Meat, eggs, dairy products, and risk of breast cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort

Cheese consumption and multiple health outcomes: an umbrella review and updated meta-analysis of prospective studies

This umbrella review aims to provide a systematic and comprehensive overview of current evidence from prospective studies on the diverse health effects of cheese consumption. We searched PubMed, Embase, and Cochrane Library to identify meta-analyses/pooled analyses of prospective studies examining the association between cheese consumption and major health outcomes from inception to August 31, 2022. We reanalyzed and updated previous meta-analyses and performed de novo meta-analyses with recently published prospective studies, where appropriate. We calculated the summary effect size, 95% prediction confidence intervals, between-study heterogeneity, small-study effects, and excess significance bias for each health outcome. We identified 54 eligible articles of meta-analyses/pooled analyses. After adding newly published original articles, we performed 35 updated meta-analyses and 4 de novo meta-analyses. Together with 8 previous meta-analyses, we finally included 47 unique health outcomes. Cheese consumption was inversely associated with all-cause mortality (highest compared with lowest category: RR = 0.95; 95% CI: 0.92, 0.99), cardiovascular mortality (RR = 0.93; 95% CI: 0.88, 0.99), incident cardiovascular disease (CVD) (RR = 0.92; 95% CI: 0.89, 0.96), coronary heart disease (CHD) (RR = 0.92; 95% CI: 0.86, 0.98), stroke (RR = 0.93; 95% CI: 0.89, 0.98), estrogen receptor-negative (ER-) breast cancer (RR = 0.89; 95% CI: 0.82, 0.97), type 2 diabetes (RR = 0.93; 95% CI: 0.88, 0.98), total fracture (RR = 0.90; 95% CI: 0.86, 0.95), and dementia (RR = 0.81; 95% CI: 0.66, 0.99). Null associations were found for other outcomes. According to the NutriGrade scoring system, moderate quality of evidence was observed for inverse associations of cheese consumption with all-cause and cardiovascular mortality, incident CVD, CHD, and stroke, and for null associations with cancer mortality, incident hypertension, and prostate cancer. Our findings suggest that cheese consumption has neutral to moderate benefits for human health.

Health effects associated with consumption of unprocessed red meat: a Burden of Proof study

Characterizing the potential health effects of exposure to risk factors such as red meat consumption is essential to inform health policy and practice. Previous meta-analyses evaluating the effects of red meat intake have generated mixed findings and do not formally assess evidence strength. Here, we conducted a systematic review and implemented a meta-regression-relaxing conventional log-linearity assumptions and incorporating between-study heterogeneity-to evaluate the relationships between unprocessed red meat consumption and six potential health outcomes. We found weak evidence of association between unprocessed red meat consumption and colorectal cancer, breast cancer, type 2 diabetes and ischemic heart disease. Moreover, we found no evidence of an association between unprocessed red meat and ischemic stroke or hemorrhagic stroke. We also found that while risk for the six outcomes in our analysis combined was minimized at 0 g unprocessed red meat intake per day, the 95% uncertainty interval that incorporated between-study heterogeneity was very wide: from 0-200 g d-1. While there is some evidence that eating unprocessed red meat is associated with increased risk of disease incidence and mortality, it is weak and insufficient to make stronger or more conclusive recommendations. More rigorous, well-powered research is needed to better understand and quantify the relationship between consumption of unprocessed red meat and chronic disease.

Diet and BMI Correlate with Metabolite Patterns Associated with Aggressive Prostate Cancer

Three metabolite patterns have previously shown prospective inverse associations with the risk of aggressive prostate cancer within the European Prospective Investigation into Cancer and Nutrition (EPIC). Here, we investigated dietary and lifestyle correlates of these three prostate cancer-related metabolite patterns, which included: 64 phosphatidylcholines and three hydroxysphingomyelins (Pattern 1), acylcarnitines C18:1 and C18:2, glutamate, ornithine, and taurine (Pattern 2), and 8 lysophosphatidylcholines (Pattern 3). In a two-stage cross-sectional discovery (n = 2524) and validation (n = 518) design containing 3042 men free of cancer in EPIC, we estimated the associations of 24 dietary and lifestyle variables with each pattern and the contributing individual metabolites. Associations statistically significant after both correction for multiple testing (False Discovery Rate = 0.05) in the discovery set and at p < 0.05 in the validation set were considered robust. Intakes of alcohol, total fish products, and its subsets total fish and lean fish were positively associated with Pattern 1. Body mass index (BMI) was positively associated with Pattern 2, which appeared to be driven by a strong positive BMI-glutamate association. Finally, both BMI and fatty fish were inversely associated with Pattern 3. In conclusion, these results indicate associations of fish and its subtypes, alcohol, and BMI with metabolite patterns that are inversely associated with risk of aggressive prostate cancer.

Association of Fruit, Vegetable, and Animal Food Intakes with Breast Cancer Risk Overall and by Molecular Subtype among Vietnamese Women

BACKGROUND

Evidence on associations between dietary intake and risk of breast cancer subtypes is limited and inconsistent. We evaluated associations of fruit, vegetable, meat, and fish consumption with risk of breast cancer overall and by molecular subtype in the Vietnamese Breast Cancer Study (VBCS).

METHOD

VBCS includes 476 incident breast cancer cases and 454 age-matched controls. Dietary habits over the past 5 years were assessed by in-person interviews using a validated food frequency questionnaire. Associations of food groups with breast cancer were evaluated via logistic regression for overall and molecular subtype with adjustment for age, education, income, family history of cancer, menopausal status, body mass index, exercise, total energy intake, and other potential dietary confounders. Odds ratio (OR) was used to approximate relative risk.

RESULTS

High fruit intake was inversely associated with breast cancer risk, with adjusted ORs [95% confidence intervals (CI)] of 0.67 (95% CI, 0.47-0.95) and 0.41 (95% CI, 0.27-0.61) for second and third tertiles versus first tertile, respectively (Ptrend < 0.001). This association was stronger for triple-negative than other subtypes (Pheterogeneity < 0.001). High intake of freshwater fish was inversely associated with overall breast cancer (ORT3vsT1 = 0.63; 95% CI, 0.42-0.95; Ptrend = 0.03). An inverse association was observed between HER2-enriched subtype and red and organ meat intake (ORT3vsT1 = 0.40; 95% CI, 0.17-0.93; Ptrend = 0.04; Pheterogeneity = 0.50).

CONCLUSIONS

High intakes of fruit and freshwater fish were associated with reduced breast cancer risk; association for the former was stronger for triple-negative subtype.

IMPACT

Our findings suggest high intakes of fruit and freshwater fish may reduce breast cancer risk among Vietnamese women.

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.

Today’s Mediterranean Diet in Greece: Findings from the National Health and Nutrition Survey—HYDRIA (2013–2014)

Background: This study aimed to investigate the food and macronutrient intake of the population in Greece and evaluate its adherence to the Greek traditional Mediterranean diet. Methods: Adults over 18 years old (n = 4011) were included from the 2013–2014 National Health and Nutrition survey—HYDRIA. Dietary intake was collected using two 24-h recall interviews and a nonquantitative food frequency questionnaire. Macronutrient intakes were calculated using an updated version of the Greek FCT. Results: Only 28.3% of the adult population had high adherence to the Greek traditional Mediterranean diet, with a higher percentage (39.7%) observed for participants over 65 years compared to those under 65 years (25.5%). Differences in adherence to the MD were observed among the four geographical regions in Greece. Younger adults had a higher intake of meat, cereals, alcoholic and nonalcoholic beverages, and sugar products than older individuals who consumed more vegetables, fruits, legumes, dairy, fish, and lipids (mainly from olive oil). Adults do not meet the international dietary recommendations for the intake of several foods and macronutrients. Conclusions: The adult Greek population, especially younger people, has headed away from the Greek traditional Mediterranean diet. These observations indicate potential detrimental consequences in terms of morbidity and mortality.

