Dietary patterns, Mediterranean diet, and endometrial cancer risk

Total Sialic Acid, Antioxidant Enzyme Activities, Trace Elements, and Vitamin Status Before and After Surgery in Women with Uterine Myoma and Endometrial Cancer

The objective of present study was to examine endometrial tissue Be, As, Cr, Mo, Sr, Ti, Tl, Cu, Co, Se, Zn, Mn, Fe, Cd, Pb, Mg, P, erythrocytes CAT, SOD, GSH-Px, GSH, MDA, serum retinol, cholecalciferol, phylloquinone, TSA, LSA, TOS, and TAS status and to evaluate the relationships between the variables. The study had 110 participants; of these, 50 were women with uterine myoma (UM), 10 were women with endometrial cancer (EC), and 50 were healthy female subjects. In the study, vitamin analyses by HPLC and element analyses were determined using ICP-OES method. It was observed that EC group was significantly lower than healthy group in terms of levels of cholecalciferol (p < 0.05), phylloquinone (p < 0.01), GSH (p < 0.05), Fe (p < 0.05), and had a significant rise in Mg/Fe (p < 0.01) and Zn/Fe (p < 0.05) in preoperative period. UM group had significantly lower retinol (p < 0.05), phylloquinone (p < 0.001), GSH-Px (p < 0.01), GSH (p < 0.01), Cr (p < 0.01), Cu (p < 0.05), Mg (p < 0.01), and Zn (p < 0.01) levels than control group in preoperative period and significantly higher levels of MDA (p < 0.01), TSA (p < 0.01), and LSA (p < 0.01) than control group. It was found that significant associations were observed between Cu-CA 15-3 (r = 0.558, p = 0.016), Mn-CA 15-3 (r = 0.511, p = 0.030), P-CA 15-3(r =  - 0.502, p = 0.034) and with UM, also between GSH-CA-125 (r =  - 0.825, p = 0.022) and with EC group. The results of correlation analysis observed that concentrations of Cu, Mn, P, and GSH together with CA 15-3 and CA-125 levels might be important for monitoring patients with UM and EC before surgery.

The influence of dietary vegetables and fruits on endometrial cancer risk: a meta-analysis of observational studies

Fruits and vegetables store many bioactive compounds and micronutrients, making their consumption ideal for maintaining good health. A previous meta-analysis in 2007 provided evidence that high vegetable and cruciferous vegetable intake might help prevent endometrial cancer (EC) development. The current study purposely explored the favorable effects of vegetables, fruits, and their other specific types using a review of the most recent papers. We conducted a systematic search through August 2021 in the PubMed and EMBASE databases on this topic, through which twenty-seven studies, consisting of 21 case-control and 6 cohort studies, were obtained. The results showed that vegetables (pooled odds ratio [OR], relative risk [RR], hazard ratio [HR] = 0.76, 95% confidence interval [CI] 0.63-0.91), cruciferous vegetables (pooled OR = 0.81, 95% CI 0.70-0.94), dark green and yellow/orange combined vegetables (pooled OR = 0.64, 95% CI 0.42-0.97), and fruits (pooled OR = 0.81, 95% CI 0.70-0.92) were strongly associated with a reduced risk of EC. These results were primarily based on studies of high quality and exhibited either by case-control only or a combination of case-control and cohort studies. Additionally, the results varied by geographic location, such as Western areas, the US, and Italy. This meta-analysis suggested that the consumption of fruits and vegetables has beneficial effects on EC risk and that specific kinds of fruits and vegetables should be recommended differently due to their outstanding bioactive components.

