The Lack of Association between Plant-Based Dietary Pattern and Breast Cancer: a Hospital-Based Case-Control Study

Unveiling the Effects of Cruciferous Vegetable Intake on Different Cancers: A Systematic Review and Dose-Response Meta-analysis

CONTEXT

Epidemiological studies indicated that cruciferous vegetable intake is associated with positive health outcomes. However, the role of cruciferous vegetables may have differential impacts on various cancers.

OBJECTIVE

This meta-analysis aims to review recent epidemiological studies on the link between cruciferous vegetables and various cancers. It seeks to identify the optimal intake dose and timing of cruciferous vegetables influencing their association with cancer risk.

DATA SOURCES

Studies on cruciferous vegetables and cancer were searched in PubMed, NCBI, Web of Science, and Elsevier databases from 1978 to June 2023.

DATA EXTRACTION

Extracted data from 226 relevant case-control and cohort studies were expressed by standardized mean difference and 95% CI, followed by the subgroup analysis to eliminate heterogeneity.

RESULTS

Intake of cruciferous vegetables can prevent cancers, with an odds ratio of 0.77 and risk ratio (RR) of 0.96. The intake levels of cruciferous vegetables associated with the risk of colorectal cancer, lung cancer, upper gastrointestinal cancer, gynecological cancer (ovarian cancer and endometrial cancer), bladder cancer, renal cancer, and prostate cancer were found to be 5.41 servings/week, 5.41 servings/week, 5.5 servings/week, 7.4 servings/week, 5.5 servings/week, 4.85 servings/week, and 3 servings/week, respectively. In a cohort followed for 2 to 15 years, limited consumption of cruciferous vegetables was correlated with a higher cancer RR. In the Asian population, cruciferous vegetables had a significant relationship with lung cancer, head and neck squamous cell carcinoma, and esophageal cancer. Conversely, cruciferous vegetables are predominantly associated with colorectal, renal, gynecological, and prostate cancer in the American population.

CONCLUSION

This study highlights the complex link between cruciferous vegetables and cancer, influenced by factors such as cancer type, region, intake level, and follow-up duration.

The association between plant-based diet indices and the risk of breast cancer: a case-control study

BACKGROUND

Previous studies examining the relationship between plant-based diets and breast cancer (BrC) have provided conflicting evidence. To address these inconsistencies, we aimed to evaluate the association between the plant-based diet index (PDI), healthful PDI (hPDI), and unhealthy PDI (uPDI) with the odds of BrC in Iranian women.

METHODS

The current case-control research was performed on 133 Iranian women with BrC and 265 controls. The study subjects were selected from hospitals in Tehran. PDI, hPDI, and uPDI were categorized into eighteen food groups based on nutrient composition similarity. The relationship between PDIs and BrC was assessed using logistic regression.

RESULTS

After adjusting for confounding factors, the chance of developing BrC was lower in the highest tertile of hPDI compared to the lowest tertile (odds ratio (OR) = 0.495; 95% confidence interval (CI): 0.274-0.891; P = 0.019). In addition, postmenopausal women in the second and last tertiles of hPDI had lower odds of BrC than those in the first tertile (T) (T2: OR = 0.342; 95% CI: 0.141-0.828; P = 0.017- T3: OR = 0.262; 95% CI: 0.107-0.639; P = 0.003) in the adjusted model. Furthermore, in premenopausal women in the highest tertile of uPDI, the odds of BrC were increased compared to the lowest tertile (OR = 2.546; 95% CI: 1.051-6.167; P = 0.038) in the adjusted model.

CONCLUSIONS

Adherence to a healthy plant-based dietary pattern, including vegetables, fruits, whole grains, nuts, and legumes, seems to be beneficial for BrC prevention, particularly in postmenopausal women. Future prospective cohort studies that consider menopausal status and the type of BrC are needed to support these findings.

