A clinical trial found significant reductions in markers that define metabolic syndrome among participants who consumed a particular blend of healthy plant polyphenols found in olive oil for 12 weeks.¹

Olive oil is a key component of the Mediterranean diet, which is high in vegetables, fruit, whole grains, legumes, nuts and seeds, and low in red or processed meat, refined grain and oils, and added sugars. The diet has been associated with a lower risk of chronic diseases, including diabetes and cardiovascular disease.

"We hypothesized that olive oil polyphenols are the primary active ingredients in olive oil, with lipids potentially playing a secondary role in its disease-fighting properties," authors George Samoutis, MD, PhD, of University of Nicosia Medical School and colleagues wrote in the February 2026 issue of Clinical Nutrition ESPEN.¹

Compared with a placebo group, participants who were given these olive oil polyphenols showed significant reductions in fasting blood glucose, hemoglobin A1c (a marker of long-term glucose control), oxidized low-density lipoprotein (LDL), triglycerides, uric acid, the liver enzyme ALT, systolic blood pressure, body mass index and fatigue scores, while estimated glomerular filtration rate (eGFR), a marker of kidney function, increased. The authors of the report concluded that olive oil polyphenols show "promise in improving key metabolic markers in patients with metabolic syndrome. The intervention was well-tolerated, with no serious adverse events reported."

The double-blind, randomized, controlled trial included 48 participants diagnosed with metabolic syndrome who were given 10 milligrams per day of a specific blend of olive oil polyphenols and 54 participants who received a placebo for 12 weeks. Blood values, waist circumference, body mass index and fatigue were assessed at the beginning and end of the study. No adverse effects were reported.