A dietary pattern derived to correlate with estrogens and risk of postmenopausal breast cancer

A prospective study of dietary patterns and the incidence of endometriosis diagnosis

BACKGROUND

Although endometriosis is a common condition-affecting ∼10% of premenopausal individuals-its etiology is unknown. Diet receives a lot of attention from patients, but studies of the role of diet are limited. Examining dietary patterns is essential to provide new insight.

OBJECTIVE

We sought to determine whether dietary patterns are associated with laparoscopically-confirmed endometriosis diagnosis.

STUDY DESIGN

We conducted a prospective cohort study among 81,997 premenopausal participants of the Nurses' Health Study II, who were followed from 1991-2015. Diet was assessed with validated food frequency questionnaires every 4 years. We examined 6 dietary patterns: Western, Prudent, Alternative Healthy Eating Index, Dietary Approaches to Stop Hypertension, an estrogen-associated pattern, and a proinflammatory pattern. Cox proportional hazard ratios and 95% confidence intervals were used to quantify the association between each of these patterns and laparoscopically-confirmed endometriosis diagnosis.

RESULTS

Three thousand eight hundred ten incident cases of endometriosis were diagnosed during 24 years of follow-up. Adherence to the Alternative Healthy Eating Index, reflecting a healthier dietary pattern, was associated with a 13% lower risk of endometriosis diagnosis (fifth vs first quintile 95% confidence interval, 0.78-0.96; Ptrend=.02). Participants in the highest quintile of the Western dietary pattern, characterized by high intake of red meat, processed meat, refined grains, and desserts, had a 27% higher risk of endometriosis diagnosis than those in the lowest quintile (95% confidence interval, 1.09-1.47; Ptrend=.004). The Prudent, Dietary Approaches to Stop Hypertension, and estrogen-associated dietary patterns did not demonstrate clear associations with endometriosis risk, and there was the suggestion of a higher risk of endometriosis diagnosis among those with a higher proinflammatory diet score (hazard ratio for fifth vs first quintile, 1.10 [95% confidence interval, 0.99-1.23]; Ptrend=.01).

CONCLUSION

Our results suggest that consuming a dietary pattern that adheres to the Alternative Healthy Eating Index-2010 recommendations lowers the risk of endometriosis diagnosis, potentially through a beneficial impact on pelvic pain. In addition, consuming a less healthy diet high in red/processed meats and refined grains may have a detrimental impact on endometriosis symptoms.

Association of plant-based diet and early onset of natural menopause

Objective

Methods

Results

Conclusion

Exposure to perfluoroalkyl substances was associated with estrogen homeostasis in pregnant women

Previous studies have suggested that perfluoroalkyl substances (PFASs) can act as endocrine disruptors, but few studies have investigated the effects of serum PFASs on estrogen homeostasis during pregnancy. The present study included 557 pregnant women in Tangshan City, North China, and determined 11 serum PFASs in the early term of pregnancy and three typical estrogens (estrone (E₁), estradiol (E₂) and estriol (E₃)) in the early (n = 557), middle (n = 339), and late (n = 286) terms of pregnancy. Sociodemographic factors and diet information were obtained by structured questionnaires. After adjusting for potential confounders, multiple linear regression model demonstrated negative associations of natural logarithmic transformed serum perfluoroundecanoic acid (Ln PFUdA) with Ln E₁and Ln E3 in the early term of pregnancy with β coefficients of -0.060 (95% confidence interval (CI): -0.101 to -0.019) and -0.041 (95% CI: -0.070 to -0.011), respectively. Ln perfluorodecanoic acid (PFDA) was negatively associated with averaged E1 in the early and middle (EM) terms of pregnancy with a β coefficient of -0.205 (95% CI: -0.357 to -0.053). Ln perfluorononanoic acid (PFNA) tended to be negatively associated with E₂ in the late term of pregnancy with a β coefficient of -0.134 (95% CI: -0.253 to -0.016) although p-value was slightly greater than 0.05 after false discovery rate (FDR) correction. Mixed effect model found that serum PFDA was negatively associated with E₁ (β = -0.123, 95% CI: -0.235 to -0.012) during the entire pregnancy. These findings suggested that exposure to PFASs disturbed estrogen homeostasis in pregnant women and the effects varied with the terms of pregnancy.

Micronutrient and Trace Element Levels in Serum of Women With Uterine Fibroids in Lagos

Background: Uterine fibroids significantly affect the quality of life of reproductive-age women. The socioeconomic cost and psychological strain on patients cannot be overemphasized. The role of diet and micronutrients on the onset and development of uterine fibroids has come under review in recent times. This study assessed the levels of some micronutrients and trace elements in the serum of women with uterine fibroids.

Methods: Eighty-eight women were recruited from the Gynecology Outpatient Clinic of Lagos University Teaching Hospital, 44 with uterine fibroids and 44 women without uterine fibroids. Blood samples were obtained and analyzed for serum levels of selected micronutrients (vitamins A, C, D, and E) and trace elements (calcium, magnesium, and phosphorus). Pelvic ultrasonography was performed on all study participants.

Results: Women with uterine fibroids had statistically significant lower serum levels of vitamin C (1.20 ± 0.59 vs 1.62 ± 1.75 mg/dl; p = 0.01), vitamin D (34.23 ±10.67 vs 37.06 ±11.46 ng/ml; p = 0.04), and calcium (2.27 ± 0.19 vs 2.32 ± 0.09 mmol/L; p = 0.02) compared with women without uterine fibroids. There was no significant difference in the serum levels of vitamins A (39.63 ± 15.71 vs 40.09 ±15.26 μ/dl; p = 0.91), vitamin E (5.44 ± 4.65 vs 5.26 ± 4.62 µg/mL; p = 0.87), magnesium (0.89 ± 0.09 vs 0.89 ± 0.08 mmol/L; p = 0.78), and phosphorus (1.29 ± 0.38 vs 1.19 ± 0.17 mmol/L; p = 0.14) in women with uterine fibroids compared to those without uterine fibroids.

Conclusion: This study showed lower serum levels of vitamin C, vitamin D, and calcium in women with uterine fibroids when compared to women without uterine fibroids. It is possible that these micronutrients and trace elements may play a role in the etiopathogenesis, progression, and/or proliferation of uterine fibroids. However, whether the findings of low serum levels of these elements are a cause or an effect of uterine fibroid, is yet to be determined.