Diabetes Risk Reduction Diet and Endometrial Cancer Risk

Diabetes increases endometrial cancer risk. We investigated the role of a diabetes risk reduction diet (DRRD) on the risk of endometrial cancer using data from a multicentric, Italian hospital-based case-control study (1992-2006) enrolling 454 histologically confirmed cases of endometrial cancer and 908 controls matched by age and center. We derived a DRRD score assigning higher scores for higher intakes of cereal fiber, fruit, coffee, polyunsaturated:saturated fatty acid ratio, and nuts and for lower glycemic load and lower intakes of red/processed meat and sugar-sweetened beverages/fruit juices. The odds ratios (OR) of endometrial cancer according to the DRRD score were derived by multiple conditional logistic regression models. The OR for high (DRRD score >24, i.e., third tertile) versus medium-low adherence to the DRRD was 0.73 (95% confidence interval, CI, 0.55-0.97). Similar results were observed after the exclusion of diabetic women (OR 0.75; 95% CI, 0.56-1.00) and allowance for total vegetable consumption (OR 0.80; 95% CI, 0.60-1.07). Inverse associations were observed in most of the analyzed subgroups. The OR for high DRRD combined with high vegetable consumption was 0.45 (95% CI, 0.28-0.73). Our results suggest that diets able to reduce diabetes risk may also reduce endometrial cancer risk. High vegetable consumption combined with high adherence to the DRRD may provide additional benefit in endometrial cancer prevention.

Association Between Diet Quality and Risk of Ovarian and Endometrial Cancers: A Systematic Review of Epidemiological Studies

Objectives

The relationship between diet quality indices and risk of ovarian and endometrial cancers were unclear. We aimed at conducting a systematic review to evaluate the epidemiological evidence.

Methods

Embase, PubMed, Web of Science and Scopus databases were searched for eligible studies up to December 2020. Epidemiological studies reported the association of the diet quality with risk of ovarian and endometrial cancers were evaluated.

Results

Eleven eligible studies were identified, of which six studies were case-control studies, four were cohort studies, and one was case-cohort study. All studies were considered as high-quality with low risk of bias. Seven studies evaluated the association of diet quality with risk of ovarian cancer. Four studies reported null association for diet quality indices such as Healthy Eating Index (HEI)-2005, HEI-2010, Mediterranean Diet Score (MDS) and Recommended Foods Score (RFS). Two studies reported significantly inverse association for Alternate Healthy Eating Index (AHEI)-2010 and Healthy Diet Score (HDS) indices. One study reported significantly increased risk of ovarian cancer associated with higher level of Dietary Guidelines for Americans Index. Dose-response analysis showed pooled relative risks of 0.98 (95%Cl: 0.95, 1.01) and 0.94 (95%Cl: 0.77, 1.13) for each 10 points increase in the HEI-2005 and AHEI-2010 indices. Seven studies evaluated the association of diet quality with risk of endometrial cancer. Three studies reported significantly inverse association of diet quality as assessed by the MDS and Diet Score Quintiles with risk of endometrial cancer. Four studies reported null association for other diet quality indices including HEI-2005, HEI-2010, RFS and HDS. Dose-response analysis showed a pooled relative risk of 0.87 (95%CI: 0.81, 0.93) for one unit increment of the MDS.

Conclusion

This study suggests little evidence on the association between diet quality and risk of ovarian cancer. Adherence to high quality diet, as assessed by MDS, might be associated with lower the risk of endometrial cancer.

A Narrative Review of the Role of Diet and Lifestyle Factors in the Development and Prevention of Endometrial Cancer

Simple Summary

The incidence and prevalence of endometrial cancer is increasing globally. The main factors involved in this increase have been the way women live today and what they eat and drink. In fact, the obesity pandemic that is sweeping across the planet is considered to be the main contributory feature. This review aims to introduce to a new audience, those that are not experts in the field, what is known about the different types of endometrial cancer and the mechanisms for their induction and protection. We also seek to summarise the existing knowledge on dietary and lifestyle factors that prevent endometrial development in susceptible populations and identify the main problem in this arena; the paucity of research studies and clinical trials that investigate the interaction(s) between diet, lifestyle and endometrial cancer risk whilst highlighting those areas of promise that should be further investigated.

Abstract

Endometrial cancer is the most common cancer affecting the reproductive organs of women living in higher-income countries. Apart from hormonal influences and genetic predisposition, obesity and metabolic syndrome are increasingly recognised as major factors in endometrial cancer risk, due to changes in lifestyle and diet, whereby high glycaemic index and lipid deposition are prevalent. This is especially true in countries where micronutrients, such as vitamins and minerals are exchanged for high calorific diets and a sedentary lifestyle. In this review, we will survey the currently known lifestyle factors, dietary requirements and hormonal changes that increase an individual’s risk for endometrial cancer and discuss their relevance for clinical management. We also examine the evidence that everyday factors and clinical interventions have on reducing that risk, such that informed healthy choices can be made. In this narrative review, we thus summarise the dietary and lifestyle factors that promote and prevent the incidence of endometrial cancer.

