There has been some talk about how antioxidant therapies could reduce the efficacy of chemotherapy. There is no scientific evidence that demonstrates such. On the contrary, antioxidants have been tested and proven to enhance the outcomes. Antioxidants work together in a reaction that quenches the reactive oxygen species, or ROS, through an oxidation-reduction process.
There is a high chance that chemotherapy could increase the production of ROS during treatment. And when ROS is overproduced, it could lead to different conditions such as rheumatic or cardiovascular disease, or complications linked to diabetes and cancers.
It is true that there is not enough clinical trials that observe the effects of using antioxidants during chemotherapy. This is mostly due to several challenges that hinder the quest for guidelines that are based on evidence in order to prescribe antioxidants while undergoing chemotherapy.
Below are some antioxidants and how they fare with some tests:
Vitamin A. Supplementation of Vitamin A has shown promising results when taken in conjunction with chemotherapy. It induces cell differentiation, and inhibits growth. It also blocks signaling pathways in cancer cells, including kinase C activity, and also the reduction of oncogenes.
In a certain study, it was shown that patients who took Vitamin A supplements had lower risks of disease progression and death. Their 5-year survival rates were higher compared to those who only took chemotherapy.
Vitamin E. Vitamin E inhibits protein tyrosine kinase, which has been observed to halt the development of tumors through apoptosis. And not only that. Vitamin E may enhance chemotherapy results by increasing the transforming growth factor beta release, stopping the growth signals in malignant cells. Studies have shown that there is significant reduction in toxicities for doses from 300 to 600 mg of Vitamin E on different cancer types.
Selenium. Playing a crucial role in the antioxidant system, being a cofactor of glutathione (GSH), which has been shown to be absorbed by normal cells. It protects against cisplatin-induced nephropathy and neuropathy. It has also been observed that the severity of side effects was reduced when Selenium is included in the supplemental dose.
Quercetin. This one, you might not have heard of before. Quercetin has been shown to enhance DNA cleavage and the formation of stable protein-DNA cleavage complexes. It has been shown to stop sensitive cancer cells from developing. While it has so far only been tested on animal subjects, it shows promising results as Quercetin can enhance cisplatin’s antitumor activities. Cisplatin is a chemotherapy drug.