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Background: Female breast cancer (BC) remains the most common cause of total cancer deaths around the world. Several studies have investigated BC biomarkers, but vital circulating biomarkers for early diagnosis of malignancy are still scarce. Thus, finding sensitive, selective and accurate biomarkers is required to get better BC outcome and to prolong patients’ survival. Therefore, this review investigated the feasibility of using circulating trace elements (TEs) as the new promising biological biomarkers for BC diagnosis and prevention. Methods: We systematically searched EMBASE, Medline, Google Scholar, PubMed, SciELO, Scopus databases or Web of Science for orginal studies presenting the significant changes in the concentrations of circulating TEs in terms of serum, plasma or blood from female breast cancer patients. Results: The search yielded 2697 articles, of which 39 were considered for this review. The study showed that four essential TEs (Se, Cu, Zn and Mn) significantly decreased when only one essential trace elemnt (Fe) increased consistently, while five toxics circulating TEs (Cd, Cr, Pb, Co, Mo) increased significantly with a significant difference compared to healthy groups. The essential TEs, Se and Cu were reported to decrease the most in fifteen and twenty-one studies, respectively. However, regarding the toxic circulating TEs, Cd and Pb were found to increase most significantly in seven studies. Among the essential TEs, Se and Zn were reported to have the most potential, with Cd and Pb having the most potential for use as new promising biomarkers to diagnose or prevent BC. Conclusion: The findings provide an insight into the TEs circulating biomarkers for early BC diagnosis and prevention. Due to its high heterogeneity, meta-analysis was not assessed; hence, futher investigation may be required on their clinical outcomes in BC with high sensitivity and specificity for accurate therapeutic response.

Phenolic acids are the most prominent group of bioactive compounds present in various plant sources. Hydroxybenzoic acids and hydroxycinnamic acids, the aromatic secondary metabolites imparting typical organoleptic characteristics to food are the major phenolic acids, and they are linked to several health benefits. Fruit and beverage crops being the richer sources of phenolic acids have been studied in depth, but phenolic acids from vegetables are largely overlooked. Though lesser in quantity in many vegetables, there is a need to explore the health benefits of the phenolic acids present in them. In this review, the importance of vegetables as a significant source of phenolic acids is emphasized. Vegetables being easily accessible throughout the year and consumed in larger quantities compared to fruits in our daily diet will probably contribute to significant health benefits. Since vegetables are often processed before consumption, the changes in phenolic acids as influenced by processing methods are highlighted. Best processing methods, pre-treatments and storage conditions for higher retention of phenolic acids have been highlighted to minimize their losses. The phenolic acids in vegetables and their health benefits have been cluster mapped, which may facilitate further research for nutraceutical development for specific health concerns. The processing stability of phenolic acids coupled with higher consumption indicates that they may be a potential source of phenolic acids in the diet. It is expected that the popularization of vegetables as a source of phenolic acids in daily diet will help in ameliorating the adverse effect of some of the lifestyle diseases.