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.

Benefits of the Mediterranean diet: Epidemiological and molecular aspects

More than 50 years after the Seven Countries Study, a large number of epidemiological studies have explored the relationship between the Mediterranean diet (MD) and health, through observational, case-control, some longitudinal and a few experimental studies. The overall results show strong evidence suggesting a protective effect of the MD mainly on the risk of cardiovascular disease (CVD) and certain types of cancer. The beneficial effects have been attributed to the types of food consumed, total dietary pattern, components in the food, cooking techniques, eating behaviors and lifestyle behaviors, among others. The aim of this article is to review and summarize the knowledge derived from the literature focusing on the benefits of the MD on health, including those that have been extensively investigated (CVD, cancer) along with more recent issues such as mental health, immunity, quality of life, etc. The review begins with a brief description of the MD and its components. Then we present a review of studies evaluating metabolic biomarkers and genotypes in relation to the MD. Other sections are dedicated to observation and intervention studies for various pathologies. Finally, some insights into the relationship between the MD and sustainability are explored. In conclusion, the research undertaken on metabolomics approaches has identified potential markers for certain MD components and patterns, but more investigation is needed to obtain valid measures. Further evaluation of gene-MD interactions are also required to better understand the mechanisms by which the MD diet exerts its beneficial effects on health. Observation and intervention studies, particularly PREDIMED, have provided invaluable data on the benefits of the MD for a wide range of chronic diseases. However further research is needed to explore the effects of other lifestyle components associated with Mediterranean populations, its environmental impact, as well as the MD extrapolation to non-Mediterranean contexts.

The relation of healthy and Western dietary patterns to the risk of endometrial and ovarian cancers: a systematic review and meta-analysis

Dietary patterns have been used to explore the association between dietary factors and risk of endometrial (EC) and ovarian cancer (OC); however, the results are inconclusive. This meta-analysis aimed to analyze these associations. Methods: Pertinent studies published prior to March 2016 were systematically searched. The common dietary patterns were selected and adjusted risk estimates were derived by comparing the highest with the lowest categories of dietary pattern scores. Results: A total of 8 studies, 5 for endometrial cancer (1 cohort and 4 case-control studies including 2617 cases and 78082 participants/controls) and 3 for ovarian cancer (1 cohort and 2 case-control studies with 2025 cases and 101482 participants/controls) were included in this meta-analysis. A lower risk of EC was shown for the highest compared with the lowest category of the healthy dietary pattern (OR = 0.84, 95% CI: 0.72-0.98; P for heterogeneity = 0.10), whereas the Western dietary pattern was related to the higher risk of EC (OR = 1.19, 95% CI: 1.01-1.41; P for heterogeneity = 0.35). No significant relationship was found between the healthy dietary pattern (OR = 1.03, 95% CI: 0.69-1.53; P for heterogeneity = 0.01) and OC, while, adherence to the western pattern was associated with a 73% higher risk of OC (OR = 1.73, 95% CI: 1.08-2.37; P for heterogeneity = 0.06). Conclusion: A Western dietary pattern might be associated with a higher risk of endometrial and ovarian cancer.

The Relationship between Dietary Patterns with Blood Pressure in Iranian Army Staffs

Background:

Hypertension is one of the most common noncommunicable diseases in the world. One of the most effective factors on blood pressure (BP) is nutrition. The aim of this study was to examine the relationship between dietary patterns and BP among military staffs.

Materials and Methods:

The study was carried out among 405 military staffs between 22 and 51 years old. Demographic, anthropometric information, and BP of participants were evaluated by standard methods. The dietary intakes were collected using a food frequency questionnaire (FFQ). Dietary patterns were identified using a posteriori method, factor analysis, and based on the FFQ. To check the relationship between BP and dietary patterns, we used multivariate linear regression in different models, relationship were adjusted for Age, sex, marital, smoking, income, body mass index, waist-to-hip ratio, family history of hypertension, energy intake, and physical activity level.

