Isoflavone soy protein supplementation and atherosclerosis progression in healthy postmenopausal women: a randomized controlled trial

Methods and baseline cardiovascular data from the Early versus Late Intervention Trial with Estradiol testing the menopausal hormone timing hypothesis

OBJECTIVE

This study aims to present methods and baseline data from the Early versus Late Intervention Trial with Estradiol (ELITE), the only clinical trial designed to specifically test the timing hypothesis of postmenopausal hormone therapy (HT). The timing hypothesis posits that HT effects depend on the temporal initiation of HT relative to time since menopause.

METHODS

ELITE is a randomized, double-blind, placebo-controlled trial with a 2 × 2 factorial design. Six hundred forty-three healthy postmenopausal women without cardiovascular disease were randomized to oral estradiol or placebo for up to 6 to 7 years according to time since menopause (<6 or ≥10 y). Carotid artery intima-media thickness (CIMT) and cardiac computed tomography were conducted to determine HT effects on subclinical atherosclerosis across menopause strata.

RESULTS

Participants in the early and late postmenopausal strata were well-separated by mean age (55.4 vs 65.4 y) and median time since menopause (3.5 vs 14.3 y). Expected risk factors (age, blood pressure, and body mass index) were associated with CIMT at baseline in both strata. In the early postmenopausal group, but not in the late postmenopausal group, we observed significant associations between CIMT and factors that may play a role in the responsiveness of atherosclerosis progression according to timing of HT initiation. These include low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, sex hormone-binding globulin, and serum total estradiol.

CONCLUSIONS

The ELITE randomized controlled trial is timely and unique. Baseline data indicate that ELITE is well-positioned to test the HT timing hypothesis in relation to atherosclerosis progression and coronary artery disease.

Beneficial effects of soy supplementation on postmenopausal atherosclerosis are dependent on pretreatment stage of plaque progression

OBJECTIVE

The objective of this study was to use a well-established monkey model of atherosclerosis to determine how life stage and preexisting atherosclerosis influence the effectiveness of high-isoflavone soy diet in inhibiting progression of atherosclerosis.

METHODS

For 34 months, premenopausal monkeys were fed an atherogenic diet, with protein derived primarily from either animal sources (casein-lactalbumin [CL], n = 37) or high-isoflavone soy beans (Soy, n = 34). Animals were ovariectomized and randomized to groups fed the same diet (CL-CL, n = 20; Soy-Soy, n = 17) or an alternate diet (CL-Soy, n = 17; Soy-CL, n = 17) for an additional 34 months. At ovariectomy, the left common iliac artery was removed to determine the amount of premenopausal atherosclerosis. At necropsy, the right common iliac artery and coronary arteries were collected, and atherosclerosis extent was quantified. CL-CL condition was considered "control."

RESULTS

Modeling Asian women who remain in Asia, monkeys fed soy protein both premenopausally and postmenopausally had a markedly reduced extent of coronary artery atherosclerosis relative to CL controls (P = 0.008). The subset of animals that modeled Asian women who migrate to a Western country (consuming soy premenopausally and CL postmenopausally) had increased progression of postmenopausal iliac artery atherosclerosis (P = 0.003) and was not protected against the development of coronary artery atherosclerosis relative to controls. Relevant to the administration of soy diets to postmenopausal Western women, monkeys fed CL premenopausally and switched to soy postmenopausally derived atheroprotective benefits only if they began the postmenopausal treatment period with relatively small (below the median) plaques. Relative to controls, this group (with small plaques at ovariectomy) had reduced progression of iliac atherosclerosis (P = 0.038) and smaller coronary artery plaques (P = 0.0001) that were less complicated (P = 0.05) relative to controls.

CONCLUSIONS

The results suggest that significant atheroprotective benefits of dietary soy are derived from treatment that begins premenopausally and continues postmenopausally or from treatment that is started during early postmenopause (when plaques are still small).

Anti-Inflammatory Diet for Atherosclerosis and Coronary Artery Disease: Antioxidant Foods

Oxidative stress plays a role in atherosclerotic diseases such as coronary artery disease (CAD), and much attention has been paid to antioxidant foods. The relationships between the consumption of vegetables and fruits and atherosclerotic diseases have been reported in many epidemiological studies showing a reduced risk of such diseases. In addition to the antioxidant vitamins C and E, green and yellow vegetables contain abundant quantities of carotenoids and polyphenols. The consumption of carotenoids and vitamins C and E has been shown to be inversely associated with CAD. However, supplementation with beta-carotene and vitamins C and E shows no beneficial effect, but rather mortality is increased with beta-carotene and vitamin E supplements. Therefore, it is recommended to consume vegetables and fruits, but vitamin supplementation is not recommended. Many epidemiological studies also report that higher consumption of fish, rich in n-3 polyunsaturated fatty acids (PUFAs), is associated with a lower risk of CAD and stroke. Antiatherosclerotic effects of n-3 PUFAs include reduced platelet aggregation, triglyceride-lowering effect, anti-inflammatory effect, and plaque stabilization, but the anti-inflammatory effect is principally responsible for preventing atherosclerosis. It is recommended to consume fish at least twice a week in patients without CAD and to consider n-3 PUFA supplements in patients with documented CAD. Regarding soy products, soy protein consumption reduces low-density-lipoprotein cholesterol and triglyceride levels. Isoflavone, a polyphenol contained in soybeans, has antiatherosclerotic property because it has a structure similar to that of estrogen and bonds with estrogen receptors. High consumption of isoflavone has been reported to be associated with a reduced risk of CAD and stroke only in women, but the preventative effect of soy products in the general population has not yet been clarified. Thus, many epidemiological studies report the promising effects of antioxidant foods, but there are many unclear points remaining with regard to the contribution of the nutritional elements found in antioxidant foods to the prevention of atherosclerotic diseases.