The association between meat and fish intake by preparation methods and breast cancer in the Carolina Breast Cancer Study (CBCS)

PURPOSE

We examined the associations between intake of meat and fish by preparation methods and breast cancer in the Carolina Breast Cancer Study, a racially diverse population-based case-control study.

METHODS

African American (AA) and European American (EA) women aged 20-74 years with a first diagnosis of invasive or in situ breast cancers were frequency matched by race and age group to controls identified through the North Carolina Division of Motor Vehicles and Medicare lists [AA: 548 cases, 452 controls; EA: 858 cases, 748 controls]. Participants self-reported meat preparation methods and intake frequencies. Adjusted odds ratios (OR) and 95% confidence intervals (CIs) were calculated using multivariable logistic regression adjusted for age, race, alcohol intake, body mass index, family income, lactation, marital status, use of oral contraceptives, postmenopausal hormone use, smoking status, and offsets.

RESULTS

Positive associations with breast cancer were observed for intakes of grilled/barbecued hamburger (≥ once/week, OR: 1.28; 95% CI 1.01, 1.63), and pan-fried/oven-broiled beef steak (≥ once/week, OR: 1.36; 95% CI 1.08, 1.72). Inverse associations were observed for pan-fried fish (≥ once/week, OR: 0.77; 95% CI 0.60, 0.98), and for grilled/ barbecued pork chops (> 0 time/week OR: 0.81, 95% CI 0.68, 0.97). Associations tended to be stronger among EA women than among AA women.

CONCLUSION

More frequent consumption of beef prepared with high temperature methods was associated with higher odds of breast cancer while more frequent consumption of pan-fried fish or grilled/barbecued pork chops was associated with lower odds of breast cancer.

Consumption of Dairy Products and the Risk of Developing Breast Cancer in Polish Women

Lack of consistency in the relationship between dairy products consumption and breast cancer (BC) risk motivated us to evaluate this association in a case-control study of BC among Polish women. The study includes 1699 women 26–79 years of age, 823 BC cases identified in Cancer Registries and 876 randomly selected controls from the national population registry. Using a validated, semiquantitative food frequency questionnaire (FFQ), the consumption of dairy products was collected for a time period of 10–15 years prior to BC diagnosis. We used logistic regression, adjusting for potential confounders, to assess the relationship between total dairy consumption as well as individual dairy groups of milk, cottage cheese and hard cheese and BC risk for premenopausal and postmenopausal women. For total consumption, a significant decrease in BC risk was observed with increased consumption of one serving/week, OR _trend = 0.98, 2% decrease in risk, for premenopausal women only. For milk, a significant decrease in BC risk was observed for an increase in consumption of one glass/week, OR _trend = 0.95, 5% decrease, in both strata of menopause. In contrast, for hard cheese, a significant increase in the risk of 10% was observed only in premenopausal women, OR _trend = 1.10. Cottage cheese consumption significantly reduced BC risk by 20%, OR _trend = 0.80, for an increase in one serving/week for postmenopausal women only. Our results show that individual dairy products have a statistically significant but bi-directional relationship with BC risk, which differs for premenopausal and postmenopausal women.

The relationship between dairy products intake and breast cancer incidence: a meta-analysis of observational studies

Background

The effect of dairy products intake on breast cancer (BC) is highly controversial. This study aims to investigate the relationship between dairy intake and BC incidence.

Methods

A search was carried out in PubMed, EBSCO, Web of Science, and Cochrane Library databases before January 2021. The primary objective was the risk of BC and intake of dairy products were exposure variables.

Results

The meta-analysis comprised 36 articles with 1,019,232 participants. Total dairy products have a protective effect on female population (hazard ratio (HR) =0.95, 95% confidence interval (CI) =0.91–0.99, p = 0.019), especially for estrogen receptor-positive (ER+) (HR = 0.79, p = 0.002) and progesterone receptor-positive (PR+) BC (HR = 0.75, p = 0.027). For ER+/PR+ BC, there is a trend of protection, but it has not reached statistical significance (HR = 0.92, p = 0.075). Fermented dairy products can reduce BC risk in postmenopausal population (HR = 0.96, 95%CI = 0.93–0.99, p = 0.021), but have no protective effect on premenopausal population (HR = 0.98, 95%CI = 0.94–1.03, p = 0.52). Non-fermented dairy products have no significant effect on BC occurrence (p > 0.05). High-fat dairy products are harmful to women, without statistical difference (HR = 1.06, 95%CI = 1.00–1.13, p = 0.066). On the contrary, low-fat dairy products can protect the premenopausal population (HR = 0.94, 95%CI = 0.89–1.00, p = 0.048).

Conclusion

The intake of dairy products can overall reduce BC risk in the female population, but different dairy products have varying effects on different BC subtypes and menopausal status.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08854-w.

Evidence Update on the Relationship between Diet and the Most Common Cancers from the European Prospective Investigation into Cancer and Nutrition (EPIC) Study: A Systematic Review

The European Prospective Investigation into Cancer and Nutrition (EPIC) is a multicentre prospective study conducted in 23 centres in 10 European countries. Here we review the findings from EPIC on the relationship between diet-related exposures and incidence or mortality from the four most frequent cancers in the European population: colorectal, breast, lung, and prostate cancer. We conducted a systematic review following PRISMA guidelines and identified 110 high-quality studies based on the EPIC cohort. Fruit and vegetable consumption had a protective effect against colorectal, breast, and lung cancer, whereas only fruit had a protective effect against prostate cancer. A higher consumption of fish and lower consumption of red and processed meat were related with a lower risk of colorectal cancer; and higher consumption of fatty fish with lower risk of breast cancer. Calcium and yogurt intake were found to protect against colorectal and prostate cancer. Alcohol consumption increased the risk for colorectal and breast cancer. Finally, adherence to the Mediterranean diet emerged as a protective factor for colorectal and breast cancer. The EPIC study results are in agreement with the latest evidence from leading authorities on cancer prevention and help to inform public prevention policies and strategies.

Consumption of red meat and processed meat and cancer incidence: a systematic review and meta-analysis of prospective studies

Red meat and processed meat consumption has been hypothesized to increase risk of cancer, but the evidence is inconsistent. We performed a systematic review and meta-analysis of prospective studies to summarize the evidence of associations between consumption of red meat (unprocessed), processed meat, and total red and processed meat with the incidence of various cancer types. We searched in MEDLINE and EMBASE databases through December 2020. Using a random-effect meta-analysis, we calculated the pooled relative risk (RR) and 95% confidence intervals (CI) of the highest versus the lowest category of red meat, processed meat, and total red and processed meat consumption in relation to incidence of various cancers. We identified 148 published articles. Red meat consumption was significantly associated with greater risk of breast cancer (RR = 1.09; 95% CI = 1.03-1.15), endometrial cancer (RR = 1.25; 95% CI = 1.01-1.56), colorectal cancer (RR = 1.10; 95% CI = 1.03-1.17), colon cancer (RR = 1.17; 95% CI = 1.09-1.25), rectal cancer (RR = 1.22; 95% CI = 1.01-1.46), lung cancer (RR = 1.26; 95% CI = 1.09-1.44), and hepatocellular carcinoma (RR = 1.22; 95% CI = 1.01-1.46). Processed meat consumption was significantly associated with a 6% greater breast cancer risk, an 18% greater colorectal cancer risk, a 21% greater colon cancer risk, a 22% greater rectal cancer risk, and a 12% greater lung cancer risk. Total red and processed meat consumption was significantly associated with greater risk of colorectal cancer (RR = 1.17; 95% CI = 1.08-1.26), colon cancer (RR = 1.21; 95% CI = 1.09-1.34), rectal cancer (RR = 1.26; 95% CI = 1.09-1.45), lung cancer (RR = 1.20; 95% CI = 1.09-1.33), and renal cell cancer (RR = 1.19; 95% CI = 1.04-1.37). This comprehensive systematic review and meta-analysis study showed that high red meat intake was positively associated with risk of breast cancer, endometrial cancer, colorectal cancer, colon cancer, rectal cancer, lung cancer, and hepatocellular carcinoma, and high processed meat intake was positively associated with risk of breast, colorectal, colon, rectal, and lung cancers. Higher risk of colorectal, colon, rectal, lung, and renal cell cancers were also observed with high total red and processed meat consumption.