Results:

Two dominant dietary patterns were identified in the participants: Healthy and western pattern. The association of dietary patterns with systolic BP (SBP) and diastolic BP (DBP) was exhibited in different models. There was no relationship between SBP and DBP with healthy pattern (P = 0.269 and P = 0.638, respectively) and western pattern (P = 0.648 and P = 0.315, respectively) after adjustments.

Conclusion:

Our findings indicated that dietary patterns did not have any significant relationship with SBP and DBP after adjustment for confounders in the healthy military. To identify the dietary patterns associated with BP in healthy military, more strong design studies and more participants should be conducted in the future.

Impact of Mediterranean Diet on Cancer: Focused Literature Review

BACKGROUND

Cancer is a major public health problem worldwide, and the number of incident cases increases every year expected to reach 17.1 million a year by 2020. There is evidence that people who adhere to the Mediterranean Diet (MediD) have lower incidence of cancer. However, cancers' location and culture studies seem to affect the MediD impact. We aimed to review these discrepant findings.

MATERIALS AND METHODS

A critical review from a focused literature search was conducted. A literature search of controlled trials from: EMBASE (1970-), MEDLINE (1950-) and PsycINFO (1960-) was undertaken. Two authors (DF and YB) independently extracted the data.

RESULTS

Out of 785 abstracts identified only 583 publications focused solely on MediD and cancer. Of these, 46 were clinical trials published since 2007. Twenty-eight trials with a total of 570,262 participants are included in accordance with inclusion criteria. Only four reported the MediD does not reduce the risk of cancer. Of the negative studies, three were undertaken in non-Mediterranean populations. Cancers of the digestive tract were studied in 11 studies. Except for pancreatic cancer, all other sites along the digestive tract demonstrated significantly reduced rate with the MediD.

CONCLUSION

The MediD is associated with reduction in overall cancer rates as well as significantly lower rates of digestive tract cancers. These effects may be accentuated in the Mediterranean countries themselves. Further studies are needed to support or refute the effects of the MediD on other cancer types.

Association between Dietary Isoflavones in Soy and Legumes and Endometrial Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Epidemiologic studies have reported conflicting findings between soy- and legume-derived dietary isoflavones and risk of endometrial cancer.

OBJECTIVE

The aim of the present meta-analysis was to quantitatively investigate the association between daily intake of soy- and legume-derived isoflavones and risk of endometrial cancer.

DESIGN

A broad search was conducted in the following electronic databases: PubMed, EMBASE, Google Scholar, the Cochrane Library, the China Knowledge Resource Integrated Database, and the Chinese Biomedical Database based on combinations of the key words endometrial cancer, isoflavone, soy, and legume for epidemiologic studies that focused on relationships between dietary isoflavones and endometrial cancer risk. A fixed-effect or random-effect model was used to pool study-specific risk estimates.

RESULTS

A total of 13 epidemiologic studies were included in the present meta-analysis, consisting of three prospective cohort studies and 10 population-based case-control studies. The final results indicated that higher dietary isoflavone levels from soy products and legumes were associated with a reduced risk of endometrial cancer (odds ratio [OR] 0.81, 95% CI 0.74 to 0.89). Low heterogeneous bias was observed (I2=11.7%; P=0.327). Subgroup analyses were conducted based on study design, source of dietary isoflavones, and study region. When restricted to study design, dietary isoflavones from soy and legumes played a role in prevention of endometrial cancer in case-control studies (OR 0.81, 95% CI 0.73 to 0.90). However, there did not appear to be an association between dietary isoflavones and endometrial cancer in cohort studies (OR 0.81, 95% CI 0.66 to 1.00). Significant associations were found between dietary isoflavones from soy products (OR 0.82, 95% CI 0.72 to 0.92) and legumes (OR 0.84, 95% CI 0.74 to 0.96) and endometrial cancer. Dietary isoflavones were associated with reduced incidence of endometrial cancer, both in Asian countries (OR 0.78, 95% CI 0.66 to 0.93) and non-Asian countries (OR 0.82, 95% CI 0.73 to 0.92).

CONCLUSIONS

The findings suggest a weak inverse association between higher consumption of dietary isoflavones from soy products and legumes and endometrial cancer risk. However, there is still a need for large, prospective epidemiologic studies that provide a higher level of evidence to verify these findings.

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.

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.

