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 pine 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 supple-mentation 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.(c) 2023 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study conducted a systematic review with meta-analysis to evaluate the effects of vitamin E consumption and/or supplementation on breast cancer risk, treatment, and outcomes. The results showed no significant association between total vitamin E consumption and breast cancer risk, but a negative correlation between vitamin E consumption and breast cancer recurrence. Vitamin E supplementation had no significant impact on breast cancer risk. Vitamin E consumption was inversely associated with breast cancer recurrence, but there was no association with breast cancer mortality.