September 17, 2023
By Angie N Choi, EdD, Author of Whole New Me: Healing From Cancer in Body, Mind, and Spirit
Alternative cancer diets, often viewed as complementary to traditional treatments, focus on using specific foods and nutrition to support healthy eating habits of cancer patients. These diets emphasize the significant impact of a natural diet on cancer prevention and management.
Alternative cancer diets such as ketogenic, Mediterranean, Paleo, vegetarian, macrobiotic, or Gerson diets are more popular with cancer patients who can take a more active role in their healthcare. Depending on factors such as type of cancer, stage, strength, motivation, beliefs, and support, cancer patients may take a passive or assertive role in their healing. In the midst of uncertainty, one thing a cancer patient can control is diet.
After being diagnosed with cancer and asking about what to eat to fight cancer, patients are often told they can eat anything they want. Doctors are well-intentioned but barely trained in nutrition and don’t realize the critical role that diet plays in the body’s terrain. Doctors are trained to use surgery and drugs to treat disease in conventional healthcare, and nutrition is not integrated into the standard of care. Although doctors can refer patients to registered dietitian nutritionists (RDNs), this is not common practice for cancer patients – a gravely missed opportunity.1,2 Working with an oncology RDN would support patients to receive customized dietary plans tailored to their needs. Thus, the onus is on patients to seek dietary information including alternative diets for cancer. In this blog, we will cover several alternative cancer diets.
Ketogenic Diet
The ketogenic diet is a low carbohydrate, moderate protein, and high fat diet. It restricts glucose, the primary fuel for cancer cell growth, and causes the body to shift to using ketone bodies derived from fat for energy. By removing glucose (carbohydrates) in the diet, cancer cells are less able to proliferate due to the lack of energy available to them, and cancer cells become more susceptible to death signals or apoptosis. One of the concerns for alternative cancer diets is that a large body of research with humans isn’t available on the effectiveness of these diets, however, studies on alternative cancer diets are on the rise. For example, there are 58 ongoing clinical trials on the ketogenic diet and cancer currently.3 The ketogenic diet creates a hostile environment for cancer cells and shows promise as an adjuvant therapy.4 I wrote another article on the ketogenic diet for cancer success stories of survivors who used the diet and are in remission.
Mediterranean Diet
The Mediterranean diet originated in dietary customs of people living near the Mediterranean Sea (Greece, Italy, Spain, Southern France). This diet is rich in foods that have antioxidants and anti-inflammatory nutrients. Studies have indicated that eating a Mediterranean diet was associated with lower rates of chronic diseases and cancer.5,6 The diet is high in fruits, vegetables, legumes (lentils and beans), nuts, seeds, whole grains, and healthy fats (unsaturated fats). Olive oil is the main source of fat used in salads and cooking. The diet is moderate in fish and seafood, and low in red meat. Herbs and spices such as oregano, garlic, basil, and rosemary are used to flavor dishes instead of too much salt.
Paleo Diet
The Paleo diet is named after the eating patterns of our ancestors during the Paleolithic age. This is a diet mostly of fish, meat, vegetables, and fruit (mostly berries) and excludes dairy and grains. Our early ancestors were hunter-gatherers not agrarians, so they didn’t grow crops and raise animals (no access to dairy and grains). It is a diet that is mostly protein and fat from animal sources with few carbohydrates – a diet that is easily digestible by humans. From a nutritional lens, the amount of food consumed is not as important as how much is actually digested. Research has also indicated that the Paleo Diet has a positive effect on metabolic diseases such as insulin resistance, type 2 diabetes, heart disease, and cancer.7,8
Vegetarian Diet
A vegetarian diet emphasizes plant-based foods such as fruits, vegetables, legumes, and whole grains. Meat is prohibited in a vegetarian diet, but some vegetarians are lacto-ovo-vegetarians who will eat eggs and dairy products. Research has indicated many health benefits of eating a plant-based diet, but “monotonous” vegetarians who eat the same food for long periods of time without variation may have nutritional deficiencies.9 Deficiencies in vitamin B12, iron, zinc, calcium, vitamin D, and essential fatty acids have been noted in vegetarians so monitoring and supplementation are important.10
Macrobiotic Diet
This diet was popularized by Japanese philosopher George Ohsawa and his student, Michio Kushi. The diet is primarily a plant-based, whole food diet with minimal processed foods. It has five main categories of foods with percentages of total foods consumed.11
- Whole cereal grains (40% – 60%)
- Vegetables (20% – 30%)
- Beans (5% – 10%) – fermented soy products (tempeh, natto, miso soup)
- Regular consumption of sea vegetables (nori, wakame, kombu, hiziki)
- Foods to be consumed a few times per week or less: fruit, white fish, seeds, and nuts
The diet is rooted in the philosophical concept of balance. All foods are characterized as yin (feminine, cool) or yang (masculine, hot). Eating in a balanced manner promotes better health than eating mostly just yin or yang foods. The seasons and individual temperaments also factor into a balanced diet. Other macrobiotic principles include undertaking physical activity, reducing exposure to pesticides and electromagnetic radiation, and reducing stress. Cancer research on the macrobiotic diet has indicated that women have modestly lower circulating estrogen levels which may be associated with lower breast cancer risk.12 However, studies are limited on the macrobiotic diet as a treatment for patients with cancer and further research is needed.
