Primary Prevention of Cardiovascular Disease With a Mediterranean Diet (PREDIMED)

PREDIMED is the large randomized trial most often cited as evidence that a Mediterranean diet prevents cardiovascular disease — and this is its 2018 republished version, reissued after a methodological correction.

In nearly 7,500 high-risk but disease-free participants, a Mediterranean diet supplemented with extra-virgin olive oil or mixed nuts reduced major cardiovascular events by roughly 30 percent compared with a control low-fat diet (hazard ratios about 0.69 and 0.72). The benefit was substantial and achieved through food rather than medication.

The asterisk is real and worth stating: the original 2013 publication was retracted and reanalyzed after it emerged that some participants had not been individually randomized (some were enrolled by household or clinic). The corrected analysis preserved the main findings, but the episode tempers certainty and is the reason the trial carries a careful caveat.

We rate the evidence strong, with that caveat. Even allowing for the randomization irregularities, PREDIMED remains the best randomized evidence that a Mediterranean dietary pattern lowers cardiovascular risk in primary prevention.