Long-term exposure to PM1 and PM2.5 is associated with serum cortisone level and meat intake plays a moderation role

BACKGROUND

Although short-term exposure to particulate matter (PM) was associated with increased glucocorticoids (GCs) levels, available evidence on associations of long-term exposure to PM and GCs levels is still scant. Previous studies has showed that meat intake is associated with sex hormones levels, but it is unknown whether meat intake is associated with GCs levels. Furthermore, the role of meat intake in the associations between PM and GCs levels remains unclear.

AIMS

The aims of this study were to explore the associations of long-term exposure to PM and GCs levels among Chinese rural adults, and the role of meat intake in these associations.

MATERIALS AND METHODS

A total of 6223 subjects were recruited from the Henan Rural Cohort Study. Serum GCs levels were measured with liquid chromatography-tandem mass spectrometry. The concentrations of PM (PM₁ and PM_2.5) for each subject were assessed with machine learning algorithms. The food frequency questionnaire (FFQ) was used to obtain each participant' information on meat intake. The effects of PM and meat intake on GCs levels were assessed using generalized linear models. In addition, modification analyses were performed to identify the role of meat intake played in the associations of PM with serum GCs levels.

RESULTS

Per 1 μg/m³ increment in PM₁ or PM_2.5 concentration was associated with a 0.364 ng/ml (95% confidence interval (CI): 0.234, 0.494) or 0.227 ng/ml (95%CI: 0.110, 0.343) increase in serum cortisone, respectively. In addition, the moderation effects of total meat intake and red meat intake on the associations of long-term exposure to PM₁ or PM_2.5 with serum cortisone were observed (P < 0.05), indicating that individuals who had high levels of PM₁ or PM_2.5 and meat intake were more susceptible to have a higher state of serum cortisone.

CONCLUSIONS

Our findings suggested that long-term exposure to PM₁ or PM_2.5 was associated with serum cortisone. Moreover, meat intake was found to be a significant moderator in the association of PM₁ or PM_2.5 with serum cortisone levels.

Uterine Fibroids and Diet

Uterine myomas or fibroids are the most common benign female tumors of the reproductive organs, associated with significant morbidity and quality of life impairment. Several epidemiological risk factors for their occurrence have been identified so far, including nutrition and dietary habits. In this investigation, authors reviewed, as a narrative review, the data about diet and uterine myoma development in order to homogenize the current data. A PubMed search was conducted for the years 1990–2020, using a combination of keywords of interest for the selected topic. The authors searched the databases, selecting the randomized clinical studies, the observational studies, and the basic (experimental), clinical, and epidemiological researches. Once they collected the articles, they analyzed them according to the number of citations of each article, starting from the most cited to the least cited articles. Subsequently, authors collected the data of each article and inserted them in the various research paragraphs, summarizing the data collected. In this way, they crossed the available data regarding the association between nutrition habits and dietary components and myoma onset and growth. Many nutrients and dietary habits are associated with myoma development risk. These factors include low intakes of fruit, vegetables, and vitamin D, as well as pollutants in food. Despite the available data on the influence of some foods on the development of fibroids, further research is mandatory to understand all the nutrition risk factors which contribute to myoma growth and how exactly these risk factors influence myoma pathogenesis.

Coffee consumption and risk of breast cancer: A Mendelian randomization study

BACKGROUND

Observational studies have reported either null or weak protective associations for coffee consumption and risk of breast cancer.

METHODS

We conducted a two-sample Mendelian randomization (MR) analysis to evaluate the relationship between coffee consumption and breast cancer risk using 33 single-nucleotide polymorphisms (SNPs) associated with coffee consumption from a genome-wide association (GWA) study on 212,119 female UK Biobank participants of White British ancestry. Risk estimates for breast cancer were retrieved from publicly available GWA summary statistics from the Breast Cancer Association Consortium (BCAC) on 122,977 cases (of which 69,501 were estrogen receptor (ER)-positive, 21,468 ER-negative) and 105,974 controls of European ancestry. Random-effects inverse variance weighted (IVW) MR analyses were performed along with several sensitivity analyses to assess the impact of potential MR assumption violations.

RESULTS

One cup per day increase in genetically predicted coffee consumption in women was not associated with risk of total (IVW random-effects; odds ratio (OR): 0.91, 95% confidence intervals (CI): 0.80-1.02, P: 0.12, P for instrument heterogeneity: 7.17e-13), ER-positive (OR = 0.90, 95% CI: 0.79-1.02, P: 0.09) and ER-negative breast cancer (OR: 0.88, 95% CI: 0.75-1.03, P: 0.12). Null associations were also found in the sensitivity analyses using MR-Egger (total breast cancer; OR: 1.00, 95% CI: 0.80-1.25), weighted median (OR: 0.97, 95% CI: 0.89-1.05) and weighted mode (OR: 1.00, CI: 0.93-1.07).

CONCLUSIONS

The results of this large MR study do not support an association of genetically predicted coffee consumption on breast cancer risk, but we cannot rule out existence of a weak association.

Diet and The Risk of Endometriosis in Iranian Women: A Case-Control Study

Background

Endometriosis is one of the most common pelvic diseases associated with dyspareunia, pelvic pain, and infertility. The primary aim of this study is to evaluate the role of diet on the risk of endometriosis among Iranian women.

Materials and Methods

This case-control study was conducted in two health research centres between 2015 and 2016. There were 207 women with endometriosis (case) and 206 women without endometriosis (control) who were evaluated by laparoscopy. The women were asked about their frequency of consumption per week of portions of se- lected dietary items in the Iranian diet in the year before the interview.

Results

The results indicated that intake of green vegetables (odds ratio [OR]=0.39, 95% confidence interval [CI]=0.21–0.74, Ptrend=0.004), red meat (OR=0.61, 95% CI=0.41–0.91, Ptrend=0.015) and dairy products (milk [OR=0.65, 95% CI=0.47–0.92, Ptrend=0.014], cheese [OR=0.53, 95% CI=0.37–0.76, Ptrend<0.001]), fresh fruit (OR=0.68, 95% CI=0.50–0.93, Ptrend=0.015) and grain legumes (OR=0.59, 95% CI=0.47–0.77; Ptrend<0.001) had a significant association with lower risk of endometriosis. Consumption of carrots, green tea, fish, eggs and oil was not significantly related to the risk of endometriosis.

