A new study from IRB Barcelona has found that a common ingredient in palm oil—palmitic acid—may play a dangerous role in helping certain cancers spread.
The research, led by Professor Salvador Aznar-Benitah and published in Nature, shows that palmitic acid can make cancers like oral cancer and melanoma more aggressive by promoting metastasis, the process where cancer moves from one part of the body to another.
Metastasis is the main reason why cancer becomes deadly. While treatments may shrink tumors or slow them down, stopping the cancer from spreading has always been one of the biggest challenges. This new study adds to growing evidence that what we eat may influence how cancer behaves in the body.
Palmitic acid is a fatty acid, one of the basic building blocks of fat. It’s found in many everyday foods, especially those made with palm oil, which is commonly used in baked goods, snacks, and processed items. While fatty acids are essential for health, this study found that not all of them act the same way when it comes to cancer.
The researchers discovered that palmitic acid encouraged cancer cells to spread more easily, while other fatty acids like oleic acid (found in olive oil) and linoleic acid (found in flaxseed) did not have the same harmful effect. In other words, not all fats are equal—some might be much riskier for people with cancer.
What makes the findings more concerning is that palmitic acid doesn’t just trigger cancer spread while it’s in the diet. The study showed that it causes long-lasting changes in the cancer cells. These changes, called epigenetic modifications, don’t alter the DNA directly but change how genes work.
Even after palmitic acid was removed from the diet, the cancer cells seemed to “remember” the exposure, staying aggressive and continuing to spread.
In mouse experiments, scientists fed the animals diets high in palmitic acid and observed that their cancer cells not only became more mobile but also changed their environment. The cancer cells built a kind of network around themselves—almost like forming connections with nearby nerves—helping them grow and spread.
This finding is important because it helps explain why some cancers are harder to control. The palmitic acid didn’t just feed the cancer; it reprogrammed the cells to thrive in other parts of the body. This ability to survive and grow in new tissues is what makes metastatic cancer so difficult to treat.
The research team is now working on potential treatments that could block this process. They’re developing therapies to stop cancer cells from using palmitic acid in this harmful way and are preparing clinical trials to test their ideas on real patients. If successful, these treatments could offer a new way to slow down or prevent cancer from spreading.
Even though the study raises serious concerns about palmitic acid, the researchers say it’s too early to recommend strict dietary changes. While avoiding foods high in palm oil might seem like a smart move, more studies are needed to confirm whether cutting out palmitic acid could help patients with cancer.
Still, the findings shine a light on how diet may affect cancer risk and progression. With palm oil in so many foods, this research could lead to changes in how we think about diet and cancer prevention.
In short, this study suggests that a common ingredient in many processed foods may not be as harmless as it seems—especially for people at risk of cancer. As scientists learn more, we may start to see diet playing a bigger role in cancer care and prevention.
For more information about cancer, please see recent studies that plant-based diets may reduce risk of colorectal cancer in men, and Low-fat diet may help stop cancer growth.
For more information about cancer, please see recent studies about How to harness the power of anti-cancer foods and supplements and results showing that Empower your plate: cancer-fighting foods and recipes.
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