Vegetable-Fruit-Soybean Dietary Pattern and Breast Cancer: A Meta-Analysis of Observational Studies

Dietary patterns and risk of multiple cancers: umbrella review of meta-analyses of prospective cohort studies

BACKGROUND

Numerous prospective cohort studies have investigated the influence of dietary patterns on the risks of various cancers, although the findings differed.

OBJECTIVES

To evaluate the associations of dietary patterns with risks of various cancers and assess the strength and validity of the evidence.

METHODS

Relevant articles were retrieved from the PubMed, EMBASE, Web of Science, and Cochrane library databases from inception to February 22, 2024. The included systematic reviews were meta-analyses of prospective cohort studies that reported an effect size to calculate the association between dietary patterns and cancer risk. The quality of the included studies was evaluated using a measurement tool to assess systematic reviews and the certainty of evidence was assessed using credibility assessment of evidence. Outcomes of interest included any incident cancers. This study was registered with PROSPERO (CRD42023425237).

RESULTS

Overall, 74 meta-analyses from 30 articles were identified. Three meta-analyses (4.1%) were graded as convincing evidence and included associations between adherence to the 2007 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) dietary recommendations (per 1-unit score increase) and lower risk of all cancers (relative risk [RR] = 0.93, 95% confidence interval [CI]: 0.92, 0.95), whereas negative associations were found comparing the highest compared with lowest categories for a prudent diet (RR = 0.89, 95% CI: 0.85, 0.93) and vegetable-fruit-soybean diet (RR = 0.87, 95% CI: 0.83, 0.92) in relation to breast cancer. After credibility assessment of evidence by Grading of Recommendations, Assessment, Development, and Evaluation, 4 (5.4%) meta-analyses were classified as high, including adherence to the 2007 WCRF/AICR dietary recommendations and decreased risks of all cancers, breast cancer, colorectal cancer, and prostate cancer.

CONCLUSIONS

These findings suggest that adherence to certain healthy dietary patterns is associated with lower risk of all cancers and certain individual cancers. This study was registered at crd.york.ac.uk, PROSPERO as CRD42023425237 and /PROSPERO/display_record.php?RecordID=425237.

Legumes: A Vehicle for Transition to Sustainability

Legumes are an excellent source of protein and have been used in the human diet for centuries. Consumption of legumes has been linked to several health benefits, including a lower risk of cardiovascular diseases, type 2 diabetes mellitus, and certain types of cancer, while legumes' high fiber content promotes digestive health. Aside from the positive health benefits, one of the most significant advantages of legumes is the low environmental footprint of their cultivation. They can be grown in a variety of climates and soil types, and they require less water and fertilizer than other crops, making them a sustainable option for farmers. Thanks to their nutritional and physicochemical properties, they are widely used by the food industry since the growing popularity of plant-based diets and the increasing demand for alternatives to meat offers the opportunity to develop legume-based meat substitutes. As the use of legumes as a source of protein becomes widespread, new market opportunities could be created for farmers and food industries, while the reduction in healthcare costs could have a potential economic impact. Achieving widespread adoption of legumes as a sustainable source of protein requires coordinated efforts by individuals, governments, and the private sector. The objective of this narrative review is to present the benefits coming from legume consumption in terms of health and environmental sustainability, and underline the importance of promoting their inclusion in the daily dietary pattern as well as their use as functional ingredients and plant-based alternatives to animal products.

Estrogens and the risk of breast cancer: A narrative review of literature

In female mammals, the development and regulation of the reproductive system and non-reproductive system are significantly influenced by estrogens (oestrogens). In addition, lipid metabolism is another physiological role of estrogens. Estrogens act through different types of receptors to introduce signals to the target cell by affecting many estrogen response elements. Breast cancer is considered mostly a hormone-dependent disease. Approximately 70% of breast cancers express progesterone receptors and/or estrogen receptors, and they are a good marker for cancer prognosis. This review will discuss estrogen metabolism and the interaction of estrogen metabolites with breast cancer. The carcinogenic role of estrogen is discussed in light of both conventional and atypical cancers susceptible to hormones, such as prostate, endometrial, and lung cancer, as we examine how estrogen contributes to the formation and activation of breast cancer. In addition, this review will discuss other factors that can be associated with estrogen-driven breast cancer.

