A common type of fat found in palm oil may make some cancers more likely to spread through the body, according to research from IRB Barcelona.
The study found that palmitic acid could encourage the spread of oral cancer and melanoma in laboratory models.
Cancer becomes especially dangerous when it spreads from its original location to other organs, a process known as metastasis. Most cancer deaths are linked to metastatic disease, because cancer that has spread widely is usually much harder to treat than a tumor that remains in one place.
Researchers have therefore been trying to understand what allows some cancer cells to leave a tumor, survive in other parts of the body and begin growing again. Diet and the way cancer cells use fats have become important areas of this research.
The team, led by Professor Salvador Aznar-Benitah, studied several fatty acids, which are basic components of the fats found in food and in the human body. They were particularly interested in palmitic acid, a saturated fatty acid that is abundant in palm oil but is also naturally present in many other foods and produced by the body.
In experiments involving mice, diets containing extra palmitic acid increased the ability of oral cancer and melanoma cells to spread. However, the researchers did not see the same effect with oleic acid or linoleic acid, two other fatty acids commonly found in foods such as olive oil, nuts, seeds and some plant oils.
One of the most striking findings was that the effect of palmitic acid did not simply disappear when exposure ended. Cancer cells that had been exposed to it for a limited period appeared to “remember” that exposure and remained more capable of spreading later.
The researchers found that palmitic acid caused changes in how certain genes behaved without changing the underlying DNA code. Scientists call these epigenetic changes, and they can act like switches that make some genes more or less active for long periods.
These changes appeared to prepare cancer cells for metastasis. In particular, the affected cancer cells became better at interacting with nerves and other parts of the tissue surrounding the tumor, creating conditions that helped them survive and spread.
The discovery is important because it may reveal a weakness that future cancer treatments could target. If scientists can interrupt the signals created after exposure to palmitic acid, they may be able to reduce the ability of cancer cells to establish themselves elsewhere in the body.
The researchers identified biological pathways involved in this process and began exploring ways to block them. Their work could eventually contribute to treatments designed specifically to prevent or slow metastasis rather than simply shrinking the original tumor.
However, the results do not prove that eating palm oil causes cancer to spread in people. Much of the work was carried out in experimental models, and the relationship between a person’s overall diet, fatty acids in the body and cancer progression is much more complicated.
The researchers also cautioned against making major dietary changes based only on these findings. People undergoing cancer treatment need enough calories and nutrients, and unnecessarily removing foods from the diet could create other health problems.
The study, led by researchers at IRB Barcelona, was published in the journal Nature. It provides new evidence that nutrients can influence the behavior of cancer cells and suggests that past exposure to certain fats may leave lasting biological changes that affect how those cells spread.
More research is needed to determine whether reducing palmitic acid in the diet can influence cancer outcomes in humans. For now, people with cancer should discuss dietary concerns with their medical team rather than changing their treatment or diet based on laboratory findings alone.
If you care about cancer, please read studies that a low-carb diet could increase overall cancer risk, and vitamin D supplements could strongly reduce cancer death.
For more health information, please see recent studies about how drinking milk affects the risks of heart disease and cancer and results showing higher intake of dairy foods linked to higher prostate cancer risk.
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