Objectives: The purpose of this cross-sectional study was to examine whether single nucleotide polymorphisms (SNPs) in enzymes that metabolize sex steroid hormones were associated with the blood levels of these hormones in postmenopausal women and if the use of menopausal hormone therapy (MHT) could modify this association.
Methods: Baseline data were collected from 932 postmenopausal women enrolled in the Minnesota Green Tea Trial. Participants filled out a questionnaire about their demographics, lifestyle factors, and medical and reproductive history.
This compilation includes the stories of 5 Native American and First Nation elders, in which they share their wisdom, experience, and opinions on Indigenous food systems and health. Each of these elders participated in the Fourth Annual Conference on Native American Nutrition, held in September 2019 at Mystic Lake Center on land of the Shakopee Mdewakanton Sioux Community in Prior Lake, Minnesota.
View Article and Find Full Text PDFThe purpose of this cross-sectional study was to examine the relationship between diet and anthropometric measures in postmenopausal women. Data collected from 937 women enrolled in the Minnesota Green Tea Trial (NTC00917735) were used for this analysis. Dietary intake and health-related data were collected via questionnaires.
View Article and Find Full Text PDFBackground: Consumption of green tea has been associated with reduced risk of breast cancer. Hormonal modulation has been suggested as one of the potential underlying mechanisms; however, it has yet to be fully elucidated in large, long-term human clinical trials.
Objective: We investigated the effects of decaffeinated green tea extract (GTE) on circulating sex hormones and insulin-like growth factor (IGF) proteins.
Previous data from this group demonstrate that the murine lung metabolizes estrogen. Production of the putative carcinogen 4-hydroxyestrogen (4-OHE) is elevated within the lungs of female vs. male mice and accelerated by tobacco smoke.
View Article and Find Full Text PDFBackground: Postmenopausal symptomatology has not been elucidated in large, long-term human clinical trials. Our objective was to measure quality of life in postmenopausal women aged 50-70 years.
Methods: A Menopause-Specific Quality of Life-Intervention (MENQOL) questionnaire was completed by women enrolled in the Minnesota Green Tea Trial (n=932) to assess vasomotor, physical, sexual, and psychosocial symptoms in the years following menopause.
Epidemiologic and animal studies suggest a protective role of green tea against breast cancer. However, the underlying mechanism is not understood. We conducted a randomized, double-blinded, placebo-controlled phase II clinical trial to investigate whether supplementation with green tea extract (GTE) modifies mammographic density (MD), as a potential mechanism, involving 1,075 healthy postmenopausal women.
View Article and Find Full Text PDFCancer Prev Res (Phila)
October 2017
Liver injury effects of green tea-based products have been reported in sporadic case reports. However, no study has examined systematically such adverse effects in an unbiased manner. We examined the potential effects of a high, sustained oral dose of green tea extract (GTE) on liver injury measures in a randomized, placebo-controlled, double-blinded phase II clinical trial, which enrolled 1,075 women with the original aim to assess the effect of daily GTE consumption for 12 months on biomarkers of breast cancer risk.
View Article and Find Full Text PDFDietary factors, such as antioxidant nutrients, contribute significantly to the maintenance of an appropriate balance between antioxidant defense and free radical production in the body. The objective of this study was to examine the relation between oxidative stress as assessed by plasma F-isoprostane (IsoP) concentration, glycemic load (GL), glycemic index (GI), intake of antioxidant nutrients, dietary fiber, and polyunsaturated fatty acids (PUFAs). This study was a cross-sectional secondary analysis of baseline data collected from a random sample of 269 postmenopausal women participating in the Minnesota Green Tea Trial.
View Article and Find Full Text PDFBackground: Weight gain often occurs after breast cancer (BC) diagnosis and obesity along with sedentary behavior are associated with increased risk of BC recurrence and mortality. The primary objective of this study was to determine whether a significant weight loss, of approximately 10%, would lead to beneficial changes in biomarkers associated with cancer and/or cancer recurrence, and quality of life (QOL) in overweight and obese BC survivors.
Methods: This parallel-arm study took place in Minneapolis, Minnesota, from January 2009 until March 2010.
Background: Green tea has been suggested to improve cardiovascular disease risk factors, including circulating lipid variables. However, current evidence is predominantly based on small, short-term randomized controlled trials conducted in diverse populations.
Objective: The aim of this study was to examine the efficacy and impact of green tea extract (GTE) supplementation high in epigallocatechin gallate (EGCG) on blood lipids in healthy postmenopausal women.
