Patients with high CV risk who adhered to a Mediterranean diet that was supplemented with nuts or extra-virgin olive oil had fewer major CV events compared with those who adhered to a reduced fat diet, according to the PREDIMED study.
“Our findings support a beneficial effect of the Mediterranean diet for the primary prevention of cardiovascular disease,” Ramon Estruch, MD, PhD, senior consultant at the internal medicine department of the Hospital Clinic (Barcelona) in Spain and associate professor at Barcelona University, and colleagues wrote.
Results were similar after exclusion of patients for whom there may have been protocol violations.
Researchers analyzed data from 7,447 patients from the PREDIMED study who were free from CVD at enrollment and had either type 2 diabetes or at least three major risk factors: hypertension, smoking, low HDL, elevated LDL, overweight or obesity, or a family history of premature CHD. Women were aged 60 to 80 years, and men were aged 55 to 80 years.
Patients were assigned a Mediterranean diet supplemented with nuts (n = 2,454; mean age, 67 years; 54% women), a Mediterranean diet supplemented with extra-virgin olive oil (n = 2,543; mean age, 67 years; 59% women) or a control diet (n = 2,450; mean age, 67 years; 60% women). All groups attended dietary training sessions at baseline and quarterly thereafter, in addition to completing questionnaires on diet adherence during each session. Those in the control group also received a leaflet with information on a low-fat diet annually.
All patients completed a general medical questionnaire, food frequency questionnaire and the Minnesota Leisure-Time Physical Activity Questionnaire on a yearly basis.
The primary endpoint was a composite of stroke, MI and CV death. Secondary endpoints included MI, stroke, CV death and all-cause death.
During a median follow-up of 4.8 years, the primary endpoint occurred in 288 patients, which affected 3.8% of patients assigned the Mediterranean diet with extra-virgin olive oil, 3.4% of those assigned a Mediterranean diet with nuts and 4.4% of the control group.
In primary analyses that adjusted for 12 baseline patient characteristics and propensity scores, the HR for a Mediterranean diet with extra-virgin olive oil was 0.69 (95% CI, 0.53-0.91) and 0.72 for a Mediterranean diet with nuts (95% CI, 0.54-0.95) compared with the control diet.
Results were similar after researchers omitted 1,588 patients who knew their group assignments or may have departed from the protocol.
“The modest between-group differences according to the food frequency questionnaire can be explained by the facts that most study participants had been consuming a baseline diet similar to the study Mediterranean diet and that the control group was given recommendations for a healthy diet, factors that raise the question of how applicable our results may be to high-risk persons in other countries,” Estruch and colleagues wrote. “Answering this question will require further research.” – by Darlene Dobkowski
Disclosures: Estruch reports he received grants from Spanish Institute of Health “Carlos III”; other support from Cerveza y Salud and Universidad Internacional de Catalunya; grants from Bicentury SA, Grand Fountaine and Novartis SA; personal fees from Brewers of Europe, FIVIN, Fundacional Cerveza y Salud, Instituto Cervantes, Lilly Laboratories, Prodeca - Generalitat de Catalunya and Wine and Culinary International Forum, and nonfinancial support from Columbia University, Fundacion Bosch i Gimpera and Harvard School of Public Health. Please see the study for all other authors’ relevant financial disclosures.