The anticancer and antiobesity effects of Mediterranean diet

Cancers have been the leading cause of death worldwide and the prevalence of obesity is also increasing in these few decades. Interestingly, there is a direct association between cancer and obesity. Each year, more than 90,000 cancer deaths are caused by obesity or overweight. The dietary pattern in Crete, referred as the traditional Mediterranean diet, is believed to confer Crete people the low mortality rates from cancers. Nevertheless, the antiobesity effect of the Mediterranean diet is less studied. Given the causal relationship between obesity and cancer, the antiobesity effect of traditional Mediterranean diet might contribute to its anticancer effects. In this regard, we will critically review the anticancer and antiobesity effects of this diet and its dietary factors. The possible mechanisms underlying these effects will also be discussed.

Olive oil exhibits osteoprotection in ovariectomized rats without estrogenic effects

The present study was designed to evaluate the effect of olive oil on bone and uterus in ovariectomized rats. A total of 34 surgically ovariectomized or sham-operated virgin Sprague-Dawley rats were divided into four groups: i) Sham-operated control rats (sham group); ii) Ovariectomized rats (OVX group); iii) Olive oil-supplemented ovariectomized rats (olive group); and iv) Diethylstilbestrol-supplemented ovariectomized rats (E₂ group). At 12 weeks following left ventricular blood sacrificed to detect plasma estradiol (E₂), interleukin-1β (IL-1β) and IL-6 levels. Bone mineral density (BMD) of the lumbar spine was evaluated using dual-energy X-ray absorptiometry, and the left femur proximal 1/3 slices were observed using transmission electron microscopy. Uterine wet weight and the uterus index (ratio of uterine wet weight and body weight) were compared, and the uterine endometrium was observed using a light microscope. In the OVX group, serum E₂ was significantly lower and IL-1β and IL-6 levels were significantly higher compared with the sham group. By contrast, serum E₂ levels increased and IL-1β levels decreased in the olive group, but showed no significant difference compared with the sham group. The lumbar spine BMD in the olive group was increased compared with OVX group. Electron microscopy revealed sparse collagen fibers in the OVX group, with decreased density and multi-cavity, showing pathological features of osteoporosis. By contrast, the situation was improved in the E₂ and olive groups, in which organelles such as the rough endoplasmic reticulum, mitochondria and Golgi apparatus were visible and active. Compared with the sham group rats, the uterine wet weight and uterine index decreased in the OVX and olive groups; however, no statistically significant difference was observed in the E₂ group. Furthermore, endometrial hyperplasia was not observed in the olive group, which were apparently different from E₂ group. The present results suggest that olive oil can effectively reduce bone loss in ovariectomized rats, and with no or only mild effects on the uterine endothelium.

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).

Mediterranean diet and risk of endometrial cancer: a pooled analysis of three Italian case-control studies

BACKGROUND

Some components of the Mediterranean diet have favourable effects on endometrial cancer, and the Mediterranean diet as a whole has been shown to have a beneficial role on various neoplasms.

METHODS

We analysed this issue pooling data from three case-control studies carried out between 1983 and 2006 in various Italian areas and in the Swiss Canton of Vaud. Cases were 1411 women with incident, histologically confirmed endometrial cancer, and controls were 3668 patients in hospital for acute diseases. We measured the adherence to the Mediterranean diet using a Mediterranean Diet Score (MDS), based on the nine dietary components characteristics of this diet, that is, high intake of vegetables, fruits/nuts, cereals, legumes, fish; low intake of dairy products and meat; high monounsaturated to saturated fatty acid ratio; and moderate alcohol intake. We estimated the odds ratios (OR) and the corresponding 95% confidence intervals (CI) for increasing levels of the MDS (varying from 0, no adherence, to 9, maximum adherence) using multiple logistic regression models, adjusted for major confounding factors.

RESULTS

The adjusted OR for a 6-9 components of the MDS (high adherence) compared with 0-3 (low adherence) was 0.43 (95% CI 0.34-0.56). The OR for an increment of one component of MDS diet was 0.84 (95% CI 0.80-0.88). The association was consistent in strata of various covariates, although somewhat stronger in older women, in never oral contraceptive users and in hormone-replacement therapy users.

