Dietary patterns and breast cancer risk among Chinese women

Identification of Chinese dietary patterns and their relationships with health outcomes: a systematic review and meta-analysis

OBJECTIVE

China has been undergoing a rapid nutrition transition in the past few decades. This review aims to characterise commonly reported dietary patterns in Chinese populations and their associations with health outcomes.

DESIGN

We searched PubMed, Embase and CNKI from inception to June 2020 to identify observational studies reporting dietary patterns or the associations between dietary patterns and health outcomes. Information regarding dietary patterns, their association with health outcomes and other related items was collected.

SETTING

Chinese population and Chinese immigrants.

PARTICIPANTS

Not applicable.

RESULTS

Results from 130 studies with over 900 000 participants were included. Six dietary patterns were identified: traditional whole-grain diet (Traditional WG), traditional non-whole-grain diet (Traditional NWG), plant-based diet (Plant-based), animal food diet (Animal-food), Western energy-dense diet (Western) and other unclassified diets (Unclassified). The Plant-based diet was associated with a reduced risk of CVD and cancer from prospective studies, reduced risk of diabetes, hypertension, cognitive impairment and depressive symptoms from all study designs. The Traditional WG diet was associated with a reduced risk of diabetes and hypertension. Animal-food diet is associated with a range of metabolic diseases, and Western diet was associated with increased risks of obesity and depressive symptoms.

CONCLUSION

Multiple dietary patterns identified reflect the diversity and transitioning of the Chinese diet. A healthy Chinese diet, comprising both the Traditional WG and Plant-based diets, was associated with reduced risks of specific undesirable health outcomes. Promoting this healthy diet will improve public health among the Chinese populations.

Dietary patterns, cooking methods and breast cancer risk in Mexico: An exploratory case-control study

Background: Nutrition has an important influence on the risk of developing breast cancer (BC). Dietary patterns can capture the complex interplay of nutrients and cooking methods can contribute to the presence of heterocyclic amines, which are potent mammary carcinogens. Research on dietary patterns, cooking methods, and their association with BC in Mexican women is scarce. Aim: To evaluate the association of dietary patterns and cooking methods with BC risk among women from the Northwest region of Mexico. Methods: This case-control study included 120 women. Eligible cases (n = 60) were diagnosed and biopsy-confirmed in the past 2 years. Control subjects (n = 60) were hospital and population-based. Dietary intake and cooking methods were respectively assessed through a food frequency questionnaire (FFQ) and the National Cancer Institute survey. We obtained dietary patterns from a K-means cluster analysis (CA), and multivariate logistic regression tested the association of dietary patterns and cooking methods with BC risk. Results: Prudent and caloric dietary patterns were identified. The caloric pattern was associated with BC risk (Model 1: ORadj: 5.07, 95%CI:1.44-17.84, p = 0.011; Model 2: ORadj: 4.99 (95%CI:1.39-17.92, p = 0.014). Intense frying, meat grilling and poultry resulted in a significant BC risk (Model 1: ORadj: 5.54,95%CI: 2.13-14.41), p < 0.001; Model 2: ORadj: 5.12, 95%CI: 1.83-14.31, p = 0.002). At Oestrogen exposure of <32 years, there was an association between dietary patterns and BC risk (ORadj: 4.69, 95%CI: 1.01-21.92, p = 0.049). The relationship between BC risk and cooking intensity was found in both strata of exposure to oestrogens: <32 years (ORadj: 3.72, 95%CI:1.04-13.33, p = 0.044), and ≥32 years (ORadj: 6.06, 95%CI:1.34-27.42, p = 0.019). Conclusions: A caloric dietary pattern rich in refined carbohydrates and saturated fat, and intense meat product cooking may increase the risk of BC in Mexican women.

High adherence to Western dietary pattern increases breast cancer risk (an EPIC-Spain study)

OBJECTIVE

To explore the association between three previously identified and validated dietary patterns (Western, Prudent and Mediterranean) and breast cancer risk by tumour subtype and menopausal status.

METHODS

Data from the Spanish cohort of the European Prospective Investigation into Cancer and Nutrition study provided epidemiological information (including diet and cancer incidence) from 24,892 women (639 breast cancer cases) recruited between 1992 and 1996. The associations between adherence to the three dietary patterns and breast cancer risk (overall and by tumour subtype) were explored by fitting multivariate Cox proportional hazards regression models stratified by region, among other variables. A possible interaction with menopausal status (changing over time) was explored.

RESULTS

No clear association of the Prudent and Mediterranean dietary patterns with breast cancer risk was found. When compared with women with a level of adherence to the Western diet in the first quartile, women with a level of adherence in the third (hazard ratio (95 % confidence interval) (HR(95%CI)):1.37 (1.07;1.77)) and fourth quartiles (1.37 (1.03;1.83)); p for curvature of splines = 0.016) showed a non-linear increased risk, especially postmenopausal women (HR (95 % CI) 1.30 (0.98;1.72) in the third and 1.42 (1.04;1.94) in the fourth quartiles; p for curvature of splines = 0.081) and for estrogen or progesterone receptor positive with human epidermal growth factor receptor 2 negative tumours (HR (95 % CI) 1.62 (1.10;2.38) and 1.71 (1.11;2.63) for the third and fourth quartiles respectively; p for curvature of splines = 0.013).

CONCLUSIONS

Intake of foods such as high-fat dairy products, red and processed meats, refined grains, sweets, caloric drinks, convenience food and sauces might be associated with a higher risk of breast cancer.

Association of food groups and dietary pattern with breast cancer risk: A systematic review and meta-analysis

BACKGROUND & AIMS

We conducted a systematic review and meta-analysis of current evidence for the association between food groups, dietary patterns, and breast cancer risk among the Asian population.

METHODS

This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. We performed a systematic literature search up to December 2022 in English in the PubMed, Web of Science, Embase, and Cochrane databases. Risk ratios (RRs) with 95% confidence intervals (CIs) were extracted as effect sizes. Publication bias was estimated by two different funnel plot methods.

RESULTS

We collected the data from 15 cohort studies and 34 case-control studies meeting the search criteria. The meta-analysis found that the consumption of fruits and, likewise, vegetables were associated with a 29% lower risk of breast cancer, respectively [RR = 0.71 (0.55, 0.93); RR = 0.71 (0.53, 0.95)]. By contrast, no significance was found between meat, soy foods, and green tea consumption and breast cancer risk (P > 0.05). However, soy protein and isoflavone intake could lower breast cancer risk by 35% and 32%, respectively [RR = 0.65 (0.51, 0.83); RR = 0.68 (0.55, 0.82)]. As for the dietary pattern, high adherence to a healthy dietary pattern and, similarly, to a healthy eating index was associated with a 38% and 51% reduction in breast cancer risk, respectively [RR = 0.62 (0.44, 0.88; RR = 0.49 (0.27, 0.87)], while high adherence to an unhealthy dietary pattern was associated with a 44% increased risk [RR = 1.44 (1.06, 1.96)]. Considering alcohol consumption, a 75% increased risk of breast cancer was found [RR = 1.75 (1.33, 2.30)].

CONCLUSION

The present meta-analysis found that high intakes of fruits, vegetables, soy protein, and soy isoflavone significantly reduced the risk of breast cancer, while high intake of alcohol had a significantly increased risk. Meat, soy food, and green tea consumption were not significantly associated with breast cancer risk. Considering dietary patterns, high adherence to a healthy eating index and a healthy dietary pattern may reduce breast cancer risk. Conversely, adherence to unhealthy dietary patterns may increase breast cancer risk. However, further studies are needed to confirm the associations between dietary patterns and breast cancer in the Asian population.

The Role of Diet Compared to Physical Activity on Women's Cancer Mortality: Results From the Third National Health and Nutrition Examination Survey

Background

Among women in the United States, cancer is the second leading cause of death. Prior studies have examined how lifestyle factors, such as diet and physical activity, influence cancer mortality. However, few have evaluated if diet or physical activity has a stronger protective effect for cancer mortality. Therefore, this study aims to evaluate and compare the impacts of diet and physical activity on women's cancer mortality.