Potential Protective Protein Components of Cow's Milk against Certain Tumor Entities

Milk and dairy products, especially from cow's milk, play a major role in the daily human diet. It is therefore hardly surprising that the subject of milk is being extensively researched and that many effects of individual milk components have been characterized as a result. With the wealth of results available today, the influence of milk on the development of various types of cancer and, in particular, its often protective effects have been shown both in vitro and in vivo and in the evaluation of large-scale cohort and case-control studies. Various caseins, diverse whey proteins such as α-lactalbumin (α-LA), bovine α-lactalbumin made lethal to tumor cells (BAMLET), β-lactoglobulin (β-LG), or bovine serum albumin (BSA), and numerous milk fat components, such as conjugated linoleic acid (CLA), milk fat globule membrane (MFGM), or butyrate, as well as calcium and other protein components such as lactoferrin (Lf), lactoferricin (Lfcin), and casomorphines, show antitumor or cytotoxic effects on cells from different tumor entities. With regard to a balanced and health-promoting diet, milk consumption plays a major role in a global context. This work provides an overview of what is known about the antitumoral properties of proteins derived from cow's milk and their modes of action.

Dairy, soy, and risk of breast cancer: those confounded milks

BACKGROUND

Associations between soy, dairy intakes and breast cancer risk are inconsistent. No studies exist with large numbers of dairy consumers and soy consumers to assess mutual confounding.

METHODS

The study cohort contains 52 795 North American women, initially free of cancer, followed for 7.9 years (29.7% were Black). Dietary intakes were estimated from food frequency questionnaires and, for 1011 calibration study subjects, from six structured 24-h dietary recalls. Incident invasive breast cancers were detected mainly by matching with cancer registries. Analyses used multivariable proportional hazards regression.

RESULTS

The participants (mean age of 57.1 years) experienced 1057 new breast cancer cases during follow-up. No clear associations were found between soy products and breast cancer, independently of dairy. However, higher intakes of dairy calories and dairy milk were associated with hazard ratios (HRs) of 1.22 [95% confidence interval (CI): 1.05-1.40] and 1.50 (95% CI 1.22-1.84), respectively, comparing 90th to 10th percentiles of intakes. Full fat and reduced fat milks produced similar results. No important associations were noted with cheese and yogurt. Substituting median intakes of dairy milk users by those of soy milk consumers was associated with HR of 0.68 (95% CI: 0.55-0.85). Similar-sized associations were found among pre- and post-menopausal cases, with CIs also excluding the null in estrogen receptor (ER+, ER-), and progesterone receptor (PR+) cancers. Less biased calibrated measurement-error adjusted regressions demonstrated yet stronger, but less precise, HRs and CIs that still excluded the null.

CONCLUSIONS

Higher intakes of dairy milk were associated with greater risk of breast cancer, when adjusted for soy intake. Current guidelines for dairy milk consumption could be viewed with some caution.

Dairy Consumption and Incidence of Breast Cancer in the 'Seguimiento Universidad de Navarra' (SUN) Project

Dairy products might influence breast cancer (BC) risk. However, evidence is inconsistent. We sought to examine the association between dairy product consumption-and their subtypes-and incident BC in a Mediterranean cohort. The SUN ("Seguimiento Universidad de Navarra") Project is a Spanish dynamic ongoing cohort of university graduates. Dairy product consumption was estimated through a previously validated 136-item food frequency questionnaire (FFQ). Incident BC was reported in biennial follow-up questionnaires and confirmed with revision of medical records and consultation of the National Death Index. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated with Cox regression models. Among 123,297 women-years of follow-up (10,930 women, median follow-up 12.1 years), we confirmed 119 incident BC cases. We found a nonlinear association between total dairy product consumption and BC incidence (p_nonlinear = 0.048) and a significant inverse association for women with moderate total dairy product consumption (HR_Q2vs.Q1 = 0.49 (95% CI 0.28-0.84); HR_Q3vs.Q1 = 0.49 (95% CI 0.29-0.84) p_trend = 0.623) and with moderate low-fat dairy product consumption (HR_Q2vs.Q1 = 0.58 (95% CI 0.35-0.97); HR_Q3vs.Q1 = 0.55 (95% CI 0.32-0.92), p_trend = 0.136). In stratified analyses, we found a significant inverse association between intermediate low-fat dairy product consumption and premenopausal BC and between medium total dairy product consumption and postmenopausal BC. Thus, dairy products, especially low-fat dairy products, may be considered within overall prudent dietary patterns.

Adherence to a Western dietary pattern and risk of bladder cancer: A pooled analysis of 13 cohort studies of the Bladder Cancer Epidemiology and Nutritional Determinants international study

Little is known about the association of diet with risk of bladder cancer. This might be due to the fact that the majority of studies have focused on single food items, rather than dietary patterns, which may better capture any influence of diet on bladder cancer risk. We aimed to investigate the association between a measure of Western dietary pattern and bladder cancer risk. Associations between adherence to a Western dietary pattern and risk of developing bladder cancer were assessed by pooling data from 13 prospective cohort studies in the "BLadder cancer Epidemiology and Nutritional Determinants" (BLEND) study and applying Cox regression analysis. Dietary data from 580 768 study participants, including 3401 incident cases, and 577 367 noncases were analyzed. A direct and significant association was observed between higher adherence to a Western dietary pattern and risk of bladder cancer (hazard ratio (HR) comparing highest with lowest tertile scores: 1.54, 95% confidence interval (CI): 1.37, 1.72; P-trend = .001). This association was observed for men (HR comparing highest with lowest tertile scores: 1.72; 95% CI: 1.51, 1.96; P-trend = .001), but not women (P-het = .001). Results were consistent with HR above 1.00 after stratification on cancer subtypes (nonmuscle-invasive and muscle-invasive bladder cancer). We found evidence that adherence to a Western dietary pattern is associated with an increased risk of bladder cancer for men but not women.

Intake of Various Food Groups and Risk of Breast Cancer: A Systematic Review and Dose-Response Meta-Analysis of Prospective Studies

Despite increasing evidence for the association of food-based dietary patterns with breast cancer risk, knowledge about the shape of the relationship and the quality of meta-evidence are insufficient. We aimed to summarize the associations between food groups and risks of breast cancer. We performed a systematic literature search of the PubMed and Embase databases up to March 2020. We included cohort, case-cohort, nested case-control studies, and follow-up studies of randomized controlled trials that investigated the relationship between breast cancer risk and at least 1 of the following food groups: red meat, processed meat, fish, poultry, egg, vegetables, fruit, dairy product (overall, milk, yogurt, and cheese), grains/cereals, nuts, legumes, soy, and sugar-sweetened beverages. Summary risk ratios (RRs) and 95% CIs were estimated using a random-effects model for linear and nonlinear relationships. Inverse linear associations were observed for vegetables (RR per 100 g/d, 0.97; 95% CI, 0.95-0.99), fruit (RR per 100 g/d, 0.97; 95% CI, 0.95-0.99), cheese (RR per 30 g/d, 0.95; 95% CI, 0.91-1.00), and soy (RR per 30 g/d, 0.96; 95% CI, 0.94-0.99), while positive associations were observed for red (RR per 100 g/d, 1.10; 95% CI, 1.03-1.18) and processed meat (RR per 50 g/d, 1.18; 95% CI, 1.04-1.33). None of the other food groups were significantly associated with breast cancer risk. A nonlinear association was observed only for milk, such that the intake of >450 g/d increased the risk, while no association was observed for lower intake amounts. High intakes of vegetables, fruit, cheese, and soy products and low intakes of red and processed meat were associated with lower risks of breast cancer. However, causality cannot be inferred from these statistical correlations.

