Dietary patterns derived with multiple methods from food diaries and breast cancer risk in the UK Dietary Cohort Consortium

Adulthood dietary and lifestyle patterns and risk of breast cancer: Global Cancer Update Programme (CUP Global) systematic literature review

BACKGROUND

An increasing number of studies in recent years investigate various dietary and lifestyle patterns and associated breast cancer (BC) risk.

OBJECTIVES

This study aimed to comprehensively synthesize and grade the evidence on dietary and lifestyle patterns and BC risk.

METHODS

Databases were systematically searched up to 31 March, 2022, for evidence from randomised controlled trials and prospective cohort studies on adherence to a dietary pattern alone or in combination with lifestyle behaviors and incidence of or mortality from primary BC in adult females. Findings in all, premenopausal, and postmenopausal females were descriptively synthesized instead of meta-analyzed due to patterns heterogeneity. An independent Global Cancer Update Programme Expert Panel graded the strength of the evidence.

RESULTS

A total of 84 publications were included. Results for patterns reflecting both a healthy diet and lifestyle were more consistent than for patterns that included diet only. There was strong-probable evidence that a priori World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) and American Cancer Society (ACS) dietary and lifestyle scores may reduce BC risk in all and postmenopausal females, whereas in premenopausal females, less evidence was found contributing to limited-suggestive grade. There was also a limited-suggestive evidence that adherence to the Healthy Lifestyle Index and other diet and lifestyle scores may reduce BC risk in postmenopausal females; a posteriori Western/Meat/Alcohol dietary patterns may increase BC risk in postmenopausal females; and Prudent/Vegetarian/Mediterranean dietary patterns may reduce BC risk in all females. For the remaining patterns, evidence was graded as limited-no conclusions.

CONCLUSIONS

Advice to adopt combined aspects of a healthy diet and lifestyle according to WCRF/AICR and ACS scores, encouraging a healthy weight, physical activity, alcohol and smoking avoidance, and a healthy diet rich in fruits, vegetables, (whole)grains and cereals and discouraging red and processed meat, can be proposed to females to lower BC risk. This review was registered at PROSPERO as ID CRD42021270129 (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021270129) on 28 August, 2021, and further updated on 4 May, 2022, in order to extend the search period.

Association of dietary patterns derived by reduced-rank regression with colorectal cancer risk and mortality

PURPOSE

Unhealthy dietary patterns contribute to an increased risk of colorectal cancer (CRC). Limited prior research has used reduced rank regression (RRR) to assess dietary patterns relative to CRC risk. This study aimed to identify dietary patterns derived by RRR and assess their associations with CRC risk and mortality.

METHODS

We used data from the multicentre Prostate, Lung, Colorectal, and Ovarian Cancer Screening (PLCO) trial. Dietary intake was assessed using a Dietary History Questionnaire. In the RRR intake of fibre, folate, and the percentage of energy from carbohydrates, saturated and unsaturated fatty acids were used as response variables. Cox models and competing risk survival regression, with age as the time scale, were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for CRC risk and mortality, respectively.

RESULTS

The median follow-up time for CRC risk (n = 1044) and mortality (n = 499) was 9.4 years (Interquartile Range: 8. 0, 10.1) and 16.9 years (11.9, 18.6), respectively. Two dietary patterns were identified: the first was characterised by high carbohydrate, folate and low fatty acid intake, and the second by high fibre and unsaturated fatty acid. Compared to participants in the first tertile of the high fibre and unsaturated fatty acid pattern, those in the third tertile had a lower risk of CRC (HR = 0.88; 95% CI: 0.76, 1.03), and colon cancer (HR = 0.85; 95% CI: 0.72, 1.01). Conversely, the high carbohydrate, high folate and low fatty acid pattern had no association with CRC outcomes. None of the dietary patterns showed associations with rectal cancer or CRC mortality.

CONCLUSION

A diet enriched with high fibre and unsaturated fatty acids may reduce the risk of CRC. These results highlight the potential protective effect of adequate fibre intake in conjunction with high consumption of unsaturated fatty acids against CRC.

Dietary Patterns and Breast Cancer Risk: A KCPS-II Cohort Study

Objective

There have been inconsistencies in the evidence for a role of dietary patterns in the development of breast cancer. In this study, we used a large-scale cohort [Korean Cancer Prevention Study-II (KCPS-II)] to examine the association between dietary patterns and breast cancer risk in Korean women.

Materials and Methods

The dietary patterns of 14,807 women from the KCPS-II were derived by factor analysis and 135 cases of breast cancer were diagnosed during the follow-up period. Cox proportional models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of breast cancer.