Conclusion

This study suggests that certain types of dietary components may be related to the risk of endometriosis.

Dietary patterns and cancer risk

Over the past decade, the search for dietary factors on which to base cancer prevention guidelines has led to the rapid expansion of the field of dietary patterns and cancer. Multiple systematic reviews and meta-analyses have reported epidemiological associations between specific cancer types and both data-driven dietary patterns determined by empirical analyses and investigator-defined dietary indexes based on a predetermined set of dietary components. New developments, such as the use of metabolomics to identify objective biomarkers of dietary patterns and novel statistical techniques, could provide further insights into the links between diet and cancer risk. Although animal models of dietary patterns are limited, progress in this area could identify the potential mechanisms underlying the disease-specific associations observed in epidemiological studies. In this Review, we summarize the current state of the field, provide a critical appraisal of new developments and identify priority areas for future research. An underlying theme that emerges is that the effectiveness of different dietary pattern recommendations in reducing risk could depend on the type of cancer or on other risk factors such as family history, sex, age and other lifestyle factors or comorbidities as well as on metabolomic signatures or gut microbiota profiles.

Dietary protein sources and tumoral overexpression of RhoA, VEGF-A and VEGFR2 genes among breast cancer patients

BACKGROUND

High protein intake may promote angiogenesis giving support to the development of metastasis according to the experimental data. However, nutritional epidemiologic evidence is inconsistent with metastasis. Therefore, we aimed to study the association between dietary intake of protein and tumoral expression levels of Ras homologous gene family member A (RhoA), vascular endothelial growth factor-A (VEGF-A), and VEGF receptor-2 (VEGFR2) in primary breast cancer (BC) patients.

METHODS

Over this consecutive case series, 177 women primary diagnosed with histopathologically confirmed BC in Tabriz (Iran) were enrolled between May 2011 and November 2016. A validated food frequency questionnaire was completed for eligible participants. Fold change in gene expression was measured using quantitative real-time PCR. Principal component factor analysis (PCA) was used to express dietary groups of proteins.

RESULTS

Total protein intake was associated with the expression level of VEGF-A in progesterone receptor-positive (PR+: β = 0.296, p < 0.01) and VEGFR2 in patients with involvement of axillary lymph node metastasis (ALNM+: β = 0.295, p < 0.01) when covariates were adjusted. High animal protein intake was correlated with overexpression of RhoA in tumors with estrogen receptor-positive (ER+: β = 0.230, p < 0.05), ALNM+ (β = 0.238, p < 0.05), and vascular invasion (VI+: β = 0.313, p < 0.01). Animal protein intake was correlated with the overexpression of VEGFR2 when tumors were positive for hormonal receptors (ER+: β = 0.299, p < 0.01; PR+: β = 0.296, p < 0.01). Based on the PCA outputs, protein provided by whole meat (white and red meat) was associated inversely with RhoA expression in ALNM+ (β = - 0.253, p < 0.05) and premenopausal women (β = - 0.285, p < 0.01) in adjusted models. Whole meat was correlated with VEGFR2 overexpression in VI+ (β = 0.288, p < 0.05) and premenopausal status (β = 0.300, p < 0.05) in adjusted models. A group composed of dairy products and legumes was correlated with the overexpression of RhoA (β = 0.249, p < 0.05) and VEGF-A (β = 0.297, p < 0.05) in VI+.

CONCLUSIONS

Based on the multivariate findings, the dietary protein could associate with the overexpression of RhoA and VEGF-VEGFR2 in favor of lymphatic and vascular metastasis in BC patients.

Healthy dietary patterns and risk and survival of breast cancer: a meta-analysis of cohort studies

PURPOSES

Dietary patterns have been found to be associated with the overall cancer risk and survival. However, the associations of healthy dietary patterns and breast cancer remain unclear. We aimed to conduct a meta-analysis of prospective cohort studies to estimate the pooled results of the association of healthy dietary patterns with breast cancer risk and survival.

METHODS

PubMed, EMBASE, and Web of Science were searched for literature published until June 24th, 2018 that examined the associations between healthy dietary patterns and breast cancer risk and survival. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated by using a random-effects model for meta-analysis.

RESULTS

There were 32 articles retrieved for the meta-analysis, with 27 for breast cancer risk and five for breast cancer survival. There was a statistically significant lower risk of breast cancer associated with healthy dietary patterns (RR = 0.93, 95% CI: 0.88, 0.98). Subgroup analysis results suggested that there was an inverse association between breast cancer risk and posterori-derived healthy patterns, but no statistically significant associations were found in other stratified subgroups (a priori-derived diet, study region, menopausal status, or breast cancer subtypes). Healthy dietary patterns were associated inversely with all-cause mortality (RR = 0.76, 95% CI: 0.63, 0.92); however, no association was found for breast cancer-specific mortality.

CONCLUSIONS

The results suggested that healthy dietary patterns might be associated with a reduced risk of breast cancer and all-cause mortality among breast cancer patients. It could be clinically relevant to promote healthy dietary patterns for breast cancer prevention and improve survival among breast cancer patients.

Interaction between diet- and exercise-lifestyle and phthalates exposure on sex hormone levels

Phthalate can affect sex hormones secretion. Exercise and diet habits affect sex hormones levels. However, interaction of phthalates exposure and diet or exercise habits with sex hormones is unclear. We enrolled 106 residents aged 11-88 years (48 males and 58 females) from two communities, Wuhan city, China during the winter of 2014 and summer of 2015. Data were collected on socio-demographic characteristics and lifestyle by a questionnaire in two seasons. Participants provided the blood and urine samples over 3 consecutive days for measuring sex hormones and urinary phthalate metabolites. We assessed the associations of urinary phthalate metabolites levels, lifestyle with hormones levels, the interaction of phthalate exposure and lifestyle with hormones levels using multivariate binary logistic regression models. High urinary mono-(2-ethyl-5-oxyhexyl) phthalate (MEOHP) levels and no exercise had an additive interaction on abnormal serum progesterone (PROG) levels in winter as well as on abnormal serum follicle-stimulating hormone (FSH) or luteinizing hormone (LH) levels in summer. High urinary MEOHP levels and red meat intake (>1 time/day) had an additive interaction with abnormal levels of serum FSH only in the winter. Phthalates exposure may confer differential susceptibility to abnormal hormones levels in individuals with no exercise or eating meat >1 time/day.