Combining individual and aggregated data to investigate the role of socioeconomic disparities on cancer burden in Italy

Quantifying socioeconomic disparities and understanding the roots of inequalities are growing topics in cancer research. However, socioeconomic differences are challenging to investigate mainly due to the lack of accurate data at individual-level, while aggregate indicators are only partially informative. We implemented a multiple imputation algorithm within a statistical matching framework that combines diverse sources of data to estimate individual-level associations between income and risk of breast and lung cancer, adjusting for potential confounding factors in Italy. The framework is computationally flexible and can be adapted to similar contexts.

Deriving the Dietary Approaches to Stop Hypertension (DASH) Score in Women from Seven Pregnancy Cohorts from the European ALPHABET Consortium

The ALPHABET consortium aims to examine the interplays between maternal diet quality, epigenetics and offspring health in seven pregnancy/birth cohorts from five European countries. We aimed to use the Dietary Approaches to Stop Hypertension (DASH) score to assess diet quality, but different versions have been published. To derive a single DASH score allowing cross-country, cross-cohort and cross-period comparison and limiting data heterogeneity within the ALPHABET consortium, we harmonised food frequency questionnaire (FFQ) data collected before and during pregnancy in ≥26,500 women. Although FFQs differed strongly in length and content, we derived a consortium DASH score composed of eight food components by combining the prescriptive original DASH and the DASH described by Fung et al. Statistical issues tied to the nature of the FFQs led us to re-classify two food groups (grains and dairy products). Most DASH food components exhibited pronounced between-cohort variability, including non-full-fat dairy products (median intake ranging from 0.1 to 2.2 servings/day), sugar-sweetened beverages/sweets/added sugars (0.3-1.7 servings/day), fruits (1.1-3.1 servings/day), and vegetables (1.5-3.6 servings/day). We successfully developed a harmonized DASH score adapted to all cohorts being part of the ALPHABET consortium. This methodological work may benefit other research teams in adapting the DASH to their study's specificities.

Associations of dairy product consumption with mortality in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Italy cohort

BACKGROUND

The relation of dairy product consumption to health and mortality is controversial.

OBJECTIVES

We investigated associations of consumption of various dairy products with mortality in the Italian cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Italy study.

METHODS

Dairy product consumption was assessed by validated semiquantitative FFQs. Multivariable Cox models stratified by center, age, and sex and adjusted for confounders estimated associations of milk (total, full fat, and reduced fat), yogurt, cheese, butter, and dairy calcium consumption with mortality for cancer, cardiovascular disease, and all causes. Nonlinearity was tested by restricted cubic spline regression.

RESULTS

After a median follow-up of 14.9 y, 2468 deaths were identified in 45,009 participants: 59% from cancer and 19% from cardiovascular disease. No significant association of consumption of any dairy product with mortality was found in the fully adjusted models. A 25% reduction in risk of all-cause mortality was found for milk intake from 160 to 120 g/d (HR: 0.75; 95% CI: 0.61, 0.91) but not for the highest (>200 g/d) category of intake (HR: 0.95; 95% CI: 0.84, 1.08) compared with nonconsumption. Associations of full-fat and reduced-fat milk consumption with all-cause and cause-specific mortality were similar to those for milk as a whole.

CONCLUSIONS

In this Italian cohort characterized by low to average milk consumption, we found no evidence of a dose-response association between milk consumption and mortality and also no association of consumption of other dairy products investigated with mortality.

Dairy Consumption in Adolescence and Early Adulthood and Risk of Breast Cancer

Background: Carcinogenic exposure in early life may be critical for subsequent breast cancer risk. Dairy consumption was examined during adolescence and early adulthood in relation to incident breast cancer in the Nurses' Health Study II cohort.Methods: For the analyses of early adulthood dairy consumption, we included 90,503 premenopausal women ages 27 to 44 years in 1991 who reported dairy consumption using a validated food-frequency questionnaire. From 1991 to 2013, 3,191 invasive breast cancer cases were identified. In 1998, 44,264 women recalled adolescent dairy consumption. This subgroup of women was followed up from 1998 to 2013; 1,318 invasive breast cancer cases were identified. Multivariate hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using the Cox proportional hazard regression.Results: Adolescent and early adulthood total dairy consumption was not associated with overall breast cancer risk (each serving/day during adolescence, total dairy HR = 1.02, 95% CI, 0.97-1.07; for early adulthood total dairy HR = 1.01, 95% CI, 0.97-1.04), as were intakes of calcium, vitamin D, and lactose. Adolescent consumption of total and high-fat dairy was associated with higher risk of estrogen and progesterone receptor negative (each serving/day: total dairy HR = 1.11, 95% CI, 1.00-1.24; high-fat dairy HR = 1.17, 95% CI, 1.04-1.31). However, higher adolescent high-fat dairy consumption was associated with lower risk of estrogen and progesterone receptor positive tumors (each serving/day HR = 0.91, 95% CI, 0.86-0.97).Conclusions: Our results suggest no overall association between dairy consumption during adolescence or early adulthood and breast cancer risk, but the findings may differ by hormone receptor status of tumors.Impact: Dairy consumption in adolescence or early adulthood may not be a significant predictor of breast cancer incidence. Cancer Epidemiol Biomarkers Prev; 27(5); 575-84. ©2018 AACR.

Dietary index scores and invasive breast cancer risk among women with a family history of breast cancer

BACKGROUND

Many epidemiologic studies have analyzed the relations of individual foods and nutrients and breast cancer risk with inconsistent results. Few studies have examined recommendation-based dietary indices and breast cancer risk.

OBJECTIVE

The aim of this study was to determine associations between recommendation-based dietary index scores and incident invasive breast cancer.

METHODS

The Sister Study is a prospective cohort of 50,884 US women (baseline: 2003-2009) who had a sister with breast cancer but no prior breast cancer themselves. We created scores for the Dietary Approaches to Stop Hypertension (DASH) diet, Alternative Mediterranean Diet (AMED), and Alternative Healthy Eating Index-2010 (AHEI-2010) from dietary intakes estimated by a baseline-validated Block food-frequency questionnaire (FFQ). We used Cox regression to estimate multivariable-adjusted HRs and 95% CIs for total invasive breast cancer risk and by estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2) status.

RESULTS

We documented 1,700 invasive breast cancer cases through 2015 (mean follow-up, 7.6 y). Individuals in the highest quartile of DASH scores had a lower risk of invasive breast cancer compared with those in the lowest quartile (HR: 0.78; 95% CI: 0.67, 0.90; P-trend = 0.001), with stronger associations for ER- (HR: 0.61; 95% CI: 0.40, 0.94; P-trend = 0.006) as well as ER-/PR- and ER-/PR-/HER2- subtypes. AHEI-2010 (HR for highest compared with lowest quartile: 0.90; 95% CI: 0.78, 1.03; P-trend = 0.15) and AMED (HR for highest compared with lowest quartile: 0.90; 95% CI: 0.77, 1.06; P-trend = 0.07) were weakly and nonsignificantly associated with breast cancer risk, but after excluding alcohol, AHEI-2010 was inversely associated with risk of ER-/PR- (HR: 0.64; 95% CI: 0.42, 0.98; P-trend = 0.04) and ER-/PR-/HER2- subtypes. We did not observe any significant interactions by menopausal status or other participant characteristics.

CONCLUSIONS

DASH scores were inversely associated with breast cancer risk; DASH and AHEI-2010 scores excluding alcohol were particularly inversely associated with risk of ER-/PR- and ER-/PR-/HER2- breast cancers. This trial was registered at clinicaltrials.gov as NCT00047970.

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.

