Fiber intake and endometrial cancer risk

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.

Dietary Carbohydrate Intake, Dietary Glycemic Load and Outcomes of In Vitro Fertilization: Findings from an Observational Italian Cohort Study

In recent decades, increasing attention has been paid to the influence of diet on reproductive health. Carbohydrates in diet affect glucose metabolism and multiple evidences showed the key role of insulin sensitivity in regulating female fertility. We designed a prospective cohort study to investigate the relation between dietary carbohydrate intake, glycemic load (GL) and the outcomes of assisted reproduction. A population of 494 female partners of couples referring to an Italian Fertility Center and eligible for in vitro fertilization (IVF) were enrolled in the study. On the day of the oocyte retrieval, information on their diet was obtained using a validated food frequency questionnaire (FFQ). We calculated the relative risk and 95% confidence interval of embryo transfer, clinical pregnancy and live birth according to the following dietary exposures: GL, glycemic index (GI) as well as the daily carbohydrate and fiber intake. A multiple regression model was used to account for the confounders. After adjusting for age, college degree, body mass index (BMI), leisure physical activity and previous assisted reproduction techniques (ART) cycles, no significant association was observed between the considered dietary exposures and the IVF outcomes. The roles of GL, carbohydrate intake and GI were assessed in strata of the cause of infertility and body mass index and no relation emerged in this further analysis. We found no clear association between the dietary carbohydrate quantity and quality and IVF outcomes in a cohort of infertile Italian women.

Association between dietary fiber and endometrial cancer: a meta-analysis

To explore a potential relationship between dietary fiber consumption and risk of endometrial cancer (EC), eligible studies published up to 30 June 2018 were retrieved via computer searches and manual review of references. Random-effects models were used to calculate summary relative risk (RR) estimates based on contrasting high- and low-fiber intake values. Sensitivity analysis was conducted, and heterogeneity among study results was explored through stratified analyses by study design, geographic region, Newcastle-Ottawa Scale (NOS) score, impact factor, and adjustment for several confounders (age, body mass index, smoking, energy intake, and education). We extracted data from 16 studies (involving 6,563 cases). There was a significant association between dietary fiber intake and EC (RR = 0.86, 95% confidence interval [CI]: 0.78, 0.93). In stratified analysis, this trend was more pronounced in the case-control studies, and in studies conducted in the Americas and Asia. The relationship was further confirmed after adjusting for education level (RR = 0.74; 95% CI: 0.60, 0.88) and age (RR = 0.70; 95% CI: 0.57, 0.83), and NOS scores of 6 (RR = 0.81; 95% CI: 0.67, 0.95) and 7 (RR = 0.75; 95% CI: 0.62, 0.88). In conclusion, our meta-analysis revealed an inverse association between dietary fiber consumption and EC risk. Further efforts should be made to confirm these findings.

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.

Dietary fiber intake and reduced risk of ovarian cancer: a meta-analysis

BACKGROUND

Epidemiological studies regarding the association between dietary fiber intake and ovarian cancer risk are still inconsistent. We aimed to review the available evidence and conduct a dose-response meta-analysis to investigate the relationship between dietary fiber intake and ovarian cancer risk.

METHODS

Relevant studies were identified by searching PubMed, EMBASE, and the Cochrane Library databases before August 2017. Studies that reported relative risk (RR) estimates with 95% confidence intervals (CIs) for the association between dietary fiber intake and risk of ovarian cancer were included. Random-effects models were used to combine the estimated effects extracted from individual study.

RESULTS

Thirteen studies, with a total of 5777 ovarian cancer cases and 142,189 participants, met the inclusion criteria. The pooled multivariable RRs of ovarian cancer for the highest vs. the lowest category of dietary fiber intake was 0.78 (95% CI: 0.70, 0.88) with no evidence of heterogeneity (I2 = 4.20%, P = 0.40). Our dose-response analysis also showed a significant inverse association between dietary fiber intake and ovarian cancer risk (an increment of 10 g/day; combined RR: 0.88; 95% CI: 0.82, 0.93). There was no evidence for a nonlinear association (P for nonlinearity = 0.83).

CONCLUSIONS

This meta-analysis suggests a significant inverse dose-response association between dietary fiber intake and ovarian cancer risk. Further studies with prospective design that take account of more potential confounders are warranted to confirm this association.