Methods

Prospective, cross-sectional data were abstracted from the Third US National Health and Nutrition Examination Survey (NHANES III) on female respondents from 1988 to 1994. Physical activity was derived from the CDC's metabolic equivalent (MET) intensity levels. Dietary classifications were derived from the USDA's healthy eating index (HEI). We utilized the National Death Index to obtain mortality follow-up information on our cohort until December 31, 2015. Chi-squared, multivariable Cox regression, and Kaplan–Meier estimates were employed for statistical analyses.

Results

Of 3,590 women (median age: 57, range: 40–89), 30% had an obese BMI (BMI≥30 kg/m²). Additionally, 22% of participants self-reported a healthy diet, 69% needed dietary improvement, and 9% had a poor diet. Furthermore, 21% reported physical inactivity, 44% did not meet physical activity guidelines, and 35% met guidelines. On multivariate analysis, healthy diet (HR: 0.70; 95% CI: 0.51–0.98; p = 0.04), but not physical activity (HR: 0.87; 95% CI: 0.55–1.38; p = 0.55), independently predicted for lower cancer mortality. Participants with a healthy diet but low exercise had decreased cancer mortality compared to participants with an unhealthy diet but high exercise (p = 0.01).

Conclusions

A healthful diet was associated with lower cancer mortality in women, even after adjusting for obesity, inflammation, and other covariates. In addition, diet may play a stronger role in reducing cancer mortality in women than physical activity.

Adherence to a western dietary pattern and risk of invasive ductal and lobular breast carcinomas: a case-control study

Little is known about the role of diet in the risk of invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) of the breast, the most common histological subtypes of breast cancer (BC). This is because, the majority of studies on the association of diet and the risk of BC are focused on single food items, and studies considering the overall diet in terms of dietary patterns are limited. Also, the potential heterogeneity in the impact of Western diet (WD) on histological subtypes of BC is not established. This, the age-frequency-matched case–control study included 1009 incident BC cases and 1009 healthy controls. The required data was obtained from the patients’ medical files and interviews using a previously validated researcher-designed questionnaire for collecting data on socio-economic and anthropometric statuses and a valid food frequency questionnaire (FFQ) to measure the participants’ dietary intake. We used multinomial logistic regression, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. A positive and significant association was observed between higher adherence to a WD and risk of IDC (OR comparing highest with the lowest tertile: 2.45, 95% CI 1.88, 3.17; p-trend < 0.001), whereas no significant association was observed between adherence to the WD and the risk of ILC (OR comparing highest with the lowest tertile: 1.63, 95% CI 0.63, 3.25) (p for heterogeneity = 0.03). The results of an analysis stratified by menopausal status suggested a similar pattern. We provided evidence that adherence to a WD raises the risk of IDC, but not ILC, suggesting different etiological mechanisms for IDC and ILC.

Association Between Dietary Patterns and Plasma Lipid Biomarker and Female Breast Cancer Risk: Comparison of Latent Class Analysis (LCA) and Factor Analysis (FA)

Background: Diet research focuses on the characteristics of "dietary patterns" regardless of the statistical methods used to derive them. However, the solutions to these methods are both conceptually and statistically different. Methods: We compared factor analysis (FA) and latent class analysis (LCA) methods to identify the dietary patterns of participants in the Chinese Wuxi Exposure and Breast Cancer Study, a population-based case-control study that included 818 patients and 935 healthy controls. We examined the association between dietary patterns and plasma lipid markers and the breast cancer risk. Results: Factor analysis grouped correlated food items into five factors, while LCA classified the subjects into four mutually exclusive classes. For FA, we found that the Prudent-factor was associated with a lower risk of breast cancer [4th vs. 1st quartile: odds ratio (OR) for 0.70, 95% CI = 0.52, 0.95], whereas the Picky-factor was associated with a higher risk (4th vs. 1st quartile: OR for 1.35, 95% CI = 1.00, 1.81). For LCA, using the Prudent-class as the reference, the Picky-class has a positive association with the risk of breast cancer (OR for 1.42, 95% CI = 1.06, 1.90). The multivariate-adjusted model containing all of the factors was better than that containing all of the classes in predicting HDL cholesterol (p = 0.04), triacylglycerols (p = 0.03), blood glucose (p = 0.04), apolipoprotein A1 (p = 0.02), and high-sensitivity C-reactive protein (p = 0.02), but was weaker than that in predicting the breast cancer risk (p = 0.03). Conclusion: Factor analysis is useful for understanding which foods are consumed in combination and for studying the associations with biomarkers, while LCA is useful for classifying individuals into mutually exclusive subgroups and compares the disease risk between the groups.

Dietary Patterns and Breast Cancer Risk in Black Urban South African Women: The SABC Study

A total of 396 breast cancer cases and 396 population-based controls from the South African Breast Cancer study (SABC) matched on age and demographic settings was included. Validated questionnaires were used to collect dietary and epidemiological data. Dietary patterns were derived using principal component analysis with a covariance matrix from 33 food groups. Odds ratios and 95% confidence intervals were estimated using conditional logistic regression. A traditional, a cereal-dairy breakfast and a processed food dietary pattern were identified, which together explained 40.3% of the total variance in the diet. After adjusting for potential confounders, the traditional dietary pattern and cereal-dairy breakfast dietary pattern were inversely associated with breast cancer risk (highest tertile versus lowest tertile) (OR = 0.72, 95%CI: 0.57-0.89, p-trend = 0.004 and OR = 0.73, 95%CI: 0.59-0.90, p-trend = 0.004, respectively). The processed food dietary pattern was not significantly associated with breast cancer risk. The results of this study show that a traditional dietary pattern and a cereal-dairy breakfast dietary pattern may reduce the risk of developing breast cancer in this population.

Association between dietary patterns and risk of breast cancer in Chinese female population: a latent class analysis

OBJECTIVE

To determine if specific dietary patterns are associated with breast cancer (BC) risk in Chinese women.

DESIGN

Latent class analysis (LCA) was performed to identify generic dietary patterns based on daily food-frequency data.

SETTING

The Chinese Wuxi Exposure and Breast Cancer Study (2013-2014).

PARTICIPANTS

A population-based case-control study (695 cases, 804 controls).

RESULTS

Four dietary patterns were identified, Prudent, Chinese traditional, Western and Picky; the proportion in the controls and cases was 0·30/0·32/0·16/0·23 and 0·29/0·26/0·11/0·33, respectively. Women in Picky class were characterised by higher extreme probabilities of non-consumption of specific foods, the highest probabilities of consumption of pickled foods and the lowest probabilities of consumption of cereals, soya foods and nuts. Compared with Prudent class, Picky class was associated with a higher risk (OR = 1·42, 95 % CI 1·06, 1·90), while the relevant association was only in post- (OR = 1·44, 95 % CI 1·01, 2·05) but not in premenopausal women. The Western class characterised by high-protein, high-fat and high-sugar foods, and the Chinese traditional class characterised by typical consumption of soya foods and white meat over red meat, both of them showed no difference in BC risk compared with Prudent class did.

CONCLUSIONS

LCA captures the heterogeneity of individuals embedded in the population and could be a useful approach in the study of dietary pattern and disease. Our results indicated that the Picky class might have a positive association with the risk of BC.

Dietary patterns and relative expression levels of PPAR-γ, VEGF-A and HIF-1α genes in benign breast diseases: case-control and consecutive case-series designs

We aimed to study dietary patterns in association with the relative expression levels of PPAR-γ, vascular endothelial growth factor-A (VEGF-A) and hypoxia-inducible factor-1α (HIF-1α) in women with benign breast disease (BBD). The study design was combinative, included a case-series and case-control compartments. Initially, eligible BBD patients (n 77, aged 19-52 years old) were recruited at Nour-Nejat hospital, Tabriz, Iran (2012-2014). A hospital-based group of healthy controls was matched for age (n 231, aged 20-63 years old) and sex. Dietary data were collected using a valid 136-item FFQ. Principal component analysis generated two main components (Kaiser-Meyer-Olkin = 0·684), including a Healthy pattern (whole bread, fruits, vegetables, vegetable oils, legumes, spices, seafood, low-fat meat, skinless poultry, low-fat dairy products, nuts and seeds) and a Western pattern (starchy foods, high-fat meat and poultry, high-fat dairy products, hydrogenated fat, fast food, salt and sweets). High adherence to the Western pattern increased the risk of BBD (ORadj 5·59; 95 % CI 2·06, 15·10; P < 0·01), whereas high intake of the Healthy pattern was associated with a 74 % lower risk of BBD (95 % CI 0·08, 0·81; P < 0·05). In the BBD population, the Western pattern was correlated with over-expression of HIF-1α (radj 0·309, P < 0·05). There were inverse correlations between the Healthy pattern and expressions of PPAR-γ (radj -0·338, P < 0·05), HIF-1α (radj -0·340, P < 0·05) and VEGF-A (radj -0·286, P < 0·05). In conclusion, new findings suggested that the Healthy pattern was associated inversely with the risk of BBD, and this could be correlated with down-regulation of PPAR-γ, VEGF-A and HIF-1α genes, which might hold promise to preclude BBD of malignant pathological transformation.

