Jeanne W. Stewart

The Soy Isoflavones for Reducing Bone Loss (SIRBL) Study: a 3-y randomized controlled trial in postmenopausal women

BACKGROUND Our previous study indicated that soy protein with isoflavones lessened lumbar spine bone loss in midlife women. OBJECTIVE We examined the efficacy of isoflavones (extracted from soy protein) on bone mineral density (BMD) in nonosteoporotic postmenopausal women. We hypothesized that isoflavone tablets would spare BMD, with biological (age, body weight, serum 25-hydroxyvitamin D) and lifestyle (physical activity, dietary intake) factors modulating BMD loss. DESIGN Our double-blind, randomized controlled trial (36 mo) included healthy postmenopausal women (aged 45.8-65.0 y) with intent-to-treat (n = 224) and compliant (n = 208) analyses. Treatment groups consisted of a placebo control group and 2 soy isoflavone groups (80 compared with 120 mg/d); women received 500 mg calcium and 600 IU vitamin D(3). Outcomes included lumbar spine, total proximal femur, femoral neck, and whole-body BMD. RESULTS Analysis of variance for intent-to-treat and compliant (> or =80%) models, respectively, showed no treatment effect for spine (P = 0.46, P = 0.21), femur (P = 0.86, P = 0.46), neck (P = 0.17, P = 0.14), or whole-body (P = 0.86, P = 0.78) BMD. From baseline to 36 mo, BMD declined regardless of treatment. In intent-to-treat and compliant models, respectively, BMD decreases were as follows: spine (-2.08%, -1.99%), femur (-1.43%, -1.38%), neck (-2.56%, -2.51%), and whole body (-1.66%, -1.62%). Regression analysis (compliant model) indicated that age, whole-body fat mass, and bone resorption were common predictors of BMD change. After adjustment for these factors, 120 mg (compared with placebo) was protective (P = 0.024) for neck BMD. We observed no treatment effect on adverse events, endometrial thickness, or bone markers. CONCLUSION Our results do not show a bone-sparing effect of extracted soy isoflavones, except for a modest effect at the femoral neck. This trial was registered at clinicaltrials.gov as NCT00043745.

Individual and Interactive Effects of Apigenin Analogs on G2/M Cell-Cycle Arrest in Human Colon Carcinoma Cell Lines

Apigenin has been previously shown to induce G2/M cell-cycle arrest in human colon cancer cell lines. The present study assessed the individual and interactive influence of seven apigenin analogs on cell cycle, cell number, and cell viability in human SW480 and Caco-2 colonic carcinoma cells. Cellular concentration of selected apigenin analogs was further assessed by high-performance liquid chromatography to assess cellular availability. The apigenin analogs studied were acacetin, chrysin, kampherol, luteolin, myricetin, naringenin, and quercetin. DNA flow cytometric analysis indicated that treatment with either chrysin or acacetin at 0 to 80 μM for 48 h resulted in cell-cycle arrest at the G2/M phase in a dose-dependent manner in the SW480 cells but not in the Caco-2 cells. The percentage of SW480 cells at G2/M also increased when cells were treated with kampherol, luteolin, or quercetin between 5 and 30 μM, but the percentage of cells in G2/M decreased at doses greater than 40 μM. Cell number was significantly decreased in a time- and dose-dependent manner following the treatments with each analog except for naringenin and myricetin. The interactive effects of these analogs with apigenin were further assessed by combining each analog at doses from 0 to 80 μM with apigenin at 20 μM, a dose at which apigenin was found to double the proportion of SW480 cells in G2/M. When either acacetin, chrysin, luteolin, kampherol, or quercetin at doses between 5 and 30 μM were combined with apigenin at 20 μM, there was an increase of 22% in the proportion of G2/M cells over that observed with 20 μM apigenin alone (P < 0.05). At doses higher than 40 μM, however, the interaction became antagonistic, and the proportion of cells in G2/M decreased below that observed with apigenin alone. Cell viability, as assessed by Trypan blue exclusion assay, significantly decreased by treatments with high doses of each agent or each agent combined with apigenin. Cellular concentration of apigenin, chrysin, or naringenin in SW480 cells significantly increased at doses of 40 μM or greater, but it was not correlated with their impact on G2/M cell-cycle arrest. The induction of cell-cycle arrest by five of seven tested apigenin analogs and the additive induction by the combination of flavonoids at low doses suggest that apigenin-related flavonoids may cooperatively protect against colorectal cancer through conjoint blocking of cell-cycle progression.

