The internet is on fire with an article just published in the New England Journal of Medicine in which researches concluded that a Mediterranean diet is much more effective than a “low-fat diet” in preventing cardiovascular disease. Unfortunately, a close and educated analysis of the study reveals that it is a load of bull and that their conclusions are simply unjustifiable, misleading and the fact that a well respected journal like NEJM ran their results is shameful.
The author’s conclusions:
Among persons at high cardiovascular risk, a Mediterranean diet supplemented with extra-virgin olive oil or nuts reduced the incidence of major cardiovascular events.
- The study noted that some authors had financial ties to food, wine and other industry groups.
- Foods were supplied by olive oil and nut producers in Spain, as well as the California Walnut Commission.
- The control group in the study or the “low-fat diet” group didn’t eat anything close to a low-fat diet, their total fat consumption decreased insignificantly in the trial (39% to 37%). The American Heart Association recommends <30% of your daily calories come from fat.
We acknowledge that, even though participants in the control group received advice to reduce fat intake, changes in total fat were small.”
- The control group was given very little support over the trial period in comparison to the intervention group.
- (Table 1). The researchers clearly did just about everything in their power to weight the outcome of the study in favor of the Mediterranean diet. They limited soda in the intervention group, but made no such recommendation in the low-fat group and soda is known to increase the risk of cardiovascular disease. They actually went so far as to recommended high intakes of high carbohydrate and starch foods like bread, potatoes and pasta.
- (Figure S5) The “low-fat” diet group patients were actually discouraged from eating fatty fish, I think we are all well aware of the cardio-protective benefits of omega-3 fatty acids at this point. Both Mediterranean diet groups were consuming fatty fish such as salmon. Unsurprisingly, if you pull up the supplemental materials for the study you will see that omega-3 fatty acid levels (alpha-linolenic acid) were significantly higher in both interventional groups.
- There was no statistically significant reduction in myocardial infarction in the study.
- There was no statistically significant reduction in death from cardiovascular causes in the study.
- There was no statistically significant reduction in any-cause death in the study.
- The only significant reduction was in death from stroke.
The only real conclusion researchers could have made is that there was a significant reduction in stroke in those consuming a Mediterranean diet high in omega‑3 fatty acids in contrast to a standard diet, anything beyond that is pure bologna. NEJM study PDF here, and supplement here.