New research from Yale shows that oleic acid, the main fat in olive oil, accelerated tumor growth in mice prone to pancreatic cancer, while omega-3 fats from fish oil cut disease development by half.
Scientists at Yale School of Medicine tested 12 high-fat diets with equal calories but different fat sources on mice genetically predisposed to pancreatic ductal adenocarcinoma. Diets rich in oleic acid led to faster tumor growth, whereas polyunsaturated fats, especially omega-3s, slowed progression. Lead author Christian Felipe Ruiz said the type of fat mattered more than the total amount. He noted that monounsaturated fats protect cancer cells from oxidation and ferroptosis, a form of cell death, while polyunsaturated fats make cells more vulnerable. The effects differed by sex, appearing stronger in males for oleic acid. The study, published in Cancer Discovery, has not been tested in humans but may inform prevention for those at higher risk of the disease.