CONCLUSIONS

Our study provides evidence for a beneficial role of the Mediterranean diet on endometrial cancer risk, suggesting a favourable effect of a combination of foods rich in antioxidants, fibres, phytochemicals, and unsaturated fatty acids.

Red meat intake and the risk of endometrial cancer: Meta-analysis of observational studies

AIM: To evaluate whether red meat intake is related to the risk of endometrial cancer (EC) using meta-analysis.

METHODS: We searched PubMed, EMBASE, and the Cochrane Library up to June 2013, using common keywords related to red meat and EC. Case-control studies and cohort studies comparing the risk of endometrial cancer among categories by the amount of intake were included. Eleven case-control studies and five cohort studies met our criteria. We performed a conventional and a dose-response meta-analysis of case-control studies using the DerSimonian-Laird method for random-effects. For cohort studies we performed a conventional meta-analysis. Publication bias was evaluated using Egger’s test.

RESULTS: In the meta-analysis of 11 case-control studies including 5419 cases and 12654 controls, higher red meat consumption was associated with an increased risk of EC [summary relative risk (SRR) = 1.43, 95%CI: 1.15-1.79; I² = 73.3% comparing extreme intake categories). In a dose-response analysis, for red meat intake of 100 g/d, SRR was 1.84 (95%CI: 1.64-2.05). In contrast, in the meta-analysis of five prospective studies including a total of 2549 cases among 247746 participants, no significant association between red meat intake and EC risk (SRR = 0.97, 95%CI: 0.85-1.11; I² = 4.9% comparing extreme intake categories) was observed.

CONCLUSION: Our meta-analysis found a significant linear association between red meat intake and EC risk based on case-control studies but this was not confirmed in prospective studies.

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

PURPOSE

Information on the role of dietary patterns and endometrial cancer risk is limited. We investigated whether dietary patterns are associated with endometrial cancer risk among women in the California Teachers Study cohort.

METHODS

Among 75,093 eligible women, 937 developed invasive endometrial cancer between 1995 and 2011. Multivariate Cox regression was performed to estimate relative risks (RR) and 95% confidence intervals (CI) associated with five dietary patterns identified by principal components factor analysis: "plant-based," "high protein/high fat," "high carbohydrates," "ethnic," and "salad and wine."

RESULTS

These dietary patterns were not associated with endometrial cancer risk overall (RR = 0.91, 95% CI: 0.72, 1.15 for the highest vs. lowest quintile of the "plant-based" dietary pattern) or by menopausal status and hormone therapy use.

CONCLUSIONS

Dietary patterns do not seem to be associated with endometrial cancer risk.

Mediterranean diet and cancer: epidemiological evidence and mechanism of selected aspects

Background

Populations living in the area of the Mediterranean Sea suffered by decreased incidence of cancer compared with those living in the regions of northern Europe and US countries, attributed to healthier dietary habits. Nowadays, we are assisting to a moving away from the traditional Mediterranean dietary pattern, but whether this changing is influencing risk of cancers is still unclear. The aim of the study was to review recent evidence on potential relationship between the adherence to the Mediterranean diet and cancer.

Discussion

The most recent pooled analyses of epidemiological studies supported strongly the hypothesis that the Mediterranean diet may play a role in preventing several types of cancers, especially those of digestive tract, whereas contrasting results were reported for hormone-dependent cancers. Specific aspects of the Mediterranean diet such as high fruit and vegetables and low red processed meat intake may explain such protective effects. Moreover, evidence regarding olive oil and whole grains increase the beneficial effects of such dietary pattern against cancer.

Conclusions

Literature evidence actually demonstrates that the increased adherence to the Mediterranean dietary pattern is beneficial to health across populations and may translate a protective effect with certain cancers.

Assessment of the estrogenicity of the diet of a healthy female Spanish population based on its isoflavone content

Phytoestrogens are natural components of plants consumed by humans. The hormonal activity of these substances has long been known. Various in vitro tests have demonstrated the agonistic or antagonistic estrogenic activity of some phytoestrogens. The objective of this study was to estimate the supply of isoflavones in the diet of a healthy adult female population and to assess its estrogenic effect. The diet was assessed by questionnaire and the estrogenicity of the estimated isoflavone content was tested by E-screen, finding a mean total estrogenic capacity of 0.129 × 10⁻¹⁰ eq.E₂ (12.9 pmol day⁻¹), corresponding to a daily isoflavone intake of 265.8 μg day⁻¹. This study offers a preliminary insight into the phytoestrogen content of the diet of a healthy active population of Spanish women. The effects of this additional hormonal burden are highly controversial, and this approach to estimating dietary phytoestrogen intake of specific populations may help to elucidate its implications for human health.

