Fruits and vegetables and ovarian cancer risk in a pooled analysis of 12 cohort studies.

Because fruits and vegetables are rich in bioactive compounds with potential cancer-preventive actions, increased consumption may reduce the risk of ovarian cancer. Evidence on the association between fruit and vegetable intake and ovarian cancer risk has not been consistent. We analyzed and pooled the primary data from 12 prospective studies in North America and Europe.

Racial differences in premenopausal endogenous hormones.

Differences in breast cancer incidence across racial groups are well documented. African Americans have the highest rates of premenopausal breast cancer and Asians have lower breast cancer rates across all age groups. We hypothesized that levels of premenopausal endogenous hormones and growth factors, risk factors that have been predictive of breast cancer, would differ by race.

Androgen receptor polymorphisms and endometrial cancer risk.

The androgen receptor (AR) gene is a transcription factor responsible for mediating the physiological effects of androgens. Evidence suggests that androgens and the androgen receptor are involved in uterine cell proliferation. A polymorphic CAG repeat in exon 1 of the AR gene encodes a polyglutamine tract that is inversely correlated with the transcriptional activity of this gene.

Folate intake and risk of breast cancer characterized by hormone receptor status.

Folate plays an important role in DNA methylation, and aberrant methylation of the estrogen receptor (ER) gene may be related to the loss of ER gene expression in breast tumors. Thus, deficient folate status has been hypothesized to be associated primarily with ER gene-negative breast tumors, but data relating folate intake to breast cancer risk according to ER status are sparse. We conducted a prospective cohort analysis of folate intake among 88,744 women in the Nurses' Health Study who completed a food frequency questionnaire in 1980 and every 2 to 4 years thereafter.

Plasma 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D and risk of breast cancer.

Several lines of evidence suggest that vitamin D may reduce incidence of breast cancer, but few epidemiologic studies have addressed the relation of plasma vitamin D metabolites to the risk of this disease. We prospectively examined the relationship between plasma levels of 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)2D] and risk of breast cancer in a case-control study nested within the Nurses' Health Study cohort. Blood samples were collected from study participants in 1989-1990.

Moderate alcohol consumption and lower levels of inflammatory markers in US men and women.

Objective: Moderate alcohol consumption is associated with substantially lower risk of cardiovascular disease (CVD). We assessed the relationship between alcohol intake and inflammatory markers to partially explain this beneficial effect.

Methods And Results: From two large prospective studies, we sampled 959 healthy male and 473 healthy female health professionals with reported alcohol intake.

Alcohol consumption and high-density lipoprotein levels: the effect of ADH1C genotype, gender and menopausal status.

We previously demonstrated that a functional polymorphism in alcohol dehydrogenase type 1C (ADH1C, also known as ADH3) modifies the association between moderate alcohol consumption and high-density lipoprotein (HDL) levels and risk of myocardial infarction among older men. In this study, we investigated the effect of the ADH1C gamma(1) and gamma(2) alleles on the relationship between alcohol consumption and HDL levels among four populations with varied exposure to endogenous and exogenous estrogens: premenopausal women, middle-to-older aged men, postmenopausal women currently using postmenopausal hormones (PMH) and postmenopausal women not currently using PMH. We observed an interaction between moderate alcohol consumption and ADH1C genotype on HDL level that was similar among middle-to-older aged men and postmenopausal women not using PMH.

Plasma C peptide level and cognitive function among older women without diabetes mellitus.

Background: Growing evidence suggests that type 2 diabetes mellitus and hyperinsulinemia may be related to diminished cognition. To help differentiate between the effects of diabetes and insulin, we examined the relation of insulin to cognitive function among nondiabetic participants of the Nurses' Health Study.

Methods: We measured the C peptide level, representing insulin secretion, in blood samples provided by 718 women from June 14, 1989, to October 4, 1990, when they were aged 61 to 69 years.

Urinary melatonin levels and breast cancer risk.

Exposure to light at night suppresses melatonin production, and night-shift work (a surrogate for such exposure) has been associated with an increased risk of breast cancer. However, the association between circulating melatonin levels and breast cancer risk is unclear. In a prospective case-control study nested within the Nurses' Health Study II cohort, we measured the concentration of the major melatonin metabolite, 6-sulphatoxymelatonin (aMT6s), in the first morning urine of 147 women with invasive breast cancer and 291 matched control subjects.

Alcohol intake and methylenetetrahydrofolate reductase polymorphism modify the relation of folate intake to plasma homocysteine.

Background: Folate intake increases plasma folate and reduces total homocysteine (tHcy) concentrations, which may lower coronary artery disease (CAD) and cancer risks. Folate metabolism may be altered by alcohol intake and 2 common polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene, 677C-->T and 1298A-->C.

Objective: We examined whether the associations between folate intake and plasma folate and tHcy concentrations were modified by alcohol intake or variations in the MTHFR gene.

The erbB2/HER2/neu receptor polymorphism Ile655Val and breast cancer risk.

The erbB2 (HER2/neu) gene is found amplified in tumours. A single nucleotide polymorphism at codon 655 (Ile655Val) has been studied in a number of case-control studies with respect to breast cancer risk, with conflicting results. The aim of the present study was to examine the association between this polymorphism and breast cancer risk in a prospective, predominantly Caucasian cohort of women, the Nurses' Health Study.

Calcium and vitamin D intake and risk of incident premenstrual syndrome.

Background: Premenstrual syndrome (PMS) is one of the most common disorders of premenopausal women. Studies suggest that blood calcium and vitamin D levels are lower in women with PMS and that calcium supplementation may reduce symptom severity, but it is unknown whether these nutrients may prevent the initial development of PMS.