Results

The following three major dietary patterns were identified: "Korean dietary pattern" (high intake of Kimchi, vegetables, and rice); "sweet dietary pattern" (high intake of soda and sugar); and "new (Western-like) dietary pattern" (high intake of dairy products, eggs, oil, fruits, and bread). After adjusting for potential confounders, neither the Korean (HR for the highest compared with the lowest tertile, 1.04; 95% CI 0.53-2.06) nor the sweet dietary patterns were associated with the risk of breast cancer. In contrast, the new (Western-like) dietary pattern was found to be significantly associated with an increased risk of breast cancer with an HR (95% CI) of 1.01 (0.65-1.60) for the second tertile and 1.61 (1.04-2.50) for the third tertile as compared with the lowest tertile. After stratifying by menopausal status, these effects were only statistically significant among premenopausal women for the third tertile, compared with those in the bottom tertile (HR 1.69; 95% CI 1.06-2.68; p = 0.028). No significant association was observed between the Korean or sweet dietary pattern and breast cancer among either pre- or postmenopausal women.

Conclusion

Our findings revealed that a greater consumption of a new (Western-like) diet was associated with an increased breast cancer risk and consequently offer a potential prevention strategy for Korean women.

Difference in Gastrointestinal Cancer Risk and Mortality by Dietary Pattern Analysis: A Systematic Review and Meta-Analysis

CONTEXT

Several studies have demonstrated that dietary patterns identified by a posteriori and hybrid methods are associated with gastrointestinal (GI) cancer risk and mortality. These studies applied different methods for analyzing dietary data and reported inconsistent findings.

OBJECTIVE

This systematic review and meta-analysis were aimed to determine the association between dietary patterns, derived using principal component analysis (PCA) and reduced rank regression (RRR), and GI cancer risk and GI cancer-caused mortality.

DATA SOURCE

Articles published up to June 2023 in English were eligible for inclusion. The Medline, SCOPUS, Cochrane Library, CINHAL, PsycINFO, ProQuest, and Web of Sciences databases were used to identify prospective studies. The Preferred Reporting Item for Systematic Review and Meta-analysis Protocol 2020 was used to report results.

DATA EXTRACTION

A total of 28 studies were eligible for inclusion. Varied approaches to deriving dietary patterns were used, including PCA (n = 22), RRR (n = 2), combined PCA and RRR (n = 1), cluster analysis (CA; n = 2) and combined PCA and CA (n = 1).

DATA ANALYSIS

Two dietary patterns, "healthy" and "unhealthy," were derived using PCA and RRR. The healthy dietary pattern was characterized by a higher intake of fruits, whole grains, legumes, vegetables, milk, and other dairy products, whereas the unhealthy dietary pattern was characterized by a higher intake of red and processed meat, alcohol, and both refined and sugar-sweetened beverages. The findings indicated that the PCA-derived healthy dietary pattern was associated with an 8% reduced risk (relative risk [RR], 0.92; 95% CI, 0.87-0.98), and the unhealthy dietary pattern was associated with a 14% increased risk (RR, 1.14; 95% CI, 1.07-1.22) of GI cancers. Similarly, the RRR-derived healthy dietary pattern (RR, 0.83; 95% CI, 0.61-1.12) may be associated with reduced risk of GI cancers. In contrast, the RRR-derived unhealthy dietary pattern (RR, 0.93; 95% CI, 0.57-1.52) had no association with a reduced risk of GI cancers. Similarly, evidence suggested that PCA-derived healthy dietary patterns may reduce the risk of death from GI cancers, whereas PCA-derived unhealthy dietary patterns may increase the risk.

CONCLUSION

Findings from prospective studies on the association of PCA-derived dietary patterns and the risk of GI cancers support the evidence of healthy and unhealthy dietary patterns as either protective or risk-increasing factors for GI cancers and for survivorship, respectively. The findings also suggest that the RRR-derived healthy dietary pattern reduces the risk of GI cancers (albeit with low precision), but no association was found for the RRR-derived unhealthy dietary pattern. Prospective studies are required to further clarify disparities in the association between PCA- and RRR-derived dietary patterns and the risk of GI cancers. Systematic review registration: PROSPERO registration no. CRD42022321644.