Associations Between Dietary Factors and Breast Cancer Risk: A Systematic Review of Evidence from the MENA Region

BACKGROUND

The Middle East and North Africa (MENA) region is witnessing a continuous rise in the incidence of breast cancer (BC). This region is characterized by distinct cultural and lifestyle habits. Despite the importance of diet as a modifiable risk factor for BC, its role in the development of BC within the MENA context has not been extensively studied. This systematic review aims to identify and synthesize existing evidence regarding the effect of different dietary factors on BC risk among women from this region.

METHODS

We systematically reviewed the scientific literature for observational studies that examined the association between specific dietary factors and the risk of BC in MENA, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Our comprehensive search included databases such as PubMed, Web of Science, ScienceDirect, and Scopus, identified a total of 18,085 records, of which 65 met our inclusion criteria and were assessed for quality using the National Institute of Health Quality Assessment Tool.

RESULTS

The findings of the 65 included studies were categorized into food groups, nutrients, and dietary patterns. Studies in the MENA region have consistently shown that the consumption of fruit and vegetables, fish and seafood, and black tea are associated with a reduced BC risk. In contrast, the intake of milk and white bread is linked to an increased risk. Specific dietary patterns such as the Mediterranean diet, a healthy plant-based diet, dietary antioxidant index, and overall healthy dietary patterns have shown a negative association with BC risk. Conversely, the dietary insulin index and load, dietary glycemic index, dietary inflammatory index, and unhealthy dietary patterns are associated with an increased risk of BC. For the remaining dietary factors, research was too limited or inconsistent to draw conclusions.

CONCLUSIONS

Our findings highlight the significant role of dietary factors in modulating BC risk among women in the MENA region, an area that faces a notable gap in research on this topic. Further studies are essential to deepen our understanding and develop targeted dietary recommendations for BC prevention in this population.

Pro-vegetarian dietary pattern and risk of breast cancer: a case-control study

BACKGROUND

There are a few conflicting results from studies assessing the association between plant-based diets, particularly pro-vegetarian dietary pattern (PDP), and breast cancer (BC) incidence. Therefore, this study aimed to investigate the association between PDP and BC odds in the Iranian population.

METHODS

This case-control study was conducted on 134 women with BC and 265 without cancer (control). Participants were selected from two referral hospitals in Tehran, Iran. Also, a validated food frequency questionnaire was used to collect food information. Logistic regression was used to assess the association between PDP and BC and the association between PDP and BC by menopausal status.

RESULTS

It was observed that in two models of logistic regression, the chance of BC was lower in the second and last tertile (T) than in the first tertile of PDP (model 1-T2: odds ratio (OR) = 0.39; 95% confidence interval (CI): 0.23-0.67; P = 0.001, and T3: OR = 0.43; 95% CI: 0.26-0.73; P = 0.002-model 2: T2: OR = 0.42; 95% CI: 0.24-0.74; P = 0.003, and T3: OR = 0.49; 95% CI: 0.27-0.88; P = 0.017). Also, according to menopausal status, the odds of developing BC in post-menopausal women in the second and last tertile of PDP was significantly lower than the first tertile in both logistic regression models.

CONCLUSIONS

The findings revealed that Iranian women who followed PDP had a lower chance of developing BC. Also, we found that a diet high in plant-based foods and low in animal products is beneficial for reducing BC odds, particularly for post-menopausal women.

Dietary Patterns Associated with Breast Cancer in the Middle East: A Scoping Review