Assessment of the effects of severe obesity and lifestyle risk factors on stage of endometrial cancer

BACKGROUND

Lifestyle risk factors, including obesity, have been associated with increased risk of endometrial cancer (EC). Women with higher obesity levels tend to have less aggressive EC disease stage and histology. This study further investigated associations between nonmodifiable risk factors, such as age, race, and grade, and modifiable lifestyle factors, such as diet and physical activity expenditure, in relation to severe obesity and late versus early EC stage at diagnosis.

METHODS

Demographic, anthropometric, and lifestyle surveys were administered to 177 women with histologically confirmed EC. Logistic regression analyses assessed the relationship between obesity and other risk factors on EC stage at diagnosis.

RESULTS

In multivariate models, body mass index (BMI) < 35 was not significantly associated with late EC stage at diagnosis (OR = 1.67, P = 0.219) when adjusting for grade and age. Grade was significantly associated with EC stage when controlling for BMI and age (OR = 8.48, P = .000). Women more than the age of 60 had a fourfold increased risk of diagnosis at late versus early EC stage when adjusting for other risk factors. Age had a confounding effect on the obesity-EC stage association.

CONCLUSIONS

Our results corroborate those of past studies showing that BMI is not an independent risk factor for EC stage and that age may have confounded the obesity-EC stage association. Because of mixed results and implications for treatment outcomes, however, further research examining these variables is warranted.

IMPACT

Our results provide further insight into the obesity EC-stage association, especially the confounding effect of age. Future studies should examine modifiable lifestyle factors in larger and more diverse populations.

Case-control study of dietary patterns and endometrial cancer risk

Dietary patterns, rather than intakes of specific foods or nutrients, may influence risk of endometrial cancer (EC). This population-based case-control study in Canada (2002-2006) included incident EC cases (n = 506) from the Alberta Cancer Registry and controls frequency age-matched to cases (n = 981). Past-year dietary patterns were defined using factor analysis of food frequency questionnaire data. Logistic regression was used to estimate EC risk within quartiles of dietary patterns. Three patterns (sweets, meat, plants) explained 23% of the variance in the dietary data. In multivariable models, EC risk was significantly reduced by 30% for women in the highest quartile of the healthier plants pattern (OR = 0.70, 95% CI 0.50-0.98, P trend = 0.02). When stratified by body mass index (BMI; kg/m(2)), risk was further reduced among overweight or obese women with a BMI ≥25 (OR = 0.57, 95% CI 0.39-0.83; P trend = 0.004). EC was not associated with the less healthy sweets and meat patterns. However, risk was modestly, but not significantly, elevated for higher intakes of the meat pattern among overweight or obese women. A mostly plant-based dietary pattern may reduce EC risk. Recommendations for risk reduction should focus on maintaining a healthy weight and the role of diet should be studied further.

Intake of fruits and vegetables, and risk of endometrial cancer in the NIH-AARP Diet and Health Study

BACKGROUND

Fruits and vegetables contain a wide variety of phytochemicals which may have anti-carcinogenic effects. Although the results of case-control studies have suggested a possible protective effect of fruit and vegetable intake on the risk of endometrial carcinoma, few cohort studies have examined this association.

MATERIALS AND METHODS

We used data from the NIH-AARP Diet and Health Study to assess the association of fruit and vegetable consumption, as well as intake of specific botanical groupings of fruits and vegetables, with endometrial cancer risk among 112,088 women who completed a food-frequency questionnaire at baseline, in 1995-1996. During 8 years of follow-up 1142 incident cases of endometrial cancer were ascertained. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI).

RESULTS

After adjustment for covariates, HRs for the highest compared to the lowest quintile of total fruit and total vegetable intake were 1.30 (95% CI 1.04-1.61, P for trend 0.05) and 1.09 (95% CI 0.90-1.33, P for trend 0.55), respectively. No inverse associations were observed for intake of any of 13 botanical groupings of fruits and vegetables.