An Estrogen-Related Dietary Pattern and Postmenopausal Breast Cancer Risk in a Cohort of Women with a Family History of Breast Cancer

Background: The results of previous studies on diet and postmenopausal breast cancer risk have been inconclusive, but there is some evidence that dietary patterns developed to correlate with estrogen levels are associated with breast cancer. We aimed to examine the association of a previously developed estrogen-related dietary pattern (ERDP) with postmenopausal breast cancer in the Sister Study.Methods: The ERDP was calculated from food frequency questionnaire responses among Sister Study participants without a personal history of cancer and who contributed postmenopausal person-time at risk. Cox proportional hazards models were used to estimate HRs and 95% confidence intervals for the association between the ERDP and postmenopausal breast cancer.Results: With more than 261,959 person-years of follow-up and 1,968 incident cases, the ERDP was not associated with total, invasive, estrogen receptor (ER)-positive or ER-negative subtypes of breast cancer. Results were robust to various sensitivity analyses.Conclusions: The results do not support previous studies observing a positive association between a proestrogenic dietary pattern and postmenopausal breast cancer risk. Null results may be partially explained by high levels of other breast cancer risk factors within the study population, such as a family history of breast cancer.Impact: An estrogen-related dietary pattern may not be a strong predictor of breast cancer risk in all populations. Future studies of diet and breast cancer should evaluate the potential for effect modification by family history and consider differences in dietary assessment tools when comparing results across study populations. Cancer Epidemiol Biomarkers Prev; 27(10); 1223-6. ©2018 AACR.

Sex consideration in diet-biomarker-related indices: a systematic review

OBJECTIVE

An index of biomarkers derived from dietary factors (diet-biomarker-related index) identifies foods and nutrients that encompass physiological potentials and provides scientific evidence for dietary patterns that increase the risk of disease associated with specific biomarkers. Although men and women have different dietary patterns and physiological characteristics, sex is not often considered when investigators develop a diet-biomarker-related index. We aimed to review whether epidemiological studies developed diet-biomarker-related indices in a sex-specific way.

DESIGN

We systematically searched for epidemiological studies that developed diet-biomarker-related indices, including (i) biomarker prediction indices that include dietary factors as explanatory variables and (ii) dietary patterns to explain biomarker variations, in the PubMed and EMBASE databases. We qualitatively reviewed the sex consideration in index development.

RESULTS

We identified seventy-nine studies that developed a diet-biomarker-related index. We found that fifty-four studies included both men and women. Of these fifty-four studies, twenty-nine (53·7 %) did not consider sex, eleven (20·3 %) included sex in the development model, seven (13·0 %) considered sex but did not include sex in the development model, and seven (13·0 %) derived a diet-biomarker-related index for men and women separately. A list of selected dietary factors that explained levels of biomarkers generally differed by sex in the studies that developed a diet-biomarker-related index in a sex-specific way.

CONCLUSIONS

Most studies that included both men and women did not develop the diet-biomarker-related index in a sex-specific way. Further research is needed to identify whether a sex-specific diet-biomarker-related index is more predictive of the disease of interest than an index without sex consideration.

Endometriosis and food habits: Can diet make the difference?

Endometriosis is a chronic, inflammatory, estrogenic-dependent disease characterized by the presence of endometrial glands outside the uterine cavity, affecting approximately 2%–10% of women in reproductive age and 30%–50% of women in general. Despite the high prevalence of the disease, not much is known about etiology, possible risk factors, and an adequate and satisfactory therapy. In the past years, many studies have focused on food intake (nutrients and food groups) and on its possible correlation with endometriosis, demonstrating how diet could be identified as a possible risk factor. Comprehensive searches in the largest medical information databases (Medline-PubMed, Embase, Lilacs, and Cochrane Library) were conducted using the Medical Subject Heading terms “diet,” “food,” “nutrition,” “fatty acids,” vitamins,” “fruit,” “vegetables,” “coffee,” “caffeine,” “fish,” “soy food,” “dairy products,” “tea,” “curcumin” combined with “endometriosis.” Purpose of this review is to revise the literature, in order to determine potential modifiable risk factors of the disease.

An estrogen-related lifestyle score is associated with risk of postmenopausal breast cancer in the PLCO cohort

PURPOSE

Healthy or unhealthy lifestyle behaviors are often adopted together. We aimed to investigate the combined effect of estrogen-related lifestyle factors on postmenopausal breast cancer risk.

METHODS

Data from 27,153 women enrolled in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial were used. We created an estrogen-related lifestyle score (ERLS) by incorporating a previously developed measure of estrogenic diet, alcohol intake, body mass index (BMI), and physical activity. The scores ranged from 0 to 6 with alcohol and BMI accounting for higher weights than the other factors. To evaluate the preventive possibilities of a low estrogen-related lifestyle and to be consistent with other published lifestyle scores, higher scores were set to correspond with potentially lower estrogenic lifestyle. The association between the ERLS and incident breast cancer was examined using Cox proportional hazards models.

RESULTS

Participants with an ERLS of 4 or ≥ 5 had a 23% (HR 0.77; 95% CI 0.67-0.89) and 34% (HR 0.66; 95% CI 0.56-0.78) lower risk of breast cancer, respectively, compared to those with an ERLS ≤ 2 after multivariable adjustment. Estimates were similar when restricting to invasive cases or estrogen receptor-positive subtypes. No single lifestyle component appeared to drive the association.

CONCLUSIONS

Our findings suggest that the combined effect of a lifestyle characterized by a low estrogenic diet, low alcohol consumption, low body weight, and high levels of physical activity are associated with a reduction in postmenopausal breast cancer risk, possibly through an influence on estrogen metabolism.

