Moderate calorie consumption increases the effectiveness of chemotherapy. This is one of the conclusions of a Portuguese-Brazilian study by the RISE Health Research Unit in association with the Federal University of Piauí, in Brazil, which sought to understand the impact of calorie restriction on the treatment of sarcomas, a rare type of cancer.

The study wasreleased on World Cancer Day, 4 February, a date promoted by the International Union Against Cancer (UICC) to raise awareness of the importance of prevention, early diagnosis and access to effective treatments.

The results of the study indicate that “calorie restriction, alone or in combination [with drugs such as doxorubicin, used in chemotherapy], significantly reduced the weight and volume of the tumour and increased the rate of tumour inhibition” and, at the same time, “protected normal cells from chemotherapy-induced damage”.

“The 40 percent reduction in calorie intake induced profound metabolic stress in the tumour microenvironment, compromising anabolic and proliferative processes essential for tumour progression,” reads the research published in the specialist journal Cancers.

Researcher Moisés Tolentino Bento da Silva (RISE-Health/ICBAS-UP) points out in a statement that “from this experimental study, carried out on animal models”, it was possible to “observe that calorie restriction – for short periods of time – can be favourable to cancer treatment”.

According to the researcher, who led the scientific work in Portugal, “the more energy consumed, the more the cancer develops and, therefore, by reducing calorie intake, we were able to reduce the energy supply to the tumour and, consequently, ensure greater effectiveness of chemotherapy”.

The researchers also found that, as well as having a positive impact on the effectiveness of chemotherapy, calorie restriction “contributes to the repair of DNA damage [caused by chemotherapy] in non-tumour tissues” and “reprogrammes lipid metabolism, reducing cholesterol and triglyceride levels” that feed malignant cells dependent on the renewal of fatty acids for energy production, proliferation and signalling of cancer and other chronic pathologies such as type II diabetes, cardiovascular diseases and neurodegenerative disorders.

Alongside a balanced diet and reduced calorie intake, the researchers also emphasise that regular physical exercise has a positive impact on cancer treatment.

“If cancer patients exercise adequately and regularly during chemotherapy, they will experience fewer side effects in various systems, such as the gastrointestinal tract. Physical exercise, together with a good diet, has great benefits for the patient’s quality of life, whether it’s preventative, during treatment or after the end of oncological treatment,” said Tolentino Bento da Silva.