Serum 25-hydroxyvitamin D is related to indicators of overall physical fitness in healthy postmenopausal women.

Objective: Inadequate vitamin D status is related to increased adiposity, risk of falls, and muscle weakness, particularly in older people. We hypothesized that serum 25-hydroxyvitamin D [25(OH)D] is related to physical fitness indices (androidal fat, whole body lean mass, balance, strength) in healthy postmenopausal women. Methods: Covariates for fitness indices included age or years since menopause, weight, 25(OH)D, energy expenditure, and calcium intake. Overall and regional (androidal fat mass = waist + hip fat) body composition was assessed (N = 242) via dual-energy x-ray absorptiometry. Results: Regression analyses revealed that 71% of variability (P ≤ 0.0001) in androidal fat mass was accounted for by weight (53.0%, P ≤ 0.0001), white blood cell (WBC) count (2.0%, P ≤ 0.0001), supplemental calcium (1.7%, P = 0.0004), years since menopause (1.1%, P = 0.0034), 25(OH)D (1.0%, P = 0.0051), and vegetable servings (0.6%, P = 0.027); 64% of variability (P ≤ 0.0001) in lean mass was accounted for by weight (63.1.%, P ≤ 0.0001), WBC count (1.4%, P = 0.0038), and 25(OH)D (1.0%, P = 0.013); 12% of variability (P ≤ 0.0001) in balance (right + left leg) was accounted for by age (3.8%, P = 0.0019), 25(OH)D (2.0%, P = 0.025), and WBC count (1.8%, P = 0.032); 14% of variability (P ≤ 0.0001) in handgrip strength (right + left) was accounted for by weight (9.3%, P ≤ 0.0001), 25(OH)D (2.4%, P = 0.013), WBC count (2.1%, P = 0.019), and age (1.6%, P = 0.044); and 22% of variability (P ≤ 0.0001) in torso strength was accounted for by site (15.0%, P ≤ 0.0001) and weight (4.6%, P = 0.0003). Conclusions: Serum 25(OH)D was the common contributor to physical fitness indices (androidal fat mass, lean mass, balance, handgrip strength) in healthy postmenopausal women.

Centrally located body fat is related to inflammatory markers in healthy postmenopausal women

Objective:C-reactive protein and fibrinogen are established atherosclerotic cardiovascular disease risk factors. These acute-phase proteins and the proinflammatory cytokines tumor necrosis factor &agr;, interleukin-6, and interleukin-1&bgr; may be elevated in obesity and with menopause. The purpose of this multicenter study was to identify whether centrally located fat and/or overall adiposity were related to these inflammatory markers in healthy postmenopausal women. Design:We used dual-energy x-ray absorptiometry to assess overall and regional body composition (fat mass in particular) in 242 postmenopausal women in relation to plasma fibrinogen, serum C-reactive protein, and these proinflammatory cytokines. Results:Multiple regression analyses revealed that 36% of the variability in C-reactive protein (F = 32.4, P ≤ 0.0001) was accounted for by androidal fat mass (16.1%, P ≤ 0.0001), white blood cells (5.6%, P ≤ 0.0001), and age (2.3%, P = 0.0045). Regression analyses revealed that 30% of the variability in fibrinogen (F = 24.5, P ≤ 0.0001) was accounted for by white blood cells (3.1%, P = 0.0015), hip fat mass (2.2%, P = 0.0081), years since menopause (0.9%, P = 0.082), and geographic site (P ≤ 0.0001). Our results indicated that androidal fat mass and hip fat mass contributed to C-reactive protein and fibrinogen, respectively, whereas we found no association between whole-body or regional fat measures and cytokines. Conclusion:Further study is warranted to determine the responsiveness of these acute-phase proteins and cytokines to loss of body fat through exercise and dietary intervention in postmenopausal women.

