Review finds two dietary fats may affect diabetes risk in opposite ways
University of Barcelona researchers say palmitic acid may disrupt insulin function, while oleic acid in olive oil may help protect it.
By Lucas Ferreira · Science & Environment Writer
3 min read
A new scientific review says two common dietary fats may push metabolic health in different directions, with one tied to processes involved in type 2 diabetes and the other linked to protective effects. The University of Barcelona said the findings point to fat quality, not only total fat intake, as a key issue in diabetes prevention and management.
The review, published in Trends in Endocrinology & Metabolism, examined research on palmitic acid and oleic acid. According to the University of Barcelona, the work was led by teams from the CIBER Area for Diabetes and Associated Metabolic Diseases at the university.
Palmitic acid is a saturated fatty acid found widely in foods. Oleic acid is a monounsaturated fatty acid found in high amounts in olive oil.
Different fats, different effects
Manuel Vázquez-Carrera, a professor at the University of Barcelona and a CIBERDEM group leader, said the review associates palmitic acid with poorer insulin sensitivity. He said oleic acid may help guard against metabolic problems related to type 2 diabetes.
The authors said palmitic acid appears to promote several cellular changes connected with metabolic disease. Xavier Palomer, the review’s first author, said the evidence links palmitic acid to buildup of harmful bioactive lipids, persistent low-level inflammation and stress in cell structures including the endoplasmic reticulum and mitochondria.
According to the researchers, those changes are connected with weaker insulin action and the development of metabolic disease. Insulin resistance is a central feature of type 2 diabetes, a condition the University of Barcelona described as affecting millions of people and carrying risks of serious complications and early death.
Oleic acid may support insulin signaling
The review found a different pattern for oleic acid, according to the University of Barcelona. The researchers said oleic acid supports storage of fat in forms that are less disruptive to metabolism and have little effect on normal cell activity.
The authors also said oleic acid helps preserve insulin signaling in tissues that are central to metabolic control, including liver, muscle and fat tissue. According to the review, oleic acid may counter some of the harmful effects linked to palmitic acid.
The University of Barcelona said those findings may help explain why diets high in monounsaturated fats, including the Mediterranean diet, have often been associated with lower rates of type 2 diabetes and related metabolic disorders. The review did not present a new clinical trial, but assessed existing evidence on the two fatty acids.
More targeted studies urged
The authors said more research is needed to explain why population studies can produce different results. Vázquez-Carrera said researchers should take into account where fatty acids come from, the broader diet in which they are consumed, how they interact with other nutrients and how food processing may alter their effects.
The research team said a clearer picture of those variables could improve assessments of how dietary fats influence metabolic health. According to the University of Barcelona, that work could support better dietary strategies for preventing and treating type 2 diabetes.
The review was written by Xavier Palomer, Ricardo Rodríguez-Calvo, Marta Tajes, Walter Wahli and Manuel Vázquez-Carrera. It was published in 2026 under the title “Palmitic and oleic acids in type 2 diabetes mellitus,” with DOI 10.1016/j.tem.2026.01.003.
This story draws on original reporting from ScienceDaily.