A dietary pattern based on estrogen metabolism is associated with breast cancer risk in a prospective cohort of postmenopausal women

Increased exposure to estrogen is a risk factor for postmenopausal breast cancer, and dietary factors can influence estrogen metabolism. However, studies of diet and breast cancer have been inconclusive. We developed a dietary pattern associated with levels of unconjugated estradiol and the ratio of 2- and 16-hydroxylated estrogen metabolites in a subsample of Prostate, Lung, Colorectal and Ovarian Screening Trial (PLCO) participants (n = 653) using reduced rank regression, and examined its association with postmenopausal breast cancer prospectively in the larger PLCO cohort (n = 27,488). The estrogen-related dietary pattern (ERDP) was comprised of foods with positively-weighted intakes (non-whole/refined grains, tomatoes, cruciferous vegetables, cheese, fish/shellfish high in ω-3 fatty acids, franks/luncheon meats) and negatively-weighted intakes (nuts/seeds, other vegetables, fish/shellfish low in ω-3 fatty acids, yogurt, coffee). A 1-unit increase in the ERDP score was associated with an increase in total (HR: 1.09, 95% CI: 1.01-1.18), invasive (HR: 1.13; 95% CI: 1.04-1.24) and estrogen receptor (ER)-positive (HR: 1.13, 95% CI: 1.02-1.24) breast cancer risk after adjustment for confounders. Associations were observed for the fourth quartile of ERDP compared with the first quartile for overall breast cancer (HR: 1.14; 95% CI: 0.98-1.32), invasive cases (HR: 1.20, 95% CI: 1.02-1.42) and ER-positive cases (HR: 1.19; 95% CI: 0.99-1.41). The increased risk associated with increasing ERDP score was more apparent in strata of some effect modifiers (postmenopausal hormone therapy non-users and non-obese participants) where the relative estrogen exposure due to that factor was lowest, although the p values for interaction were not statistically significant. Results suggest a dietary pattern based on estrogen metabolism is positively associated with postmenopausal breast cancer risk, possibly through an estrogenic influence.

Coffee Intake Decreases Risk of Postmenopausal Breast Cancer: A Dose-Response Meta-Analysis on Prospective Cohort Studies

Aim: A dose-response meta-analysis was conducted in order to summarize the evidence from prospective cohort studies regarding the association between coffee intake and breast cancer risk. Methods: A systematic search was performed in electronic databases up to March 2017 to identify relevant studies; risk estimates were retrieved from the studies and linear and non-linear dose-response analysis modelled by restricted cubic splines was conducted. A stratified and subgroup analysis by menopausal and estrogen/progesterone receptor (ER/PR) status, smoking status and body mass index (BMI) were performed in order to detect potential confounders. Results: A total of 21 prospective studies were selected either for dose-response, the highest versus lowest category of consumption or subgroup analysis. The dose-response analysis of 13 prospective studies showed no significant association between coffee consumption and breast cancer risk in the non-linear model. However, an inverse relationship has been found when the analysis was restricted to post-menopausal women. Consumption of four cups of coffee per day was associated with a 10% reduction in postmenopausal cancer risk (relative risk, RR 0.90; 95% confidence interval, CI 0.82 to 0.99). Subgroup analyses showed consistent results for all potential confounding factors examined. Conclusions: Findings from this meta-analysis may support the hypothesis that coffee consumption is associated with decreased risk of postmenopausal breast cancer.

Coffee Intake Decreases Risk of Postmenopausal Breast Cancer: A Dose-Response Meta-Analysis on Prospective Cohort Studies

Aim: A dose-response meta-analysis was conducted in order to summarize the evidence from prospective cohort studies regarding the association between coffee intake and breast cancer risk. Methods: A systematic search was performed in electronic databases up to March 2017 to identify relevant studies; risk estimates were retrieved from the studies and linear and non-linear dose-response analysis modelled by restricted cubic splines was conducted. A stratified and subgroup analysis by menopausal and estrogen/progesterone receptor (ER/PR) status, smoking status and body mass index (BMI) were performed in order to detect potential confounders. Results: A total of 21 prospective studies were selected either for dose-response, the highest versus lowest category of consumption or subgroup analysis. The dose-response analysis of 13 prospective studies showed no significant association between coffee consumption and breast cancer risk in the non-linear model. However, an inverse relationship has been found when the analysis was restricted to post-menopausal women. Consumption of four cups of coffee per day was associated with a 10% reduction in postmenopausal cancer risk (relative risk, RR 0.90; 95% confidence interval, CI 0.82 to 0.99). Subgroup analyses showed consistent results for all potential confounding factors examined. Conclusions: Findings from this meta-analysis may support the hypothesis that coffee consumption is associated with decreased risk of postmenopausal breast cancer.

The Effects of Berberis Vulgaris Juice on Insulin Indices in Women with Benign Breast Disease: A Randomized Controlled Clinical Trial

The aim of this study was to investigate the effect of Berberis vulgaris (BV) juice consumption on insulin homeostasis, glycemic profiles of patients with benign breast disease (BBD). This parallel design, triple-blind, randomized and placebo controlled clinical trial was conducted on 85 eligible women diagnosed with BBD who recruited from Nour-Nejat hospital, Tabriz, Iran. Participants were randomly allocated into either intervention group who received BV juice (480 mL/day, n = 44) or BV juice placebo at the same time (480 mL/day, n = 41). After a 7 day run-in period, treatments were administered for the duration of 8 weeks. Participants, care givers and those who assessed laboratory analyses were blinded to the assignments (IRCT registry no: IRCT2012110511335N2). The relative treatment effects of BV supplementation showed decreased serum levels of insulin for 19%, C-peptide for 8%, homeostasis model assessment of insulin resistance index (HOMA-IR) for 16% and glucose to insulin ratio for 22% but HOMA-B increased 44% relative to placebo group over 8 weeks BV supplementation. Although these changes were not statistical significant, the mean changes for C-peptide and HOMA-B were significant just after adjusting for baseline data and covariates. Administration of BV juice showed controlling effects on HOMA related indices, consequently might have beneficial effects on insulin signaling-related functions in women with benign breast tumor.

Dietary Patterns and Colorectal Cancer Risk: A Review of 17 Years of Evidence (2000-2016)

PURPOSE OF REVIEW

Colorectal cancer (CRC) is a global public health problem, with an estimated 1.4 million cases diagnosed worldwide in 2012. Evidence suggests that diet may be important for primary prevention.

RECENT FINDINGS

The 2017 WCRF/AICR Continuous Update Project on colorectal cancer concluded that there is convincing evidence linking several individual dietary factors with CRC risk but the evidence for dietary patterns was limited and inconclusive. Also, previous reviews and meta-analyses have not critically synthesized various dietary patterns. This review synthesized data from dietary patterns studies over a 17-year period from 2000 to 2016.