Health benefits of legume seeds

Pulses have been part of human nutrition for centuries. They are also used in folk medicine as products with multidirectional medicinal effects. They are annual plants representing the Fabaceae family. Their edible part is the fruit, i.e. the so-called pods. Whole pods or their parts can be eaten, depending on the species and fruit ripeness. Beans, peas, peanuts, chickpeas, lentils, broad beans and soybeans are edible legume species. Legume seeds are characterized by high nutritional value. Compared to seeds from other plants, they have high protein content ranging, on average, from 20% to 35%, depending on the type, growing conditions and maturity of the fruit. This review focuses on various health-promoting properties of legumes and presents their nutritional value and compounds exerting health-promoting effects. Many pulses have a low glycemic index, which is important for prevention and treatment of diabetes. In addition to their low glycemic index and high fiber content, pulses have α-amylase and α-glucosidase inhibitors, which reduce the absorption of glucose from the gastrointestinal tract. These compounds have antidiabetic and anti-inflammatory effects. Pulses have been shown to contain bioactive peptides with angiotensin-converting enzyme inhibitory properties; hence, they are useful in the treatment of cardiovascular diseases. Pulses used in the nutrition of obese individuals provide compounds with pancreatic lipase inhibitory properties, thus promoting weight reduction and control. © 2023 Society of Chemical Industry.

Consumption and supplementation of vitamin E in breast cancer risk, treatment, and outcomes: A systematic review with meta-analysis

BACKGROUND

Robust evidence have shown diet or dietary components in playing a direct role on cancer chemoprevention such as breast cancer (BC), and also prevention against cancer therapy side effects. In this context, vitamin E isoforms have been associated with tumor suppression pathways, mainly related to proliferation, invasion, metastasis, tumor metabolism and chemoresistance.

OBJECTIVE

Therefore, we performed a systematic review with meta-analysis to assess the effects of vitamin E consumption and/or supplementation on breast cancer risk, treatment, and outcomes.

METHODS

The studies were selected in the electronic databases PubMed, Science Direct, Scopus and Web of Science.

RESULTS

A total of 22 articles were selected, which nine manuscripts we perform the meta-analysis. The summary effect estimate did not indicate any significant association between consumption versus non-consumption of total vitamin E and breast cancer risk. After assessing the effects of vitamin E supplementation on breast cancer risk, only two had data for comparison and vitamin E supplementation presented no impact on breast cancer risk. However, the summary effect estimate from the included studies indicated that vitamin E consumption was inversely associated with breast cancer recurrence in the control group. There are no significant results regarding dietary or supplemental vitamin E intake and BC risk reduction.

CONCLUSION

Finally, regarding recurrence, survival, and mortality, the results indicated that vitamin E consumption was inversely associated with breast cancer recurrence, although no association was found for breast cancer mortality.

Eriodictyol inhibits breast carcinogenesis by targeting circ_0007503 and repressing PI3K/Akt pathway

BACKGROUND

Eriodictyol in citrus fruits, Eriodictyon californicum and several Chinese herbal medicines shows great promise for chronic disease prevention, including cancers. However, its role in chemopreventive activities against breast carcinogenesis is unknown.

PURPOSE

In the present study, we investigated the chemopreventive effect and the underlying mechanism of eriodictyol on carcinogens-induced breast carcinogenesis in vivo and in vitro.

METHODS

The carcinogenic transformation in MCF10A cells was induced by the environmental carcinogens in vitro. The chemopreventive effect in vivo was evaluated by using the experimental model of 1-methyl-1-nitrosourea (MNU)-induced mammary tumorigenesis in rats. The activation of the PI3K/Akt pathway was detected by western blot assay; the levels of circular RNAs (circRNAs) were measured by qRT-PCR.

RESULTS

First, eriodictyol significantly reduces cells viability and induces apoptosis in breast cancer cells in a dose-dependent manner in vitro (P < 0.05). Next, eriodictyol could effectively suppress environmental carcinogens-induced acquisition of carcinogenic properties in human breast epithelial cell MCF10A (P < 0.05). In vivo, eriodictyol administration reduces the incidence of mammary tumor by 50% in carcinogen-treated female rats (P < 0.05). Further study revealed that eriodictyol represses the PI3K/Akt signaling pathway and down-regulates the level of circ_0007503 in breast cancer cells and in breast carcinogenesis (P < 0.01). When the effect of eriodictyol on circ_0007503 was blocked by transfection of a circ_0007503 over-expression plasmid, the cytotoxic effects and the suppression of the PI3K/Akt pathway of eriodictyol in breast cancer cells were significantly reduced (P < 0.05).

CONCLUSION

Our data indicated that eriodictyol could effectively suppress breast carcinogenesis in vitro and in vivoThe mechanism may be attributed to targeting circ_0007503 and inhibiting PI3K/Akt pathway.

Causal language use in systematic reviews of observational studies is often inconsistent with intent: A systematic survey

OBJECTIVE

We systematically evaluated causal language use in systematic reviews of observational studies and explored the relation between language use and the intent of the investigation.

