Adhering to a Mediterranean diet high in extra-virgin olive oil intake reduced the risk for diabetes by 40% in patients at high risk due to pre-existing cardiovascular conditions, according to study findings.
“We found that a long-term intervention with a high-quality dietary pattern akin to the traditional Mediterranean diet and rich in [extra-virgin olive oil] could reduce the incidence of diabetes in older persons at high cardiovascular risk,” Jordi Salas-Savadó, MD, PhD, of the Universitat Rovira i Virgili in Reus, Spain, and colleagues wrote. “Of note, this dietary pattern is palatable and has a high potential for long-term sustainability, with obvious public health implications for primary prevention of diabetes.”
In the PREDIMED study, patients aged 55 to 80 years were randomly assigned to one of three diets: Mediterranean diet supplemented with extra-virgin olive oil (n=1,154), Mediterranean diet supplemented with nuts (n=1,240), or a control diet (n=1,147). Energy restrictions and physical activity increases were not implemented or advised.
During the median 4.1 years of follow-up, researchers found that both Mediterranean diet groups had increased adherence scores, as measured by a questionnaire, and those scores were higher than the control group (P<.010 for all yearly comparisons). In further evidence, urine hydroxytyrosol levels increased among patients using the Mediterranean diet supplemented with extra-virgin olive oil (P<.05), whereas plasma alpha-linolenic acid levels increased in those using the diet supplemented by nuts (P<.05). No such changes were seen in the control group.
During the course of follow-up, 273 patients developed new-onset diabetes: 80 patients in the group eating a Mediterranean diet supplemented with extra-virgin olive oil; 92 in the group eating a Mediterranean diet supplemented with nuts; and 101 in the control group.
“When both Mediterranean diet groups were merged, a 30% relative risk reduction vs. control was apparent,” the researchers wrote (HR=0.7, 95% CI; 0.54-0.92). The extra-virgin olive oil supplemented group showed a 40% risk reduction, whereas the nut group showed an 18% risk reduction, according to data.
Disclosure: Please see study for a full list of researchers’ financial disclosures.