SUMMARY

We included 49 studies (28 cohort and 21 case-control) that examined the association of index-based and empirically-derived dietary patterns and CRC risk. A synthesis of food group components comprising the different index-based and empirically-derived patterns revealed two distinct dietary patterns associated with CRC risk. A "healthy" pattern, generally characterized by high intake of fruits and vegetables, wholegrains, nuts and legumes, fish and other seafood, milk and other dairy products, was associated with lower CRC risk. In contrast, the "unhealthy" pattern, characterized by high intakes of red meat, processed meat, sugar-sweetened beverages, refined grains, desserts and potatoes was associated with higher CRC risk. It is notable that the number of food groups, the intake quantity, the exact types of foods in each food group, differed between populations, yet the two dietary patterns remained consistent across regions, especially in empirically-derived patterns, an indication of the high reproducibility of these patterns. However, findings for CRC risk in both index-based and empirically-derived patterns, differed by sex, with stronger associations among men than women; study design, a higher proportion of case-control studies reported significant findings compared to prospective studies. Consuming a dietary pattern high in fruits and vegetables and low in meats and sweets is protective against CRC risk. However, important questions remain about mechanisms underlying differences by sex; life-course timing of exposure to dietary patterns; interaction of dietary patterns with the microbiome or with lifestyle factors including physical activity; and elucidation of subsite differences.

Coffee Decreases the Risk of Endometrial Cancer: A Dose-Response Meta-Analysis of Prospective Cohort Studies

AIM

The aim of this study was to perform a comprehensive meta-analysis of the association between coffee consumption and risk of endometrial cancer.

METHODS

Eligible studies were identified by searching the PubMed and EMBASE databases. The dose-response relationship as well as the risk of endometrial cancer for the highest versus the lowest categories of coffee consumption were assessed. Subgroup analyses considering the menopausal and receptor statuses, the smoking status, and the BMI (Body Mass Index) were performed in order to identify potential confounders.

RESULTS

We identified a total of 12 studies eligible for meta-analysis. A dose-response meta-analysis showed a decreased risk of endometrial cancer. Moreover, a subgroup analysis indicated that coffee consumption is significantly associated with a decreased risk of postmenopausal cancer. Increasing coffee consumption by four cups per day was associated with a 20% reduction in endometrial cancer risk (relative risk (RR) 0.80; 95% confidence interval (CI) 0.72 to 0.89) and with a 24% reduction in postmenopausal cancer risk (RR 0.76; 95% CI 0.69 to 0.83).

CONCLUSIONS

Our findings suggest that increased coffee consumption is associated with decreased risk of endometrial cancer, and this association is observed also for postmenopausal cancer.

Serum Iron:Ferritin Ratio Predicts Healthy Body Composition and Reduced Risk of Severe Fatty Liver in Young Adult Women

Dysregulated iron metabolism is associated with altered body composition and nonalcoholic fatty liver disease (NAFLD); however, mechanisms underlying this association remain undefined. We investigated this association in 117 women. Middle-aged women (≥45 years old (y)) were heavier and had lower serum iron, higher serum hepcidin, ferritin, and severe NAFLD incidence than young adult women (<45 y). Age-adjusted linear regression analysis revealed that young adult women with the highest serum iron:ferritin ratio (Tertile 3) had a 5.08-unit increased percentage of muscle mass [β = 5.08 (1.48-8.68), p < 0.001] and a 1.21-unit decreased percentage visceral fat mass [β = -1.21 (-2.03 to -0.39), p < 0.001] compared with those with the lowest serum iron:ferritin ratio (Tertile 1; reference). The iron:ferritin dietary pattern, characterized by high consumption of beef, lamb, dairy products, fruits, and whole grains, and low consumption of refined carbohydrates (rice, noodles, and bread and pastries), and deep- and stir-fried foods, predicted a 90% [odds ratio: 0.10, 95% confidence interval: 0.02-0.47, p < 0.001] reduced risk of mild vs. moderate and severe NAFLD in young adult women. Our findings suggest that the serum iron:ferritin ratio more accurately predicts body composition and reduced risk of severe fatty liver progression in young adult women compared to middle-aged women.

Development and validation of empirical indices to assess the insulinaemic potential of diet and lifestyle

The glycaemic and insulin indices assess postprandial glycaemic and insulin response to foods, respectively, which may not reflect the long-term effects of diet on insulin response. We developed and evaluated the validity of four empirical indices to assess the insulinaemic potential of usual diets and lifestyles, using dietary, lifestyle and biomarker data from the Nurses' Health Study (NHS, n 5812 for hyperinsulinaemia, n 3929 for insulin resistance). The four indices were as follows: the empirical dietary index for hyperinsulinaemia (EDIH) and the empirical lifestyle index for hyperinsulinaemia (ELIH); the empirical dietary index for insulin resistance (EDIR) and the empirical lifestyle index for insulin resistance (ELIR). We entered thirty-nine FFQ-derived food groups in stepwise linear regression models, and defined indices as patterns most predictive of fasting plasma C-peptide, for the hyperinsulinaemia pathway (EDIH and ELIH), and of theTAG:HDL-cholesterol ratio, for the insulin-resistance pathway (EDIR and ELIR). We evaluated the validity of indices in two independent samples from NHS-II and Health Professionals Follow-up Study (HPFS) using multivariable-adjusted linear regression analyses to calculate relative concentrations of biomarkers. The EDIH is comprised of eighteen food groups; thirteen were positively associated with C-peptide and five were inversely associated. The EDIR is comprised of eighteen food groups; ten were positively associated with TAG:HDL-cholesterol and eight were inversely associated. Lifestyle indices had fewer dietary components, and included BMI and physical activity as components. In the validation samples, all indices significantly predicted biomarker concentrations - for example, the relative concentrations of the corresponding biomarkers comparing extreme index quintiles in the HPFS were EDIH, 1·29 (95 % CI 1·22, 1·37); ELIH, 1·78 (95 % CI 1·68, 1·88); EDIR, 1·44 (95 % CI 1·34, 1·55); and ELIR, 2·03 (95 % CI 1·89, 2·19); all P trend<0·0001. The robust associations of these novel hypothesis-driven indices with insulin response biomarker concentrations suggest their usefulness in assessing the ability of whole diets and lifestyles to stimulate and/or sustain insulin secretion.

