A popular gym supplement used by millions to improve muscle strength could have another potential benefit, helping the immune system fight cancer. A new study by researchers from the University of California, Los Angeles, has found that creatine may help boost the body's cancer-fighting cells and improve the effectiveness of immunotherapy treatments.
Creatine is naturally produced by the body and is best known as a fitness supplement that helps increase supplies of adenosine triphosphate (ATP), the energy source needed by cells.
Previous research had shown that creatine could help killer T cells, which are part of the immune system's defence against cancer, attack tumours more effectively. The latest study has revealed that creatine also supports dendritic cells, which guide and activate T cells during an immune response.
Researchers said these findings could open new possibilities for improving cancer immunotherapy, a treatment that trains the immune system to target cancer cells. However, current immunotherapy treatments work effectively only for a proportion of patients.
"What this study shows is that creatine doesn't just help the T cells fighting cancer, it also energises the entire system that supports them," said immunologist Lili Yang.
To understand creatine's role, researchers studied cancer tumours in mice and examined the activity of genes linked to nutrients in dendritic cells. They found that the creatine transporter, which allows cells to absorb creatine, was much more active in tumour-related dendritic cells.
When researchers removed this transporter from dendritic cells grown in laboratories, the cells became weaker and were less effective at activating cancer-fighting T cells.
In another experiment, scientists increased creatine levels in mice with melanoma. They found that tumour growth slowed and the number and activity of dendritic cells increased.
The researchers said creatine metabolism appears to play an important role in controlling how dendritic cells support the immune system's response against cancer.
However, scientists stressed that the findings are still at an early stage. The research has only been tested in mice and laboratory-grown human cells, and clinical trials are needed to confirm whether creatine can improve cancer treatments in people.
Researchers also warned that cancer patients should not start taking creatine supplements without consulting their doctors.
Creatine is generally considered safe when taken at recommended doses, but its effects can vary depending on a person's health condition.
The next step will be clinical trials to test whether creatine supplementation can improve outcomes for patients receiving immunotherapy.
If future studies confirm the results, researchers believe creatine could become a low-cost way to support cancer treatments because it is widely available and already used for certain medical conditions.
The study was published in the journal iScience.