Mediterranean diet: Fighting breast cancer naturally: A review

The effects and mechanisms of the Mediterranean diet (MD) on the incidence, recurrence, and prevention of breast cancer (BC) have been extensively investigated since the 1990s. Recent years have witnessed significant advancements in understanding the relationship between the components of the MD and BC, particularly in terms of their role and adherence. This comprehensive review focuses on several key aspects: the influence of the adherence of MD in cohort studies conducted across different regions on BC, the effects and mechanisms of individual component or main components as well as the supplementation of vitamins, drugs, exercise, and other factors of MD on BC; the variations in the impact of the MD on premenopausal and postmenopausal women, as well as different types in BC cases; the possible mechanisms underlying the development, recurrence, and prevention of BC in relation to the MD; and the interaction effects of individual genetic polymorphisms with the MD. Based on current research findings, this review highlights the key issues and identifies future research directions in investigating the relationship between the MD and BC. Furthermore, it suggests that healthy women of various ages and BC patients should adhere to MD in order to prevent BC or improve the prognosis.

Sex-specific associations of empirically derived dietary patterns with colorectal cancer risk in a Korean population: a case‒control study

Dietary patterns may be a crucial modifiable factor in colorectal cancer (CRC) risk. This study aimed to examine the associations of dietary patterns derived from two methods with CRC risk in Korea. In a study of 1420 CRC patients and 2840 control participants, we obtained dietary patterns by principal component analysis (PCA) and reduced rank regression (RRR) using 33 predefined food groups. The associations between dietary patterns and CRC risk were assessed using unconditional logistic regression models to calculate odds ratios (ORs) and 95% confidence intervals (CIs). We identified two similar dietary patterns, derived from PCA 1 (prudent) and RRR (healthy), characterized by higher consumption of green/yellow vegetables, light-colored vegetables, fruits, eggs, and milk in both men and women. In women, higher prudent and healthy pattern scores were significantly associated with a lower risk of CRC (prudent, ORQ4 vs. Q1 = 0.59, 95% CI 0.40-0.86, P for trend = 0.005; healthy, ORQ4 vs. Q1 = 0.62, 95% CI 0.43-0.89, P for trend = 0.007). In men, a significant inverse association between dietary pattern and risk of rectal cancer was found only for the healthy dietary pattern (ORQ4 vs. Q1 = 0.66, 95% CI 0.45-0.97, P for trend = 0.036). Compared with the dietary pattern derived by PCA, the RRR dietary pattern had a slightly stronger association with a lower risk of distal colon cancer (ORQ4 vs. Q1 = 0.58, 95% CI 0.35-0.97, P for trend = 0.025) and rectal cancer (ORQ4 vs. Q1 = 0.29, 95% CI 0.15-0.57, P for trend < 0.001) in women. Our findings suggest cancer prevention strategies focusing on a diet rich in vegetables, fruits, eggs, and milk. Moreover, the use of both PCA and RRR methods may be advantageous to explore the associations between dietary patterns and risk of CRC.

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.

Major dietary patterns in the United Kingdom Women's Cohort Study showed no evidence of prospective association with pancreatic cancer risk

Diet is a modifiable risk factor for pancreatic cancer. We hypothesized that specific dietary patterns would increase/decrease pancreatic cancer risk. We evaluated the association of dietary patterns with pancreatic cancer risk in the UK Women's Cohort Study. Dietary patterns were assessed at enrollment using: (1) self-reported practice of vegan/vegetarian dietary habits, (2) diet quality indices (World Health Organization Healthy Diet Indicator and Mediterranean Diet Score), and (3) principal component analysis-derived dietary patterns. The association of dietary patterns with pancreatic cancer incidence was quantified using Cox regression survival analysis. Over a median follow-up of 19 years of 35,365 respondents, there were 136 incident cases of pancreatic cancer. No association between dietary habits/quality and pancreatic cancer incidence was evident after adjustments (hazard ratio (95% confidence interval): self-reported omnivores vs vegan/vegetarian dietary habit: 1.13 (0.73-1.76); per-unit increase in World Health Organization Healthy Diet Indicator scores: 0.99 (0.91-1.09); per-unit increase in Mediterranean Diet Score: 0.92 (0.83-1.02). Similarly, no association of principal component analysis-derived dietary patterns with pancreatic cancer risk was evident ("prudent:" 1.02 [0.94-1.10]; ``meat-based:'' 1.00 [0.92-1.09]; ``fast-food, sugar-sweetened beverages, and carbohydrate-rich snacks:'' 0.96 [0.86-1.07]; ``cereal and dairy-rich:'' 1.04 [0.94-1.16], and ``low-diversity and lowfat:'' 1.00 [0.89-1.13]). In this prospective cohort of women, several major dietary patterns were of poor quality. There was no evidence of a prospective association between any of the dietary patterns explored and pancreatic cancer incidence.