A Systematic Review of the Efficacy of Bioactive Compounds in Cardiovascular Disease: Phenolic Compounds

The prevalence of cardiovascular diseases (CVD) is rising and is the prime cause of death in all developed countries. Bioactive compounds (BAC) can have a role in CVD prevention and treatment. The aim of this work was to examine the scientific evidence supporting phenolic BAC efficacy in CVD prevention and treatment by a systematic review. Databases utilized were Medline, LILACS and EMBASE, and all randomized controlled trials (RCTs) with prospective, parallel or crossover designs in humans in which the effects of BAC were compared with that of placebo/control were included. Vascular homeostasis, blood pressure, endothelial function, oxidative stress and inflammatory biomarkers were considered as primary outcomes. Cohort, ecological or case-control studies were not included. We selected 72 articles and verified their quality based on the Scottish Intercollegiate Guidelines Network, establishing diverse quality levels of scientific evidence according to two features: the design and bias risk of a study. Moreover, a grade of recommendation was included, depending on evidence strength of antecedents. Evidence shows that certain polyphenols, such as flavonols can be helpful in decreasing CVD risk factors. However, further rigorous evidence is necessary to support the BAC effect on CVD prevention and treatment.

Urinary phytoestrogens and cancer, cardiovascular, and all-cause mortality in the continuous National Health and Nutrition Examination Survey

PURPOSE

Experimental studies suggest that phytoestrogen intake alters cancer and cardiovascular risk. This study investigated the associations of urinary phytoestrogens with total cancer (n = 79), cardiovascular (n = 108), and all-cause (n = 290) mortality among 5179 participants in the continuous National Health and Nutrition Examination Survey (1999-2004).

METHODS

Urinary phytoestrogens were measured using high-performance liquid chromatography with tandem mass spectrometric detection. Survival analysis was performed to evaluate hazard ratios (HRs) and 95 % confidence intervals (CIs) for each of the three outcomes in relation to urinary phytoestrogens.

RESULTS

After adjustment for confounders, higher urinary concentrations of total enterolignans were associated with a reduced risk of death from cardiovascular disease (HR for tertile 3 vs. tertile 1 0.48; 95 % CI 0.24, 0.97), whereas higher urinary concentrations of total isoflavones (HR for tertile 3 vs. tertile 1 2.14; 95 % CI 1.03, 4.47) and daidzein (HR for tertile 3 vs. tertile 1 2.05; 95 % CI 1.02, 4.11) were associated with an increased risk. A reduction in all-cause mortality was observed for elevated urinary concentrations of total enterolignans (HR for tertile 3 vs. tertile 1 0.65; 95 % CI 0.43, 0.96) and enterolactone (HR for tertile 3 vs. tertile 1 0.65; 95 % CI 0.44, 0.97).

CONCLUSIONS

Some urinary phytoestrogens were associated with cardiovascular and all-cause mortality in a representative sample of the US population. This is one of the first studies that used urinary phytoestrogens as biomarkers of their dietary intake to evaluate the effect of these bioactive compounds on the risk of death from cancer and cardiovascular disease.

Effect of soy nuts and equol status on blood pressure, lipids and inflammation in postmenopausal women stratified by metabolic syndrome status

OBJECTIVE

Soy has been associated with lower risk of cardiovascular disease in Asian countries which consume daily soy. Our study examined whether production of equol, an estrogen metabolite, affected the ability of soy nuts to improve cardiovascular risk factors.

MATERIALS/METHODS

Sixty postmenopausal women participated in a randomized, controlled, crossover trial of a Therapeutic Lifestyle Changes (TLC) diet alone and a TLC diet in which 0.5 cup of soy nuts (25 g of soy protein and 101 mg of aglycone isoflavones) replaced 25 g of nonsoy protein daily. Each diet was followed for 8 weeks at the end of which blood pressure (BP), lipid levels, adhesion molecules and inflammatory markers were measured.

RESULTS

Women with MetS had significantly higher baseline body mass index (BMI), BP, triglycerides (TG), and soluble intercellular adhesion molecule (sICAM) than women without MetS. In women with MetS on the soy diet, significant reductions in diastolic BP (7.7%; P=0.02), TG (22.9%; P=0.02), C-reactive protein (CRP) (21.4%; P=0.01) and sICAM (7.3%; P=0.03) were noted among equol producers compared to levels on the TLC diet. No significant changes were noted in equol nonproducers. Similarly, in women without MetS, only equol producers had significant reductions in diastolic BP (3.3%, P=0.02) and CRP (30%, P=0.04). In contrast to women with MetS, TG and sICAM levels were not affected in women without MetS, a finding possibly related to lower baseline levels.

CONCLUSIONS

Cardiovascular risk reduction with soy nuts is not uniform and may be greater among producers of equol.

Abnormal blood rheology and chronic low grade inflammation: possible risk factors for accelerated atherosclerosis and coronary artery disease in Lewis negative subjects

OBJECTIVE

To test the hypothesis that abnormal hemorheology and chronic low-grade inflammation are more prevalent in Lewis negative individuals, possibly contributing to premature atherosclerosis.

METHODS AND RESULTS

We enrolled 223 healthy subjects (154 females, mean age: 64yrs). Conventional risk factors, markers of inflammation and hemorheological profiles were measured; Lewis blood group was determined by serology. Conventional risk factors (age, gender, BMI, blood pressure, lipid profile, smoking habit) did not differ among Lewis phenotypes. However, markers of inflammation (WBC, hs-CRP, ESR) were significantly elevated and rheological parameters (RBC aggregation, plasma viscosity) were abnormal in Lewis negative subjects, especially when compared to the Le(a-b+) group.

CONCLUSIONS

With a prevalence of 33% in select populations, our data support the hypothesis that Le(a-b-) represents a pro-inflammatory phenotype that may contribute to the elevated cardiovascular risk in this group.

Consumption of nuts and legumes and risk of stroke: a meta-analysis of prospective cohort studies

BACKGROUND AND AIM

The relationships between dietary nuts and legume intake and risk of stroke are inconsistent. We summarized the evidence by a meta-analysis of prospective cohort studies.

