Oleanolic Acid-Enriched Olive Oil Attenuates Kidney Function Decline in Patients With Type 2 Diabetes: Results From the OLTRAD Randomised Controlled Trial.

In 30 seconds

This prespecified, exploratory secondary analysis of the OLTRAD randomised controlled trial assessed kidney outcomes in 97 patients with type 2 diabetes assigned to oleanolic acid (OA)-enriched or control olive oil for 12 months alongside standard therapy. OA-enriched oil attenuated eGFR decline compared with control among participants whose baseline eGFR was 60-90 mL/min/1.73 m 2 (time × group interaction p = 0.010); no significant interaction was found in those with normal baseline eGFR. The intervention also prevented the rise in urinary albumin-to-creatinine ratio seen with control oil. Findings are exploratory, and the trial was not powered for renal outcomes.

Key findings

• Among participants with baseline eGFR of 60-90 mL/min/1.73 m 2, OA-enriched oil attenuated eGFR decline (time × group interaction p = 0.010).
• OA-enriched oil prevented the increase in uACR observed with control oil.
• OA reduced aldose reductase concentration and increased glyoxalase-I activity, with lower circulating methylglyoxal; carboxymethyllysine was unchanged.
• OA-enriched oil reduced ROS and MDA levels, while MDA increased with control oil.

Why it matters

Kidney function decline and albuminuria are important complications of type 2 diabetes. These findings suggest that OA-enriched olive oil may influence renal outcomes in people with mildly impaired baseline eGFR, alongside changes in AGE-related pathways and oxidative stress. The subgroup-specific, exploratory results provide a rationale for further study, but do not establish a renal benefit or its clinical importance.

What to keep in mind

This was an exploratory secondary analysis, and the trial was powered for glycemic control rather than renal outcomes. The reported eGFR effect was limited to participants with mildly impaired baseline eGFR.