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 in the same paper governs how you should apply that.

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. The result stands, though it 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: 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 and diets delivered by dietitians. This is a randomized trial, not a study built on 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, so coordinate them 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.