METHODS AND RESULTS

We systematically searched the MEDLINE and EMBASE databases up to 31 January 2014. Random-effects models were used to calculate summary relative risks (SRRs) and 95% confidence intervals (CIs). Between-study heterogeneity was assessed using the Cochran's Q and I(2) statistics. Eight prospective studies with a total of 468,887 subjects and 10,493 stroke events were included in the meta-analysis. Overall, a diet containing greater amounts of legumes may be not associated with a lower risk of stroke (SRR = 0.95, 95% CI: 0.84-1.08; P(heterogeneity) = 0.091, I(2) = 43.2%); however, a diet containing greater amounts of nuts may be associated with a lower risk of stroke (SRR = 0.90, 95% CI: 0.81-0.99; P(heterogeneity) = 0.527, I(2) = 0). Gender significantly modified the effects of nut consumption on stroke risk, and high nut intake was associated with reduced risk of stroke in women (SRR = 0.85, 95% CI: 0.75-0.97) other than in men (SRR = 0.95, 95% CI: 0.82-1.11).

CONCLUSION

The current meta-analysis provides some evidences for the hypothesis that high intake of dietary nut was inversely associated with stroke risk, whereas dietary legumes intake was not associated with stroke risk.

Red clover isoflavones enriched with formononetin lower serum LDL cholesterol-a randomized, double-blind, placebo-controlled study

BACKGROUND

Although postmenopausal combined hormone replacement therapy reduces the risk of hip fracture, long-term use may be associated with an increased risk of breast cancer, and in women more than 10 years after menopause it is associated with an increased risk of cardiovascular disease. Isoflavones, because of preferential binding to estrogen receptor beta, may retain the beneficial effects on bone but lessen the adverse effects on the breast.

OBJECTIVE

The objective of this study was to study the effects of an isoflavone obtained from red clover (Rimostil) on bone mineral density, and on low-density lipoprotein (LDL) cholesterol.

DESIGN

In a double-blind, randomized, placebo-controlled trial, 50 mg of Rimostil was given to women who were menopausal for at least 1 year. Bone mineral density of the spine, femoral neck and forearm and serum LDL cholesterol were measured at baseline and at 6-month intervals. The duration of follow-up was 2 years.

RESULTS

There was no beneficial effect of Rimostil on bone density at any site. There was a 12% fall in serum LDL cholesterol in the Rimostil-treated arm, which was significantly greater than the 2% drop seen in the control arm (P=0.005).

Absorption, distribution, metabolism, and excretion of isoflavonoids after soy intake

Soy is the major source of dietary exposure to isoflavonoids (IFLs). Accumulating evidence supports a role for soy and IFLs in the protection against many chronic diseases including cancer. After soy intake we found a biphasic IFL appearance pattern in plasma as well as in urine that we suggest to be due to IFL absorption in the small intestine (ca. 10%) during the first 2h after intake and IFL absorption in the large intestine (ca. 90%) 4-6 h after intake. While each IFL disappears from the circulation at different times excellent correlations between urinary and circulating IFL values were discovered and algorithms to convert urinary excretion values into circulating levels were established. We suggest the term 'apparent bioavailability' when using urinary data to describe IFL exposure. The IFL bioavailability was found to be influenced by gut bacteria, oral antibiotic treatment (OABX), and an individual's age and health status. While daidzein (DE) and genistein start to be absorbed minutes after intake, equol (EQ) appears in plasma only after a minimum of 8h following soy intake owing to the required transit time of DE to the colon where the conversion of DE to EQ takes place by intestinal microbiota. We have also shown that the apparent IFL bioavailability is higher in children than adults, higher in healthy versus non-healthy individuals, and decreased in children but increased in adults during OABX. Finally, we propose to use a urinary EQ/DE ratio of 0.018 with a DE threshold to identify EQ producers. With this cutoff definition we observed that EQ production is inconsistent over time in 5-30% of both premenopausal and postmenopausal women.

Soy food consumption, cardiometabolic alterations and carotid intima-media thickness in Chinese adults

BACKGROUND AND AIM

The associations between soy food consumption, cardiometabolic disturbances and subclinical atherosclerosis remain controversial due to limited evidence. We examined the associations of habitual soy food consumption with cardiometabolic disturbances and carotid intima-media thickness (CIMT).

METHODS AND RESULTS

We included 2939 subjects (2135 women and 804 men) aged 50-75 years in this community-based cross-sectional study. Dietary data and other covariates were collected using interviewer-administered questionnaires. We determined CIMT in relation to each subject's common carotid artery, internal carotid artery, carotid bifurcation, blood lipids, glucose and urine acid, blood pressure and waist circumference. A logistic regression model was applied to estimate the odd ratios (ORs) and 95% confidence intervals (CIs), and linear regression was used to estimate the regression coefficient and 95% CIs. After adjusting for potential confounders, we found that greater consumption of soy protein (6.1 vs. 0.5 g/d) was inverse associated with the presence of elevated total cholesterol (TC), dyslipidemia, abdominal obesity and hyperuricemia in women, and with abdominal obesity in men, although no significant sex-soy interactions were observed (P: 0.145-0.985). The consumption of soy protein and isoflavones was inversely associated with the number of cardiometabolic disturbances among women, but not men. There were no significant associations of soy protein and isoflavones with CIMT thickening and other cardiometabolic disturbances.

CONCLUSION

Greater soy consumption was associated with a lower presence of elevated TC, dyslipidemia, hyperuricemia and less number of cardiometabolic disturbances components in women.

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.

Bioavailability, bioactivity and impact on health of dietary flavonoids and related compounds: an update

There is substantial interest in the role of plant secondary metabolites as protective dietary agents. In particular, the involvement of flavonoids and related compounds has become a major topic in human nutrition research. Evidence from epidemiological and human intervention studies is emerging regarding the protective effects of various (poly)phenol-rich foods against several chronic diseases, including neurodegeneration, cancer and cardiovascular diseases. In recent years, the use of HPLC-MS for the analysis of flavonoids and related compounds in foods and biological samples has significantly enhanced our understanding of (poly)phenol bioavailability. These advancements have also led to improvements in the available food composition and metabolomic databases, and consequently in the development of biomarkers of (poly)phenol intake to use in epidemiological studies. Efforts to create adequate standardised materials and well-matched controls to use in randomised controlled trials have also improved the quality of the available data. In vitro investigations using physiologically achievable concentrations of (poly)phenol metabolites and catabolites with appropriate model test systems have provided new and interesting insights on potential mechanisms of actions. This article will summarise recent findings on the bioavailability and biological activity of (poly)phenols, focusing on the epidemiological and clinical evidence of beneficial effects of flavonoids and related compounds on urinary tract infections, cognitive function and age-related cognitive decline, cancer and cardiovascular disease.