Dietary Patterns and Risk of Invasive Ductal and Lobular Breast Carcinomas: A Systematic Review and Meta-analysis

The histopathologic subtypes of breast cancer, including invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC), differ in terms of risk factors, progression, and response to treatment. The PubMed/Medline, Web of Science, and Scopus databases were searched up to February 2020 for published studies on the association between dietary patterns (Western diet [WD] or Mediterranean diet [WD]) and the risk of IDC/ILC of breast. Multivariable adjusted relative risk (RR) and 95% confidence intervals (CIs) comparing the highest and lowest categories of WD and MD patterns were combined by using the random-effects meta-analyses. After searching the databases, 10 eligible studies on the association of diet and IDC (7 articles) and ILC (3 articles) were included in the analysis. A statistically significant adverse association was observed between MD and IDC in case-control studies (RR = 0.47; 95% CI, 0.39-0.55; I² = 85.1%; P < .001). However, the association was nonsignificant in cohort studies (RR = 0.98; 95% CI, 0.92-1.05; I² = 88.8%; P = .003). The pooled analysis also suggested a significant and direct association between the WD and the risk of IDC (RR = 1.36; 95% CI, 1.18-1.53; I² = 63.7%; P = .017). The risk of ILC for the highest compared to the lowest category of MD was highly protective (RR = 0.76; 95% CI, 0.64-0.87; I² = 89.2%; P < .001), and a marginally significant association was found between the WD and risk of ILC (RR = 1.45; 95% CI, 1.04-1.86), with no heterogeneity (I² = 0; P = .52). This meta-analysis provides supporting evidence for the association between MD decreased risk of IDC and ILC of the breast and the association between WD and increased risk of IDC and ILC. Further investigations are needed to better understand the reasons behind the etiologic mechanisms of how dietary patterns affect patients differently by common breast cancer subtypes, including IDC and ILC.

Dietary Habits and Breast Cancer Risk: A Hospital-Based Case-Control Study in Chinese Women

PURPOSE

To investigate the relationship between dietary habits and breast cancer (BC) risk in Chinese women.

PATIENTS AND METHODS

We performed a hospital-based matched case-control study that included 654 BC cases and 654 healthy controls matched by age and residence. A qualified structured questionnaire was used to collect detailed sociodemographic factors and information about dietary habits. The odds ratios (ORs) and 95% confidence intervals were calculated with unconditional logistic regression analysis; the patients were grouped according to their estrogen receptor (ER) status and analyzed separately. The propensity score analysis was performed according to different postmenopause status.

RESULTS

ER-negative BC participants with intake of cured foods had increased BC risk (adjusted OR, 2.72, P = .017). Participants diagnosed as having ER-positive BC with intake of grilled foods had increased BC risk compared to those who did not consume such foods (adjusted OR, 2.14, P = .026). After propensity score analysis, fried (OR, 3.19, P = .001) and grilled (OR, 1.77, P = .031) food were considered to be risk factors for BC in premenopausal women; and fried (OR, 1.61, P = .006), grilled (OR, 4.62, P = .001), and smoked foods (OR, 2.28, P = .001) are considered risk factors for BC in postmenopausal women.

CONCLUSION

Chinese women who ate cured, grilled, and fried foods had higher BC risk. Consumption of smoked food might contribute to increased BC risk in Chinese women.

Milk Consumption Decreases Risk for Breast Cancer in Korean Women under 50 Years of Age: Results from the Health Examinees Study

Epidemiologic studies regarding breast cancer risk related to milk consumption remain controversial. The aim of this study was to evaluate the association between milk consumption and the risk for breast cancer. A total of 93,306 participants, aged 40-69 years, were included in the prospective cohort study in the Health Examinees-Gem (HEXA-G) study between 2004 and 2013. Dietary intake was assessed using a validated food frequency questionnaire. Information on cancer diagnosis in the eligible cohort was retrieved from the Korea Central Cancer Registry through 31 December 2014. The Cox proportional hazards model was used to estimate multivariate hazard ratios (HRs) and 95% confidence intervals (CIs). A total of 359 breast cancer cases were observed over a median follow-up period of 6.3 years. Milk consumption was not associated with decreased risk for breast cancer in the total population (p for trend = 0.0687). In women under 50 years of age, however, milk consumption was inversely associated with breast cancer risk. In the comparison between highest (≥1 serving/day) and lowest (<1 serving/week) intake categories of milk, the multivariate HR (95% CI) was 0.58 (0.35-0.97, p for trend = 0.0195)) among women under 50 years of age. In conclusion, our findings show that milk consumption in Korean women aged 50 or younger is associated with a decreased risk for breast cancer, when compared to those who never or rarely consumed milk. Further studies need to be conducted to assess this relationship and confirm these results.

The Association between Dietary Patterns and Breast Cancer Pathobiological Factors Progesterone Receptor (PR) and Estrogen Receptors (ER): New Findings from Iranian Case-Control Study

Background: Breast cancer (BrCa) is the most frequently diagnosed cancer among females and second cancer after lung cancer in many societies. Ignoring the phenotypes of the BrCa can affect the interpretation of the association between diet and BrCa. The aim of this study was to determine the association between dietary patterns and estrogen receptor (ER), and progesterone receptor (PR) status in women with BrCa. Methods: This study includes 150 cases of BrCa. Controls were 150 healthy adults, frequency matching based on age. The individual information, food frequency questionnaire, and physical activity were completed while interviews. Information about the pathologic factors obtained from patients' files. Factor analysis method used to determine the dietary patterns; logistic regression used to measure the odds ratios. Results: Getting upper median intake of unhealthy diet had a strong association with BrCa-positive ER and positive PR (OR: 4.98, 95% CI: 2.65-9.34 and OR: 4.99, 95% CI: 2.56-9.75, respectively) compared to under median intake of unhealthy diet. In addition, the protective effect of the healthy diet was stronger on BrCa-negative ER, negative PR (OR: 0.11, 95% CI: 0.04-0.34 and OR: 0.10, 95% CI: 0.03-0.25, respectively). Conclusion: The protective effect of a healthy dietary pattern was stronger on BrCa negative ER and negative PR. The unhealthy dietary pattern had a strong association with BrCa positive ER and positive PR.

Associations between dietary patterns and the risk of breast cancer: a systematic review and meta-analysis of observational studies

BACKGROUND

Epidemiologic evidence suggests that certain dietary patterns were associated with breast cancer risk, but the results have been inconclusive. We assessed the associations between different dietary patterns and the risk of breast cancer by conducting a meta-analysis of observational studies.

METHODS

Relevant articles were searched in PubMed, Embase, and Cochrane library databases through September 2017. Multivariable-adjusted relative risks (RRs) and 95% confidence intervals (CIs) comparing the highest and lowest categories of Western and prudent dietary patterns were combined by using the random-effects meta-analyses.

RESULTS

We identified 32 eligible articles including 14 cohort and 18 case-control studies (34 Western and 35 prudent studies). The pooled analyses found that a Western dietary pattern was associated with a 14% increased risk (RR 1.14, 95% CI 1.02, 1.28), whereas a prudent dietary pattern was associated with an 18% reduced risk of breast cancer (RR 0.82, 95% CI 0.75, 0.89). In addition, sub-group analyses showed that the positive association between a Western dietary pattern and breast cancer risk was significant among postmenopausal (RR 1.20, 95% CI 1.06, 1.35), but not premenopausal women (RR 1.18, 95% CI 0.99, 1.40), and significant for hormone receptor-positive tumors (RR 1.18, 95% CI 1.04, 1.33), but not receptor-negative tumors (RR 0.97, 95% CI 0.83, 1.12). In contrast, the inverse association between a prudent dietary pattern and breast cancer was significant in premenopausal (RR 0.77, 95% CI 0.61, 0.98), but not postmenopausal women (RR 0.88, 95% CI 0.74, 1.03), and significant for both hormone receptor-positive and receptor-negative tumors.

