November 21, 2023
By Angie N Choi, EdD, Author of Whole New Me: Healing From Cancer in Body, Mind, and Spirit
Metabolic therapies are typically dietary treatments that alter metabolism to combat diseases such as cancer, type 2 diabetes, and epilepsy. Metabolic diets limit glucose in the body and include ketogenic diets, calorie reduction diets, extremely low carbohydrate diets, and fasting.1 Non-dietary metabolic treatments such as hyperbaric oxygen therapy (HBOT) help reduce inflammation and promote healing by incorporating greater amounts of oxygen into blood cells. In this article, several metabolic therapies for cancer will be explained.
Ketogenic Diets
Ketogenic diets are high fat, moderate protein, and low carbohydrate diets that produces ketone bodies instead of glucose as fuel for the body. When we stop eating carbohydrates whether through a carb-restrictive diet or fasting, our bodies burn their glucose stores in the liver in the form of glycogen and metabolically switch over to using ketones for fuel.2 The keto diet effectively starves cancer cells of glucose, their primary fuel source. Humans have evolved to be able to survive on ketones when food is scarce as our early ancestors experienced when they could not obtain food. The body and the brain are able to utilize ketones for energy; however, cancer cells are unable to utilize ketones to fuel their rapid growth. This metabolic inflexibility in cancer cells allows us to exploit this weakness by adopting a ketogenic diet.3 When the ketogenic diet is used as a dietary therapy for cancer, it is called a therapeutic ketogenic diet. If you’d like to read about my process, I wrote another article about my successful experience healing from ovarian cancer with the ketogenic diet.
Calorie Reduction Diets
Early research studies have indicated the positive effects of caloric reduction on tumors in mice.4,5 Positive effects on tumor cells were due to caloric content independent of the type of diet.6 The caloric count of the food was more significant than the nutritional content or specified diet for fighting tumor growth.6 In comparisons between caloric restriction and a ketogenic diet for brain cancer, results indicated a synergistic effect between the two metabolic treatments. For example, when mice were fed a ketogenic diet but could eat as much as they liked, tumors did not shrink; however, if they ate a reduced-calorie ketogenic diet that lowered body weight, tumors reduced significantly.7,8 Calorie-restrictive diets are most effective soon after diagnosis when individuals have greater energy.
Extremely Low Carbohydrate Diets
There are several popular low carbohydrate or low glycemic diets, but for cancer, an extremely low carbohydrate intake is necessary. Glucose is the primary fuel for cancer cells, and when it is severely restricted, cancer cells cannot generate the enormous amount of energy they need to proliferate.3 This makes cancer cells more sensitive to cellular death signaling or apoptosis. Typically, cancer cells are insensitive to these signals to die off and continue to grow.3 Low carbohydrate diets also positively affect health by increasing insulin sensitivity, decreasing inflammation, and inhibiting angiogenesis (the formation of cancer cells’ blood network to bring in nutrients).9 All of these positive effects of low-carb diets place increased stress on cancer cells.
Fasting
Fasting is another metabolic therapy for cancer, but it can be difficult for people to do prolonged fasts especially if they are already in a weakened state. Intermittent fasting (IF) is an alternative for those unable to undergo strict water fasts and shows promise for inhibiting tumor growth, though the relationship between long-term IF and harm from low calorie intake is not well studied.10 For patients undergoing chemotherapy, short-term fasting reduced treatment side effects, protected healthy cells from the toxicity of treatment, and demonstrated greater efficacy on cancer cells.11,12 In my case, after recovering from surgery, I combined intermittent fasting with the therapeutic ketogenic diet. I ate during a 6-hour window from 9:00 am to 3:00 pm (breakfast and lunch) and fasted until the next day. Approximately once a month, I also did a 1-3 day water fast. This combination put further metabolic pressure on cancer cells.
Hyperbaric Oxygen Therapy
Hyperbaric oxygen therapy (HBOT) is another metabolic therapy that raises the amount of oxygen in tissues expressed in atmospheres (atmospheric pressure at sea level).13 Cancer cells thrive in hypoxic (low oxygen) environments by adapting their cellular metabolism. HBO saturates cells with oxygen to put metabolic stress on tumor cells. HBO exhibited anti-cancer effects (decrease in blood glucose, decrease in tumor growth rate and increase in mean survival time) in mice when combined with a ketogenic diet but not as a stand-alone treatment.14 Although there were concerns about HBO’s safety and a potential proliferative effect for tumors in early research, recent research indicated that HBO had a low risk of complications, did not increase growth in tumors, and reduced cancer growth for breast cancer, but not for cervical and bladder cancers.15
In conclusion, metabolic therapies are gaining attention as effective, non-toxic treatments that can act synergistically with other treatments for greater effectiveness against cancer. There is a growing body of scientific literature on the efficacy of metabolic therapies and anecdotal stories of individuals – many with terminal cancers – who have successfully used metabolic approaches to heal from cancer.16 As always though with cancer, individuals may present with diverse physical, mental, and environmental terrain. Many have undergone standard treatments like surgery, chemotherapy, or radiation and may be weakened, so the impact of dietary therapies must be considered individually. Moreover, some dietary therapies may be better for some individuals given their conditions. Working with registered dietitians or certified nutritionists who specialize in the metabolic approach is highly recommended while also keeping your specialty oncologists or doctors informed. It is important to ask if your dietitian or nutritionist is familiar with the metabolic approach to cancer as not all are. Cancer patients may also ask their oncologists or doctors for referrals to registered dietitians. Adherence to these diets may be challenging in the beginning so professional, nutritional support is highly recommended.
References
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8Zhou, W., Mukherjee, P., Kiebish, M.A. et al. The calorically restricted ketogenic diet, an effective alternative therapy for malignant brain cancer. Nutr Metab (Lond) 4, 5 (2007).
9Szypowska A, Regulska-Ilow B. Significance of low-carbohydrate diets and fasting in patients with cancer. Roczniki Państwowego Zakładu Higieny. 2019;70(4).
10Zhao X, Yang J, Huang R, Guo M, Zhou Y, Xu L. The role and its mechanism of intermittent fasting in tumors: friend or foe? Cancer Biol Med.2021 Feb 15;18(1):63-73.
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12de Groot, S., Pijl, H., van der Hoeven, J. J., & Kroep, J.R. (2019). Effects of short-term fasting on cancer treatment. Journal of Experimental & Clinical Cancer Research, 38(1), 1-14.
13Tibbles, PM, & Edelsberg, JS. (1996). Hyperbaric-oxygen therapy. New England Journal of Medicine, 334(25),1642-1648.
14Poff, AM, Ari, C, Seyfried, TN, & D’Agostino, DP. (2013). The ketogenic diet and hyperbaric oxygen therapy prolong survival in mice with systemic metastatic cancer. PloS one, 8(6), e65522.
15Moen I, Stuhr LE. Hyperbaric oxygen therapy and cancer–a review. Target Oncol. 2012 Dec;7(4):233-42.
16Cancer Evolution. Evidence-based metabolic, lifestyle, and nutritional therapies for cancer prevention and treatment. Available at: https://cancerevolution.film. Accessed November 20, 2023.