Soy foods, isoflavones, and the health of postmenopausal women

Over the past 2 decades, soy foods have been the subject of a vast amount of research, primarily because they are uniquely rich sources of isoflavones. Isoflavones are classified as both phytoestrogens and selective estrogen receptor modulators. The phytoestrogenic effects of isoflavones have led some to view soy foods and isoflavone supplements as alternatives to conventional hormone therapy. However, clinical research shows that isoflavones and estrogen exert differing effects on a variety of health outcomes. Nevertheless, there is substantial evidence that soy foods have the potential to address several conditions and diseases associated with the menopausal transition. For example, data suggest that soy foods can potentially reduce ischemic heart disease through multiple mechanisms. Soy protein directly lowers blood low-density lipoprotein-cholesterol concentrations, and the soybean is low in saturated fat and a source of both essential fatty acids, the omega-6 fatty acid linoleic acid and the omega-3 fatty acid alpha-linolenic acid. In addition, soflavones improve endothelial function and possibly slow the progression of subclinical atherosclerosis. Isoflavone supplements also consistently alleviate menopausal hot flashes provided they contain sufficient amounts of the predominant soybean isoflavone genistein. In contrast, the evidence that isoflavones reduce bone loss in postmenopausal women is unimpressive. Whether adult soy food intake reduces breast cancer risk is unclear. Considerable evidence suggests that for soy to reduce risk, consumption during childhood and/or adolescence is required. Although concerns have been raised that soy food consumption may be harmful to breast cancer patients, an analysis in 9514 breast cancer survivors who were followed for 7.4 y found that higher postdiagnosis soy intake was associated with a significant 25% reduction in tumor recurrence. In summary, the clinical and epidemiologic data indicate that adding soy foods to the diet can contribute to the health of postmenopausal women.

Hormone replacement therapy and the association with coronary heart disease and overall mortality: clinical application of the timing hypothesis

Conclusions from randomized controlled trial (RCT) data over the past 10 years has spanned from presumed harm to consistency with observational data that hormone replacement therapy (HRT) decreases the risk for coronary heart disease (CHD) as well as overall mortality in women who are recently postmenopausal. Multiple clinical studies including randomized trials and observational studies converge with animal experimentation to show a consistency that HRT decreases CHD risk and overall mortality in primary prevention when HRT is started at the time of or soon after menopause. The totality of data supports the "timing" hypothesis that posits that HRT effects are dependent on when HRT is started in relation to age and/or time-since-menopause. The totality of data shows that HRT decreases CHD and overall morality when started in women who are less than 60 years old and/or less than 10 years postmenopausal, providing a "window-of-opportunity". Further evidence shows that women who start HRT when in their 50s and continued for 5-30 years that there is an increase of 1.5 quality-adjusted life-years (QALYs). Additionally, HRT is highly cost-effective at $2438 per QALY gained. The totality of data converges to show a consistency between randomized trials and observational studies that when started in women at or near menopause and continued long-term, HRT decreases CHD and overall mortality compared with women who do not use HRT. This article is part of a Special Issue entitled 'Menopause'.

The association between carotid intima media thickness and individual dietary components and patterns

AIMS

To review: 1) the correlation between individual dietary components and carotid intima media thickness (cIMT); 2) the relationship between dietary patterns and cIMT; 3) the effect of dietary interventions on cIMT progression.

DATA SYNTHESIS

An electronic search for epidemiological and intervention trials investigating the association between dietary components or patterns of intake and cIMT was performed in PUBMED, EMBASE and the Cochrane Library. Epidemiological data shows that a higher intake of fruit, wholegrains and soluble fibre and lower consumption of saturated fat in favour of polyunsaturated fat is associated with lower cIMT. In people at high risk of cardiovascular disease >93 g/day of fruit is associated with lower cIMT. Lower cIMT has also been observed when >0.79 serves/day of wholegrains and >25 g/day of fibre, predominately in the soluble form is consumed. Saturated fat is positively associated with cIMT, for every 10 g/day increase in saturated fat cIMT is 0.03 mm greater. Olive oil is inversely associated with cIMT, with a benefit seen when >34 g/day is consumed. While there are many epidemiological studies exploring the association between dietary intake and cIMT there are few intervention studies. Intervention studies show that a Mediterranean diet may reduce cIMT progression, especially in those with a higher cIMT.

CONCLUSIONS

A Mediterranean style dietary pattern, which is high in fruits, wholegrains, fibre and olive oil and low in saturated fat, may reduce carotid atherosclerosis development and progression. However further research from randomised controlled trials is required to understand the association between diet and cIMT and the underlying mechanisms.

Effect of prior oophorectomy on changes in bone mineral density and carotid artery intima-media thickness in postmenopausal women

OBJECTIVE

To determine the effect of prior oophorectomy in healthy postmenopausal women on the rate of loss of bone mineral density (BMD) and rate of increase in carotid artery intima-media thickness (CIMT).

DESIGN

Secondary analysis from a randomized controlled trial.

SETTING

University-based research clinic.

PATIENT(S)

Two hundred twenty-two healthy postmenopausal women in the Greater Los Angeles area.

INTERVENTION(S)

Baseline and annual screening of BMD and assessment of CIMT every 6 months for a total of 3 years.

MAIN OUTCOME MEASURE(S)

Changes in BMD and CIMT during postmenopausal years.

RESULT(S)

Among women who were menopausal for more than 10 years, the rate of CIMT progression was statistically significantly less in women with intact ovaries compared with those in women with prior oophorectomy. In women 5-10 years postmenopause, there was a trend toward a slower loss of BMD in those who retained their ovaries, and in women more than 10 years postmenopause there was significantly less BMD loss in those who retained their ovaries.

