Great-looking results from a big randomized diet study reported today in the New York Times:
About 30 percent of heart attacks, strokes and deaths from heart disease can be prevented in people at high risk if they switch to a Mediterranean diet rich in olive oil, nuts, beans, fish, fruits and vegetables, and even drink wine with meals, a large and rigorous new study has found….
Scientists randomly assigned 7,447 people in Spain who were overweight, were smokers, or had diabetes or other risk factors for heart disease to follow the Mediterranean diet or a low-fat one.
Low-fat diets have not been shown in any rigorous way to be helpful, and they are also very hard for patients to maintain — a reality borne out in the new study, said Dr. Steven E. Nissen, chairman of the department of cardiovascular medicine at the Cleveland Clinic Foundation.
Now, I am not a low-fat dude. Long ago I dated somebody who was into Dean Ornish and every time she “sauteed” onions in water a little piece of me died. I pour a lot of olive oil on things, because I like it (especially Frantoia, which the guys at the Italian grocery in the Trenton Farmer’s Market turned me on to when I lived in Princeton) and because mainstream nutritional wisdom has been promoting monounsaturated fats for a long time now. But I do think low-fat gets kind of a bad rap from the NYT piece. Even more so in some of the other coverage, like the LA Times, which headlines their story “Mediterranean diet, with olive oil and nuts, beats low-fat diet.” The Times, at least, points out far down in the piece that the “low-fat” group, while counseled to reduce fat, didn’t actually do so. To get numbers, you have to go to the supplemental material of the original paper. There, you find that the Mediterranean eaters were getting 41% of their calories from fat, while the “low-fat” arm got 37%. A low-fat diet is 22%. Random googling suggests that most vegans are getting 20%-30% of their calories from fat.
In other words, the study doesn’t really show that the Mediterranean diet is better for you than eating low-fat; it shows that hardly anybody is capable of eating low-fat, which is a different thing entirely.