Identification of molecular targets for dietary energy restriction prevention of skin carcinogenesis: An idea cultivated by Edward Bresnick

Dietary energy restriction (DER) has long been known to strikingly inhibit carcinogenesis in many animal models. The animal data has been corroborated by recent and ongoing epidemiological studies demonstrating the importance of energy balance, physical exercise and obesity in human cancer. Dr. Edward Bresnick provided key insights into this important area of research and pivotal direction for the authors research while he served as Director of the Eppley Institute for Research in Cancer, Omaha, NE. These insights moved this research toward demonstrating that DER reduced the expression of key protein kinase C isoforms in mouse skin. More recent studies have uncovered downstream events that are inbibited by DER including blockage of tumor promoter activation of Raf‐1, ERK 1,2 and AP‐1 expression. Parallel studies have demonstrated the DER inhibition of these key cellular signaling events in mouse skin carcinogenesis are dependent upon an intact adrenal gland because adrenalectomized mice fed DER diet did not have reduced tumor burden or inhibited signaling and blocked AP‐1 activation as was observed in DER mice with intact adrenal glands. In addition, the DER inhibition of tumorigenesis and AP‐1 signaling was restored in adrenalectomized mice that were given corticosterone in the drinking water. This showed that in mice in the chemical carcinogenesis protocol glucocorticoid hormone plays a major role in mediating DER prevention of cancer. Studies are ongoing to further assess the mechanism of DER modulation of skin cancer by assessing impacts on transcriptional regulation and expression of genes that are critical in skin carcinogenesis.

Contribution of Serum Inflammatory Markers to Changes in Bone Mineral Content and Density in Postmenopausal Women: A 1-Year Investigation

Bone formation and resorption are influenced by inflammatory processes. We examined the relationships among inflammatory markers and bone mineral content (BMC) and density (BMD) and determined the contribution of inflammatory markers to 1-yr changes in BMC and BMD in healthy postmenopausal women. This analysis included 242 women at baseline from our parent Soy Isoflavones for Reducing Bone Loss project who were randomly assigned to 1 of 3 treatment groups: placebo, 80 mg/d soy isoflavones, or 120 mg/d soy isoflavones. BMD and BMC from the lumbar spine (LS), total proximal femur (hip), and whole body were measured by dual energy X-ray absorptiometry and the 4% distal tibia by peripheral quantitative computed tomography. Serum inflammatory markers (C-reactive protein, interleukin [IL]-1 beta, IL-6, tumor necrosis factor-alpha [TNF-alpha], and white blood cell count [WBC]) were measured at baseline, 6, and 12 mo. Because of attrition or missing values, data analysis at 12 mo includes only 235 women. Significant associations among IL-6, TNF-alpha, and WBC were observed with percent change in LS, hip, and whole body BMC and BMD. Multiple regression analysis indicated that in combination inflammatory markers accounted for 1.1-6.1% of the variance to the observed 12-mo changes in BMC and BMD. Our results suggest that modifying inflammatory markers, even in healthy postmenopausal women, may possibly reduce bone loss.

