For those looking for a controversial topic within the realm of cancer, whether or not to consume antioxidants alongside cancer therapy is it. Although there are clear pros and cons supporting each school of thought, the science has shown that consuming the right antioxidants alongside the right chemo or radiation treatment is not only safe, but shows great promise in supporting and improving patients’ outcomes. 


What are antioxidants and how are they used in cancer? 


Antioxidants are substances that help prevent or slow the damage to cells caused by free radicals. More specifically, antioxidants help keep your body from essentially self-oxidizing by donating part of themselves to cells that are unstable and in the midst of causing harm to other cells around it. Similar to the way metal rusts over time, cells within your body also ‘rust’ or oxidize as well. Most antioxidants are derived from plant sources and foods (such as vegetables and fruit), however the body also has the ability to create its own antioxidants within itself. When it comes to cancer, antioxidants play a powerful role in terms of prevention (read more here), however their benefits and safety alongside chemotherapy or radiation continually come into question. Thankfully, given the ongoing research and support about antioxidants, their specific benefits are proving to be of great value. 


Why is there controversy amongst antioxidant use during cancer treatment?


So what’s the controversy about antioxidants and cancer treatment all about? Well, when it comes to many cancer therapies, one of the general mechanism of actions is based on killing cancer cells by way of creating free radicals and oxidizing them in a pro-oxidative fashion. As described above, antioxidants have the potent ability to balance and protect cells from being oxidized from free radicals, so on one hand, chemotherapy or radiation creates free radicals and oxidation while on the other hand antioxidants protect cells from being oxidized.


How are antioxidants safe and beneficial alongside cancer therapies? 


Despite many chemotherapies (and radiation) treatments being pro-oxidative, the safe and judicious use of antioxidants can be of great benefit. Cancer therapies create aldehydes (a by-product of cancer cells to cancer treatments), which ultimately affect how a cancer cell responds in the face of its respective cancer drug. When it comes to healthy cells, every cell within the body is constantly progressing through its own natural life cycle. Certain stages of each cycle are more predictive to that of cellular growth and replication, whereas others cause cells to stagnate and become more self protective. In terms of cancer cells, they act the same way. Because chemotherapies can only be effective if a cancer cell is within a certain life cycle stage, treatments need to be timed exactly in line with such cell cycle phases (this is one or many reasons why chemotherapy treatments sometimes work yet other times fail). This of course is impossible to predict or align. Aldehydes tend to stop (or arrest) cancer cell progression (which is good!), however also prevents the incoming cancer therapies to effectively work by reducing cancer cells’ ability to enter certain phases. Allowing these cells to enter these phases, or cellular checkpoints make the cancer cell susceptible to cancer drug destruction and death. Antioxidants have been repeatedly shown to allow the cancer cell cycle to continue into these checkpoints so that pro-oxidative therapies have full capacity to kill. Not only that, but by therapeutically dosing antioxidants throughout treatment, more healthy cells are supported and spared amidst incoming toxic treatments. 


There is a lot to learn and understand when it comes to the proper use of antioxidants during chemotherapy and radiation, so self prescribing is a risk that can be extremely hazardous. Antioxidants can actually be detrimental alongside certain cancer therapies, and every chemotherapy  drug class (or radiation therapy) responds very different to its presence. In addition, many natural antioxidants impart various effects on cancer drugs, whether positive in some cases and negative in others. The safest way to begin supporting your drug therapy with antioxidants is to moderately consume them in whole food form within a healthy diet (still with some limitations, parameters and risk). If you’re considering antioxidant use alongside your current cancer therapy plan, consult both with your cancer care oncologist as well as with an experienced naturopathic or integrative cancer focused doctor first.


Dr Jeremy Hayman, ND is a cancer focused naturopathic doctor and helps patients at Cornerstone Naturopathic Inc. feel better, live better, and achieve optimal wellness and health. Years of patient care coupled with dedication to personal life balance has helped Dr Jeremy employ the adage that “your approach to health should be simple”.