Indices of Mediterranean diet adherence and breast cancer risk in a community-based cohort

Introduction

A Mediterranean-style dietary pattern is believed to have cancer-protective effects. We compared the prospective associations between adherence to four established Mediterranean diet indices and breast cancer risk (including total, postmenopausal, and hormone receptor positive cases) in women in the Framingham Offspring Study.

Methods

The four indices used two different approaches to measuring adherence to a Mediterranean diet: (a) scores based on the population-specific median intakes of Mediterranean diet-related foods in a given population (i.e., alternate Mediterranean Diet (aMED) index and Mediterranean Diet Score (MDS) index), and (b) scores based on compliance with recommended intakes of relevant foods from the Mediterranean diet pyramid [i.e., Mediterranean Diet (MeDiet) index and Mediterranean Style Dietary Pattern (MSDP) index]. Dietary data were derived from semiquantitative food frequency questionnaires collected in 1991-95. Participants included 1579 women aged ≤ 30 years who were free of prevalent cancer. Women were followed through 2014, and Cox proportional-hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for various confounders.

Results

During a median follow-up of approximately 18 years, 87 breast cancer cases were documented. Women in the highest (vs. lowest) score category of the pyramid-based scores (i.e., MeDiet or MSDP) had approximately 45% statistically significantly lower breast cancer risks. These effects were even stronger for any hormone receptor positive cases using the MeDiet index (highest vs. lowest score categories: HR = 0.45, 95% CI: 0.22-0.90). Neither of the median intake-based scores (i.e., aMED, MDS) was associated with breast cancer risk.

Discussion

Our results suggest that the methodology and the composition of Mediterranean diet indices influence their ability to assess conformity to this specific diet pattern and predict breast cancer risk.

Dietary Fat Intake: Associations with Dietary Patterns and Postmenopausal Breast Cancer-A Case-Control Study

The aim of this study was to assess the associations of dietary fat intake with BC occurrence and dietary patterns. This case-control study involved 420 women aged 40−79 years from northeastern Poland, including 190 newly diagnosed BC cases. Dietary data were collected using a food frequency questionnaire (62-item FFQ-6®). The Quick Food Scan of the National Cancer Institute and the Percentage Energy from Fat Screener scoring procedures were used to estimate the percentage energy from dietary fat (Pfat). The odds of BC occurrence was three times higher in the Pfat > 32%. The Pfat > 32% was positively associated with the ‘Non-Healthy’ DP and inversely associated with the Polish-aMED® score, ‘Prudent’ DP, and ‘Margarine and Sweetened Dairy’ DP. This case-control study suggests that a higher dietary fat intake (>32%) may contribute to an increased occurrence of peri- and postmenopausal breast cancer in women. Given the obtained results, an unhealthy dietary pattern characterized by the consumption of highly processed, high in sugar foods and animal fat foods should be avoided to reduce fat intake. Instead, the frequent consumption of low-processed plant foods, fish, and moderate consumption of low-fat dairy should be recommended since this pro-healthy diet is inversely associated with dietary fat intake.

An updated systematic review and meta-analysis on adherence to mediterranean diet and risk of cancer

PURPOSE

The aim of current systematic review was to update the body of evidence on associations between adherence to the Mediterranean diet (MedDiet) and risk of cancer mortality, site-specific cancer in the general population; all-cause, and cancer mortality as well as cancer reoccurrence among cancer survivors.

METHODS

A literature search for randomized controlled trials (RCTs), case-control and cohort studies published up to April 2020 was performed using PubMed and Scopus. Study-specific risk estimates for the highest versus lowest adherence to the MedDiet category were pooled using random-effects meta-analyses. Certainty of evidence from cohort studies and RCTs was evaluated using the NutriGrade scoring system.

RESULTS

The updated search revealed 44 studies not identified in the previous review. Altogether, 117 studies including 3,202,496 participants were enclosed for meta-analysis. The highest adherence to MedDiet was inversely associated with cancer mortality (RRcohort: 0.87, 95% CI 0.82, 0.92; N = 18 studies), all-cause mortality among cancer survivors (RRcohort: 0.75, 95% CI 0.66, 0.86; N = 8), breast (RRobservational: 0.94, 95% CI 0.90, 0.97; N = 23), colorectal (RRobservational: 0.83, 95% CI 0.76, 0.90; N = 17), head and neck (RRobservational: 0.56, 95% CI 0.44, 0.72; N = 9), respiratory (RRcohort: 0.84, 95% CI 0.76, 0.94; N = 5), gastric (RRobservational: 0.70, 95% CI 0.61, 0.80; N = 7), bladder (RRobservational: 0.87, 95% CI 0.76, 0.98; N = 4), and liver cancer (RRobservational: 0.64, 95% CI 0.54, 0.75; N = 4). Adhering to MedDiet did not modify risk of blood, esophageal, pancreatic and prostate cancer risk.