CONCLUSIONS

The results of the current meta-analysis suggest a possible increased risk of breast cancer associated with a Western dietary pattern and a reduced risk with a prudent dietary pattern. Large-scale cohort studies with a high quality need to be conducted to further confirm the findings of the current meta-analysis. As dietary patterns are modifiable, these findings may provide viable strategies for breast cancer prevention through changes in dietary intake.

Dietary patterns and breast cancer risk among Iranian women: A case-control study

AIM

Breast cancer is the most common cancer among women worldwide. Most previous studies focused on individual nutrients or foods rather than overall dietary patterns. We aimed to assess the association between major dietary patterns and breast cancer risk.

METHOD

In a hospital-based case-control study, 134 women diagnosed as breast cancer and 267 controls were recruited from referral hospitals in Tehran, Iran. Dietary intakes were evaluated by using a validated 168-item food frequency questionnaire. Dietary pattern were identified by factor analysis. Odds ratios (OR) were estimated using logistic regression.

RESULTS

Two dietary patterns were extracted: healthy and unhealthy. The "Healthy" dietary pattern was loaded for high consumptions of fruits, vegetables, seeds, legume, fish and sea foods, whole grains, liquid oils, olive oils and olive and lack of salt intake. "Unhealthy" dietary pattern was characterized by high factor loadings for sweets, soft drinks, mayonnaise, solid oils, processed meat, fried and boiled potato and salt intake. In multivariate logistic regression analyses, the healthy dietary pattern was not associated with breast cancer risk (OR: 0.83; 95%CI: 0.36, 1.89; P-trend = 0.50), while women in the highest quartile of the unhealthy dietary pattern had a significantly increased breast cancer risk (OR: 2.21; 95%CI: 1.04, 4.690; P-trend = 0.009). When stratified by menopausal status, unhealthy dietary pattern showed inverse association with breast cancer risk only among post-menopausal women (OR: 3.56; 95%CI: 1.16, 10.95; P-trend = 0.008).

CONCLUSIONS

Our findings showed that an unhealthy dietary pattern might be associated with higher risk of breast among Iranian women.

Possible role of diet in cancer: systematic review and multiple meta-analyses of dietary patterns, lifestyle factors, and cancer risk

Context

Evidence of an association between dietary patterns derived a posteriori and risk of cancer has not been reviewed comprehensively.

Objective

The aim of this review was to investigate the relation between a posteriori-derived dietary patterns, grouped as healthy or unhealthy, and cancer risk. The relation between cancer risk and background characteristics associated with adherence to dietary patterns was also examined.

Data Sources

PubMed and Embase electronic databases were searched.

Study Selection

A total of 93 studies including over 85 000 cases, 100 000 controls, and 2 000 000 exposed individuals were selected.

Data Extraction

Data were extracted from each identified study using a standardized form by two independent authors.

Results

The most convincing evidence (significant results from prospective cohort studies) supported an association between healthy dietary patterns and decreased risk of colon and breast cancer, especially in postmenopausal, hormone receptor-negative women, and an association between unhealthy dietary patterns and increased risk of colon cancer. Limited evidence of a relation between an unhealthy dietary pattern and risk of upper aerodigestive tract, pancreatic, ovarian, endometrial, and prostatic cancers relied only on case-control studies. Unhealthy dietary patterns were associated with higher body mass index and energy intake, while healthy patterns were associated with higher education, physical activity, and less smoking. Potential differences across geographical regions require further evaluation.

Conclusions

The results suggest a potential role of diet in certain cancers, but the evidence is not conclusive and may be driven or mediated by lifestyle factors.

Adipocytokines and breast cancer

A substantial number of studies have revealed that a growing list of cancers might be influenced by obesity. In this regard, one of the most prominent and well-characterized cancers is breast cancer, the leading cause of cancer death among women. Obesity is associated with an increased risk for the occurrence and development of breast cancer particular in postmenopausal women. Moreover, the relationship between adiposity and breast cancer risk is complex, with associations that differ depending on when body size is assessed (eg, premenopausal vs postmenopausal obesity) and when breast cancer is diagnosed (ie, premenopausal vs postmenopausal disease). Obesity is mainly due to excessive fat accumulation in the regional tissue. Adipocytes in obese individuals produce endocrine, inflammatory, and angiogenic factors to affect adjacent breast cancer cells. Adipocytokines, are biologically active polypeptides that are produced either exclusively or substantially by adipocytes, play a critical and complex role, and act by endocrine, paracrine, and autocrine pathways in the malignant progression of breast cancer. Furthermore, the increased levels of leptin, resistin, and decreased adiponectin secretion are directly associated with breast cancer development. And there are also many studies indicating that adipocytokines could mediate the survival, growth, invasion, and metastasis of breast cancer cells by different cellular and molecular mechanisms to reduce the survival time and prompt the malignancy. In present review, we discuss the correlations between several adipocytokines and breast cancer cells in obesity as well as the underlying signaling pathways to provide the novel ideas for the prevention and treatment of breast cancer.

Association between dietary protein intake and type 2 diabetes varies by dietary pattern

BACKGROUND

Epidemiological studies have demonstrated that high total protein intake was related to type 2 diabetes mellitus (T2DM) risks. However, few studies considered the impact of dietary pattern.

OBJECTIVE

We examined the associations between protein intake and T2DM in different dietary patterns.

METHODS

We used the demographic and dietary information of adults aged 18-75 years from the China Health and Nutrition Survey (2009), consisting of 4113 women and 4580 men. Dietary data was collected by using 24-h recalls combined with a food inventory for 3 consecutive days. Cluster analysis was used to classify subjects into groups, as determined by major sources of protein. Logistic regression models were used to calculate odds ratios (OR) and 95% confidence interval (95% CI) of T2DM according to the energy-adjusted protein intake.

RESULTS

All participants were divided into three patterns according to the dietary source of protein (legumes and seafood, red meat, refined grains). Overall, plant protein intake was significantly and inversely associated with T2DM. In the subgroup analysis by dietary patterns, extreme quartile of plant protein intake was also inversely related to T2DM in the "legumes and seafood" group [OR = 0.58, 95% CI (0.33-0.96)]. Total protein intake and animal protein intake were positively related to T2DM in the "red meat" group [OR: 3.12 (1.65-5.91) and 3.48 (1.87-6.60), respectively]. However, the association of animal protein intake was reversed in the "refined grains" group [OR = 0.55, 95% CI 0.32-0.89].

CONCLUSIONS

The association between protein intake and T2DM varies by dietary pattern. Dietary pattern may be considered into the recommendation of protein intake for diabetes prevention.

Is vegetarian diet associated with a lower risk of breast cancer in Taiwanese women?

Background

Studies on the relationship between vegetarian diet and breast cancer in Asian populations are limited. This study aimed to investigate the relationship between vegetarian diet, dietary patterns, and breast cancer in Taiwanese women.

Methods

This case-control study compared the dietary patterns of 233 breast cancer patients and 236 age-matched controls. A questionnaire about vegetarian diets and 28 frequently-consumed food items was administered to these 469 patients in the surgical department of Taipei Tzu Chi Hospital. Serum biochemical status was also examined.

Results

There were no significant differences between the two groups for age, education, family history, oral contraceptive usage, or regular exercise. However, the cancer group presented with both a higher body mass index and an older age of primiparity (P < 0.05). Two food items (shellfish and seafood) were highly correlated (correlation coefficient = 0.77), so shellfish was excluded to avoid multicollinearity. A factor analysis of 27 food items produced five dietary patterns: meat, processed meat, fruit/vegetable/soybean, dessert/sugar, and fermented food. Multivariate logistic regression showed that meat/fat and processed meat dietary patterns were associated with breast cancer risk (odds ratio (OR): 2.22, 95% CI 1.67–2.94, P < 0.001; OR: 1.49, 95% CI 1.09–2.04, P = 0.013, respectively). Vegetarian diet, high isoflavone intake, and high albumin levels were inversely associated with breast cancer risk (P < 0.05). Vegetarians had a higher daily soy isoflavone intake than non-vegetarians (25.9 ± 25.6 mg vs. 18.1 ± 15.6 mg, P < 0.001).