CONCLUSION(S)

As time from menopausal transition increases, retained ovaries are associated with a slower rate of bone loss and a slower rate of thickening of the carotid artery wall compared with rates in menopausal women with oophorectomy.

Exploring the benefits and challenges of establishing a DRI-like process for bioactives

Bioactives can be defined as: "Constituents in foods or dietary supplements, other than those needed to meet basic human nutritional needs, which are responsible for changes in health status" (Office of Disease Prevention and Health Promotion, Office of Public Health and Science, Department of Health and Human Services in Fed Reg 69:55821-55822, 2004). Although traditional nutrients, such as vitamins, minerals, protein, essential fatty acids and essential amino acids, have dietary reference intake (DRI) values, there is no such evaluative process for bioactives. For certain classes of bioactives, substantial scientific evidence exists to validate a relationship between their intake and enhanced health conditions or reduced risk of disease. In addition, the study of bioactives and their relationship to disease risk is a growing area of research supported by government, academic institutions, and food and supplement manufacturers. Importantly, consumers are purchasing foods containing bioactives, yet there is no evaluative process in place to let the public know how strong the science is behind the benefits or the quantitative amounts needed to achieve these beneficial health effects. This conference, Bioactives: Qualitative Nutrient Reference Values for Life-stage Groups?, explored why it is important to have a DRI-like process for bioactives and challenges for establishing such a process.

Effects of equol on gene expression in female cynomolgus monkey iliac arteries

BACKGROUND AND AIMS

To examine effects of equol, the soy phytoestrogen metabolite, on gene expression in the monkey iliac artery.

METHODS AND RESULTS

A high fat/high cholesterol diet was fed to eight ovariectomized cynomolgus monkeys for 6.5 years. After biopsy of the left iliac artery, the animals were randomized to two treatment groups for 8 months; the treatment groups were equol (23.7 mg/100 g diet, n = 4) and vehicle (n = 4). The right iliac artery was removed at necropsy. Gene expression in the iliac arteries in response to equol was determined by DNA microarray. Comparison of atherosclerotic lesions and plasma lipids at pre-versus post-equol treatment time points and in vehicle versus equol treatment groups did not identify any significant differences. Despite the lack of effect of equol on these parameters, 59 genes were down-regulated and 279 were up-regulated in response to equol. Comparison of these data to previous work identified 10 genes regulated in opposite directions by equol compared to presence of atherosclerosis plaque (Menopause 2011; 18:1087-1095) and 55 genes differentially expressed in the same direction in response to both equol and estradiol (Eyster et al., Menopause 2014;21:143-152.).

CONCLUSIONS

Similar responses of genes to both equol and estradiol may reflect the extent to which equol serves as a natural selective estrogen receptor modulator in the arteries. Opposite responses of 10 genes to equol versus the presence of atherosclerosis implicates those genes in the potential protective effects of equol in arteries.

Whole soy, but not purified daidzein, had a favorable effect on improvement of cardiovascular risks: a 6-month randomized, double-blind, and placebo-controlled trial in equol-producing postmenopausal women

SCOPE

Equol is produced by the intestinal bacteria from isoflavone daidzein. Studies have reported the health benefits of soy can only present or more pronounced in equol producers. This 6-month randomized controlled trial examined the effect of whole soy (soy flour) and purified daidzein on cardiovascular biomarkers and carotid intima-media thickness (CIMT) in prehypertensive postmenopausal women who were equol producers.

METHODS AND RESULTS

Two hundred seventy eligible women were randomized to either one of the three treatments: 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) daily each for 6 months. Fasting venous samples were obtained at baseline and end of trial for testing glucose, lipids, high sensitivity C-reactive protein (hs-CRP), and free fatty acid. Changes in common CIMT were also assessed. Serum LDL-C decreased by 7.95% (95% CI: -15.09∼-0.81%) and 6.32% (95% CI: -13.45∼0.08%), and serum hs-CRP decreased by 0.164 (95% CI: -0.309∼-0.019) and 0.054 (95% CI: -0.199∼0.012) in the whole soy group compared with daidzein and milk placebo groups, respectively. No significant change in CIMT was found.

CONCLUSION

Whole soy, but not purified daidzein, had a beneficial effect on reduction of LDL-C and hs-CRP among prehypertensive equol-producing postmenopausal women.

Associations between urine excretion of isoflavonoids and cognition in postmenopausal women in the Women's Isoflavone Soy Health clinical trial

OBJECTIVES

To determine effect of change in urine excretion of isoflavonoids on cognitive change.

DESIGN

Post hoc analysis of isoflavonoid exposure (mean 2.7 years) during the randomized, placebo-controlled, double-blind Women's Isoflavone Soy Health trial.

SETTING

General community.

PARTICIPANTS

Healthy postmenopausal women (N = 350).

INTERVENTION

Twenty-five grams of isoflavone-rich soy protein (91 mg of aglycone weight isoflavones: 52 mg genistein, 36 mg daidzein, 3 mg glycitein) or milk protein-matched placebo provided daily.

MEASUREMENTS

Overnight urine excretion, fasting plasma levels of isoflavonoids, and cognitive function measured at baseline and endpoint.

RESULTS

Three hundred women (age: mean 61, range 45-92) completed both cognitive assessments and did not use hormone replacement therapy during the trial. Mean on-trial change from baseline in urine excretion of isoflavonoids was not significantly associated with change in a composite score of global cognition (P = .39). Secondary analyses indicated that change in urine excretion of isoflavonoids was inversely associated with change in a factor score representing general intelligence (P = .02) but not with factor scores representing verbal or visual episodic memory. Mean differences in this general intelligence factor score between women in the lowest and highest quartiles of isoflavonoid change were equivalent to an approximate 4.4-year age-associated decline. Analyses based on plasma isoflavonoid levels yielded similar but attenuated results.

CONCLUSION

In healthy postmenopausal women, long-term changes in isoflavonoids are not associated with global cognition, supporting clinical trial results, although greater isoflavonoid exposure from dietary supplements is associated with decrements in general intelligence but not memory; this finding requires confirmation in future studies.