Higher frequency of dairy intake is associated with a reduced risk of breast cancer: Results from a case-control study in Northern and Eastern China

The association between dairy intake and breast cancer risk has not been well investigated, especially in the Chinese population. This study aimed to examine the association between the weekly frequency of dairy intake and the risk of breast cancer among women in Northern and Eastern China, and to investigate whether the association varied by hormone receptor status. A total of 1,286 cases of breast cancer and 1,461 controls were enrolled in this study. Dairy intake was obtained using a food-frequency questionnaire (FFQ). Frequency of dairy intake per week was divided into four categories (<1 day/week, 1–2 days/week, 3–4 days/week and 5–7 days/week). Unconditional multivariate logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CI). Stratified analyses were performed by residence, age, and education level. Separate analyses were also conducted for different estrogen receptor (ER) and progesterone receptor (PR) status. This analysis revealed that weekly frequency of dairy intake was strongly inversely associated with breast cancer risk, with an adjusted OR for intake 5–7 days/week of 0.53 (95% CI=0.39–0.72, P<0.001 for trend). In the stratified analyses, women who consumed dairy 5–7 days/week had a lower risk of breast cancer in urban areas (OR=0.45, 95% CI=0.30–0.66, P<0.001 for trend), in the group 45–59 years old (OR=0.39, 95% CI=0.26–0.60, P<0.001 for trend), and in the group educated to senior high school or above (OR=0.39, 95% CI=0.25–0.59, P<0.001 for trend). There was an inverse association between the weekly frequency of dairy intake and the risk of ER⁺, PR⁺, and ER⁺PR⁺ breast cancer (all P<0.001 for trend). These results indicated that the weekly frequency of dairy intake was inversely associated with the risk of breast cancer among women in Northern and Eastern China.

Animal foods and postmenopausal breast cancer risk: a prospective cohort study

The role of diet on breast cancer risk is not well elucidated but animal food sources may play a role through, for example, the pathway of the insulin-like growth factor 1 system or cholesterol metabolism. The aim of this study was to evaluate the association between animal foods and the risk of postmenopausal breast cancer. This study was embedded in the Rotterdam Study, a population-based prospective cohort study of subjects aged 55 years and over (61 % female). Dietary intake of different animal foods was assessed at baseline using a validated FFQ and adjusted for energy intake using the residual method. We performed Cox proportional hazards modelling to analyse the association between the intake of the different food sources and breast cancer risk after adjustment for socio-demographic, lifestyle and metabolic factors. During a median follow-up of 17 years, we identified 199 cases of breast cancer (6·2 %) among 3209 women. After adjustment for multiple confounders, no consistent association was found between the intake of red meat intake, poultry, fish or dairy products and breast cancer risk. However, we found that egg intake was significantly associated with a higher risk of breast cancer (hazard ratioQ4 v. Q1: 1·83; 95 % CI 1·20, 2·79; Ptrend=0·01). In conclusion, this study found that dietary egg intake but no other animal foods was associated with a higher risk of postmenopausal breast cancer. Further research on the potential mechanisms underlying this association is warranted.

Milk and yogurt intake and breast cancer risk: A meta-analysis

Different patterns of milk and breast cancer rates across countries suggest that several components of milk could affect breast cancer risk. However, the components of diet are complex including milk that could potentially influence risk. Some milk products such as whole milk and cheese have a high fat content which may increase risk. Moreover, milk products may contain pesticides which have carcinogenic potential. In contrast, some contents of milk such as calcium and vitamin D have been hypothesized to reduce breast cancer risk. Therefore, we performed this meta-analysis to derive a more precise estimation of the association between dairy food intake and breast cancer risk. Using the data from 8 available publications, we examined low-fat/skim milk, whole milk, and yogurt in relation to risk of breast cancer by meta-analysis. Pooled odds ratio (OR) with 95% confidence interval (CI) was used to assess the association. However the results of all milk models and the available epidemiologic evidence do not support a strong association between the consumption of milk or milk products and breast cancer risk. Further studies with larger participants worldwide are needed to validate the relationship of dairy food intake and breast cancer.

Diet and risk of breast, endometrial and ovarian cancer: UK Women's Cohort Study

This study aimed to investigate the association between diet and the risk of breast, endometrial and ovarian cancer in the UK Women's Cohort Study. A total of 35 372 women aged 35-69 years were enrolled between 1995 and 1998 and completed a validated 217-item FFQ. The individual foods were collapsed into sixty-four main food groups and compared using Cox proportional models, adjusting for potential confounders. Hazard ratio (HR) estimates are presented per portion increase in food items. After approximately 18 years of follow-up, there were 1822, 294 and 285 cases of breast, endometrial and ovarian cancer, respectively. A high consumption of processed meat and total meat was associated with an increased risk of breast and endometrial cancer. High intake of tomatoes (HR 0·87, 99 % CI 0·75, 1·00) and dried fruits (HR 0·60, 99 % CI 0·37, 0·97) was associated with a reduced risk of breast and endometrial cancer, respectively. Mushroom intake was associated with a higher risk of ovarian cancer (HR 1·57, 99 % CI 1·09, 2·26). Subgroup analysis by pre- or postmenopausal cancer further demonstrated an association between processed meat intake and both postmenopausal breast cancer and endometrial cancer. Intake of dried fruits was associated with a reduced risk of postmenopausal endometrial cancer (HR 0·55, 99 % CI 0·31, 0·98). Our findings suggest that while some foods may trigger the risk of these cancers, some foods may also be protective; supporting the call for further randomised controlled trials of dietary interventions to reduce the risk of cancer among pre- and postmenopausal women.

Meat intake, methods and degrees of cooking and breast cancer risk in the MCC-Spain study

OBJECTIVE

To analyse the relationship of the risk of breast cancer (BC) to meat intake, preference regarding degree of cooking ('doneness') and cooking methods, using data from a population-based case-control study (MCC-Spain).

STUDY DESIGN

1006 Histologically confirmed incident BC cases and 1370 controls were recruited in 10 Spanish provinces. Participants were 23-85 years old. They answered an epidemiological survey and a food frequency questionnaire. BC risk was assessed overall, by menopausal status and by pathological subtypes, using logistic and multinomial regression mixed models adjusted for known confounding factors and including province as a random effects term.

MAIN OUTCOME MEASURES

Breast cancer and pathological subtype.

RESULTS

High total intake of meat (ORQ4-Q1 (95% IC) = 1.39 (1.03-1.88)) was associated with increased BC risk among post-menopausal women. Similar results were found for processed/cured meat (ORQ4-Q1 (95% IC) = 1.47 (1.10-1.97)), and this association was particularly strong for triple-negative tumours (ER-, PR- and HER2-) (ORQ4-Q1 (95% IC) = 2.52 (1.15-5.49)). Intakes of well-done (ORwell-donevsrare (95% CI) = 1.62 (1.15-2.30)) and stewed (OR (95% CI) = 1.49 (1.20-1.84)) red meat were associated with increased BC risk, with a high risk observed for HR+ tumours (ER+/PR+ and HER2-). Pan-fried/bread-coated fried white meat, but not doneness preference, was associated with an increased BC risk for all women (OR (95% CI) = 1.38 (1.14-1.65)), with a stronger association for pre-menopausal women (OR (95% CI) = 1.78 (1.29-2.46)).

CONCLUSION

The risk of developing BC could be reduced by moderating the consumption of well-done or stewed red meat, pan-fried/bread-coated fried white meat and, especially, processed/cured meat.

Expression and replication of virus-like circular DNA in human cells

The consumption of bovine milk and meat is considered a risk factor for colon- and breast cancer formation, and milk consumption has also been implicated in an increased risk for developing Multiple Sclerosis (MS). A number of highly related virus-like DNAs have been recently isolated from bovine milk and sera and from a brain sample of a MS patient. As a genetic activity of these Acinetobacter-related bovine milk and meat factors (BMMFs) is unknown in eukaryotes, we analyzed their expression and replication potential in human HEK293TT cells. While all analyzed BMMFs show transcriptional activity, the MS brain isolate MSBI1.176, sharing homology with a transmissible spongiform encephalopathy-associated DNA molecule, is transcribed at highest levels. We show expression of a replication-associated protein (Rep), which is highly conserved among all BMMFs, and serological tests indicate a human anti-Rep immune response. While the cow milk isolate CMI1.252 is replication-competent in HEK293TT cells, replication of MSBI1.176 is complemented by CMI1.252, pointing at an interplay during the establishment of persistence in human cells. Transcriptome profiling upon BMMF expression identified host cellular gene expression changes related to cell cycle progression and cell viability control, indicating potential pathways for a pathogenic involvement of BMMFs.