STUDY DESIGN AND SETTING

We searched Embase, Medline, and Epistemonikos. We randomly selected 199 reviews published in 2019, stratified in a 1:1 ratio by use and non-use of the GRADE approach to rating quality of evidence.

RESULTS

Of 199 reviews of observational studies 56.8% had causal intent. Reviews with causal intent were more likely to investigate therapeutic clinical intervention (33.6% vs 12.8%). While 78.8% of those with causal intent used causal language in one or more sections of the title, abstract, or main text, only 4.4% consistently used causal language throughout the manuscript, and 21.2% did not use causal language at all. Of reviews without causal intent, 51.2% used causal language somewhere in the manuscript.

CONCLUSION

Systematic reviews of observational studies sometimes do and sometimes do not have causal intent. Both those are inconsistent in causal language use and often use language inconsistent with the intent. Journal policies would better serve clarity of thinking and appropriateness of inferences by demanding authors clearly specify their intent and consistently use language consistent with that intent.

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

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

Factors for the Primary Prevention of Breast Cancer: A Meta-Analysis of Prospective Cohort Studies

Background: This report provided the effect of 15 preventable factors on the risk of breast cancer incidence.

Study design: A systematic review and meta-analysis.

Methods: A detailed research was conducted on PubMed, Web of Science, and Scopus databases in January 2020. Reference lists were also screened. Prospective cohort studies addressing the associations between breast cancer and 15 factors were analyzed. Between-study heterogeneity was investigated using the χ², τ², and I² statistics. The probability of publication bias was explored using the Begg and Egger tests and trim-and-fill analysis. Effect sizes were expressed as risk ratios (RRs) with 95% confidence intervals (CIs) using a random-effects model.

Results: Based on the results, out of 147,083 identified studies, 197 were eligible, including 19,413,702 participants. The RRs (95% CI) of factors associated with breast cancer were as follows: cigarette smoking 1.07 (1.05, 1.09); alcohol drinking 1.10 (1.07, 1.12); sufficient physical activity 0.90 (0.86, 0.95); overweight/obesity in premenopausal 0.92 (0.82, 1.03) and postmenopausal 1.18 (1.13, 1.24); nulliparity 1.16 (1.03, 1.31); late pregnancy 1.37 (1.25, 1.50); breastfeeding 0.87 (0.81, 0.93); ever using oral contraceptive 1.00 (0.96, 1.05); ever using estrogen 1.13 (1.04, 1.23); ever using progesterone 1.02 (0.84, 1.24); ever using estrogen/progesterone 1.60 (1.42, 1.80); ever taking hormone replacement therapy 1.26 (1.20, 1.32); red meat consumption 1.05 (1.00, 1.11); fruit/vegetable consumption 0.87 (0.83, 0.90); and history of radiation therapy, based on single study 1.31 (0.87, 1.98).

Conclusions: This meta-analysis provided a clear picture of several factors associated with the development of breast cancer. Moreover, the useful information in this study may be utilized for ranking and prioritizing preventable risk factors to implement effective prevention programs.

Dietary Pattern at 18-Month Post-Diagnosis and Outcomes of Breast Cancer Among Chinese Women with Early-Stage Breast Cancer

Background

Evidence of the association between dietary pattern and outcomes of breast cancer was limited in Asian women, including Chinese.

Patients and Methods

A prospective cohort study was initiated among Chinese breast cancer patients to investigate lifestyle habits and outcomes of breast cancer. At each follow-up, validated food frequency questionnaires (FFQ) were used to assess patients’ dietary intake. This study included 1226 patients with invasive early-stage breast cancer with detailed data at 18-month follow-up after cancer diagnosis. Factor analysis was used to derive dietary patterns, whereby two dietary patterns were identified. Cox proportional hazards models were used to investigate associations between dietary patterns and time to outcome, including breast cancer recurrence, overall mortality and breast cancer-specific mortality.

Results

With a median follow-up time of 54.1 months, 165 patients had breast cancer recurrence and 98 deaths occurred. Two dietary patterns were identified: “Western dietary pattern” characterized by high intake of refined grains and cakes, red and processed meat and oil; “healthy dietary pattern” characterized by high consumption of vegetables and fruits. Participants in the highest tertile of “Western dietary pattern” did not have a higher risk of breast cancer recurrence (P_trend = 0.89), overall mortality (P_trend = 0.48) and breast cancer-specific mortality (P_trend = 0.75). Similarly, a null association existed between “healthy dietary pattern” and outcomes of breast cancer.

Conclusion

Neither dietary pattern was associated with risk of breast cancer recurrence, all-causes death or death from breast cancer. Prospective follow-up is still needed to further confirm the association between specific dietary pattern and outcomes of breast cancer.