Diet in cancer

For patients, a diagnosis of oncology is not only a long and complex diagnostic and therapeutic process, but also a necessity for adapting to a new reality. One of the fundamental aspects of daily life for cancer patients is nutrition. Nutritional status is a significant factor in prognosis, so diet is crucial at every stage of treatment.

The influence of eating habits on the development of cancer 

With the gradual decline in smoking on a global scale, poor dietary habits (and the resulting obesity) are becoming among the most significant risk factors for developing cancer. A disproportionately high intake of meat rich in animal oils or deep-frying foods can increase the incidence of colon cancer, stomach cancer, and prostate cancer. At the same time, regular consumption of fruits and vegetables (especially garlic, cabbage, broccoli, and cauliflower), which includes a high intake of folic acid, selenium, vitamin B12, vitamin D, antioxidants (e.g., carotenoids and lycopene), and moderate consumption of low-fat milk and whole-grain bread, may reduce the risk of breast cancer and cancers of the entire digestive system, including the oral cavity.

Modern evidence-based medicine most often focuses on the Mediterranean diet , with a simultaneous increase in interest in the ketogenic diet .

The United Nations Educational, Scientific and Cultural Organization (UNESCO) recognized the former in 2010 as "intangible cultural heritage of France, Italy, Greece, Spain and Morocco.".

Diet in cancer

Mediterranean diet 

The Mediterranean diet is characterized by a high consumption of: vegetables, legumes, fresh fruit, unrefined cereals, nuts and olive oil (especially extra virgin); moderate consumption of fish and dairy products, low consumption of red meat and occasional consumption of alcohol (mainly red wine) with main meals.

Although the results of available scientific studies should be interpreted with caution (due to a number of variables, such as geographic area and its associated air pollution levels, lifestyle, hereditary factors, and food source), the Mediterranean diet may have a protective effect against cancer. This is particularly true with high consumption of olive oil and fresh vegetables and fruit, thanks to the anti-inflammatory and antioxidant properties of these foods. It is also important to consider the negative role of hormones and antibiotics present in consumed foods (e.g., estradiol, progesterone, and androgen are considered carcinogenic, while antibiotic resistance, by altering gut flora, contributes to an increased risk of colon cancer). It is also important to combine the diet with regular physical activity.

Ketogenic diet for cancer patients

The ketogenic diet is based on a 3:1 ratio of fat and protein to carbohydrates. Limited consumption of simple and complex sugars results in the oxidation of fatty acids to produce ketone bodies (the most common of which are β-hydroxybutyric acid, acetone, and acetoacetic acid), which are the body's primary energy source. It is speculated that following a low-carbohydrate diet may reduce insulin resistance, inflammation, and alter gene expression in ways that enhance anticancer potential.

Although research on the ketogenic diet is currently in its early stages, preliminary scientific reports suggest the possibility of reducing the toxicity of chemotherapy and thus improving the quality of life, especially in patients with malignant tumors of the central nervous system.

Important!

Nutrition in cancer should be considered an integral part of cancer treatment. Patient-physician collaboration should include efforts to achieve a sustainable, healthy, and conscious lifestyle, especially in the face of a cancer diagnosis. A balanced diet, focused on reducing so-called "empty calories" in high-carbohydrate foods, along with regular physical activity, can help both reduce the risk of cancer and improve treatment outcomes if diagnosed.

Dr. Karol Rawicz-Pruszyński, MD, PhD
, Surgeon, professor at the Medical University of Lublin