The Mediterranean Diet Trial That Measured Heart Attacks, Not Weight

Most diet research measures weight, or a number in blood. CORDIOPREV measured heart attacks. One thousand and two people with established coronary heart disease were randomized to a Mediterranean diet or a low-fat diet and followed for seven years, with the endpoint a composite of myocardial infarction, revascularization, ischemic stroke, peripheral artery disease and cardiovascular death. The Mediterranean diet won: 87 events against 111.^[1] One detail governs how you should apply that, and it is in the same paper.

The trial

A single-center randomized trial at Reina Sofia University Hospital in Córdoba, Spain. Patients aged 20 to 75 with established coronary heart disease were assigned one-to-one to a Mediterranean diet or a low-fat diet, delivered by a team of dietitians. Physicians, investigators and the clinical endpoint committee were masked; participants obviously could not be, because people know what they are eating.^[1]

A log-rank p of 0.039 and adjusted hazard ratios whose confidence intervals stop just short of 1 (0.541–0.957 at one end, 0.568–0.998 at the other) describe a real but not overwhelming margin. This is a genuine result that would not have survived much more attrition.

⛔ The finding that is usually dropped

The effect was concentrated in men. Among 414 men on the Mediterranean diet, 67 (16.2%) had a primary endpoint event, against 94 of 413 (22.8%) on the low-fat diet — a multiadjusted hazard ratio of 0.669, log-rank p = 0.013. Among the 175 women in the trial, no difference was found between the groups.^[1]

How to read it if you are on a GLP-1

This trial is secondary prevention: everyone in it had already been diagnosed with coronary heart disease. It does not establish what a Mediterranean diet does for someone without that diagnosis, and it was not a weight-loss trial — the endpoint was cardiovascular events, not kilograms.

What it does offer is unusual and worth having: a dietary pattern tested to the standard we expect of drugs. Most nutrition advice you will meet alongside a GLP‑1 has nothing like this behind it. If you have established heart disease, this is the strongest dietary evidence in the field and it is worth raising with your cardiologist.

• Secondary prevention in people with existing coronary heart disease. Not a general-population result.
• Seven years, hard clinical endpoints, delivered by dietitians — not a self-reported food-frequency questionnaire.
• Benefit clear in men; no difference detected among the 175 women, who were too few to power the comparison.
• Not a weight-loss trial. Nothing here says a Mediterranean diet outperforms another for losing weight.
• ⚠ Diet changes alongside a GLP-1 can affect glucose control and medication needs. Worth coordinating with whoever prescribes.

For what the drugs themselves do on cardiovascular endpoints, see where the evidence is strongest; for the protein side of eating well during weight loss, protein targets and the lab panel.