Calorie Restriction and Cancer Treatments

Limiting calories during cancer treatments often enhances outcomes. 
Written by Keith Bishop, C.N., B.Sc. Pharmacy 

Cancer is caused by various factors such as genetic mutations, exposure to radiation or chemicals, and unhealthy food and lifestyle. However, recent animal and human studies suggest that restricting food intake can enhance cancer survival rates.

Restricting food intake, also known as caloric restriction (CR), involves reducing the number of calories consumed while still maintaining essential nutrients. CR offers several health benefits, including improved insulin sensitivity, reduced inflammation, and increased longevity.

In humans, some studies have shown that CR can improve cancer chemotherapy treatment outcomes. In a study published in the Journal Cancer Research, researchers found that patients with breast cancer who followed a CR diet during chemotherapy had fewer side effects and a better quality of life compared to those who did not follow a CR diet. In another study, patients with prostate cancer who followed a CR diet had a slower rate of PSA progression, indicating a potential delay in cancer progression. While yet another study found benefits in patients with pancreatic cancer, colorectal cancer, triple negative breast cancer.

There are several reasons CR may benefit cancer treatments including reducing oxidative stress, and enhancing the immune system. CR also reduces the levels of IGF-1 (insulin like growth factor 1), a hormone that promotes cell growth and proliferation, which can contribute to cancer development.

Despite the promising results, CR is not a cure for cancer, and it is not recommended as the only treatment for cancer. Instead, it is recommended as an adjunct therapy to conventional cancer treatments such as chemotherapy, radiation therapy, and surgery. Moreover, CR can be challenging to implement and maintain, as it requires a significant change in lifestyle, including diet and exercise habits. Therefore, it is important to consult with a healthcare professional before starting a CR diet.

In conclusion, restricting food intake, or caloric restriction, can potentially enhance cancer survival rates. While the exact mechanisms are not yet fully understood, studies have shown that CR can slow down the progression of cancer in animals and improve cancer treatment outcomes in humans. However, CR is not a cure for cancer and should only be used as an adjunct therapy to conventional cancer treatments. Furthermore, it is essential to consult with your healthcare professional before starting a CR diet to ensure that it is safe and appropriate.

References Include

Das M, Webster NJG. Obesity, cancer risk, and time-restricted eating. Cancer Metastasis Rev. 2022;41(3):697-717. doi:10.1007/s10555-022-10061-3 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9470651/

Vidoni C, Ferraresi A, Esposito A, et al. Calorie Restriction for Cancer Prevention and Therapy: Mechanisms, Expectations, and Efficacy. J Cancer Prev. 2021;26(4):224-236. doi:10.15430/JCP.2021.26.4.224 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8749320/

Ligorio F, Fucà G, Provenzano L, et al. Exceptional tumour responses to fasting-mimicking diet combined with standard anticancer therapies: A sub-analysis of the NCT03340935 trial. Eur J Cancer. 2022;172:300-310. doi:10.1016/j.ejca.2022.05.046 https://pubmed.ncbi.nlm.nih.gov/35810555/

Zorn S, Ehret J, Schäuble R, et al. Impact of modified short-term fasting and its combination with a fasting supportive diet during chemotherapy on the incidence and severity of chemotherapy-induced toxicities in cancer patients - a controlled cross-over pilot study. BMC Cancer. 2020;20(1):578. Published 2020 Jun 22. doi:10.1186/s12885-020-07041-7 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7310229/

Wright JL, Plymate S, D'Oria-Cameron A, et al. A study of caloric restriction versus standard diet in overweight men with newly diagnosed prostate cancer: a randomized controlled trial. Prostate. 2013;73(12):1345-1351. doi:10.1002/pros.22682 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3767289/