Conclusions

Vegetarian diets show as protective role against breast cancer risk, while meat and processed meat dietary patterns are associated with a higher breast cancer risk.

Electronic supplementary material

The online version of this article (10.1186/s12889-017-4819-1) contains supplementary material, which is available to authorized users.

The association of dietary pattern and breast cancer in Jiangsu, China: A population-based case-control study

This study aims to examine the association of breast cancer with dietary patterns among Chinese women. A population-based case-control study was conducted in Jiangsu, China. Newly diagnosed primary breast cancer patients were recruited as cases (n = 818). Controls (n = 935), selected from the general population, were frequency matched to cases. A validated food frequency questionnaire was used to assess dietary intake. Dietary patterns were identified by factor analysis and multivariable odds ratios (OR) and 95% confidence intervals (CI) were estimated. Four dietary patterns were identified: salty, vegetarian, sweet and traditional Chinese. The traditional Chinese pattern was found to be robustly associated with a lower risk of breast cancer among both pre- and post-menopausal women (4^thvs. 1^st quartile: OR for pre- and post-menopausal women was 0.47 and 0.68, respectively). Women with high factor scores of the sweet pattern also showed a decreased risk of breast cancer (4^thvs. 1^st quartile: OR for pre- and post-menopausal women was 0.47 and 0.68, respectively). No marked association was observed between a vegetarian pattern or a salty pattern and breast cancer. These findings indicate that dietary patterns of the traditional Chinese and the sweet may favorably associate with the risk of breast cancer among Chinese women.

Dietary patterns: a literature review of the methodological characteristics of the main step of the multivariate analyzes

OBJECTIVE

To describe the solutions adopted in the multiple steps of the use of multivariate techniques to obtain a dietary pattern (DP) concerning: the objective of the studies, the selection of the method for measuring food intake, the criteria for grouping the foods, the number of food groups used, the number of DP obtained, and the nomenclature criteria.

METHODS

The articles were selected from MEDLINE and Lilacs scientific databases using the following keywords: "dietary patterns" versus "factor analysis"; "principal components analysis"; "cluster analysis" and "reduced regression rank." The initial search resulted in 1,752 articles. After inclusion and exclusion criteria, 189 publications were selected.

RESULTS

The following aspects were relevant among the studies: the prevalence of the principal component analysis (PCA); the prevalence of the use of 4 to 5 DPs in the studies of association with health outcomes; the use of 30 or more food groups from the food frequency questionnaire (FFQ); the prevalence of studies that associated DPs with health outcomes and socioeconomic factors; and the heterogeneity of criteria used throughout the analytical stages of the multivariate techniques.

CONCLUSION

The heterogeneity between the publications concentrates on the criteria for food grouping, the nomenclature, and the number of dietary patterns calculated, which varied depending on the number of food groups present in these analyses. To understand, apply, and explore in full, the multivariate techniques has become necessary in order to improve the reliability of the results and, consequently, to improve the relationships with health outcomes and socioeconomic factors.

Relationship between Chinese medicine dietary patterns and the incidence of breast cancer in Chinese women in Hong Kong: a retrospective cross-sectional survey

Background

This retrospective cross-sectional study aimed to investigate the relationship between Chinese medicine (CM) dietary patterns (hot, neutral, and cold) and the incidence of breast cancer among Chinese women in Hong Kong.

Methods

Breast cancer cases (n = 202) and healthy controls (n = 202) were matched according to demographics. Chinese women residing in Hong Kong for the past 7 years were recruited by media advertisements (e.g., via newspapers, radio, and posters). The control participants were recruited by convenience sampling from health workshops held in clinics and communities of 15 districts of Hong Kong. After completing test–retest reliability, all participants were asked to complete diet pattern questionnaires about their food preferences and dietary patterns. The Student’s unpaired t test, Chi square test, and logistic regression were conducted using SPSS software.

Results

Three major CM dietary patterns were identified: hot, neutral, and cold. The participants with breast cancer exhibited a stronger preference for hot food than the control group (Chi square test, P < 0.001). A higher frequency of breast cancer was associated with a higher frequency of dining out for breakfast (4–5 times per week, Chi square test, P = 0.015; 6–7 times per week, Chi square test, P < 0.001) and lunch (4–5 times per week, Chi square test, P < 0.001; 6–7 times per week, Chi square test, P = 0.006). The participants with no history of breast cancer consumed CM supplements and Guangdong soups (1–2 times per week, Chi square test, P = 0.05; >3 times per week, Chi square test, P < 0.001) more frequently than those with breast cancer.

Conclusions

Non-breast cancer participants adopted a neutral (healthy and balanced) dietary pattern, and consumed CM supplements and Guangdong soups more frequently.

Electronic supplementary material

The online version of this article (doi:10.1186/s13020-017-0138-9) contains supplementary material, which is available to authorized users.

Behavioral risk factors of breast cancer in Bangui of Central African Republic: A retrospective case-control study

Breast cancer is recognized as a major public health problem in developing countries; however, there is very little evidence of behavioral factors associated with breast cancer risk. This study was conducted to identify lifestyles as risk factors for breast cancer among Central African women. A case-control study was conducted with 174 cases confirmed histologically by the pathology unit of the National Laboratory and 348 age-matched controls. Data collection tools included a questionnaire with interviews and medical records of patients. Data were analyzed using SPSS software version 20. Odd ratio (OR) and 95% confidence intervals (95% CI) were obtained by unconditional logistic regression. In total, 522 women were studied with a mean age of 45.8 (SD = 13.4) years. By unconditional logistic regression model, women with breast cancer were more likely to have attained illiterate and elementary education level [11.23 (95% CI, 4.65-27.14) and 2.40 (95% CI, 1.15-4.99)], married [2.09 (95% CI, 1.18-3.71)], positive family history [2.31 (95% CI, 1.36-3.91)], radiation exposure [8.21 (95% CI, 5.04-13.38)], consumption charcuterie [10.82 (95% CI, 2.39-48.90)], fresh fish consumption [4.26 (95% CI, 1.56-11.65)], groundnut consumption [6.46 (95% CI, 2.57-16.27)], soybean consumption [16.74 (95% CI, 8.03-39.84)], alcohol [2.53 (95% CI, 1.39-4.60)], habit of keeping money in bras[3.57 (95% CI, 2.24-5.69)], overweight [5.36 (95% CI, 4.46-24.57)] and obesity [3.11(95% CI, 2.39-20.42)]. However, decreased risk of breast cancer was associated with being employed [0.32 (95% CI, 0.19-0.56)], urban residence [0.16 (95% CI, 0.07-0.37)], groundnut oil consumption [0.05 (95% CI, 0.02-0.14)], wine consumption [0.16 (95% CI, 0.09-0.26)], non habit of keeping cell phone in bras [0.56 (95% CI, 0.35-0.89)] and physical activity [0.71(95% CI, 0.14-0.84)]. The study showed that little or no education, marriage, positive family history of cancer, radiation exposure, charcuterie, fresh fish, groundnut, soybean, alcohol, habit of keeping money in bras, overweight and obesity were associated with breast cancer risk among Central African women living in Bangui. Women living in Bangui should be more cautious on the behavioral risk associated with breast cancer.

Dietary Patterns and Risk of Breast Cancer in Women in Guilan Province, Iran

BACKGROUND

Several studies have pointed to roles of dietary and food groups in the pathogenesis of breast cancer, but information on dietary patterns among women with breast cancer and their healthy counterparts in Iran is limited. Therefore the present investigation was conducted in Guilan province in 2014-2015.

MATERIALS AND METHODS

In a case-control study, 450 women with breast cancer and one of their relatives (third-rank) were investigated. At first the phone numbers of patients in Razi Hospital in radiotherapy and chemotherapy and oncology centers of Guilan were taken. Data were collected through telephone interviews by the researcher. The questionnaire had two parts comprising demographic clinical and food frequency data including a list of 40 food items. To analyze the variables, Chi-square test and univariate logistic regression models were used.

