Tumor cells are characterized by the utilization of glucose for energy outside the cellular mitochondria. Healthy cells metabolize glucose inside the cell mitochondria. This difference shows us a weakness in the tumor cell's metabolism of glucose for energy, because since it does so outside the mitochondria, it produces much less energy than the healthy cell.
How does the tumor cell compensate for this energy deficiency?
The tumor cell needs to metabolize large amounts of glucose to obtain the energy necessary for its growth. Therefore, the tumor cell has in its membrane many receptors for circulating glucose to bind to. These are the GLUT 1 receptors.
The ketogenic diet consists of drastically decreasing carbohydrates in the diet, as these are the source of glucose. Instead they are replaced with large amounts of healthy fats.
With not enough glucose available to use as an energy source in the body, the body begins to form ketone bodies from fats. Ketone bodies can be used by healthy cells for energy, but not by tumor cells.
On the other hand, the decrease in circulating glucose lowers blood insulin levels. Insulin acts as a stimulant of tumor growth, so by decreasing insulin levels in the blood, it hinders tumor growth.
Ketone bodies also alter amino acid metabolism and reduce the formation of new blood vessels surrounding the tumor.
The ketogenic diet in cancer is different from the usual ketogenic diets, since in cancer we have to take into account a series of aspects:
- The amount of daily protein should be restricted and it should be selected what type of protein should be consumed. Red meat and poultry should be eliminated.
- The amount of total calories per day should be monitored, adjusting to the patient's weight and condition. It is important to adjust calories to meet the needs of healthy cells, but not to overdo it so as not to feed the tumor cells.
- The type of fats consumed are the so-called "healthy fats" and they also have to be fats with a high ketogenic index.
It is important to have well planned diet with recipes that meet all the above requirements.
On the other hand, blood glucose and blood ketone bodies should be monitored to obtain the glucose/ketone ratio, which should be in a certain range to reduce tumor growth.
Ketogenic diets for cancer treatment are used in metabolic cancer therapy, so they must always be accompanied by nutritional supplements that help block the metabolic pathways of tumor cells.
Recent scientific studies on the ketogenic diet in the treatment of cancer:
- Murphy S, Rahmy S et al. (2024). Ketogenic diet alters the epigenetic and immune landscape of prostate cancer to overcome resistance to immune checkpoint blockade therapy. Cancer Res. 2024 Apr 8. doi: 10.1158/0008-5472.CAN-23-2742. Epub ahead of print. PMID: 38588411.
- Talib WH, Al-Dalaeen et al. (2023). Ketogenic diet in cancer management. Curr Opin Clin Nutr Metab Care. 2023 Jul 1;26(4):369-376. doi: 10.1097/MCO.0000000000000944. Epub 2023 May 9. PMID: 37265176.
- Pinato DJ. (2022)Ketogenic Diet as a Chemopreventative and Therapeutic Strategy for Colon Cancer. Gastroenterology. 2022 Jun 18:S0016-5085(22)00664-3. doi: 10.1053/j.gastro.2022.06.046. Epub ahead of print. PMID: 35728685.
- Weber DD, Aminzadeh-Gohari S, et al. (2020) Ketogenic diet in the treatment of cancer - Where do we stand? Mol Metab. 2020 Mar;33:102-121. doi: 10.1016/j.molmet.2019.06.026.
- Minzer S. (2020). Effectiveness of Ketogenic Diets on the Survival of Adult Oncological Patients. Nutr Cancer. 2020 Oct 19:1-11. doi: 10.1080/01635581.2020.1836243