Effect of isoflavone soy protein supplementation on endometrial thickness, hyperplasia, and endometrial cancer risk in postmenopausal women: a randomized controlled trial

OBJECTIVE

This study aims to determine whether long-term isoflavone soy protein (ISP) supplementation affects endometrial thickness and rates of endometrial hyperplasia and cancer in postmenopausal women.

METHODS

In this randomized, double-blind, placebo-controlled trial, 350 postmenopausal women aged 45 to 92 years were randomized to a total daily dose of 154 mg of ISP or a milk protein-matched placebo for a 3-year period. Women with a surgically absent uterus were excluded from the analysis (final study population, N = 224). The main outcome measures were as follows: mean change in endometrial thickness on transvaginal ultrasound from baseline until up to 36 months of follow-up and the incidence of endometrial sampling, endometrial hyperplasia, and endometrial cancer.

RESULTS

A total of 666 visits among 224 participants were evaluated. Treatment groups did not significantly differ on the mean baseline or on-trial changes in endometrial thickness. Of the 103 placebo-treated participants, 7 (6.8%) underwent endometrial biopsy; 6 (85.7%) of these biopsies were benign. One woman in the placebo group was diagnosed with complex endometrial hyperplasia with atypia and underwent hysterectomy. The pathology result from this surgical operation was stage IB endometrial cancer. Of the 121 participants in the soy group, 9 (7.4%) underwent endometrial biopsy. The results were benign in all nine cases (100%). Although the rate of hyperplasia/malignancy was higher in the placebo group (14.3% vs 0%), the difference was not statistically significant.

CONCLUSIONS

Three-year ISP supplementation has no effect on endometrial thickness or on the rates of endometrial hyperplasia and cancer in postmenopausal women.

Soy proteins and isoflavones reduce interleukin-6 but not serum lipids in older women: a randomized controlled trial

Soy foods contain several components, notably, isoflavones and amino acids, that may improve cardiovascular health. We evaluated the long-term effect of soy protein and/or soy isoflavones supplementation on serum lipids and inflammatory markers using a 1-year randomized, double-blind, placebo-control, clinical trial in 131 healthy ambulatory women older than 60 years. We hypothesized that soy protein, in combination with isoflavones, would have the largest positive effect on coronary heart disease risk factors (serum lipids and inflammatory markers) compared with either intervention alone and that, within groups receiving isoflavones, equol producers would have more positive effects on coronary heart disease risk factors than nonequol producers. After a 1-month baseline period, participants were randomized into 1 of 4 intervention groups: soy protein (18 g/d) and isoflavone tablets (105 mg/d isoflavone aglycone equivalents), soy protein and placebo tablets, control protein and isoflavone tablets, or control protein and placebo tablets. T Tests were used to assess differences between equol and nonequol producers. Ninety-seven women completed the trial. Consumption of protein powder and isoflavone tablets did not differ among groups, and compliance with study powder and tablets was 79% and 90%, respectively. After 1 year, in the entire population, there were either no or little effects on serum lipids and inflammatory markers, regardless of treatment group. Equol producers, when analyzed separately, had significant improvements in total cholesterol/high-density lipoprotein and low-density lipoprotein/high-density lipoprotein ratios (-5.9%, P = .02; -7.2%, P = .04 respectively). Soy protein and isoflavone (either alone or together) did not impact serum lipids or inflammatory markers. Therefore, they should not be considered an effective intervention to prevent cardiovascular disease because of lipid modification in healthy late postmenopausal women lacking the ability to produce equol.

Do differences in risk factors explain the lower rates of coronary heart disease in Japanese versus U.S. women?

BACKGROUND

Mortality from coronary heart disease (CHD) in women in Japan is one of the lowest in developed countries. In an attempt to shed some light on possible reasons of lower CHD in women in Japan compared with the United States, we extensively reviewed and analyzed existing national data and recent literature.

METHODS

We searched recent epidemiological studies that reported incidence of acute myocardial infarction (AMI) and examined risk factors for CHD in women in Japan. Then, we compared trends in risk factors between women currently aged 50-69 years in Japan and the United States, using national statistics and other available resources.

RESULTS

Recent epidemiological studies have clearly shown that AMI incidence in women in Japan is lower than that reported from other countries, and that lipids, blood pressure (BP), diabetes, smoking, and early menopause are independent risk factors. Comparing trends in risk factors between women in Japan and the United States, current levels of serum total cholesterol are higher in women in Japan and levels have been similar at least since 1990. Levels of BP have been higher in in Japan for the past 3 decades. Prevalence of type 2 diabetes has been similar in Japanese and white women currently aged 60-69 for the past 2 decades. In contrast, rates of cigarette smoking, although low in women in both countries, have been lower in women in Japan.

CONCLUSIONS

Differences in risk factors and their trends are unlikely to explain the difference in CHD rates in women in Japan and the United States. Determining the currently unknown factors responsible for low CHD mortality in women in Japan may lead to new strategy for CHD prevention.

Components of air pollution and cognitive function in middle-aged and older adults in Los Angeles

While experiments in animals demonstrate neurotoxic effects of particulate matter (PM) and ozone (O3), epidemiologic evidence is sparse regarding the relationship between different constituencies of air pollution mixtures and cognitive function in adults. We examined cross-sectional associations between various ambient air pollutants [O3, PM2.5 and nitrogen dioxide (NO2)] and six measures of cognitive function and global cognition among healthy, cognitively intact individuals (n=1496, mean age 60.5 years) residing in the Los Angeles Basin. Air pollution exposures were assigned to each residential address in 2000-06 using a geographic information system that included monitoring data. A neuropsychological battery was used to assess cognitive function; a principal components analysis defined six domain-specific functions and a measure of global cognitive function was created. Regression models estimated effects of air pollutants on cognitive function, adjusting for age, gender, race, education, income, study and mood. Increasing exposure to PM2.5 was associated with lower verbal learning (β=-0.32 per 10 μg/m(3) PM2.5, 95% CI=-0.63, 0.00; p=0.05). Ambient exposure to NO2 >20 ppb tended to be associated with lower logical memory. Compared to the lowest level of exposure to ambient O3, exposure above 49 ppb was associated with lower executive function. Including carotid artery intima-media thickness, a measure of subclinical atherosclerosis, in models as a possible mediator did not attenuate effect estimates. This study provides support for cross-sectional associations between increasing levels of ambient O3, PM2.5 and NO2 and measures of domain-specific cognitive abilities.