CONCLUSION

In conclusion, our results suggest that highest adherence to the MedDiet was related to lower risk of cancer mortality in the general population, and all-cause mortality among cancer survivors as well as colorectal, head and neck, respiratory, gastric, liver and bladder cancer risks. Moderate certainty of evidence from cohort studies suggest an inverse association for cancer mortality and colorectal cancer, but most of the comparisons were rated as low or very low certainty of evidence.

Patterns of Omega-3 and Omega-6 Fatty Acid Dietary Intake and Melanoma Thickness at Diagnosis

BACKGROUND

Experimental evidence suggests that dietary intakes of omega-3 and omega-6 polyunsaturated fatty acids have divergent effects on melanoma growth, but epidemiologic evidence on their combined effect is lacking.

METHODS

In 634 Australian patients with primary melanoma, we assessed prediagnosis consumption of 39 food groups by food frequency questionnaires completed within 2 months of diagnosis. We derived, by reduced rank regression, dietary patterns that explained variability in selected omega-3 and omega-6 fatty acid intakes. Prevalence ratios (PR) and 95% confidence intervals (CI) for the association between tertiles of dietary patterns and melanoma thickness >2 mm versus ≤2 mm were estimated using Poisson regression.

RESULTS

Overall omega-3 fatty acid intakes were low. Two major fatty acid dietary patterns were identified: "meat, fish, and fat," positively correlated with intakes of all fatty acids; and "fish, low-meat, and low-fat," positively correlated with long-chain omega-3 fatty acid intake, and inversely with medium-chain omega-3 and omega-6 fatty acid intakes. Prevalence of thick melanomas was significantly higher in those in the highest compared with lowest tertile of the "meat, fish, and fat" pattern (PR, 1.40; 95% CI, 1.01-1.94), especially those with serious comorbidity (PR, 1.83; 95% CI, 1.15-2.92) or a family history (PR, 2.32; 95% CI, 1.00-5.35). The "fish, low-meat, and low-fat" pattern was not associated with melanoma thickness.

CONCLUSIONS

People with high meat, fish, and fat intakes, who thus consumed relatively high levels of omega-3 and high omega-6 fatty acid intakes, are more likely to be diagnosed with thick than thin melanomas.

IMPACT

High omega-3 and omega-6 fatty acid intakes may contribute to patients' presentation with thick melanomas.

Nutrient intake patterns and breast cancer risk among Jordanian women: a case-control study

OBJECTIVES

Breast cancer (BC) is the most common type of cancer worldwide. Globally, BC is rapidly becoming a major common health problem among women. This study aimed to evaluate the association between nutrient intake patterns and BC risk among Jordanian women.

METHODS

A total of 400 Jordanian women 20-65 years of age were recruited in this case-control study. Two hundred women recently diagnosed with BC were matched in age, income, and marital status to 200 BC-free women. A food frequency questionnaire was used to assess nutrient intake patterns.

RESULTS

In this study, 3 nutrient intake patterns were identified: a high vitamin C and β-carotene nutrient intake pattern; a high calcium, phosphorus, and vitamin D nutrient intake pattern; and a high-fat nutrient intake pattern. A significant increase in BC risk was associated with the high vitamin C and β-carotene nutrient pattern (the highest for the fourth quartile; odds ratio [OR], 5.42; 95% confidence interval [CI], 2.11 to 13.91; ptrend=0.001). In the high calcium, phosphorus, and vitamin D nutrient pattern, a significant inverse trend was detected for the risk of BC. The high-fat nutrient pattern showed a significant direct association with BC risk in the third (OR, 3.88; 95% CI, 1.58 to 9.51) and fourth (OR, 3.87; 95% CI, 1.53 to 9.77) quartiles (ptrend=0.001).

CONCLUSIONS

A significant increase in BC risk was detected for the high vitamin C and β-carotene nutrient intake pattern and the high-fat nutrient intake pattern. However, for the high calcium, phosphorus, and vitamin D nutrient intake pattern, a significant inverse trend was observed.

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.