Red and processed meat consumption and breast cancer: UK Biobank cohort study and meta-analysis

AIM

Red and processed meat may be risk factors for breast cancer due to their iron content, administration of oestrogens to cattle or mutagens created during cooking. We studied the associations in UK Biobank and then included the results in a meta-analysis of published cohort studies.

METHODS

UK Biobank, a general population cohort study, recruited participants aged 40-69 years. Incident breast cancer was ascertained via linkage to routine hospital admission, cancer registry and death certificate data. Univariate and multivariable Cox proportional hazard models were used to explore the associations between red and processed meat consumption and breast cancer. Previously published cohort studies were identified from a systematic review using PubMed and Ovid and a meta-analysis conducted using a random effects model.

RESULTS

Over a median of 7 years follow-up, 4819 of the 262,195 women developed breast cancer. The risk was increased in the highest tertile (>9 g/day) of processed meat consumption (adjusted hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.08-1.35, p = 0.001). Collation with 10 previous cohort studies provided data on 40,257 incident breast cancers in 1.65 million women. On meta-analysis, processed meat consumption was associated with overall (relative risk [RR] 1.06, 95% CI 1.01-1.11) and post-menopausal (RR 1.09, 95% CI 1.03-1.15), but not pre-menopausal (RR 0.99, 95% CI 0.88-1.10), breast cancer. In UK Biobank and the meta-analysis, red meat consumption was not associated with breast cancer (adjusted HR 0.99 95% CI 0.88-1.12 and RR 1.03, 95% CI 0.99-1.08, respectively).

CONCLUSIONS

Consumption of processed meat, but not red meat, may increase the risk of breast cancer.

Dietary Factors and Female Breast Cancer Risk: A Prospective Cohort Study

Breast cancer is the leading cause of cancer in females and has become a major global health priority. This prospective cohort study investigated the association of dietary factors, including food items and dietary habits, with the risk of breast cancer in Korean women. Study participants were women aged 30 years or older, recruited from the National Cancer Center in South Korea between August 2002 and May 2007. They were followed until December 2014 using the Korea Central Cancer Registry to identify breast cancer cases. Among 5046 non-pre-diagnosed cancer participants, 72 breast cancer cases were prospectively identified. Participants with breast cancer had a significantly higher educational level (college or higher: 58.3% vs. 39.5%, p = 0.01), were more likely to have ever smoked (22.2% vs. 7.8%, p < 0.001), and were more likely to have a history of benign breast tumors (10% vs. 4%, p = 0.02) than non-cases. Consumption of grilled meat conferred a significantly higher risk of breast cancer in all women (hazard ratio (HR) 1.77, 95% confidence interval (CI) 1.09–2.85) and in postmenopausal women (HR 3.06, 95% CI 1.31–7.15). High-cholesterol food intake was associated with a higher risk in all women (HR 1.69, 95% CI 1.01–2.82). Irregular meal intake was associated with an elevated risk in all women (HR 2.19, 95% CI 1.20–3.98, p for trend = 0.01) and in premenopausal women (HR 2.35, 95% CI 1.13–4.91, p for trend = 0.03). Our findings suggest that grilled meat and high-cholesterol food intake and irregular eating habits may be associated with a higher risk of breast cancer. Further studies with longer follow-up periods that include information on portion size, hormone receptor status, carcinogen levels in grilled meat, and a classification of foods by source are required.

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.

Dietary Guidelines for Breast Cancer Patients: A Critical Review

Current dietary guidelines for breast cancer patients (BCPs) fail to address adequate dietary intakes of macro- and micronutrients that may improve patients' nutritional status. This review includes information from the PubMed and Biomed Central databases over the last 15 y concerning dietary guidelines for BCPs and the potential impact of a personalized, nutrient-specific diet on patients' nutritional status during and after antineoplastic treatment. Results indicated that BCPs should receive a nutritional assessment immediately after diagnosis. In addition, they should be encouraged to pursue and maintain a healthy body weight [body mass index (BMI; in kg/m²) 20-24.9], preserving their lean mass and avoiding an increase in fat mass. Therefore, after nutritional status diagnosis, a conservative energy restriction of 500-1000 kcal/d could be considered in the dietary intervention when appropriate. Based on the reviewed information, we propose a personalized nutrition intervention for BCPs during and after antineoplastic treatment. Specifications in the nutritional therapy should be based on the patients' nutritional status, dietary habits, schedule, activities, and cultural preferences. BCPs' daily energy intake should be distributed as follows: <30% fat/d (mainly monounsaturated and polyunsaturated fatty acids), ∼55% carbohydrates (primarily whole foods such as oats, brown rice, and fruits), and 1.2-1.5 g protein ⋅ kg^-1 ⋅ d^-1 to avoid sarcopenic obesity. Findings suggest that 5-9 servings/d of fruits (∼150 g/serving) and vegetables (∼75 g/serving) should be encouraged. Garlic and cruciferous vegetables must also be part of the nutrition therapy. Adequate dietary intakes of food-based macro- and micronutrients rich in β-carotene and vitamins A, E, and C can both prevent deterioration in BCPs' nutritional status and improve their overall health and prognosis.

Dietary Protein Sources and Incidence of Breast Cancer: A Dose-Response Meta-Analysis of Prospective Studies

Protein is important to the human body, and different sources of protein may have different effects on the risk of breast cancer. Thus, we conducted a meta-analysis to investigate the association between different dietary protein sources and breast cancer risk. PubMed and several databases were searched until December 2015. Relevant articles were retrieved according to specific searching criteria. Forty-six prospective studies were included. The summary relative risk (RR) for highest versus lowest intake was 1.07 (95% confidence interval (CI) 1.01-1.14, I² = 34.6%) for processed meat, 0.92 (95% CI 0.84-1.00, I² = 0%) for soy food, 0.93 (95% CI 0.85-1.00, I² = 40.1%) for skim milk, and 0.90 (95% CI 0.82-1.00, I² = 0%) for yogurt. Similar conclusions were obtained in dose-response association for each serving increase: total red meat (RR: 1.07; 95% CI 1.01-1.14, I² = 7.1%), fresh red meat (RR: 1.13; 95% CI 1.01-1.26, I² = 56.4%), processed meat (RR: 1.09; 95% CI 1.02-1.17, I² = 11.8%), soy food (RR: 0.91; 95% CI 0.84-1.00, I² = 0%), and skim milk (RR: 0.96; 95% CI 0.92-1.00, I² = 11.9%). There was a null association between poultry, fish, egg, nuts, total milk, and whole milk intake and breast cancer risk. Higher total red meat, fresh red meat, and processed meat intake may be risk factors for breast cancer, whereas higher soy food and skim milk intake may reduce the risk of breast cancer.

Healthy Lifestyle Pattern is Protective Against 30-Yr Cancer Incidence in Men and Women: A Cohort Study

OBJECTIVES

Investigate associations of healthier behaviors with 30-yr cancer incidence.

SUBJECTS/METHODS

In 1982, 632 healthy men and women (ages 40-70) were interviewed for nutritional habits using a Food Frequency Questionnaire and a 24-h physical activity questionnaire. Blood pressure, weight, and height were measured, and blood was drawn for biochemical profiles. Thirteen and four subjects were excluded due to cancer diagnosis ≤1 yr from recruitment and extreme values of reported total daily calorie intake, respectively.

RESULTS

During a mean follow-up of 24.2 yr, 146 cancer incident patients (23.7%) were documented. Total cancer risk was 38% lower in the medium vegetable intake tertile [adjusted hazards ratio (HR) = 0.62, 95%confidence interval (CI): 0.40-0.95], and 66% higher in the medium fruit intake tertile (adjusted HR = 1.66, 95%CI: 1.08-2.55) compared to the lowest tertile. The risk of gastrointestinal cancers was 3 times greater for the highest, compared to the lowest, dairy consumption tertile (HR = 3.06, 95%CI: 1.01-9.23). "Healthy lifestyle" (normal BMI, never smoked, consuming high levels of dietary fiber and vegetables, and more physically active) reduced overall cancer risk (adjusted HR = 0.63, 95%CI: 0.44-0.91) as compared to the rest of the cohort.