Timing hypothesis for postmenopausal hormone therapy: its origin, current status, and future

OBJECTIVE

This work aims to review preclinical/clinical cardiovascular studies that led to randomized trials of the risks and benefits of postmenopausal hormone therapy (HT), the pathobiological basis for the timing hypothesis, and subset analyses of randomized trials that tend to support the timing hypothesis; to elaborate experimental data that might inform the results of recent trials; and to summarize evidence regarding how early is early enough for the initiation of HT.

METHODS

This work used interpretive literature review.

RESULTS

Preclinical and large observational studies provided what was considered at the time to be convincing evidence that HT provided protection against progressing coronary artery atherosclerosis. Those findings prompted three randomized, placebo-controlled, prospective trials to determine the risks and benefits of HT. None provided any evidence that HT had any beneficial effects on preexisting coronary artery atherosclerosis. Monkey studies provided clear evidence that HT was effective in slowing the progression of coronary artery atherosclerosis only when administered soon after surgical menopause and that benefit was lost if estrogen therapy was delayed until the plaques had become complicated. The phenomenon was referred to as the "timing hypothesis," and evidence for its translation into postmenopausal women was sought in subset analyses of data from the Women's Health Initiative and from newly planned prospective trials.

CONCLUSIONS

Current data are both supportive and not supportive of the timing hypothesis. However, evidence indicating that estrogens administered in the perimenopausal transition or early in menopause are not harmful to the cardiovascular system and, when given for a few years for the treatment of menopausal symptoms, may slow the progression of atherosclerosis and reduce the postmenopausal cardiovascular disease burden seems convincing.

Vascular function and atherosclerosis progression after 1 y of flavonoid intake in statin-treated postmenopausal women with type 2 diabetes: a double-blind randomized controlled trial

BACKGROUND

In healthy participants, short-term flavan-3-ol and isoflavone intakes improve vascular function; however, the potential combined benefit of these compounds on atherosclerosis progression remains unclear for those at elevated risk of cardiovascular disease.

OBJECTIVE

The objective was to examine whether combined isoflavone and flavan-3-ol intake alters vascular function in postmenopausal women with type 2 diabetes mellitus (T2DM).

DESIGN

A double-blind, parallel-design, placebo-controlled 1-y trial was conducted in postmenopausal T2DM patients randomly assigned to a split dose of 27 g flavonoid-enriched chocolate/d [850 mg flavan-3-ols (90 mg epicatechin) + 100 mg isoflavones (aglycone equivalents)/d] or matched placebo. Intima-media thickness of the common carotid artery (CCA-IMT), pulse wave velocity (PWV), augmentation index, blood pressure (BP), and vascular biomarkers were assessed.

RESULTS

A total of 93 patients completed the trial. Overall, the flavonoid intervention did not significantly change CCA-IMT, augmentation index, or BP, but pulse pressure variability improved (flavonoid: -0.11 ± 0.07 mm Hg/min; placebo: 0.10 ± 0.11 mm Hg/min; P = 0.04). In a subgroup with PWV data, net improvements were observed [flavonoid (n = 18): -0.07 ± 0.38 m/s; placebo (n = 17): 0.68 ± 0.25 m/s; P = 0.01], which equated to a 10% CV risk reduction. Equol producers (n = 17) had larger reductions in diastolic BP, mean arterial pressure, and PWV (-2.24 ± 1.31 mm Hg, -1.24 ± 1.30 mm Hg, and -0.68 ± 0.40 m/s, respectively; P < 0.01) compared with non-equol producers (n = 30).

CONCLUSIONS

Although the 1-y intervention did not change CCA-IMT or BP, clinically relevant improvements in arterial stiffness were observed; equol producers were particularly responsive. Flavonoids may augment existing therapeutic strategies to reduce cardiovascular disease risk in postmenopausal T2DM patients, and longer studies are needed to examine the effects on atherosclerosis progression. This trial was registered at clinicaltrials.gov as NCT00677599.

An update on menopausal hormone replacement therapy in women and cardiovascular disease

PURPOSE OF REVIEW

This review presents the available evidence for effects of menopausal hormone replacement therapy (MHT), more specifically estrogen, and selective estrogen receptor modulators on the cardiovascular system with a focus on randomized controlled trials (RCTs) published since 2010.

RECENT FINDINGS

In contrast to early observational studies, the Women's Health Initiative, the largest randomized controlled trial of MHT in generally healthy women, suggested harmful cardiovascular effects. Subsequent subanalyses of the Women's Health Initiative and other studies suggest the cardiovascular effects of MHT may vary by age and time since menopause, giving rise to a 'timing hypothesis'. Recent trials have looked at this issue by evaluating surrogate markers of cardiovascular disease (CVD) or CVD events adjudicated as secondary outcomes in RCTs and show a reduction in events with MHT.

SUMMARY

Athough the data overall do not support the use of MHT or selective estrogen receptor modulator for primary prevention of CVD, evidence is accumulating that careful use of MHT for perimenopausal symptoms may not carry CVD harm. This review highlights some of the strengths and weaknesses of these recent reports. Ongoing studies of MHT will shed more light on the interaction between age or time after menopause and the vascular effects of MHT.

Self-reported menopausal symptoms, coronary artery calcification, and carotid intima-media thickness in recently menopausal women screened for the Kronos early estrogen prevention study (KEEPS)

OBJECTIVE

To determine whether self-reported menopausal symptoms are associated with measures of subclinical atherosclerosis.

DESIGN

Cross-sectional analysis.

SETTING

Multicenter, randomized controlled trial.

