Consumption of olive oil and risk of breast cancer in U.S. women: results from the Nurses' Health Studies

Adherence to the Mediterranean diet and its protective effects against colorectal cancer: a meta-analysis of 26 studies with 2,217,404 participants

Colorectal cancer (CRC) is a major global health concern and represents a significant public health challenge in Hungary, where it exhibits some of the highest morbidity and mortality rates in the European Union. The Mediterranean diet has been suggested to reduce the incidence of CRC, but comprehensive evidence from diverse study designs is needed to substantiate this effect. A systematic literature search was conducted in PubMed, ClinicalTrials.gov, CENTRAL, and the Web of Science to identify randomized controlled trials and human clinical trials from 2008 to 2024 to identify relevant studies. Statistical analysis was performed using the https://metaanalysisonline.com web application using a random effects model to estimate the pooled hazard rates (HRs). Forest plots, funnel plots, and Z-score plots were utilized to visualize results. We identified 15 clinical trials and 9 case-control studies, encompassing a total of 2,217,404 subjects. The pooled analysis indicated that adherence to the Mediterranean diet significantly reduced the prevalence of CRC (HR = 0.84, 95% CI = 0.78-0.91, p < 0.01). This protective effect was consistent across sexes, with HRs of 0.85 (95% CI = 0.75-0.97, p = 0.01) for males and 0.88 (95% CI = 0.79-0.99, p = 0.03) for females. Case-control studies specifically showed a substantial effect (HR = 0.51, 95% CI = 0.38-0.68, p < 0.01). Notable heterogeneity was observed across studies, yet the a priori information size was substantially below the cumulative sample size, ensuring sufficient data for reliable conclusions. The findings from this meta-analysis reinforce the protective role of the Mediterranean diet against CRC. The results of this meta-analysis will inform dietary interventions designed to mitigate CRC risk, which are conducted within the framework of the Semmelweis Study, an ongoing comprehensive cohort study at Semmelweis University, designed to explore the multifaceted causes of unhealthy aging in Hungary. These interventions aim to explore the practical application of Mediterranean dietary patterns in reducing CRC incidence among the Hungarian population.

Hydroxytyrosol, a Component of Olive Oil for Breast Cancer Prevention in Women at High Risk of Cancer

Background: This study evaluates the effects of hydroxytyrosol (HT), a component of olive oil, on mammographic breast density reduction. We explored effects of HT on Wnt β-catenin and other pathways involved in cancer stem cell renewal, DNA repair, cell proliferation, and differentiation. Methods: Twenty-five milligrams per day oral dose of HT was given for 12 months in pre- and postmenopausal women at increased risk of breast cancer. Out of 51 patients enrolled, 41 completed the study. The annualized percent decrease in maximum mammographic volumetric breast density (max VBD%) between baseline (BL) and end of treatment (EOT) was analyzed. RNA sequencing (RNA-Seq) and multiplex analysis was performed on the breast biopsies to compare the BL with EOT samples. Results: Max VBD% showed a nonsignificant change; however, in women 60 years or older, the max VBD% decrease was significant (3.7%, p = 0.0391), especially in those with high BL mammographic density. Using RNA-Seq, 3330 unique transcripts were identified (p < 0.05). Mitotic telophase/cytokinesis and DNA damage were upregulated, whereas Wnt, Notch, and oxidative stress-induced senescence pathways were downregulated (p < 0.05). These pathways were confirmed by NanoString nCounter where significant decrease in proliferative genes (RELA and CDK4) and Wnt pathway (R-HSA-195721 and R-HAS-201681) was observed (p < 0.05). Conclusions: HT reduced breast density only in women over 60 years, especially in those with high BL breast density. HT also reduced proliferation and affected the Wnt signaling pathway. This study lays the foundation for future larger studies in exploring a natural compound with well tolerability and overall nontoxic profile for chemoprevention of breast cancer. Trial Registration: ClinicalTrials.gov identifier: NCT02068092.

Advances in Diet and Physical Activity in Breast Cancer Prevention and Treatment

There is currently a growing interest in diets and physical activity patterns that may be beneficial in preventing and treating breast cancer (BC). Mounting evidence indicates that indeed, the so-called Mediterranean diet (MedDiet) and regular physical activity likely both help reduce the risk of developing BC. For those who have already received a BC diagnosis, these interventions may decrease the risk of tumor recurrence after treatment and improve quality of life. Studies also show the potential of other dietary interventions, including fasting or modified fasting, calorie restriction, ketogenic diets, and vegan or plant-based diets, to enhance the efficacy of BC therapies. In this review article, we discuss the biological rationale for utilizing these dietary interventions and physical activity in BC prevention and treatment. We highlight published and ongoing clinical studies that have applied these lifestyle interventions to BC patients. This review offers valuable insights into the potential application of these dietary interventions and physical activity as complimentary therapies in BC management.

Olive oil intake and cardiovascular disease, cancer, and all-cause mortality: a systematic review and dose-response meta-analysis of prospective cohort studies

Background: Currently, the reported links between olive oil intake and cardiovascular disease (CVD), cancer morbidity and mortality, and all-cause mortality are inconsistent. The aim of this meta-analysis is to study the reported correlations of olive oil intake with CVD, coronary heart disease (CHD), stroke and cancer incidence and mortality, and all-cause mortality. Methods: PubMed, Embase, and Web of Science were searched until March 7, 2024. Pooled relative risks (RRs) and 95% confidence intervals (CIs) were estimated by the random-effects model. Nonlinear dose-response relationships were modeled with restricted cubic splines. This study has been registered at PROSPERO (CRD42023419001). Results: Overall, 30 articles covering 2 710 351 participants were identified. Higher olive oil intake was linked with a reduced risk of CVD incidence (RR: 0.85; 95% CI: 0.77, 0.93), CHD incidence (RR: 0.85; 95% CI: 0.72, 0.99), CVD mortality (RR: 0.77; 95% CI: 0.67, 0.88), and all-cause mortality (RR: 0.85; 95% CI: 0.81, 0.89). For a 10 g d-1 increment of olive oil intake, the risk of CVD incidence, stroke incidence, CVD mortality, and all-cause mortality decreased by 7%, 5%, 8%, and 8%, respectively. No association was found between olive oil intake and cancer incidence and mortality. Nonlinear relationships between olive oil intake and CVD and all-cause mortality were observed, with a reduced risk from intakes ranging from 0 to 18 g d-1 and 0 to 22 g d-1, respectively. Conclusion: Our study found that high olive oil intake was related to a lower risk of CVD and CHD incidence and CVD mortality and all-cause mortality.