Associations of Dietary Patterns and Metabolic-Hormone Profiles with Breast Cancer Risk: A Case-Control Study

Breast cancer is the most diagnosed cancer in women worldwide. Studies regarding complex breast cancer aetiology are limited and the results are inconclusive. We investigated the associations between dietary patterns (DPs), metabolic-hormone profiles (M-HPs), and breast cancer risk. This case-control study involved 420 women aged 40⁻79 years from north-eastern Poland, including 190 newly-diagnosed breast cancer cases. The serum concentration of lipid components, glucose, and hormones (oestradiol, progesterone, testosterone, prolactin, cortisol, insulin) was marked in 129 post-menopausal women (82 controls, 47 cases). The food frequency consumption was collected using a validated 62-item food frequency questionnaire. A posteriori DPs or M-HPs were derived with a Principal Component Analysis (PCA). Three DPs: 'Non-Healthy', 'Prudent', and 'Margarine and Sweetened Dairy' and two M-HPs: 'Metabolic-Syndrome' and 'High-Hormone' were identified. The 'Polish-adapted Mediterranean Diet' ('Polish-aMED') score was calculated. The risk of breast cancer risk was three-times higher (odds ratio (OR): 2.90; 95% confidence interval (95% Cl): 1.62⁻5.21; p < 0.001) in the upper tertile of the 'Non-Healthy' pattern (reference: bottom tertile) and five-times higher (OR: 5.34; 95% Cl: 1.84⁻15.48; p < 0.01) in the upper tertile of the 'High-Hormone' profile (reference: bottom tertile). There was a positive association of 'Metabolic-Syndrome' profile and an inverse association of 'Polish-aMED' score with the risk of breast cancer, which disappeared after adjustment for confounders. No significant association between 'Prudent' or 'Margarine and Sweetened Dairy' DPs and cancer risk was revealed. Concluding, a pro-healthy diet is insufficient to reduce the risk of breast cancer in peri- and postmenopausal women. The findings highlight the harmful effect of the 'High-Hormone' profile and the 'Non-Healthy' dietary pattern on breast cancer risk. In breast cancer prevention, special attention should be paid to decreasing the adherence to the 'Non-Healthy' pattern by reducing the consumption of highly processed food and foods with a high content of sugar and animal fat. There is also a need to monitor the concentration of multiple sex hormones in the context of breast cancer risk.

Meta-analysis of the association between the dietary inflammatory index (DII) and breast cancer risk

BACKGROUND

Recent studies have reported mixed results on the association between the pro-inflammatory dietary index and risk of breast cancer. We perform this comprehensive meta-analysis to figure out whether high dietary inflammatory index (DII) score is a risk factor for the occurrence of breast cancer.

METHODS

We comprehensively searched the PubMed, EMBASE and Cochrane databases to identify included studies updated to September 12, 2017. All studies that reported risk estimates by comparing the highest DII score to the lowest were assessed.

RESULTS

A total of seven observational studies were identified: three case controls and four cohorts, involving 319,993 participants. Overall, the meta-analysis reported that individuals with the highest DII score were associated with a 25% increased risk of breast cancer versus those with the lowest DII score (relative risk [RR] = 1.25; 95% confidence interval [CI] 1.09-1.44; I² = 82.7%, p = 0.000). Upon stratified analysis, significant positive associations remained for postmenopausal women (RR = 1.15; 95% CI 1.02-1.30; p = 0.020), case-control studies (RR = 1.68; 95% CI 1.13-2.49; p = 0.010), Asia (RR = 2.30; 95% CI 1.7-3.12; p = 0.0031) and Europe (RR = 1.26; 95% CI 1.01-1.58; p = 0.0477). When analysed on hormonal receptor status, 36% increased risk was explored for hormone-receptor negative.

CONCLUSION

This meta-analysis suggested that more pro-inflammatory diets (higher DII scores) are associated with increased breast cancer incidence. However, the research is not about significant associations but about moderate effect sizes.

Associations of Mediterranean Diet and a Posteriori Derived Dietary Patterns with Breast and Lung Cancer Risk: A Case-Control Study

