. This review aimed to clarify the effect of soy isoflavones on bone mineral density (BMD) and turnover markers in menopausal women. PubMed and the Cochrane Library were searched in July 2011 for relevant meta-analyses of randomized controlled trials evaluating effects of soy isoflavones on BMD and bone turnover markers. Three meta-analyses evaluated the effects of soy isoflavones on lumbar spine, total hip, femoral neck, and trochanter BMD. Soy isoflavones significantly improved lumbar spine BMD in a moderate manner, but did not affect total hip, femoral neck, and trochanter BMD in menopausal women. Ingestion of soy isoflavones for six months appeared to be enough to exert a beneficial effect on lumbar spine BMD. Two meta-analyses evaluated the effects of soy isoflavones on a bone resorption marker (urine deoxypyridinoline) and two formation markers (serum alkaline phosphatase and osteocalcin). Soy isoflavones significantly decreased urine deoxypyridinoline in a moderate manner, but did not affect serum alkaline phosphatase and osteocalcin in menopausal women. Soy isoflavones may prevent postmenopausal osteoporosis and improve bone strength thus decreasing risk of fracture in menopausal women by increasing lumbar spine BMD and decreasing bone resorption marker urine deoxypyridinoline. Further studies are needed to address factors affecting the magnitude of the beneficial effects of soy isoflavones and to assess the possible interactions between soy isoflavones and anti-osteoporosis drugs, and to verify effects on BMD of other skeletal sites and other bone turnover markers.