Gerson Diet
The Gerson diet was created by Dr. Max Gerson, a German physician. The diet is one of mostly raw vegetables, freshly squeezed vegetable and fruit juices every hour, and coffee or castor oil enemas. Other components of the diet include restricting salt, fat, and protein (temporarily), and supplementing with iodine, thyroid tablets, and vitamin C.13 This diet also focuses on stimulating the immune system and detoxification of the body. There is little research on the effectiveness of the Gerson diet for patients with active cancer, but some anecdotal evidence suggests that Gerson therapy supported patients both physically and psychologically despite being given poor prognoses originally.14
Although cancer patients may be willing to try alternative diets, they should be aware that diet alone may not be enough to cure active cancers. Patients may also waste time with alternative diets that may not work for them; however, this is not to discourage patients from using diet to support immune and metabolic functions in the body for healing. Healing from cancer is multifaceted and is influenced by individual lifestyle factors. Cancer patients should be educated on the important role of diet and nutrition as part of their treatment. Whether patients undergo standard treatment (surgery, chemotherapy, radiation) do a complimentary approach (diet as an adjunct to other treatment), or use diet as the main therapy, working with a registered dietitian nutritionist (RDN) trained in therapeutic diets for cancer is recommended. Here’s another article I wrote on choosing cancer nutritionists or oncology dietitians if you’d like to read more.
References
1Sullivan ES, Rice N, Kingston E, Kelly A, Reynolds JV, Feighan J, Power DG, Ryan AM. A national survey of oncology survivors examining nutrition attitudes, problems and behaviours, and access to dietetic care throughout the cancer journey. Clinical Nutrition ESPEN. 2021 Feb 1;41:331-9.
2Joseph R, Hart NH, Bradford N, Agbejule OA, Koczwara B, Chan A, Wallen MP, Chan RJ. Diet and exercise advice and referrals for cancer survivors: an integrative review of medical and nursing perspectives. Supportive Care in Cancer. 2022 Oct;30(10):8429-39.
3National Library of Medicine. ClinicalTrials.gov. https://clinicaltrials.gov/search?cond=cancer&intr=Ketogenic%20Diet. Accessed September 16, 2023.
4 Weber DD, Aminzadeh-Gohari S, Tulipan J, Catalano L, Feichtinger RG, Kofler B. Ketogenic diet in the treatment of cancer–where do we stand? Molecular Metabolism. 2020 Mar 1;33:102-21.
5Mentella MC, Scaldaferri F, Ricci C, Gasbarrini A, Miggiano GA. Cancer and Mediterranean diet: a review. Nutrients. 2019 Sep 2;11(9):2059.
6La Vecchia C. Mediterranean diet and cancer. Public Health Nutrition. 2004 Oct;7(7):965-8.
7Cordain L. The Paleo Diet: Lose Weight and Get Healthy by Eating the Foods You Were Designed to Eat. Hoboken: John Wiley & Sons; 2010.
8Andromalos L. The Paleo Diet. In Clinical Guide to Popular Diets. 2018 Jan 29 (pp. 71-86). CRC Press.
9McEvoy CT, Temple N, Woodside JV. Vegetarian diets, low-meat diets and health: a review. Public Health Nutrition. 2012 Dec;15(12):2287-94.
10Marsh K, Zeuschner C, Saunders A. Health implications of a vegetarian diet: a review. American Journal of Lifestyle Medicine. 2012 May;6(3):250-67.
11Horowitz J, Tomita M. The macrobiotic diet as treatment for cancer: review of the evidence. The Permanente Journal. 2002;6(4):34.
12Kushi LH, Cunningham JE, Hebert JR, Lerman RH, Bandera EV, Teas J. The macrobiotic diet in cancer. The Journal of Nutrition. 2001 Nov 1;131(11):3056S-64S.
13Weitzman S. Alternative nutritional cancer therapies. International Journal of Cancer. 1998;78(S11):69-72.
14Molassiotis A, Peat P. Surviving against all odds: Analysis of 6 case studies of patients with cancer who followed Gerson therapy. Integrative Cancer Therapies. 2007;6(1): 80-88.