Lung cancer in men and breast cancer in women are the most commonly diagnosed cancers in Poland and worldwide. Results of studies involving dietary patterns (DPs) and breast or lung cancer risk in European countries outside the Mediterranean Sea region are limited and inconclusive. This study aimed to develop a ‘Polish-adapted Mediterranean Diet’ (‘Polish-aMED’) score, and then study the associations between the ‘Polish-aMED’ score and a posteriori-derived dietary patterns with breast or lung cancer risk in adult Poles. This pooled analysis of two case-control studies involved 560 subjects (280 men, 280 women) aged 40–75 years from Northeastern Poland. Diagnoses of breast cancer in 140 women and lung cancer in 140 men were found. The food frequency consumption of 21 selected food groups was collected using a 62-item Food Frequency Questionnaire (FFQ)-6. The ‘Polish-adapted Mediterranean Diet’ score which included eight items—vegetables, fruit, whole grain, fish, legumes, nuts and seeds—as well as the ratio of vegetable oils to animal fat and red and processed meat was developed (range: 0–8 points). Three DPs were identified in a Principal Component Analysis: ‘Prudent’, ‘Non-healthy’, ‘Dressings and sweetened-low-fat dairy’. In a multiple logistic regression analysis, two models were created: crude, and adjusted for age, sex, type of cancer, Body Mass Index (BMI), socioeconomic status (SES) index, overall physical activity, smoking status and alcohol abuse. The risk of breast or lung cancer was lower in the average (3–5 points) and high (6–8 points) levels of the ‘Polish-aMED’ score compared to the low (0–2 points) level by 51% (odds ratio (OR): 0.49; 95% confidence interval (Cl): 0.30–0.80; p < 0.01; adjusted) and 63% (OR: 0.37; 95% Cl: 0.21–0.64; p < 0.001; adjusted), respectively. In the middle and upper tertiles compared to the bottom tertile of the ‘Prudent’ DP, the risk of cancer was lower by 38–43% (crude) but was not significant after adjustment for confounders. In the upper compared to the bottom tertile of the ‘Non-healthy’ DP, the risk of cancer was higher by 65% (OR: 1.65; 95% Cl: 1.05–2.59; p < 0.05; adjusted). In conclusion, the Polish adaptation of the Mediterranean diet could be considered for adults living in non-Mediterranean countries for the prevention of the breast or lung cancers. Future studies should explore the role of a traditional Mediterranean diet fitted to local dietary patterns of non-Mediterranean Europeans in cancer prevention.

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.

Empirically Derived Dietary Patterns in UK Adults Are Associated with Sociodemographic Characteristics, Lifestyle, and Diet Quality

The aim of this study was to examine empirical dietary patterns in UK adults and their association with sociodemographic characteristics, lifestyle factors, self-reported nutrient intake, nutrient biomarkers, and the Nutrient-based Diet Quality Score (NDQS) using National Diet and Nutrition Survey data 2008–2012 (n = 2083; mean age 49 years; 43.3% male). Four patterns explained 13.6% of the total variance: ‘Snacks, fast food, fizzy drinks’ (SFFFD), ‘Fruit, vegetables, oily fish’ (FVOF), ‘Meat, potatoes, beer’ (MPB), and ‘Sugary foods, dairy’ (SFD). ‘SFFFD’ was associated positively with: being male; smoking; body mass index (BMI); urinary sodium; intake of non-milk extrinsic sugars (NMES), fat and starch; and negatively with: age; plasma carotenoids; and NDQS. ‘FVOF’ was associated positively with: being non-white; age; income; socioeconomic classification (National Statistics Socio-economic Classifications; NSSEC); plasma carotenoids; intake of non-starch polysaccharides and polyunsaturated fatty acids. It was negatively associated with: being male, smoking, BMI, urinary sodium, intake of saturated fat; and NMES and NDQS. Whilst the patterns explained only 13.6% of the total variance, they were associated with self-reported nutrient intake, biomarkers of nutrient intake, sociodemographic and lifestyle variables, and the NDQS. These findings provide support for dietary patterns analyses as a means of exploring dietary intake in the UK population to inform public health nutrition policy and guidance.

Adherence to Mediterranean Diet and Risk of Cancer: An Updated Systematic Review and Meta-Analysis