RESULTS

In each group, 225 subjects were investigated. The majority of samples in both groups of experiment and control were consumed than two glasses of milk and dairy products per day. Regarding consumption of meat and its products, 56% of the cancer group had more than three servings per day while 26.7% of the control group had less than 2 servings per day. The majority of subjects had less than six servings of cereal per day. Some 54. 7 % of the cancer and 62.2 % of the control group consumed less than two servings of fruit per day. Consumption of vegetables in experimental and control groups were 52.9% and 76.9% respectively, more than five servings per day. There was a meaningful difference between two groups regarding the consumption of milk and dairy items (OR=0.6,95%CI= 0.4-0.9), meat and its products (OR=0.49,95%CI=0.3-0.7), bread and cereals (OR=0.4,95%CI=0.2-0.8), vegetables (OR=0.5,95%CI= 0.3-0.9). (P-value<0.05).

CONCLUSIONS

The results of this study emphasize the importance of informing women, particularly those at higher risk of breast cancer, in relation to dietary factors.

Reproducibility of data-driven dietary patterns in two groups of adult Spanish women from different studies

The objective of the present study was to assess the reproducibility of data-driven dietary patterns in different samples extracted from similar populations. Dietary patterns were extracted by applying principal component analyses to the dietary information collected from a sample of 3550 women recruited from seven screening centres belonging to the Spanish breast cancer (BC) screening network (Determinants of Mammographic Density in Spain (DDM-Spain) study). The resulting patterns were compared with three dietary patterns obtained from a previous Spanish case-control study on female BC (Epidemiological study of the Spanish group for breast cancer research (GEICAM: grupo Español de investigación en cáncer de mama)) using the dietary intake data of 973 healthy participants. The level of agreement between patterns was determined using both the congruence coefficient (CC) between the pattern loadings (considering patterns with a CC≥0·85 as fairly similar) and the linear correlation between patterns scores (considering as fairly similar those patterns with a statistically significant correlation). The conclusions reached with both methods were compared. This is the first study exploring the reproducibility of data-driven patterns from two studies and the first using the CC to determine pattern similarity. We were able to reproduce the EpiGEICAM Western pattern in the DDM-Spain sample (CC=0·90). However, the reproducibility of the Prudent (CC=0·76) and Mediterranean (CC=0·77) patterns was not as good. The linear correlation between pattern scores was statistically significant in all cases, highlighting its arbitrariness for determining pattern similarity. We conclude that the reproducibility of widely prevalent dietary patterns is better than the reproducibility of more population-specific patterns. More methodological studies are needed to establish an objective measurement and threshold to determine pattern similarity.

Meat and milk intake in the rice-based Korean diet: impact on cancer and metabolic syndrome

Over a few decades, Korean diet has changed from traditional diet, mainly composed of rice and vegetables, to Westernised diet rich, in meat and milk, along with the economic development and globalisation. Increasing prevalence of diet-related chronic diseases such as cancer and metabolic syndrome (MetS) is becoming a heavy burden to society and requires further attention. In this review, the association of meat and milk consumption with cancer and MetS among Koreans was discussed. Previous meta-analyses showed that meat intake was positively associated with increased risk of cancers, especially colon, as well as obesity and type 2 diabetes mellitus, and that the intake of milk and dairy products was negatively associated with colorectal cancer, obesity, and type 2 diabetes mellitus, based on studies conducted mostly in Western countries. In Korea and other Asian countries, the association of meat and milk intake with cancers were inconclusive and varied by types of cancers. Conversely, milk intake was negatively associated with MetS risk as reported in Western countries. The difference in results between Korea and Western countries might come from the differences in dietary patterns and study designs. Most Koreans still maintain traditional dietary pattern, although rapid change towards Westernised diet is underway among the younger age group. Randomised clinical trials or prospective cohort studies with consideration of combined effects of various dietary factors in Korea and other Asian countries are needed to elucidate the impact of meat and milk or related dietary patterns in their diet.

Breast Cancer Challenges and Screening in China: Lessons From Current Registry Data and Population Screening Studies

BACKGROUND

As one of its responses to the increasing global burden of breast cancer (BC), China has deployed a national registration and BC screening campaign. The present report describes these programs and the initial results of these national BC control strategies, highlighting the challenges to be considered.

MATERIALS AND METHODS

The primary BC incidence and prevalence data were obtained from the Chinese National Central Cancer Registry. MapInfo software was used to map the geographic distribution and variation. The time trends were estimated by the annual percentage of change from 2003 to 2009. The description of the screening plans and preliminary results were provided by the Ministry of Health.

RESULTS

Chinese cancer registries were primarily developed and activated in the East and Coastal regions of China, with only 12.5% of the registries located in West China. Geographic variation was noted, with the incidence of BC higher in North China than in South China and in urban areas compared with rural areas. Of great interest, these registries reported that the overall BC incidence has been increasing in China, with an earlier age of onset compared with Western countries and a peak incidence rate at age 50. In response to this increasing incidence and early age of onset, BC screening programs assessed 1.46 million women aged 35-59 years, using clinical breast examinations and ultrasound as primary screening tools between 2009 and 2011. The diagnostic rate for this screening program was only 48.0/10(5) with 440 cases of early stage BC. Early stage BC was detected in nearly 70% of screened patients. Subsequently, a second-generation screening program was conducted that included older women aged 35-64 years and an additional 6 million women were screened.

CONCLUSION

The cancer registration system in China has been uneven, with a greater focus on East rather than West China. The data from these registries demonstrate regional variation, an increasing BC incidence, and an early age of onset. The 2009 to 2011 BC screening program targeting women aged 35-59 years had a low detection rate that resulted in a second-generation screening program that extended the cohort size and ages screened to 35-64 years.

IMPLICATIONS FOR PRACTICE

Cancer registration has been active in China for decades; however, a national survey of registries has not been routinely reported. This study used MapInfo to describe the reported data and found asymmetric registration activities, geographic variations in breast cancer (BC) burdens, and an increasing incidence with a peak at age 50. The initial Chinese BC screening programs focused on a relatively young population of women aged 35-59 years and had a low detection rate, but 69.7% of patients had early stage BC. Older women were included in the second-generation screening programs, and an additional 6 million women were screened. Consideration of regional variations and age is necessary to optimize the efficiency and utility of BC screening in China, with the ultimate goal to reduce BC mortality.

Association between vegetable, fruit and carbohydrate intake and breast cancer risk in relation to physical activity

BACKGROUND

Although the nutritional may exert effect on the breast cancer risk, it is not clear whether the role diet is the same in sedentary and physically active women. The aim of this study was to evaluate the association between fruit, vegetable and carbohydrate intake and the risk of breast cancer among Polish women considering their physical activity level.

MATERIALS AND METHODS

A case-control study was conducted that included 858 women with histological confirmed breast cancer and 1,085 controls, free of any cancer diagnosis, aged 28-78 years. The study was based on a self-administered questionnaire to ascertain physical activity, dietary intake, sociodemographic characteristics, reproductive factors, family history of breast cancer, current weight and high, and other lifestyle factors. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated in unconditional logistic regression analyses including a broad range of potential confounders.

RESULTS

With comparison of the highest vs lowest quartile of intake, strong significant associations were observed for total vegetables (OR=0.37, 95%CI=0.20-0.69 P for trend <0.01 and OR=0.53, 95%CI=0.29-0.96, P for trend <0.02), and total fruits (OR=0.47, 95%CI=0.25-0.87, P for trend <0.05 and OR=0.47, 95%CI=0.24-0.90, P for trend <0.02) among women characterized by the lowest and the highest quartile of physical activity. No associations were observed for total carbohydrate intake. Additional analysis showed a positive association for sweets and desert intake among women in the lowest quartile of physical activity (OR=3.49, 95%CI=1.67-7.30, P for trend <0.009) for extreme quartiles of intake comparing to the referent group.

CONCLUSIONS

The results suggest that a higher consumption of vegetable and fruit may be associated with a decreased risk of breast cancer, especially among women who were low or most physically active throughout their lifetimes. These findings do not support an association between diet high in carbohydrate and breast cancer. However, a higher intake of sweets and deserts may by associated with an increased risk of breast cancer among women who were less physically active.