Breast cancer (BC) is the most predominant malignancy in Arab women in the Middle East, and yearly increases in occurrence by 37.5 and mortality rates by 15.2 for every 100,000 in 2019. This review explores the gap in research investigating the role of dietary patterns and BC in Middle Eastern countries. Furthermore, we analyze the evidence connecting these patterns to BC prevalence in the region, discussing implications for public health and preventive strategies. PubMed, ProQuest, and Cochrane databases were searched up to November 2023. Articles published in English from 2000 to 2023 were identified. Our search included dietary patterns (DP), their association with BC and specific to Middle Eastern Regions. The majority of existing research is concentrated in Iran, with limited illustration from Saudi Arabia, Turkey, and Jordan, and a notable absence of studies from other Middle Eastern countries. We found that dietary intervention is closely related to the occurrence, development, and prognosis of BC. Most DPs such as the Dietary Approaches to Stop Hypertension, Mediterranean, Plant-based and Paleolithic diets are identified to decrease the probability of BC by being rich sources of fiber, healthy fats, and vitamins and minerals. However, there are few DPs that increase the risk of BC, because of the existence of foods such as unhealthy fats, low fiber, sugars, and fried foods in those patterns which contribute to increasing the risk factors associated with BC. This review highlights the intricate connection between DPs and the risk of BC in the Middle East, revealing potential protective effects and heightened risks linked to specific dietary elements.

Scoping review of the association of plant-based diet quality with health outcomes

Introduction

The association of plant-based dietary patterns with health outcomes has traditionally been assessed without considering nutritional value. The plant-based dietary index (PDI), first published in 2016, overcomes this limitation with both a healthful PDI (hPDI) and an unhealthful PDI (uPDI), based on the quality of plant foods consumed plus the frequency of animal foods. We sought to summarize the breadth of research using the hPDI and uPDI to gain insight into how the quality of plant-based dietary patterns might be associated with health outcomes.

Methods

Scoping review of studies that used the PDI, hPDI, or uPDI to report associations with health outcomes. Multiple databases were searched from 2010 through April 2023 with 2 authors independently assessing eligibility and extracting data. In addition to assessing the association of the indices to health outcomes, we determined the frequency of concordant or discordant findings for hPDI versus PDI and for hPDI versus uPDI.

Results

We included 95 articles (54% longitudinal, 37% cross-sectional, and 9% case-control) with a median sample size of 3,646. Higher hPDI levels were associated with favorable health outcomes in 36% of comparisons (most often for obesity, mortality, diabetes, cardiovascular disease, and psychiatric disorders), compared to 25% for the PDI and only 2% for the uPDI. Conversely, higher levels of the uPDI were associated with unfavorable health outcomes in 33% of comparisons, in contrast to under 1% for the hPDI and 2% for the PDI. When the hPDI association to an outcome was discordant with the uPDI or PDI, the significance and directionality always favored the hPDI over the uPDI, and nearly always favored the hPDI over the PDI.

Discussion

Dietary indices that account for the quality of plant foods can show health benefits that might be missed by a generic plant-based index. A greater focus on the quality of plant foods could improve nutrition guidelines, raise awareness about the benefits of adding unrefined plant foods to the diet, and empower consumers to make incremental additions of such foods to displace unhealthy foods. We anticipate increasing use of indices that address food quality in future research.

Long-term adherence to healthful and unhealthful plant-based diets and breast cancer risk overall and by hormone receptor and histologic subtypes among postmenopausal females

BACKGROUND

Epidemiological studies assessing the influence of vegetarian diets on breast cancer (BC) risk have produced inconsistent results. Few studies have assessed how the incremental decrease in animal foods and the quality of plant foods are linked with BC.

OBJECTIVES

Disentangle the influence of plant-based diet quality on BC risk between postmenopausal females.

METHODS

Total of 65,574 participants from the E3N (Etude Epidémiologique auprès de femmes de la Mutuelle Générale de l'Education Nationale) cohort were followed from 1993-2014. Incident BC cases were confirmed through pathological reports and classified into subtypes. Cumulative average scores for healthful (hPDI) and unhealthful (uPDI) plant-based diet indices were developed using self-reported dietary intakes at baseline (1993) and follow-up (2005) and divided into quintiles. Cox proportional hazards models were used to estimate adjusted HR and 95% CI.