The aim of the present systematic review and meta-analysis was to gain further insight into the effects of adherence to Mediterranean Diet (MedD) on risk of overall cancer mortality, risk of different types of cancer, and cancer mortality and recurrence risk in cancer survivors. Literature search was performed using the electronic databases PubMed, and Scopus until 25 August 2017. We included randomized trials (RCTs), cohort (for specific tumors only incidence cases were used) studies, and case-control studies. Study-specific risk ratios, hazard ratios, and odds ratios (RR/HR/OR) were pooled using a random effects model. Observational studies (cohort and case-control studies), and intervention trials were meta-analyzed separately. The updated review process showed 27 studies that were not included in the previous meta-analysis (total number of studies evaluated: 83 studies). An overall population of 2,130,753 subjects was included in the present update. The highest adherence score to a MedD was inversely associated with a lower risk of cancer mortality (RRcohort: 0.86, 95% CI 0.81 to 0.91, I² = 82%; n = 14 studies), colorectal cancer (RRobservational: 0.82, 95% CI 0.75 to 0.88, I² = 73%; n = 11 studies), breast cancer (RRRCT: 0.43, 95% CI 0.21 to 0.88, n = 1 study) (RRobservational: 0.92, 95% CI 0.87 to 0.96, I² = 22%, n = 16 studies), gastric cancer (RRobservational: 0.72, 95% CI 0.60 to 0.86, I² = 55%; n = 4 studies), liver cancer (RRobservational: 0.58, 95% CI 0.46 to 0.73, I² = 0%; n = 2 studies), head and neck cancer (RRobservational: 0.49, 95% CI 0.37 to 0.66, I² = 87%; n = 7 studies), and prostate cancer (RRobservational: 0.96, 95% CI 0.92 to 1.00, I² = 0%; n = 6 studies). Among cancer survivors, the association between the adherence to the highest MedD category and risk of cancer mortality, and cancer recurrence was not statistically significant. Pooled analyses of individual components of the MedD revealed that the protective effects appear to be most attributable to fruits, vegetables, and whole grains. The updated meta-analysis confirms an important inverse association between adherence to a MedD and cancer mortality and risk of several cancer types, especially colorectal cancer. These observed beneficial effects are mainly driven by higher intakes of fruits, vegetables, and whole grains. Moreover, we were able to report for the first time a small decrease in breast cancer risk (6%) by pooling seven cohort studies.

Adherence to Mediterranean diet and risk of cancer: an updated systematic review and meta-analysis of observational studies

The aim of the present systematic review and meta-analysis of observational studies was to gain further insight into the effects of adherence to Mediterranean Diet (MD) on overall cancer mortality, incidence of different types of cancer, and cancer mortality risk in cancer survivors. Literature search was performed using the electronic databases PubMed, and EMBASE until 2 July 2015. We included either cohort (for specific tumors only incidence cases were used) or case-control studies. Study specific risk ratios, hazard ratios, and odds ratios (RR/HR/OR) were pooled using a random effect model. The updated review process showed 23 observational studies that were not included in the previous meta-analysis (total number of studies evaluated: 56 observational studies). An overall population of 1,784,404 subjects was included in the present update. The highest adherence score to an MD was significantly associated with a lower risk of all-cause cancer mortality (RR: 0.87, 95% CI 0.81-0.93, I(2) = 84%), colorectal cancer (RR: 0.83, 95% CI 0.76-0.89, I(2) = 56%), breast cancer (RR: 0.93, 95% CI 0.87-0.99, I(2) =15%), gastric cancer (RR: 0.73, 95% CI 0.55-0.97, I(2) = 66%), prostate cancer (RR: 0.96, 95% CI 0.92-1.00, I(2) = 0%), liver cancer (RR: 0.58, 95% CI 0.46-0.73, I(2) = 0%), head and neck cancer (RR: 0.40, 95% CI 0.24-0.66, I(2) = 90%), pancreatic cancer (RR: 0.48, 95% CI 0.35-0.66), and respiratory cancer (RR: 0.10, 95% CI 0.01-0.70). No significant association could be observed for esophageal/ovarian/endometrial/and bladder cancer, respectively. Among cancer survivors, the association between the adherence to the highest MD category and risk of cancer mortality, and cancer recurrence was not statistically significant. The updated meta-analyses confirm a prominent and consistent inverse association provided by adherence to an MD in relation to cancer mortality and risk of several cancer types.

Does a Mediterranean-Type Diet Reduce Cancer Risk?

Overall cancer incidence has been observed to be lower in Mediterranean countries compared to that in Northern countries, such as the UK, and the USA. There is increasing evidence that adherence to a Mediterranean dietary pattern correlates with reduced risk of several cancer types and cancer mortality. In addition, specific aspects of the Mediterranean diet, such as high consumption of fruit and vegetables, whole grains, and low processed meat intake, are inversely associated with risk of tumor pathogenesis at different cancer sites. The purpose of this review is to summarize the available evidence regarding the association between the Mediterranean diet and cancer risk from clinical trials, prospective cohort studies, and case-control studies. Furthermore, we focused on the different definitions of a Mediterranean diet in an attempt to assess their efficiency. Observational studies provide new evidence suggesting that high adherence to a Mediterranean diet is associated with reduced risk of overall cancer mortality as well as a reduced risk of incidence of several cancer types (especially cancers of the colorectum, aerodigestive tract, breast, stomach, pancreas, prostate, liver, and head and neck).