Prevention of type 2 diabetes in prediabetic patients by using functional olive oil enriched in oleanolic acid: The prediabole study, a randomised controlled trial

AIM: To assess whether the regular intake of an oleanolic acid (OA)-enriched olive oil is effective in the prevention of diabetes. METHODS: In the PREDIABOLE study, prediabetic individuals (impaired fasting glucose and impaired glucose tolerance) of both sexes (176 patients, aged 30-80 years) were randomized to receive 55 mL/day of OA-enriched olive oil (equivalent dose 30 mg OA/day) [intervention group (IG)] or the same oil not enriched [control group (CG)]. The main outcome was the incidence of new-onset type 2 diabetes in both groups. RESULTS: Forty-eight new diabetes cases occurred, 31 in the CG and 17 in the IG. The multivariate-adjusted hazard ratio was 0.45 (95% CI, 0.24-0.83) for the IG compared with the CG. Intervention-related adverse effects were not reported. CONCLUSIONS: The intake of OA-enriched olive oil reduces the risk of developing diabetes in prediabetic patients. The results of the PREDIABOLE study promote the use of OA in new functional foods and drugs for the prevention of diabetes in individuals at risk of developing it.