PATIENT(S)

Recently menopausal women (n = 868) screened for the Kronos Early Estrogen Prevention Study (KEEPS).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Baseline menopausal symptoms (hot flashes, dyspareunia, vaginal dryness, night sweats, palpitations, mood swings, depression, insomnia, irritability), serum E2 levels, and measures of atherosclerosis were assessed. Atherosclerosis was quantified using coronary artery calcium (CAC) Agatston scores (n = 771) and carotid intima-media thickness (CIMT). Logistic regression model of menopausal symptoms and E2 was used to predict CAC. Linear regression model of menopausal symptoms and E2 was used to predict CIMT. Correlation between length of time in menopause with menopausal symptoms, E2, CAC, and CIMT were assessed.

RESULT(S)

In early menopausal women screened for KEEPS, neither E2 nor climacteric symptoms predicted the extent of subclinical atherosclerosis. Palpitations and depression approached significance as predictors of CAC. Other symptoms of insomnia, irritability, dyspareunia, hot flashes, mood swings, night sweats, and vaginal dryness were not associated with CAC. Women with significantly elevated CAC scores were excluded from further participation in KEEPS; in women meeting inclusion criteria, neither baseline menopausal symptoms nor E2 predicted CIMT. Years since menopause onset correlated with CIMT, dyspareunia, vaginal dryness, and E2.

CONCLUSION(S)

Self-reported symptoms in recently menopausal women are not strong predictors of subclinical atherosclerosis. Continued follow-up of this population will be performed to determine whether baseline or persistent symptoms in the early menopause are associated with progression of cardiovascular disease.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00154180.

Can breast cancer patients use soyafoods to help reduce risk of CHD?

Over the past 20 years, the popularity of soyafoods has increased in part because of research suggesting that these foods convey health benefits independent of their nutrient content. For example, in 1999, the US Food and Drug Administration approved a health-claim for soyafoods and CHD based on the hypocholesterolaemic effects of soya protein. However, soyafoods have become controversial in recent years because of concerns that their uniquely rich phyto-oestrogen (isoflavone) content may cause untoward effects in some individuals. Most notable in this regard is the concern that soyafoods are contraindicated for breast cancer patients and women at high risk of developing this disease. Furthermore, the hypocholesterolaemic effects of soya protein have been challenged. However, the results of recently published meta-analyses indicate that soya protein directly lowers circulating LDL-cholesterol levels by approximately 4 %. There is also intriguing evidence that soyafoods reduce CHD risk independent of their effects on lipid levels. In regard to the breast cancer controversy, recently published clinical and epidemiological data do not support observations in rodents that soyabean isoflavones increase breast cancer risk. In postmenopausal women, isoflavone exposure does not adversely affect breast tissue density or breast cell proliferation. Furthermore, both US and Chinese prospective epidemiological studies show that post-diagnosis soya consumption is associated with an improved prognosis. Therefore, soyafoods should be considered by women as healthy foods to include in diets aimed at reducing the risk of CHD regardless of their breast cancer status.

Long-term soy isoflavone supplementation and cognition in women: a randomized, controlled trial

OBJECTIVE

To determine the cognitive effects of long-term dietary soy isoflavones in a daily dose comparable to that of traditional Asian diets.

METHODS

In the double-blind Women's Isoflavone Soy Health trial, healthy postmenopausal women were randomly allocated to receive daily 25 g of isoflavone-rich soy protein (91 mg of aglycone weight of isoflavones: 52 mg of genistein, 36 mg of daidzein, and 3 mg glycitein) or milk protein-matched placebo. The primary cognitive endpoint compared between groups at 2.5 years was change from baseline on global cognition, a composite of the weighted sum of 14 neuropsychological test score changes. Secondary outcomes compared changes in cognitive factors and individual tests.

RESULTS

A total of 350 healthy postmenopausal women aged 45-92 years enrolled in this trial; 313 women with baseline and endpoint cognitive test data were included in intention-to-treat analyses. Adherence in both groups was nearly 90%. There was no significant between-group difference on change from baseline in global cognition (mean standardized improvement of 0.42 in the isoflavone group and 0.31 in the placebo group; mean standardized difference 0.11, 95% confidence interval [CI] -0.13 to 0.35). Secondary analyses indicated greater improvement on a visual memory factor in the isoflavone group (mean standardized difference 0.33, 95% CI 0.06-0.60) but no significant between-group differences on 3 other cognitive factors or individual test scores, and no significant difference within a subgroup of younger postmenopausal women.

CONCLUSION

For healthy postmenopausal women, long-term dietary soy isoflavone supplementation in a dose comparable to that of traditional Asian diets has no effect on global cognition but may improve visual memory.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that long-term dietary supplementation with isoflavone-rich soy protein does not improve global cognition of healthy postmenopausal women.

The timing hypothesis for coronary heart disease prevention with hormone therapy: past, present and future in perspective

Over the past decade, two informative events in primary prevention of coronary heart disease (CHD) have occurred for women's health. The first concerns hormone replacement therapy (HRT) where data have come full circle from presumed harm to consistency with observational data that HRT initiation in close proximity to menopause significantly reduces CHD and overall mortality. The other concerns sex-specific efficacy of CHD primary prevention therapies where lipid-lowering and aspirin therapy have not been conclusively shown to significantly reduce CHD and, more importantly, where there is lack of evidence that either therapy reduces overall mortality in women. Cumulated data support a 'window-of-opportunity' for maximal reduction of CHD and overall mortality and minimization of risks with HRT initiation before 60 years of age and/or within 10 years of menopause and continued for 6 years or more. There is a substantial increase in quality-adjusted life-years over a 5-30-year period in women who initiate HRT in close proximity to menopause, supporting HRT as a highly cost-effective strategy for improving quality-adjusted life. Although primary prevention therapies and HRT contrast in their efficacy to significantly reduce CHD and especially overall mortality in postmenopausal women, the magnitude and types of risks associated with HRT are similar to those associated with other medications commonly used in women's health. The cumulated data highlight the importance of studying the HRT cardioprotective hypothesis in women representative of those from whom the hypothesis was generated.