Written By: Dr. Adam McLeod, ND, BSc (Hon)
I see a lot of patients with cancer at my clinic. The vast majority of my patients tell me that their oncologist bluntly told them that it doesn’t matter what they eat during their chemotherapy or radiation treatments. Some of these oncologists are so ingrained with this belief and they give zero dietary advice because they are convinced that diet will not make a difference.
As a molecular biologist this rationale made no sense to me. During these aggressive therapies every cell in the body is under an enormous amount of stress. The metabolic demands on your cells are obviously increased so that they can survive in the presence of these toxins. If the metabolic demands are increased then they clearly need nutrients to supply this demand. There is a big difference in the nutrient content of a Twinkie compared to an apple. Logic dictates that this difference in nutrients should make a big difference when your cells are bathed in chemotherapy and radiation in an effort to kill cancer.
Could all of these oncologists be wrong? They are very educated and if they feel so passionately about role of diet (or lack thereof) in cancer then surely there must be a scientific reason for this. I decided to look at peer-reviewed articles that study how diets affect patients during chemotherapy and radiation. It turns out that this attitude from oncologists is not based on logic or scientific fact. The evidence is clear; diet makes a big difference when patients are on chemotherapy and radiation. Oncologists who claim to be practicing evidence based medicine need to stop telling patients that it makes no difference because this is not what the evidence shows.
Many studies have been done on humans and rats, which clearly show positive affects from diet during chemotherapy. When given a diet that is rich in nutrients, rats are able to tolerate significantly higher doses of chemotherapy and radiation1,2. This is consistent with the ultimate goal of keeping your cells strong so that chemotherapy can be better tolerated by the patient. A recent article in the journal “The Oncologist” breaks down the different mechanisms as to how caloric restriction can enhance the effects of chemotherapy and radiation3. The conclusion of their research is: “Caloric restriction by fasting is likely an effective method to potentiate the cytotoxicity of chemotherapy and radiation therapy because of the overlapping induction of molecular profiles, and it may also provide a beneficial means of improving the overall health and metabolic profiles of patients. At this time, clinical trials evaluating caloric restriction as a complementary therapy in the treatment of cancer are warranted.” Caloric restriction is a method where the patient maintains their nutrient status while decreasing the number of calories that they are ingesting. Pilot trials have been completed on the ketogenic diet and how it affects the quality of life in advanced cancer patients. The results clearly show that specific diets can improve quality of life in these patients4. These are just a few examples of how different diets can impact your health during chemotherapy.
Diet alone is not a cure for cancer but when used properly it can help patients maintain their nutrient status during chemotherapy and radiation. I know that oncologists sincerely want the best for their patients and I have great respect for the work that they do. However, when they are asked about diet it is probably better that they say, “I don’t know” rather than “Don’t waste your time with diets because it won’t make a difference.” Unfortunately, oncologists do not get any training in nutrition and its role in cancer therapy. Their lack of training in nutrition is very apparent when you consider their position on the subject despite the evidence showing that it can be an effective tool6.
The bottom line is that diet does make a difference as this is what the evidence shows. There is no question that a healthy balanced diet will make it easier for patients to tolerate chemotherapy and radiation. Even though many of these patients have low energy levels during chemotherapy it is important to point out that research indicates patients are willing and able to adhere to specific diets during chemotherapy5. Anyone who eats a low quality diet will have lower energy and consequently a lower quality of life (recall the movie “Supersize Me”). This is common sense and this concept obviously applies to those who are undergoing chemotherapy and radiation. It is not uncommon in my practice for patients to be going through chemotherapy and radiation with minimal side effects because they are nutritionally supported during this process. If you eat a high quality diet under the supervision of a Naturopathic doctor (ND), then your cells with be better nourished to deal with the stresses of cancer and the aggressive treatments associated with cancer.
He currently practices at his clinic in Vancouver, British Columbia.http://www.yaletownnaturopathic.com
1) Bounous G, Le Bel E, Shuster J, Gold P, Tahan WT, Bastin E. Dietary protection during radiation therapy.. PubMed PMID: 807995.
2) Richard F. Branda, Zhuan Chen, Elice M. Brooks, Shelly J. Naud, Thomas D. Trainer, John J. McCormack, Diet modulates the toxicity of cancer chemotherapy in rats, Journal of Laboratory and Clinical Medicine, Volume 140, Issue 5, November 2002, Pages 358-368, ISSN 0022-2143
3) Champ, Colin E., et al. “Nutrient restriction and radiation therapy for cancer treatment: when less is more.” The oncologist 18.1 (2013): 97-103.
4) Schmidt, Melanie, et al. “Effects of a ketogenic diet on the quality of life in 16 patients with advanced cancer: A pilot trial.” Nutr Metab (Lond) 8.1 (2011): 54.
5) von Gruenigen, Vivian E., et al. “Feasibility of a lifestyle intervention for ovarian cancer patients receiving adjuvant chemotherapy.” Gynecologic oncology 122.2 (2011): 328-333.
6) Rock, C. L., Doyle, C., Demark-Wahnefried, W., Meyerhardt, J., Courneya, K. S., Schwartz, A. L., Bandera, E. V., Hamilton, K. K., Grant, B., McCullough, M., Byers, T. and Gansler, T. (2012), Nutrition and physical activity guidelines for cancer survivors. CA: A Cancer Journal for Clinicians, 62: 242–274. doi: 10.3322/caac.21142