Evaluating dietary patterns: the role of reduced rank regression

PURPOSE OF REVIEW

The purpose of review is to present methodological issues as well as most relevant recent developments on the application of a statistical method to derive dietary patterns: reduced rank regression (RRR). RRR can be used efficiently in nutritional epidemiology to identify dietary patterns associated with selected response variables that have known relations with a disease outcome of interest. This has the advantage of building on a priori knowledge of biological relations, by including plausible intermediates between diet and the outcome of interest.

RECENT FINDINGS

This statistical method has been applied first in nutritional epidemiology about 1 decade ago. Since then, more than 60 publications were published applying the RRR. This method is considerably dependent on an adequate selection of response variables. These response sets were most often a combination of nutrients or of selected endogenous biomarkers. But also variables of intermediate clinical phenotype or contaminants were selected. However, applying this method, several methodological issues, such as, for example, selection of responses, simplification, and validation of the derived pattern should be taken into account.

SUMMARY

RRR is a modern statistical method to derive dietary patterns that can be used to test specific hypothesis on pathways from diet to development of a disease.

The Western dietary pattern is associated with increased serum concentrations of free estradiol in postmenopausal women: implications for breast cancer prevention

Little is known about the possible influence of food consumption on the serum concentrations of endogenous sex hormones in postmenopausal women. We evaluated the relationships of the Western dietary pattern with serum concentrations of free estradiol and testosterone of postmenopausal women to test the hypothesis that a highly Western dietary pattern is associated with high serum concentrations of these hormones. We used data from a representative subsample of 305 women from the control group of a population-based case-control study conducted in Mexico from 2004 to 2007. A Western dietary pattern index value was compared with log natural serum concentrations of testosterone and estradiol using multiple linear regression models. The median values of serum concentrations of free estradiol and testosterone were 0.26 pg/mL (interquartile range, 0.14-0.43) and 0.40 pg/mL (interquartile range, 0.30-0.70), respectively. A multiple linear regression model showed that for each unit increase in the Western dietary pattern index, there was a 16.2% increase in the serum concentrations of free estradiol (β=0.15; 95% confidence interval [CI], 0.01-0.29); for each additional serving per week of chicken eggs, the increase was 31.0% (β=0.27; 95% CI, 0.106-0.441); for each additional serving per week of red meat, the increase was 64.9% (β=0.50; 95% CI, 0.01-1.01). There was no relationship found between dietary patterns and serum concentrations of free testosterone. The present findings suggest that intake of a Western diet, particularly of chicken eggs and meat, increases serum concentrations of free estradiol; these results have implications for breast cancer prevention.

Vegetarian diet and reduced uterine fibroids risk: A case-control study in Nanjing, China

AIM

The aim of this study was to investigate whether a vegetarian diet correlates with a potential reduced risk of uterine fibroids.

MATERIAL AND METHODS

We used data from a case-control study conducted in Southeast University Zhongda Hospital between February 2010 and December 2014. Cases included 600 Chinese Han women with uterine fibroids (case group) whose clinical diagnosis dated back no more than 1 year. Controls were 600 patients without uterine fibroids as well as healthy volunteers (control group). All of the information gathered through the questionnaire survey was analyzed for the risk factors of the uterine fibroids pathogenesis.

RESULTS

The multifactor analysis showed that women with uterine fibroids reported a less frequent consumption of broccoli (odds ratio [OR]: 0.552; 95% confidence interval [CI]: 0.316-0.964), cabbage (OR: 0.446; 95%CI: 0.211-0.943), Chinese cabbage (OR: 0.311; 95%CI: 0.102-0.946), tomato (OR: 0.453; 95%CI: 0.241-0.853), and apple (OR: 0.416; 95%CI: 0.213-0.814) (P < 0.05).

CONCLUSION

The original evidence from this epidemiological investigation shows that a high consumption of broccoli, cabbage, Chinese cabbage, tomato and apple seems to be a protective factor for uterine fibroids. We suggest that greater intake of fresh fruits and cruciferous vegetables may be able to reduce the incidence of uterine fibroids.

An estrogen-associated dietary pattern and breast cancer risk in the Swedish Mammography Cohort

High endogenous hormone levels have been associated with breast cancer and dietary factors have the potential to influence breast cancer risk through effects on hormone levels. Dietary patterns derived from reduced rank regression provide a way to identify food groups correlated with hormones and subsequently examine food patterns that may be associated with breast cancer risk. We investigated whether a dietary pattern previously correlated with estradiol and estrone sulfate was associated with breast cancer in the prospective Swedish Mammography Cohort. Among 37,004 primarily postmenopausal women diet was assessed with a food frequency questionnaire. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs). During 15 years of follow-up 1,603 cases of breast cancer were identified. A higher estrogen dietary pattern score was associated with an increased risk of breast cancer. Women in the highest quartile of estrogen pattern score had a 29% (95% CI = 1.08-1.55) increased risk of breast cancer compared to women in the lowest quartile (p(trend) = 0.006). When the association was examined by estrogen-receptor status, it was only significant for those with estrogen-receptor-positive tumors; however, in the competing risk analysis there were no significant differences in the effect estimates by receptor subtype (p(heterogeneity) = 0.65). Our findings suggest that a dietary pattern associated with higher estrogen levels may increase breast cancer risk. However, whether the influence of this dietary pattern is through a direct effect on estrogen levels deserves further study.

Dietary components and uterine leiomyomas: a review of published data

Some studies have considered the association between diet and uterine fibroid risk, but the issue is largely unsettled. To identify potential modifiable risk factors for fibroid development, we have herein systematically reviewed prior publications dealing with this aspect. Comprehensive searches in electronic databases were conducted to collect studies published on association between uterine leiomyomas and both nutrients and food groups. We identified 13 publications deriving from 4 case-control, 3 cross-sectional, and 4 cohort studies. A protective effect has been demonstrated for consumption of fruits and green vegetables in both case-control and cohort studies. Moreover, very recent cross-sectional and case-control studies evaluating serum levels of 25-hydroxyvitamin-D3 tend to indicate that vitamin D insufficiency, which may in part be due to the diet intake, may play an important role in the development of uterine fibroids. No association was found with the intake of fibers, vitamin C and E, phytoestrogens and carotenoids, whereas association was controversial for the consumption of meat, fish, dairy products, and vitamin A. Most data have also been discussed herein in light of the available experimental and animal model results. These findings may be useful in devising nutritional strategies to reduce leiomyoma risk in humans.