Adherence to a healthy Nordic food index and breast cancer risk: results from a Swedish cohort study

BACKGROUND

A healthy Nordic dietary pattern has shown beneficial effects in relation to several chronic diseases. However, no study has evaluated the association between a healthy Nordic food index (HNFI) and risk of breast cancer.

METHODS

We conducted a prospective cohort study including 44,296 women, aged 29-49 at baseline in 1991-1992, who completed a food frequency questionnaire at baseline, and have been followed up ever since, through the Swedish Cancer Registry and Cause of Death Registry. Each woman was assigned a HNFI score ranging from 0 to 6. We calculated multivariable relative risks (RRs) and 95% confidence intervals (CIs) using Poisson regression models with attained age as the underlying timescale. The association between the HNFI and risk of breast cancer was assessed both overall, by menopausal status and by hormone receptor status.

RESULTS

A total of 1,464 breast cancer cases were diagnosed during a median follow-up time of 20 years. A higher adherence to the HNFI was not associated with a lower risk of breast cancer overall, nor of varied hormone receptor status, or when we examining premenopausal and postmenopausal women separately. The multivariable RRs (95% CI) for breast cancer per 1-point increment in the HNFI were 1.02 (95% CI 0.98-1.06) for all women, 1.01 (95% CI 0.95-1.08) for premenopausal women, and 1.02 (95% CI 0.97-1.07) for postmenopausal women.

CONCLUSION

Adherence to a HNFI was not associated with breast cancer incidence in this cohort of relatively young women, regardless of menopausal status or hormone receptor status.

Dietary patterns and breast cancer: a case-control study in women

PURPOSE

Since dietary habits have been associated with breast cancer, the tested research hypothesis was the associations between food patterns, as derived through multivariate methods, and breast cancer.

METHODS

In a case-control study, Two-hundred and fifty consecutive, newly diagnosed breast cancer female patients (56 ± 12 years) and 250 one-to-one age-matched, healthy controls were studied. A standardized, validated questionnaire assessing various socio-demographic, clinical, lifestyle, and dietary characteristics was applied through face-to-face interviews. Factor analysis, with principal components method, was applied to extract dietary patterns from 86 foods or food groups consumption reported by the controls.

RESULTS

Three components were derived explaining 43% of the total variation in consumption. Component 1 was characterized by the consumption of potatoes, red meat and its products, poultry and white meat, dairy products, use of margarine/butter in cooking or at the table, consumption of sausages, fried food as well as grilled meat or fish; component 2 was characterized by the consumption of whole grains, fruits, and vegetables; and component 3 was characterized by olive oil and fish consumption. After adjusting for various confounders, components 2 and 3 were favorably associated with the absence of having breast cancer [odds ratio (OR) 0.60, 95% CI 0.47-0.75 and OR 0.81, 95% CI 0.66-0.99, respectively], while component 1 was not significantly associated with the disease.

CONCLUSIONS

Adherence to healthy dietary patterns (including whole grains, fruits, and vegetables, olive oil, and fish) seems to be favorable in not having breast cancer, among middle-aged women.

Dietary patterns and breast cancer risk among women

OBJECTIVE

Breast cancer is the most common type of cancer in women worldwide. Several studies have examined the role of single nutrients and food groups in breast cancer pathogenesis but fewer investigations have addressed the role of dietary patterns. Our main objective was to identify the relationship between major dietary patterns and breast cancer risk among Iranian women.

DESIGN

Hospital-based case-control study.

SETTING

Shohada Teaching Hospital, Tehran, Iran.

SUBJECTS

Overall, 100 female patients aged 30-65 years with breast cancer and 174 female hospital controls were included in the present study. Dietary intake was assessed using a valid and reliable semi-quantitative FFQ consisting of 168 food items.

RESULTS

Two dietary patterns were identified explaining 24·31 % of dietary variation in the study population. The 'healthy' food pattern was characterized by the consumption of vegetables, fruits, low-fat dairy products, legumes, olive and vegetable oils, fish, condiments, organ meat, poultry, pickles, soya and whole grains; while the 'unhealthy' food pattern was characterized by the consumption of soft drinks, sugars, tea and coffee, French fries and potato chips, salt, sweets and desserts, hydrogenated fats, nuts, industrial juice, refined grains, and red and processed meat. Compared with the lowest tertile, women in the highest tertile of the 'healthy' dietary pattern score had 75 % decreased risk of breast cancer (OR = 0·25, 95 % CI 0·08, 0·78), whereas women in the highest tertile of the 'unhealthy' dietary pattern had a significantly increased breast cancer risk (OR = 7·78, 95 % CI 2·31, 26·22).

CONCLUSIONS

A healthy dietary pattern may be negatively associated with breast cancer risk, while an unhealthy dietary pattern is likely to increase the risk among Iranian women.

Breast cancer and dietary patterns: a systematic review

This systematic review collates research on the topic of dietary patterns and breast cancer risks. The literature search targeted epidemiological studies published up to December 2012 and was conducted using the Medline (U.S. National Library of Medicine, Bethesda MD, USA) and Lilacs (Latin American and Caribbean Health Sciences, São Paulo, Brazil) databases. The following search terms were used: breast cancer, breast neoplasm, breast carcinoma, diet, food, eating habits, dietary patterns, factor analysis, and principal component analysis. Only studies that used factor analysis techniques and/or principal component analysis were eligible, and a total of 26 studies were included. The findings of these studies suggest the Mediterranean dietary pattern and diets composed largely of vegetables, fruit, fish, and soy are associated with a decreased risk of breast cancer. There was no evidence of an association between traditional dietary patterns and risk of breast cancer, and only one study showed a significant increase in risk associated with the Western dietary pattern. Diets that include alcoholic beverages may be associated with increased risk.

Dietary patterns and breast cancer risk in the California Teachers Study cohort

BACKGROUND

Evidence that diet is associated with breast cancer risk is inconsistent. Most studies have examined risks associated with specific foods and nutrients, rather than measures of overall diet.

OBJECTIVE

This study aimed to evaluate dietary patterns and their relation to breast cancer risk in a large cohort of women.

DESIGN

Data from 91,779 women in the California Teachers Study cohort were analyzed, including data from 4140 women with a diagnosis of invasive breast cancer made between 1995 and 2009. Five predominant dietary patterns were identified by using principal components factor analysis: a plant-based diet, high in fruit and vegetables; a high-protein, high-fat diet, high in meats, eggs, fried foods, and high-fat condiments; a high-carbohydrate diet, high in convenience foods, pasta, and bread products; an ethnic diet, high in legumes, soy-based foods, rice, and dark-green leafy vegetables; and a salad and wine diet, high in lettuce, fish, wine, low-fat salad dressing, and coffee and tea.

RESULTS

The plant-based pattern was associated with a reduction in breast cancer risk (RR: 0.85; 95% CI: 0.76, 0.95 for the highest compared with the lowest consumption quintile; P-trend = 0.003); risk reduction was greater for estrogen receptor-negative progesterone receptor-negative (ER-PR-) tumors (RR: 0.66; 95% CI: 0.48, 0.91; P-trend = 0.03). The salad and wine pattern was associated with an increased risk of estrogen receptor-positive progesterone receptor-positive tumors (RR: 1.29; 95% CI: 1.12, 1.49); this effect was only slightly attenuated after adjustment for alcohol consumption.

CONCLUSION

The finding that greater consumption of a plant-based dietary pattern is associated with a reduced breast cancer risk, particularly for ER-PR- tumors, offers a potential avenue for prevention.

Risk factors for breast cancer among Chinese women: a 10-year nationwide multicenter cross-sectional study

Background

The characteristics of established risk factors for breast cancer may vary among countries. A better understanding of local characteristics of risk factors may help in devising effective prevention strategies for breast cancer.

Methods

Information on exposures to risk factors was collected from the medical charts of 4211 women with breast cancer diagnosed during 1999–2008. The distributions of these exposures among regions, and by menopausal status and birth period, were compared with the χ² test. Crude associations between the selected factors and breast cancer were estimated using the cases in the present study and a representative control population, which was selected from qualified published studies.