CONCLUSIONS

Our findings reinforce the importance of lifestyle-related factors, which are relatively low-cost and may contribute to reduction in the burden of malignant diseases.

Red meat, poultry, and fish intake and breast cancer risk among Hispanic and Non-Hispanic white women: The Breast Cancer Health Disparities Study

PURPOSE

There is suggestive but limited evidence for a relationship between meat intake and breast cancer (BC) risk. Few studies included Hispanic women. We investigated the association between meats and fish intake and BC risk among Hispanic and NHW women.

METHODS

The study included NHW (1,982 cases and 2,218 controls) and the US Hispanics (1,777 cases and 2,218 controls) from two population-based case-control studies. Analyses considered menopausal status and percent Native American ancestry. We estimated pooled ORs combining harmonized data from both studies, and study- and race-/ethnicity-specific ORs that were combined using fixed or random effects models, depending on heterogeneity levels.

RESULTS

When comparing highest versus lowest tertile of intake, among NHW we observed an association between tuna intake and BC risk (pooled OR 1.25; 95 % CI 1.05-1.50; trend p = 0.006). Among Hispanics, we observed an association between BC risk and processed meat intake (pooled OR 1.42; 95% CI 1.18-1.71; trend p < 0.001), and between white meat (OR 0.80; 95% CI 0.67-0.95; trend p = 0.01) and BC risk, driven by poultry. All these findings were supported by meta-analysis using fixed or random effect models and were restricted to estrogen receptor-positive tumors. Processed meats and poultry were not associated with BC risk among NHW women; red meat and fish were not associated with BC risk in either race/ethnic groups.

CONCLUSIONS

Our results suggest the presence of ethnic differences in associations between meat and BC risk that may contribute to BC disparities.

Red and processed meat, nitrite, and heme iron intakes and postmenopausal breast cancer risk in the NIH-AARP Diet and Health Study

Previous studies have shown inconsistent associations between red and processed meat intake and breast cancer risk. N-nitroso compounds and heme iron have been hypothesized as contributing factors. We followed 193,742 postmenopausal women in the NIH-AARP Diet and Health Study and identified 9,305 incident breast cancers (1995-2006). Dietary intake was assessed using a food frequency questionnaire at baseline. We adjusted daily intakes of meat, nitrite and heme iron for energy intake using the nutrient density method. We estimated multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) by quintiles of dietary exposures for all breast cancer, by stage (in-situ, localized, regional/distant) and by estrogen/progesterone receptor (ER/PR) status using Cox proportional hazards regression. Total red meat intake was positively associated with risk of regional/distant cancer (p-trend = 0.02). The risk was 25% higher in the highest vs. lowest intake quintile (95% CI = 1.03-1.52). Higher processed red meat intake (Q5 vs. Q1) was associated with 27% higher risk of localized breast cancer (95% CI = 1.01-1.27, p-trend = 0.03) and a 19% higher risk of regional/distant cancer (95% CI = 0.98-1.44, p-trend = 0.10). In addition, higher nitrite intake from processed red meat was positively associated with localized cancer (HR for Q5 vs. Q1 = 1.23, 95% CI = 1.09-1.39, p-trend < 0.0001). Heme iron intake was positively associated with breast cancer risk overall and all cancer stages (p-trend = 0.02-0.05). No heterogeneity was observed in risk associations by hormone receptor status. Our findings suggest that high consumption of red meat and processed meat may increase risk of postmenopausal breast cancer. Added nitrite and heme iron may partly contribute to these observed associations.

Meat consumption and breast cancer: a case-control study in women

BACKGROUND

The relationship between meat intake and breast cancer has been inconsistent .

OBJECTIVE

The aim of this work was to evaluate the association between meat intake and breast cancer, in women.

DESIGN

A case-control study with 250 consecutive, newly diagnosed breast-cancer-female-patients (56 ± 12 years) and 250, one-to-one age-matched controls was conducted. A standardized, validated questionnaire assessing various socio-demographic, clinical, lifestyle and dietary characteristics was applied through face-to-face interviews. Data on consumption of red, white, processed and grilled meat were also recorded. Overall dietary habits were assessed through the level of adherence to the Mediterranean diet using the MedDietScore (theoretical range 0-55).

RESULTS

Processed meat intake, even for 1-2 times/week,was associated with a 2.7-fold (OR= 2.65, 95% CI 1.36, 5.14) (p= 0.004) higher likelihood of having breast cancer, while daily intake increased the likelihood by a 2.8-fold (OR = 2.81, 95% CI 1.13, 6.96) (p = 0.026), after various adjustments made. Red, white and grilled meat intake was not significantly associated with the outcome when the same adjustments were made.

CONCLUSIONS

This study suggested that only daily processed-meat intake was consistently associated with increased odds of breast-cancer.

Egg intake and cancers of the breast, ovary and prostate: a dose–response meta-analysis of prospective observational studies

Evidence suggests that egg intake may be implicated in the aetiology of sex hormone-related cancers. However, dose–response relationships between egg intake and such cancers are unclear. Thus, we conducted a dose–response meta-analysis to summarise the dose–response relationships between egg consumption and the risk of breast, prostate and gynaecological cancers. A literature search was performed using PubMed and Embase up to April 2015 to identify relevant prospective observational studies. Summary relative risk (RR) and 95 % CI were estimated using a random-effects model. For breast cancer, the linear dose–response meta-analysis found a non-significantly increased risk (RR for an increase of 5 eggs consumed/week: 1·05, 95 % CI 0·99, 1·11, n 16 023 cases). Evidence for non-linearity was not statistically significant (Pnon-linearity= 0·50, n 15 415 cases) but consuming ≥ 5 eggs/week was significantly associated with an increased risk of breast cancer compared with no egg consumption, with the summary RR being 1·04 (95 % CI 1·01, 1·07) for consuming 5 eggs/week and 1·09 (95 % CI 1·03, 1·15) for consuming about 9 eggs/week. For other cancers investigated, the summary RR for an increase of 5 eggs consumed/week was 1·09 (95 % CI 0·96, 1·24, n 2636 cases) for ovarian cancer; 1·47 (95 % CI 1·01, 2·14, n 609 cases) for fatal prostate cancer, with evidence of small-study effects (PEgger= 0·04). No evidence was found for an association with the risk of total prostate cancer. While our conclusion was tempered by the potential for publication bias and confounding, high egg intake may be associated with a modestly elevated risk of breast cancer, and a positive association between egg intake and ovarian and fatal prostate cancers cannot be ruled out.

Adaptation to Lactose in Lactase Non Persistent People: Effects on Intolerance and the Relationship between Dairy Food Consumption and Evalution of Diseases

Dairy foods contain complex nutrients which interact with the host. Yet, evolution of lactase persistence has divided the human species into those that can or cannot digest lactose in adulthood. Such a ubiquitous trait has differential effects on humanity. The literature is reviewed to explore how the divide affects lactose handling by lactase non persistent persons. There are two basic differences in digesters. Firstly, maldigesters consume less dairy foods, and secondly, excess lactose is digested by colonic microflora. Lactose intolerance in maldigesters may occur with random lactose ingestion. However, lactose intolerance without maldigestion tends to detract from gaining a clear understanding of the mechanisms of symptoms formation and leads to confusion with regards to dairy food consumption. The main consequence of intolerance is withholding dairy foods. However, regular dairy food consumption by lactase non persistent people could lead to colonic adaptation by the microbiome. This process may mimic a prebiotic effect and allows lactase non persistent people to consume more dairy foods enhancing a favorable microbiome. This process then could lead to alterations in outcome of diseases in response to dairy foods in lactose maldigesters. The evidence that lactose is a selective human prebiotic is reviewed and current links between dairy foods and some diseases are discussed within this context. Colonic adaptation has not been adequately studied, especially with modern microbiological techniques.