Dietary Fiber Intake and Endometrial Cancer Risk: A Systematic Review and Meta-Analysis

Epidemiological studies are inconclusive regarding the association between dietary fiber intake and endometrial cancer risk. Thus, we aimed to conduct a meta-analysis to clarify the association between dietary fiber and endometrial cancer risk. We searched the PubMed and ISI Web databases for relevant studies through March 2018. The association between dietary fiber and endometrial cancer risk was evaluated by conducting a meta-analysis including 3 cohort and 12 case⁻control studies. A significant negative association was observed between total dietary fiber intake and endometrial cancer risk in 11 case⁻control studies (odds ratios (OR) 0.76, 95% confidence interval (CI): 0.64⁻0.89, I² = 35.2%, p = 0.117), but a marginal positive association was observed in three cohort studies (relative risk (RR) 1.22, 95% CI: 1.00⁻1.49, I² = 0.0%, p = 0.995). Particularly, a negative association was observed in North America (OR = 0.70, 95% CI: 0.59⁻0.83, I² = 8.9%, p = 0.362). In addition, a positive association was observed in cereal fiber (RR = 1.26, 95% CI: 1.03⁻1.52, I² = 0.0%, p = 0.530, 3 cohort studies) and a negative association was observed in vegetable fiber (OR = 0.74, 95% CI: 0.58⁻0.94, I² = 0.0%, p = 0.445, 3 case⁻control studies). In conclusion, negative associations with endometrial cancer risk were observed for higher total dietary fiber intake and higher vegetable fiber intake in the case⁻control studies. However, results from the cohort studies suggested positive relationships of higher total fiber intake and higher cereal fiber intake with endometrial cancer risk.

Fruit and vegetables and cancer risk: a review of southern European studies

High intakes of fruit and vegetables may reduce the risk of cancer at several sites. Evidence has been derived mainly from case-control studies. We reviewed the relationship between consumption of vegetables and fruit and the risk of several common cancers in a network of Italian and Swiss case-control studies including over 10,000 cases of fourteen different cancers and about 17,000 controls. Data were suggestive of a protective role of vegetable intake on the risk of several common epithelial cancers. OR for the highest compared with the lowest levels of consumption ranged from 0.2 (larynx, oral cavity and pharynx) to 0.9 (prostate). Inverse associations were found for both raw and cooked vegetables, although for upper digestive tract cancers the former were somewhat stronger. Similar inverse associations were found for cruciferous vegetables. Frequent consumption of allium vegetables was also associated with reduced risk of several cancers. Fruit was a favourable correlate of the risk of several cancers, particularly of the upper digestive tract, with associations generally weaker than those reported for vegetables. A reduced risk of cancers of the digestive tract and larynx was found for high consumption of citrus fruit. Suggestive protections against several forms of cancer, mainly digestive tract cancers, were found for high consumption of apples and tomatoes. High intakes of fibres, flavonoids and proanthocyanidins were inversely related to various forms of cancer. In conclusion, data from our series of case-control studies suggested a favourable role of high intakes of fruit and vegetables in the risk of many common cancers, particularly of the digestive tract. This adds evidence to the indication that aspects of the Mediterranean diet may have a favourable impact not only on CVD, but also on several common (epithelial) cancers, particularly of the digestive tract.

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.

Dietary components and uterine leiomyomas: a review of published data

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

Whole grain, dietary fiber, and incidence of endometrial cancer in a Danish cohort study

Whole grains and dietary fiber might be inversely associated with endometrial cancer risk through their effects on sex hormone metabolism and body fat. We investigated whether a higher intake of whole grains and dietary fiber was associated with a lower incidence of endometrial cancer in the Diet, Cancer and Health cohort of 29,875 women aged 50-64 years at enrollment in 1993-1997. Information on diet and lifestyle was derived from self-administered questionnaires. The incidence rate ratios and 95% confidence intervals were estimated based on a Cox proportional hazards model. Of the 24,418 women included as cohort members, 217 had a diagnosis of endometrial cancer. No clear associations were found between intake of whole grains or dietary fiber and the incidence of endometrial cancer.

Diet and endometriosis risk: a literature review

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