Methods: We conducted a case-control study nested within the prospective Nurses' Health Study II cohort.

Mathematical models of ovarian cancer incidence.

Background: Pike has proposed "protected time" as one summary method for modeling reproductive risk factors in relation to ovarian cancer incidence. We evaluate this and other approaches to summarizing risk for ovarian cancer.

Methods: We identified 472 incident cases of ovarian cancer during 2,298,068 person-years of follow-up of 24- to 55-year-old premenopausal women at cohort inception.

Carbohydrate intake and glycemic index in relation to the odds of early cortical and nuclear lens opacities.

Background: Animal studies suggest a role for dietary carbohydrate in cataractogenesis. However, few published human studies have evaluated associations between carbohydrate nutrition and lens opacification.

Objective: Our objective was to test the hypothesis that long-term carbohydrate intake and dietary glycemic index are associated with the odds of early cortical and nuclear opacities.

Caffeinated coffee, decaffeinated coffee, and caffeine in relation to plasma C-peptide levels, a marker of insulin secretion, in U.S. women.

Objective: Coffee consumption is associated with reduced risk of type 2 diabetes, but the mechanism is not clearly understood. Elevated C-peptide, as a marker of insulin secretion, has been linked to insulin-resistant type 2 diabetes. In this study, we examined consumption of caffeinated and decaffeinated coffee and total caffeine in relation to concentrations of plasma C-peptide.

Plasma vitamin B6 and the risk of colorectal cancer and adenoma in women.

Background: Vitamin B6, whose main circulating form is pyridoxal 5'-phosphate (PLP), is important in one-carbon metabolism, which is critical for DNA synthesis and DNA methylation, both of which are potentially involved in colorectal carcinogenesis. However, no previous epidemiologic studies have directly evaluated the association of plasma PLP with risk for colorectal neoplasia.

Methods: We conducted a prospective nested case-control study of 32,826 female participants of the Nurses' Health Study who provided blood specimens in 1989-1990.

Prospective study of dietary fat and risk of cataract extraction among US women.

The authors examined prospectively the association between dietary fat intake and cataract extraction in adult women from the Nurses' Health Study. A total of 71,083 women were followed prospectively for up to 16 years between 1984 and 2000. Dietary fat was assessed by repeated food frequency questionnaires.

The Nurses' Health Study: lifestyle and health among women.

The Nurses' Health Study has grown from a simple questionnaire-based study initiated in 1976 to a rich resource of information collected over 29 years. Important details about lifestyle have been collected throughout the study and, as the study has progressed, blood samples and DNA from buccal cells have been collected and stored. Tumour samples have also been collected from participants who developed cancer.

Plasma sex hormone concentrations and subsequent risk of breast cancer among women using postmenopausal hormones.

Background: Sex hormone concentrations are associated with breast cancer risk among women not using postmenopausal hormones (PMH); however, whether a relationship exists among PMH users is unknown. Therefore, we conducted a prospective, nested case-control study within the Nurses' Health Study (NHS) cohort to examine the association between plasma sex hormone concentrations and postmenopausal breast cancer among women using PMH at blood collection.

Methods: Blood samples were collected from 1989 to 1990.

Long-term nutrient intake and 5-year change in nuclear lens opacities.

Objective: To determine if usual nutrient intake is related to a 5-year change in the amount of lens nuclear opacification assessed by computer-assisted image analysis.

Design: A sample of 408 Boston, Mass-area women from the Nurses' Health Study aged 52 to 74 years at baseline participated in a 5-year study related to nutrition and vision. Usual nutrient intake was calculated as the average intake from 5 food frequency questionnaires that were collected over a 13- to 15-year period before the baseline evaluation of lens nuclear density.

A prospective study of C-peptide, insulin-like growth factor-I, insulin-like growth factor binding protein-1, and the risk of colorectal cancer in women.

Hyperinsulinemia, hyperglycemia, and elevated insulin-like growth factor (IGF)-1 levels have been implicated in the etiology of colorectal cancer. However, the joint effects of insulin and IGF-I have not been considered, and whether hyperinsulinemia or hyperglycemia is more etiologically relevant is unclear. IGF binding protein-1 (IGFBP-1) has been hypothesized to mediate the effects of insulin, but epidemiologic data on IGFBP-1 are sparse.

Lipoprotein (a) and coronary heart disease among women: beyond a cholesterol carrier?

Aims: With its homology with plasminogen, lipoprotein(a) [Lp(a)] may be related to thrombosis and inflammation. We assessed the role of Lp(a) in coronary heart diseases (CHD) by a recently developed assay that is not affected by the plasminogen-like Kringle-type-2 repeats.

Methods And Results: Of 32 826 women from the Nurses' Health Study, who provided blood at baseline, we documented 228 CHD events during 8 years of follow-up.

Dietary fat intake and early age-related lens opacities.

Background: Dietary fat may affect lens cell membrane composition and function, which are related to age-related cataract.

Objective: The objective of the study was to examine the association between long-term dietary fat intake and the prevalence of age-related nuclear, cortical, and posterior subcapsular lens opacities.

Design: Women (n = 440) aged 53-73 y from the Boston area without previously diagnosed cancer, diabetes, or cataract were selected from the Nurses' Health Study cohort.

CYP19 (aromatase) haplotypes and endometrial cancer risk.

Endogenous estrogen exposure is an important determinant of endometrial cancer risk. Aromatase, encoded by CYP19, catalyzes the aromatization of androstenedione and testosterone to estrone and estradiol, respectively. Several common genetic polymorphisms in CYP19 have been identified, including a TCT insertion/deletion and a (TTTA)(n) repeat polymorphism in intron IV as well as a 3'UTR C/T polymorphism.