Oestrogen levels in serum and urine of premenopausal women eating low and high amounts of meat

OBJECTIVE

Based on the hypothesis that high-meat diets may increase breast cancer risk through hormonal pathways, the present analysis compared oestrogens in serum and urine by meat-eating status.

DESIGN

Intervention with repeated measures.

SETTING

Two randomized soya trials (BEAN1 and BEAN2) among premenopausal healthy women.

SUBJECTS

BEAN1 participants completed seven unannounced 24 h dietary recalls and donated five blood and urine samples over 2 years. BEAN2 women provided seven recalls and three samples over 13 months. Serum samples were analysed for oestrone (E₁) and oestradiol (E₂) using RIA. Nine oestrogen metabolites were measured in urine by LC-MS. Semi-vegetarians included women who reported consuming <30 g of red meat, poultry and fish daily, and pescatarians those who reported consuming <20 g of meat/poultry but >10 g of fish daily. All other women were classified as non-vegetarians. We applied mixed models to compute least-square means by vegetarian status adjusted for potential confounders.

RESULTS

The mean age of the 272 participants was 41·9 (SD 4·5) years. Serum E₁ (85 v. 100 pg/ml, P = 0·04) and E₂ (140 v. 154 pg/ml, P = 0·04) levels were lower in the thirty-seven semi-vegetarians than in the 235 non-vegetarians. The sum of the nine urinary oestrogen metabolites (183 v. 200 pmol/mg creatinine, P = 0·27) and the proportions of individual oestrogens and pathways did not differ by meat-eating status. Restricting the models to the samples collected during the luteal phase strengthened the associations.

CONCLUSIONS

Given the limitations of the study, the lower levels of serum oestrogens in semi-vegetarians than non-vegetarians need confirmation in larger populations.

Maternal diet, prenatal exposure to dioxin-like compounds and birth outcomes in a European prospective mother-child study (NewGeneris)

Maternal diet can result in exposure to environmental contaminants including dioxins which may influence foetal growth. We investigated the association between maternal diet and birth outcomes by defining a dioxin-rich diet. We used validated food frequency questionnaires to assess the diet of pregnant women from Greece, Spain, United Kingdom, Denmark and Norway and estimated plasma dioxin-like activity by the Dioxin-Responsive Chemically Activated LUciferase eXpression (DR-CALUX®) bioassay in 604 maternal blood samples collected at delivery. We applied reduced rank regression to identify a dioxin-rich dietary pattern based on dioxin-like activity (DR-CALUX®) levels in maternal plasma, and calculated a dioxin-diet score as an estimate of adherence to this dietary pattern. In the five country population, dioxin-diet score was characterised by high consumption of red and white meat, lean and fatty fish, low-fat dairy and low consumption of salty snacks and high-fat cheese, during pregnancy. The upper tertile of the dioxin-diet score was associated with a change in birth weight of -121g (95% confidence intervals: -232, -10g) compared to the lower tertile after adjustment for confounders. A small non-significant reduction in gestational age was also observed (-1.4days, 95% CI: -3.8, 1.0days). Our results suggest that maternal diet might contribute to the exposure of the foetus to dioxins and dioxin-like compounds and may be related to reduced birth weight. More studies are needed to develop updated dietary guidelines for women of reproductive age, aiming to the reduction of dietary exposure to persistent organic pollutants as dioxins and dioxin-like compounds.

MicroRNA 'signature' during estrogen-mediated mammary carcinogenesis and its reversal by ellagic acid intervention

Dysregulated miRNA expression has been associated with the development and progression of cancers, including breast cancer. The role of estrogen (E2) in regulation of cell proliferation and breast carcinogenesis is well-known. Recent reports have associated several miRNAs with estrogen receptors in breast cancers. Investigation of the regulatory role of miRNAs is critical for understanding the effect of E2 in human breast cancer, as well as developing strategies for cancer chemoprevention. In the present study we used the well-established ACI rat model that develops mammary tumors upon E2 exposure and identified a 'signature' of 33 significantly modulated miRNAs during the process of mammary tumorigenesis. Several of these miRNAs were altered as early as 3 weeks after initial E2 treatment and their modulation persisted throughout the mammary carcinogenesis process, suggesting that these molecular changes are early events. Furthermore, ellagic acid, which inhibited E2-induced mammary tumorigenesis in our previous study, reversed the dysregulation of miR-375, miR-206, miR-182, miR-122, miR-127 and miR-183 detected with E2 treatment and modulated their target proteins (ERα, cyclin D1, RASD1, FoxO3a, FoxO1, cyclin G1, Bcl-w and Bcl-2). This is the first systematic study examining the changes in miRNA expression associated with E2 treatment in ACI rats as early as 3 week until tumor time point. The effect of a chemopreventive agent, ellagic acid in reversing miRNAs modulated during E2-mediated mammary tumorigenesis is also established. These observations provide mechanistic insights into the new molecular events behind the chemopreventive action of ellagic acid and treatment of breast cancer.

Diet and endometriosis risk: a literature review

A connection between dietary factors and endometriosis onset has become a topic of interest mostly due to the observation that physiological and pathological processes of the disease can be influenced by diet. This paper systematically reviews prior publications dealing with this aspect in order to identify potentially modifiable risk factors. Comprehensive searches in the electronic databases MEDLINE, EMBASE and Science Citation Index Expanded were conducted to identify published studies evaluating the association between food intake (nutrients and food groups) and endometriosis. Eleven studies were identified: 10 case-control and one cohort study. Information on diet was collected using food frequency questionnaires in seven studies, while in one study the questionnaire focused on caffeine and alcohol intake. Women with endometriosis seem to consume fewer vegetables and omega-3 polyunsaturated fatty acids and more red meat, coffee and trans fats but these findings could not be consistently replicated. Most data have also been discussed herein in light of the available experimental and animal model results. At present, evidence supporting a significant association between diet and endometriosis is equivocal. Further studies are needed to clarify the role of diet on endometriosis risk and progression.