In a recent study published in the journal Nature, researchers at IRB Barcelona identified one type of dietary fatty acid that promotes tumour expansion.

The study details the mechanism by which dietary palmitic acid, which is commonly found in palm oil, can increase metastasis in oral cancer and melanoma skin cancer. Palm oil is an ingredient found in numerous everyday products, from chocolate to toothpaste and shampoo. (Updated Jan 5, 2025)

According to the researchers, tumour cells that are temporarily exposed to a diet rich in palmitic acid can develop a more aggressive profile, which can remain as “memory” within the tumor cell.

This change causes cancer cells to conserve greater metastatic capacity, even months after having been exposed to the fatty acid. This effect was not seen in the presence of oleic acid (abundant in olive oil) or linoleic acid (omega-6).

Since having discovered how palmitic acid alters the cancer genome to make it more aggressive, researchers have started developing therapies to interrupt this process.

Metastasis, which is a medical term used to refer to the spread of a primary tumour to other parts of the body, is responsible for ninety per cent of cancer deaths in the world.

In the study, researchers found that adding palmitic acid into the diet of mice not only contributed to metastasis, but also had long lasting effects on the genome.

Cancer cells that were exposed to palmitic acid even for just a short period of time remained highly metastatic long after the fatty acid had been removed from the diet.

Cancer neural network

For a tumour cell to metastasize, first it must detach from the tumour of origin, enter the bloodstream or lymphatic system, reach another organ, and survive and grow there.

In this study, the authors found that a diet rich in palmitic acid allowed tumour cells to form a neural network around the tumour. This produces a regenerative environment for the tumour, which the cells use to their advantage to grow and spread.

How to slow down metastasis

One of the key elements in the formation of the neural network that promotes metastasis are the so-called Schwann cells, which surround and protect neurons. The study published in the journal Nature demonstrates that various approaches to block Schwann cells inhibit the development of this neural network, thereby preventing metastasis.

“This discovery paves the way for research into and the development of therapies that specifically block cancer metastasis, a process that is almost always the cause of death by cancer,” concludes Dr. Gloria Pascual, associate researcher in the Stem Cells and Cancer lab at IRB Barcelona and co-first author of the paper together with Dr. Diana Domínguez.

While the research team believes it is still too early to determine what type of diet could help cancer patients slow down the metastatic process, based on the results from this study, reducing the amount of palmitic acid in your diet could be a step in the right direction.