Role of poultry meat in a balanced diet aimed at maintaining health and wellbeing: an Italian consensus document

The relationship between the consumption of meat and health is multifaceted, and it needs to be analyzed in detail, with specific attention to the relevant differences that characterize the effects of the different meat types, as yet considered by only a limited literature. A variable but moderate energy content, highly digestible proteins (with low levels of collagen) of good nutritional quality, unsaturated lipids (mainly found in the skin and easily removed), B-group vitamins (mainly thiamin, vitamin B6, and pantothenic acid), and minerals (like iron, zinc, and copper) make poultry meat a valuable food. Epidemiological studies performed across the world, in highly diverse populations with different food preferences and nutritional habits, provide solid information on the association between poultry consumption, within a balanced diet, and good health. Consumption of poultry meat, as part of a vegetable-rich diet, is associated with a risk reduction of developing overweight and obesity, cardiovascular diseases, and type 2 diabetes mellitus. Also, white meat (and poultry in particular) is considered moderately protective or neutral on cancer risk. The relevance of poultry meat for humans also has been recognized by the UN Food and Agricultural Organization (FAO), who considers this widely available, relatively inexpensive food to be particularly useful in developing countries, where it can help to meet shortfalls in essential nutrients. Moreover, poultry meat consumption also contributes to the overall quality of the diet in specific ages and conditions (prior to conception, during pregnancy up to the end of breastfeeding, during growth, and in the geriatric age) and is suitable for those who have an increased need for calorie and protein compared to the general population.

Vitamin D in cancer chemoprevention

CONTEXT

There is increasing evidence that Vitamin D (Vit D) and its metabolites, besides their well-known calcium-related functions, may also exert antiproliferative, pro-differentiating, and immune modulatory effects on tumor cells in vitro and may also delay tumor growth in vivo.

OBJECTIVE

The aim of this review is to provide fresh insight into the most recent advances on the role of Vit D and its analogues as chemopreventive drugs in cancer therapy.

METHODS

A systematic review of experimental and clinical studies on Vit D and cancer was undertaken by using the major electronic health database including ISI Web of Science, Medline, PubMed, Scopus and Google Scholar.

RESULTS AND CONCLUSION

Experimental and clinical observations suggest that Vit D and its analogues may be effective in preventing the malignant transformation and/or the progression of various types of human tumors including breast cancer, prostate cancer, colorectal cancer, and some hematological malignances. These findings suggest the possibility of the clinical use of these molecules as novel potential chemopreventive and anticancer agents.

Adult lactose digestion status and effects on disease

BACKGROUND

Adult assimilation of lactose divides humans into dominant lactase-persistent and recessive nonpersistent phenotypes.

OBJECTIVES

To review three medical parameters of lactose digestion, namely: the changing concept of lactose intolerance; the possible impact on diseases of microbial adaptation in lactase-nonpersistent populations; and the possibility that the evolution of lactase has influenced some disease pattern distributions.

METHODS

A PubMed, Google Scholar and manual review of articles were used to provide a narrative review of the topic.

RESULTS

The concept of lactose intolerance is changing and merging with food intolerances. Microbial adaptation to regular lactose consumption in lactase-nonpersistent individuals is supported by limited evidence. There is evidence suggestive of a relationship among geographical distributions of latitude, sunhine exposure and lactase proportional distributions worldwide.

DISCUSSION

The definition of lactose intolerance has shifted away from association with lactose maldigestion. Lactose sensitivity is described equally in lactose digesters and maldigesters. The important medical consequence of withholding dairy foods could have a detrimental impact on several diseases; in addition, microbial adaptation in lactase-nonpersistent populations may alter risk for some diseases. There is suggestive evidence that the emergence of lactase persistence, together with human migrations before and after the emergence of lactase persistence, have impacted modern-day diseases.

CONCLUSIONS

Lactose maldigestion and lactose intolerance are not synonymous. Withholding dairy foods is a poor method to treat lactose intolerance. Further epidemiological work could shed light on the possible effects of microbial adaptation in lactose maldigesters. The evolutionary impact of lactase may be still ongoing.

Adolescent meat intake and breast cancer risk

The breast is particularly vulnerable to carcinogenic influences during adolescence due to rapid proliferation of mammary cells and lack of terminal differentiation. We investigated consumption of adolescent red meat and other protein sources in relation to breast cancer risk in the Nurses' Health Study II cohort. We followed prospectively 44,231 women aged 33-52 years who, in 1998, completed a detailed questionnaire about diet during adolescence. Relative risks (RR) and 95% confidence intervals (95%CI) were estimated using Cox proportional hazard regression. We documented 1132 breast cancer cases during 13-year follow-up. In multivariable Cox regression models with major breast cancer risk factors adjustment, greater consumption of total red meat in adolescence was significantly associated with higher premenopausal breast cancer risk (highest vs. lowest quintiles, RR, 1.43; 95%CI, 1.05-1.94; Ptrend  = 0.007), but not postmenopausal breast cancer. Adolescent intake of poultry was associated with lower risk of breast cancer overall (RR, 0.76; 95%CI, 0.60-0.97; for each serving/day). Adolescent intakes of iron, heme iron, fish, eggs, legumes and nuts were not associated with breast cancer. Replacement of one serving/day of total red meat with one serving of combination of poultry, fish, legumes, and nuts was associated with a 15% lower risk of breast cancer overall (RR, 0.85; 95%CI, 0.74-0.96) and a 23% lower risk of premenopausal breast cancer (RR, 0.77; 95%CI, 0.64-0.92). In conclusion, higher consumption of red meat during adolescence was associated with premenopausal breast cancer. Substituting other dietary protein sources for red meat in adolescent diet may decrease premenopausal breast cancer risk.

Dietary protein sources in early adulthood and breast cancer incidence: prospective cohort study

OBJECTIVE

To investigate the association between dietary protein sources in early adulthood and risk of breast cancer.

DESIGN

Prospective cohort study.

SETTING

Health professionals in the United States.

PARTICIPANTS

88,803 premenopausal women from the Nurses' Health Study II who completed a questionnaire on diet in 1991.

MAIN OUTCOME MEASURE

Incident cases of invasive breast carcinoma, identified through self report and confirmed by pathology report.

RESULTS

We documented 2830 cases of breast cancer during 20 years of follow-up. Higher intake of total red meat was associated with an increased risk of breast cancer overall (relative risk 1.22, 95% confidence interval 1.06 to 1.40; P(trend) = 0.01, for highest fifth v lowest fifth of intake). However, higher intakes of poultry, fish, eggs, legumes, and nuts were not related to breast cancer overall. When the association was evaluated by menopausal status, higher intake of poultry was associated with a lower risk of breast cancer in postmenopausal women (0.73, 0.58 to 0.91; P(trend) =0.02, for highest fifth v lowest fifth of intake) but not in premenopausal women (0.93, 0.78 to 1.11; P(trend) = 0.60, for highest fifth v lowest fifth of intake). In estimating the effects of exchanging different protein sources, substituting one serving/day of legumes for one serving/day of red meat was associated with a 15% lower risk of breast cancer among all women (0.85, 0.73 to 0.98) and a 19% lower risk among premenopausal women (0.81, 0.66 to 0.99). Also, substituting one serving/day of poultry for one serving/day of red meat was associated with a 17% lower risk of breast cancer overall (0.83, 0.72 to 0.96) and a 24% lower risk of postmenopausal breast cancer (0.76, 0.59 to 0.99). Furthermore, substituting one serving/day of combined legumes, nuts, poultry, and fish for one serving/day of red meat was associated with a 14% lower risk of breast cancer overall (0.86, 0.78 to 0.94) and premenopausal breast cancer (0.86, 0.76 to 0.98).

CONCLUSION

Higher red meat intake in early adulthood may be a risk factor for breast cancer, and replacing red meat with a combination of legumes, poultry, nuts and fish may reduce the risk of breast cancer.