RESULTS

During a mean follow-up of 21 y, 3968 incident postmenopausal BC cases were identified. There was a nonlinear association between adherence to hPDI and BC risk (Pnonlinear < 0.01). Compared to participants with low adherence to hPDI, those with high adherence had a lower BC risk [HRQ3 compared withQ1 (95% CI): 0.79 (0.71, 0.87) and HRQ4 compared with Q1 (95% CI): 0.78 (0.70, 0.86)]. In contrast, higher adherence to unhealthful was associated with a linear increase in BC risk [Pnonlinear = 0.18; HRQ5 compared with Q1 (95% CI): 1.20 (1.08, 1.33); Ptrend < 0.01]. Associations were similar according to BC subtypes (Pheterogeneity > 0.05 for all).

CONCLUSIONS

Long-term adherence to healthful plant foods with some intake of unhealthy plant and animal foods may reduce BC risk with an optimal risk reduction in the moderate intake range. Adherence to an unhealthful plant-based diet may increase BC risk. These results emphasize the importance of the quality of plant foods for cancer prevention. This trial was registered at clinicaltrials.gov (NCT03285230).

Dietary patterns and breast cancer risk, prognosis, and quality of life: A systematic review

Background

Statistics indicate that the morbidity of breast cancer is increasing globally, and its (overall figures) incidence has now surpassed that of lung cancer for the first time. The relation between a whole dietary pattern, rather than of a single food or nutrient, and breast cancer (BC) should be examined for findings to capture the complexities of diet and the potential for synergism between dietary components. Hence, the effects of dietary patterns on breast cancer have recently attracted increasing attention.

Objective

To systematically review the effects of dietary patterns on breast cancer risk, prognosis, and quality of life in survivors.

Methods

This systematic review was conducted following PRISMA guidelines and was registered in PROSPERO. Data from Ovid, China Biomedical Literature Database, Wanfang Data Knowledge Service Platform, CNKI, PubMed, Weipu, The Cochrane Library, Duxiu Data, ProQuest, Embase, Web of Science, and Scopus Database were retrieved and evaluated.

Results

A total of 47 studies that investigated the association between eating patterns and breast cancer were identified. Ten studies evaluated the effect of the model on treatment outcome and prognosis of breast cancer and two cross-sectional studies examined the influence of dietary patterns on quality of life. The resulting favorable dietary patterns were shown to regulate metabolic biomarkers, antioxidants, anti-inflammatory agents, and protective genes, and inhibit cell proliferation and invasion.

Conclusion

Numerous studies have examined the effects of healthy eating, plant-based, anti-inflammation, low-fat, and other favorable dietary patterns in relation to breast cancer. However, few studies reported significant associations and the studies had limitations, suggesting that the current findings should be interpreted with caution.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, CRD4202 2350171.

Urinary Antibiotics and Dietary Determinants in Adults in Xinjiang, West China

The Xinjiang autonomous region, located in west China, has a unique ethnic structure and a well-developed livestock industry. People in this region have a high risk of exposure to antibiotics, but the exposure level to antibiotics in relation to dietary determinants is unknown. In this study, 18 antibiotics, including four human antibiotics (HAs), four veterinary antibiotics (VAs), and 10 preferred veterinary antibiotics (PVAs) were detected in the urine of approximately half of the 873 adults in Xinjiang, including Han Chinese (24.6%), Hui (25.1%), Uighur (24.6%), and Kazakh (25.7%). Logistic regression was used to analyze the association between antibiotic exposure levels and adult diet and water intake. The detection percentage of antibiotics in the urine of adults in Xinjiang ranged from 0.1% to 30.1%, with a total detection percentage of all antibiotics of 49.8%. HAs, VAs and PVAs were detected in 12.3%, 10.3%, and 40.5%, respectively. Fluoroquinolones were the antibiotics with the highest detection percentage (30.1%) and tetracyclines were the antibiotics with the highest detected concentration (17 ng/mL). Adults who regularly ate pork, consumed fruit daily, and did not prefer a plant-based diet were associated with thiamphenicol, norfloxacin, and fluoroquinolones, respectively. These results indicated that adults in the Xinjiang autonomous region were extensively exposed to multiple antibiotics, and some types of food were potential sources of exposure. Special attention should be paid to the health effects of antibiotic exposure in humans in the future.