Results

As compared with cases from less developed regions, those from more developed regions were significantly more likely to be nulliparous, had fewer childbirths (P < 0.05), and were less likely to have breastfed (P = 0.08). As compared with premenopausal cases, postmenopausal cases were more likely to be overweight and to have breastfed and had more childbirths (P < 0.05). The number of live births and rate of breastfeeding decreased in relation to birth period (P for trends <0.001). Overweight, late menopause, and family history of breast cancer were significantly associated with breast cancer among Chinese women.

Conclusions

Breast cancer incidence was associated with nulliparity and history of breastfeeding. Population attributable risks should be assessed, especially for more developed areas and young women. The effects of body mass index, age at menopause, and family history of breast cancer should be given priority during assessment of breast cancer risk among Chinese women.

Dietary intake of vegetables, fruits, and meats/beans as potential risk factors of acute myeloid leukemia: a Texas case-control study

Diet has been identified as a risk factor for some cancers, but its role in adult de novo acute myeloid leukemia (AML) is unclear. This study was conducted at the University of Texas MD Anderson Cancer Center to evaluate associations between consumption of vegetables, fruits, and meats with AML risk among Texas residents. All participants, 323 adult de novo AML cases and 380 frequency-matched controls, completed demographic and food frequency questionnaires. Overall, AML risk was significantly decreased among those who consumed the most dark green vegetables, seafood, and nuts/seeds; and it was significantly increased among greatest consumers of red meat. Among men, AML risk was lowest among those whose consumption was in the highest quartile for fruits [odds ratio (OR) = 0.25, 95% confidence interval (CI) = 0.10-0.69], poultry (OR = 0.28, 95%CI = 0.10-0.78), and seafood (OR = 0.39, 95%CI = 0.16-0.96) compared to those in the lowest. Among women, risk was lowest among those whose consumption was in the highest quartile of dark-green vegetables (OR = 0.28, 95%CI = 0.12-.68), orange vegetables (OR = 0.40, 95%CI = 0.17-.96) and nuts/beans (OR = 0.26, 95%CI = 0.11-0.60). Based on these findings, interventions can be developed to modify intake of specific dietary components to reduce cancer risk.

Is Usual Dietary Pattern Related to the Risk of Developing Breast Cancer?

Dietary patterns capture total diet providing a more comprehensive understanding of the effect of diet on chronic disease risk. Dietary patterns have been associated with several chronic diseases, including cardiovascular disease and selected cancers; however, the association with breast cancer remains unclear. The objective of this review was to examine critically the most recent literature on dietary patterns and breast cancer and report on current results, new developments, and future directions. Seven case-control and cohort studies from multiple countries have been published during the previous year (2011-2012). Many have analyzed a posteriori dietary patterns via factor and principal component analysis. Whereas results remain mixed, the majority of studies indicate healthier patterns decrease breast cancer risk, although patterns higher in meat and alcohol increase risk. Future studies that examine the associations between diet and tumor subtypes and collect dietary data at younger ages and, if possible, longitudinally would be beneficial.

Fruit and vegetable consumption among migrants in Switzerland

OBJECTIVE

To assess the relative risk of low daily fruit and vegetable consumption for six large migrant groups in Switzerland.

DESIGN

Cross-sectional health survey carried out 2007 (Swiss Health Survey) and 2010 (Swiss Migrant Health Survey) in Switzerland. Multinomial logistic regression models were used to estimate relative risk rates (RRR) of migrants relative to Swiss nationals.

SETTING

Data obtained from representative samples of Swiss and foreign nationals living in Switzerland.

SUBJECTS

A random sample (n =14637) of the Portuguese, German, Italian, Turkish, Serbian, Kosovan and Swiss permanent resident adult population (17-64 years old) was interviewed.

RESULTS

The proportion of participants who adhered to the recommended fruit and vegetable consumption was below one-third in all study populations. Compared with Swiss nationals, the relative risk of low daily fruit and vegetable intake relative to recommended intake was higher in Turkish nationals (RRR = 2.92, 95 % CI 1.91, 4.48; P = 0.0000) and Kosovan nationals (RRR = 4.76, 95 % CI 3.01, 7.55; P = 0.0000). The respective relative risks of Portuguese, Serbian, German and Italian nationals were not significantly different from the Swiss reference group.

CONCLUSIONS

Initiatives for the promotion of fruit and vegetable consumption should continue to address the population at large. At the same time, programmes that are tailored to the specific needs of migrants from Turkey and Kosovo should be considered.

A dietary pattern associated with LINE-1 methylation alters the risk of developing cervical intraepithelial neoplasia

There is a paucity of research examining the relationships between dietary patterns and risk of developing precancerous lesions as well as biomarkers associated with such dietary patterns. The purpose of the current study was to identify dietary patterns that are associated with higher grades of cervical intraepithelial neoplasia (CIN 2+) and to determine whether these dietary patterns are associated with the degree of DNA methylation in the long interspersed nucleotide elements (L1s) of peripheral blood mononuclear cells (PBMCs), a biomarker associated with risk of developing CIN 2+. Study population consisted of 319 child-bearing age women. Dietary patterns were derived by factor analysis. The degree of PBMC L1 methylation was assessed by pyrosequencing. Logistic regression models were used to evaluate the associations between dietary patterns and CIN 2+. Similar models were used to evaluate the associations between dietary patterns and degree of PBMC L1 methylation in women free of CIN 2+. Women with the unhealthiest dietary pattern were 3.5 times more likely to be diagnosed with CIN 2+ than women with the healthiest dietary pattern [OR = 3.5; 95% confidence interval (CI), 1.2-10.1; P = 0.02]. Women at risk for developing CIN 2+ with the healthiest dietary pattern were 3.3 times more likely to have higher PBMC L1 methylation than women with the unhealthiest dietary pattern (OR = 3.3; 95% CI, 1.0-10.6; P = 0.04). Our findings suggest that human papilloma virus associated risk of developing CIN 2+ may be reduced by improving dietary patterns. The degree of PBMC L1 methylation may serve as a biomarker for monitoring the effectiveness of dietary modifications needed for reducing the risk of CIN 2+.

The role of soy isoflavones in menopausal health: report of The North American Menopause Society/Wulf H. Utian Translational Science Symposium in Chicago, IL (October 2010)

OBJECTIVES

If and to what extent soy protein, soy isoflavones, and their metabolites, including S(--)-equol, have beneficial effects on women's health is currently unclear. The North American Menopause Society (NAMS)/Utian Translational Science Symposium on Soy and Soy Isoflavones convened October 9-10, 2010, to clarify basic and clinical research findings as they relate to the risk and benefits of soy products for peri- and postmenopausal women.

METHODS

A working group of faculty and panelists composed of clinical and research experts in the fields of women's health and botanicals met during a 2-day translational symposium to cover the latest evidence-based science on isoflavones as they affect menopausal symptoms, breast and endometrial cancer, atherosclerosis, bone loss, and cognition. Full descriptions of the bioavailability and pharmacokinetics of isoflavones were also presented. Subspecialty groups then broke off with the goal of translating the information into a report for general medical practice and identifying further research areas. All faculty and panelists reviewed the final report, which was then approved by the NAMS Board of Trustees.

RESULTS

From the hundreds of studies reviewed in this report, there are mixed results of the effects on midlife women. Soy-based isoflavones are modestly effective in relieving menopausal symptoms; supplements providing higher proportions of genistein or increased in S(--)-equol may provide more benefits. Soy food consumption is associated with lower risk of breast and endometrial cancer in observational studies. The efficacy of isoflavones on bone has not been proven, and the clinical picture of whether soy has cardiovascular benefits is still evolving. Preliminary findings on cognitive benefit from isoflavone therapy support a "critical window" hypothesis wherein younger postmenopausal women derive more than older women.

CONCLUSIONS

Several areas for further research have been identified on soy and midlife women. More clinical studies are needed that compare outcomes among women whose intestinal bacteria have the ability to convert daidzein to equol (equol producers) with those that lack that ability (equol nonproducers) in order to determine if equol producers derive greater benefits from soy supplementation. Larger studies are needed in younger postmenopausal women, and more research is needed to understand the modes of use of soy isoflavone supplements in women. The interrelations of other dietary components on soy isoflavones consumed as a part of diet or by supplement on equol production also require further study, as do potential interactions with prescription and over-the-counter medications. And finally, greater standardization and documentation of clinical trial data of soy are needed.