2-Phenethyl isothiocyanate (PEITC), a natural product found as a conjugate in watercress and other cruciferous vegetables, is an inhibitor of the metabolic activation and lung carcinogenicity of the tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in F344 rats and A/J mice. We carried out a clinical trial to determine whether PEITC also inhibits the metabolic activation of NNK in smokers. Cigarette smokers were recruited and asked to smoke cigarettes containing deuterium-labeled [pyridine-D4]NNK for an acclimation period of at least 1 week.
View Article and Find Full Text PDFBackground: Green tea extract (GTE) consumption has been linked to favorable changes in adiposity and bone mineral density (BMD), although it is unknown if these effects are due to green tea catechins or caffeine. The catechol-O-methyltransferase (COMT) genotype may also modify these associations.
Objective: We examined the impact of decaffeinated GTE on body composition (using dual-energy X-ray absorptiometry) and obesity-associated hormones.
Nutritional and body weight recommendations for cardiovascular diseases are well established, yet there are no equivalent guidelines for peripheral arterial disease (PAD). This cross-sectional study measured the prevalence of cardiovascular-related nutritional and body composition risk factors in sixty PAD patients and their association with PAD severity. A diet that exceeds daily recommended intake of fat and that falls short of recommended intakes of fiber, folate, and vitamin D was associated with increased leg pain and walking difficulty.
View Article and Find Full Text PDFJ Nutr
January 2016
Background: Green tea consumption has been associated with favorable changes in body weight and obesity-related hormones, although it is not known whether these changes result from green tea polyphenols or caffeine.
Objective: We examined the impact of decaffeinated green tea extract (GTE) containing 843 mg of (-)-epigallocatechin-3-gallate on anthropometric variables, obesity-associated hormones, and glucose homeostasis.
Methods: The Minnesota Green Tea Trial was a 12-mo randomized, double-blind, placebo-controlled clinical trial of 937 healthy postmenopausal women assigned to either decaffeinated GTE (1315 mg total catechins/d) or a placebo, stratified by catechol-O-methyltransferase (COMT) genotype.
Unlabelled: Medical and surgical interventions for elevated breast cancer risk (e.g., BRCA1/2 mutation, family history) focus on reducing estrogen exposure.
View Article and Find Full Text PDFObjective: To assess the relationship between SHBG and 18 other hormonal and metabolic parameters in well characterized, normally cycling premenopausal women.
Design: Cross-sectional study.
Setting: University general clinical research center.
Patient Prefer Adherence
August 2015
Peripheral arterial disease (PAD) is a group of syndromes characterized by chronic and progressive atherosclerosis with a high burden of physical disability and cardiovascular morbidity and mortality. Recruiting patients for clinical research is therefore challenging. In this article, we describe and evaluate our methods for recruiting participants for a cross-sectional feasibility study of PAD, nutritional status, and body composition.
View Article and Find Full Text PDFPurpose: The Minnesota Green Tea Trial (MGTT) was a randomized, placebo-controlled, double-blinded trial investigating the effect of daily green tea extract consumption for 12 months on biomarkers of breast cancer risk.
Methods: Participants were healthy postmenopausal women at high risk of breast cancer due to dense breast tissue with differing catechol-O-methyltransferase (COMT) genotypes. The intervention was a green tea catechin extract containing 843.
Green tea is thought to provide health benefits, though adverse reactions to green tea extract (GTE) have been reported. We conducted a randomized, double-blind, placebo-controlled study of GTE on breast cancer biomarkers, including mammographic density, in which 1075 postmenopausal women were randomly assigned to consume GTE containing 843 mg (-)-epigallocatechin-3-gallate (EGCG) or placebo daily for one year. There were no significant differences in % of women with adverse events (AEs, 75.
View Article and Find Full Text PDFContemp Clin Trials
March 2015
Purpose: Women at elevated risk for breast cancer are motivated to reduce their risk. Current approaches rely primarily on hormonal intervention. A preventive exercise intervention might address the same hormonal issues, yet have fewer serious side effects and less negative impact on quality of life as compared to prophylactic mastectomy.
View Article and Find Full Text PDFResearch studies have suggested that chronic consumption of high glycemic index foods may lead to chronically high oxidative stress. This is important because oxidative stress is suspected to be an early event in the etiology of many disease processes. We hypothesized that dietary glycemic index and glycemic load were positively associated with oxidative stress assessed by plasma F2-isoprostanes in healthy, premenopausal women (body mass index [BMI] = 24.
View Article and Find Full Text PDFObjective: This study aims to assess the overall safety and potential endometrium-stimulating effects of soy isoflavone tablets consumed (3 y) by postmenopausal women and to determine endometrial thickness response to treatment among compliant women, taking into account hormone concentrations and other hypothesized modifying factors.
Methods: We randomized healthy postmenopausal women (aged 45.8-65.