Centrally located body fat is related to appetitive hormones in healthy postmenopausal women

OBJECTIVE Body composition and energy homeostasis are thought to affect the appetitive hormones: adiponectin, leptin, insulin, and ghrelin. This study examined whether centrally located fat and/or overall adiposity were related to these appetitive hormones in healthy postmenopausal women. DESIGN Overall and regional body composition was assessed by dual-energy X ray absorptiometry in relation to plasma adiponectin, serum leptin, serum insulin, and plasma ghrelin in 242 postmenopausal women. RESULTS Regression analyses revealed that the androidal-to-gynoidal fat mass ratio (18.0%), age (3.2%), and white blood cell count (1.8%) accounted for 28% of the variability in adiponectin (F=22.2; P<0.0001); androidal (waist+hip) fat mass (66.0%), androidal fat mass(2) (6.2%), whole-body lean mass (2.2%), and age (0.8%) accounted for 69% of the variability in leptin (F=102.5; P<0.0001). Regression analyses revealed that sagittal abdominal diameter (8.4%), glucose (5.4%), white blood cell count (2.6%), and dietary omega-3 fatty acids (2.0%) accounted for 32% of the variability in insulin (F=20.8; P<0.0001); waist circumference (12.7%), hip lean mass (2.0%), and white blood cell count (1.9%) accounted for 26% of the variability in ghrelin (F=20.7; P<0.0001). Our results indicated that centralized fat mass was the primary contributor to these appetitive hormones in healthy postmenopausal women. CONCLUSION Since central adiposity in postmenopausal women was related to appetitive hormones, minimizing weight gain during the menopausal transition may optimize appetitive hormones, thereby facilitating appetite control and weight maintenance.

Blood plasma lipoprotein and tissue cholesterol of calves fed soybean oil, corn oil, vegetable shortening or tallow☆

The objective of this study was to determine cholesterol content of blood plasma, blood plasma lipoproteins and tissues of calves fed fats of differing compositions. Groups of 2-week-old calves were fed one of the following fats in a reconstituted milk formula: soybean oil, corn oil, vegetable shortening or tallow. The diets contained no dry feed or added cholesterol. Blood plasma cholesterol concentrations increased with time for all groups. After 15 weeks, cholesterol concentrations were greater in the blood, liver and fat of the groups fed soybean oil and corn oil than in those of the groups fed vegetable shortening and tallow. Low density lipoprotein was identified as the carrier of the increased amounts of cholesterol noted in the blood.

Iron Absorption from Iron-enriched Aspergillus oryzae is Similar to Ferrous Sulfate in Healthy Female Subjects

Abstract Background Iron deficiency anemia (IDA) remains a global health issue, affecting mainly children and adolescent and pregnant women. Because of problems associated with current iron compounds used in both supplementation and fortification areas, there is an emerging interest in new natural iron sources to combat IDA. Objective The objective of this study was to compare the iron absorption of iron-enriched Aspergillus oryzae [Aspiron (ASP)] with FeSO4 in humans. Methods Iron absorption was assessed using stable isotope and serum iron response methods after oral intake of iron by healthy women in 2 separate studies. In the first study, ASP was intrinsically labelled with 58Fe into a dry form containing 8% iron. Subjects (n = 16, 18–35 y) were randomly assigned to consume liquid semipurified meals labelled with 2 stable iron isotopes, 57FeSO4 (10 mg) and ASP containing 2 mg 58Fe and 8 mg natural abundance iron, in 2 visits. Isotope enrichment was measured 2 wk after the last meal was eaten. In the second study, 17 subjects were randomly assigned to consume a test meal with 3 iron supplements during 3 separate visits: FeSO4, 10 mg Fe, and ASP in 2 iron doses, 10 mg and 20 mg. Changes in serum iron were measured at regular intervals for 4 h after supplementation. Results The first study showed that the difference in iron absorption from FeSO4 and ASP was not significant (17.18% ± 14.2% compared to 15.14% ± 12.3%; P = 0.07). The results of the second study suggested that the iron from ASP was released slowly compared to FeSO4 and the area under the curve did not reflect the absorption of ASP iron, but rather the rate of iron release. Conclusions Iron-enriched A. oryzae has high relative bioavailability and may cause lower iron surges into the blood compared to FeSO4.