Search

Background and Aims: The inflammatory process is a response mechanism to any stressor agent. Emerging novel therapeutic options derived mainly from natural products such as bromelain have been used to reduce the significant side effects of available anti-inflammatory drugs. Bromelain is an enzyme complex derived from Ananas comosus, known for its anti-inflammatory potential and good tolerance. Therefore, the aim was to assess whether bromelain supplementation exerts anti-inflammatory effects in adults., Methods: The systematic review was registered in PROSPERO (n° CRD42020221395), and the search was performed in MEDLINE, Scopus, Web of Science, and Cochrane Library. The terms used in the search were: "bromelains", "bromelain", "randomized clinical trial", and "clinical trial". Eligibility criteria were: randomized clinical trials with participants aged 18 years or over, of both sexes, who received supplementation with bromelain alone or in combination with other oral compounds, with an evaluation of inflammatory parameters as primary and secondary outcomes, published in English, Portuguese or Spanish., Results: 1375 studies were retrieved, of which 269 were duplicates. Seven (7) randomized controlled trials were eligible for the systematic review. In most studies, supplementation with bromelain, isolated or in combined therapy, reduced inflammatory parameters. Regarding the reduction of inflammatory parameters among studies with associated bromelain, two presented reduction of inflammatory parameters, while in the evaluation of bromelain treated alone, two studies also showed reduction. In relation to doses supplemented, the studies with associated bromelain ranged from 99.9 to 1200 mg/day and the supplementation time ranged from 3 to 16 weeks. Moreover, the inflammatory parameters evaluated were: IL-12, PGE-2, COX-2, IL-6, IL-8, TNF-α, IL-1β, IL-10, CRP, NFγ B1, PPAR-α, TNF, TRAF, MCP-1 and adiponectin. In studies with isolated bromelain supplementation, it ranged from 200 to 1050 mg/day for 1 week to 16 weeks. Markers associated with inflammation varied between studies, including IL-2, IL-5, IL-6, IL-8, IL-10, IL-13, IFNγ and MCP-1, PGE-2, CRP and fibrinogen. Eleven (11) participants experienced side effects, and two discontinued treatment in the studies. The reported adverse effects were mainly gastrointestinal but well tolerated., Conclusion: The general effect of bromelain supplementation on inflammation is inconsistent because of population heterogeneity, doses used, treatment duration, and parameters evaluated. The observed effects are punctual and isolated, and further standardization is needed to establish doses, supplementation time, and which type of inflammatory condition is indicated., Competing Interests: Declaration of competing interest All authors declare no conflicts of interest., (Copyright © 2023 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.)

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., Competing Interests: Declaration of competing interest The authors declare that there are no conflict of interest., (Copyright © 2023 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.)

Background: Vitamin E has been investigated for its antitumor potential, including the ability to change cancer gene pathways as well as promote antioxidant and pro-oxidant activity., Objective: Therefore, this systematic review aimed to evaluate antitumor and chemopreventive activity of different vitamin E isoforms (tocopherols and tocotrienols) through in vitro and in vivo studies., Method: The systematic review was registered in PROSPERO (No. CRD4202126207) and the search was carried out in four electronic databases (PubMed, Science Direct, Scopus and Web of Science) in June 2021 by three independent reviewers. The search equation used was: "Supplementation" AND ("Vitamin E" OR Tocopherol OR Tocotrienol) AND "breast cancer" AND (chemotherapy OR therapy OR prevention). In vitro studies and animal models of breast cancer supplemented with tocopherol or tocotrienol vitamers, alone or in combination, were included., Results: The results revealed 8546 relevant studies that were initially identified in our search. After analysis, a total of 12 studies were eligible for this systematic review. All studies included animal models, and 5 of them also performed in vitro experiments on cancer cell lines. The studies performed supplementation with tocopherols, mixtures (tocopherols and tocotrienols) and synthetic vitamin E forms. There was an significant association of estradiol, dendritic cells and pterostilbene in combined therapy with vitamin E. Vitamin E delayed tumor development, reduced tumor size, proliferation, viability, expression of anti-apoptotic and cell proliferation genes, and upregulated pro-apoptotic genes, tumor suppressor genes and increased immune response. The effects on oxidative stress markers and antioxidant activity were conflicting among studies. Only one study with synthetic vitamin E reported cardiotoxicity, but it did not show vitamin E genotoxicity., Conclusion: In conclusion, vitamin E isoforms, isolated or associated, showed antitumor and chemopreventive activity. However, due to studies heterogeneity, there is a need for further analysis to establish dose, form, supplementation time and breast cancer stage., (Copyright © 2022 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.)

This review systematically investigated observational studies in humans that evaluated the dietary intake of branched-chain amino acids (BCAA) and its association with insulin resistance. A search implemented through the electronic databases of PubMed, Scopus, and Web of Science. The evaluation of insulin resistance or the risk of developing insulin resistance in humans were the variables of interest in the search for articles. After using the selection criteria, three studies included in this review. The Food Frequency Questionnaire (FFQ) was the instrument used to evaluate the diet in all of the selected studies. Overall, 1940 studies identified and three thoroughly reviewed. We found only one study with positive effects of BCAA on insulin resistance; the other two reviewed studies did not demonstrate positive effects of the dietary intake of BCAA, individually or the sum of three amino acids on variables of interest. In this sense, the associations between BCAA and insulin resistance are inconsistent, potentially due to other longitudinal outcomes., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2020 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.)