Oleic acid, the main fat in olive oil, could have an unexpected effect: it promotes the development of pancreatic cancer. Although known to be good for the cardiovascular system, this fatty acid accelerates tumor growth in mice. In contrast, omega-3s from fish oil reduce the occurrence of the disease by half.
The team from Yale University tested twelve high-fat diets on animal models genetically predisposed to pancreatic cancer. Each diet contained the same number of calories but different lipid sources, reflecting our modern eating habits. The researchers found that the type of fat directly influences tumor progression.
Illustration image Pixabay
Christian Felipe Ruiz, co-author of the study published in
Cancer Discovery, explains that the effect can be radically opposite depending on the fatty acid consumed.
Diets enriched in oleic acid, found in olive oil, safflower oil, and lard, accelerated tumor formation in male rodents. In contrast, diets based on omega-3s, such as fish oil, reduced tumor burden by 50%. The scientists observed a direct relationship between the ratio of monounsaturated to polyunsaturated fatty acids and disease progression. The higher this ratio, the more the tumors developed.
The key mechanism lies in ferroptosis, a form of programmed cell death triggered by lipid oxidation. Polyunsaturated fatty acids, like omega-3s, oxidize easily, making cancer cells vulnerable to this destruction. Conversely, monounsaturated fatty acids like oleic acid in olive oil resist oxidation, protecting tumors. According to the researchers, this balance between protective and vulnerable fats largely determines the fate of malignant cells.
The study revealed notable differences between sexes. Oleic acid only promoted tumors in males, while the protective effects of omega-3s were present in both sexes. The authors called for further investigation into these differences to refine future nutritional recommendations.
Although these findings have not yet been confirmed in humans, they open avenues for the prevention of pancreatic cancer, one of the deadliest. People at risk, such as those with chronic pancreatitis or late-onset diabetes, could benefit from personalized dietary advice. The researchers plan to study whether altering the composition of fats in the blood could serve as an early warning signal. One question often arises: what to change in one's diet? This study is beginning to answer it.