CONCLUSIONS

Results from this large prospective study do not support a protective role of a high intake of fruits or vegetables on the risk of endometrial cancer in older women.

Analysis of dietary patterns in epidemiological researchThis paper is one of a selection of papers published in the CSCN–CSNS 2009 Conference, entitled Are dietary patterns the best way to make nutrition recommendations for chronic disease prevention?

Dietary patterns have been used to summarize diet consumption and to evaluate how diet is associated with diseases in epidemiological research. However, there are many issues surrounding both the use and interpretation of dietary patterns. These issues include how to collect, summarize, and create dietary patterns, as well as how to interpret the results. Because labels are given arbitrarily to dietary patterns to help characterize the pattern in a meaningful way, it is often not clear from the literature as to the consistency of results among studies. Additionally, the utilization of dietary patterns as a tool for public health messages is a topic that is unresolved. These issues are discussed in this paper.

Dietary iron intake and risk of endometrial cancer: a population-based case-control study in Shanghai, China

Dietary red meat and animal fat have been linked to endometrial cancer (EC) risk, but the impact of bioavailable iron in animal-derived foods has been less well studied. Our objective was to investigate the effects of iron and fats on the risk of EC in a large, population-based, case-control study. The Shanghai Endometrial Cancer Study enrolled 1,204 EC cases and 1,212 controls who completed in-person interviews, including a food frequency questionnaire. Animal-derived iron and fat intakes were calculated from dietary intakes and food composition tables. Logistic regression models were used to evaluate independent and joint effects of iron and fat on EC risk. Animal-derived iron intake was positively associated with EC risk [adjusted OR = 1.9; 95% CI = 1.4-2.7, P(trend) < 0.01, highest vs. lowest quartile], predominantly after menopause (OR = 2.2; 95%CI = 1.4-3.4, P(trend) < 0.01) and in women with BMI >or= 25 kg/m(2)(OR = 3.2; 95% CI = 1.4-7.5 in postmenopausal obese women, P(trend) < 0.01). Animal-derived fat was also associated with postmenopausal EC risk (OR = 1.7; 95% CI = 1.2-2.5, P(trend) < 0.01). Multiplicative interactions between animal-derived iron and BMI or animal-derived fat intake were not observed. Animal-derived iron intake is associated with increased risk of EC after menopause and among obese women. Avoidance of animal-derived (heme) iron may reduce the risk of EC in these women.

Dietary patterns and breast cancer risk in Asian American women

BACKGROUND

The role of diet as a cause of breast cancer in Asian Americans has not been adequately studied.

OBJECTIVE

We investigated the association between dietary patterns and breast cancer risk in Asian Americans.

DESIGN

This population-based case-control study in Los Angeles County compared dietary patterns between 1248 Asian American women with incident breast cancer and 1148 age-, ethnicity-, and neighborhood-matched controls. The relation between dietary patterns and serum concentrations of estrogens, androgens, and sex hormone-binding globulin (SHBG) was investigated in 2172 postmenopausal control women.

RESULTS

We used a scoring method proposed by Trichopoulou et al (1) and found that adherence to a Mediterranean diet was inversely associated with risk; the odds ratio (OR) was 0.65 (95% CI: 0.44, 0.95) in women with the highest scores (> or = 8; most adherent) compared with those with the lowest scores (0-3; P for trend = 0.009), after adjustment for key covariates. We also used factor analysis and identified 3 dietary patterns (Western-meat/starch, ethnic-meat/starch, and vegetables/soy). In a combined index of the 3 patterns, women who were high consumers of Western and ethnic meat/starch and low consumers of the vegetables/soy diets showed the highest risk (OR: 2.19; 95% CI: 1.40, 3.42; P for trend = 0.0005). SHBG concentrations were 23% lower in women with a high intake of the meat/starch pattern and a low intake of the vegetables/soy pattern than in those with a low intake of the meat/starch pattern and a high intake of the vegetables/soy pattern (P for trend = 0.069).

CONCLUSION

Our results suggest that a diet characterized by a low intake of meat/starches and a high intake of legumes is associated with a reduced risk of breast cancer in Asian Americans.