Is the Mediterranean diet really overhyped and based on shabby science?
Is the Mediterranean diet really overhyped and based on shabby science? R
May is Mediterranean Diet Month and, as I’m sure you’re aware, the Mediterranean-style diet is widely hailed as one of the healthiest diet patterns you can choose—despite the fact that you end up eating almost half your calories in the form of fat. (Our own government still recommends that we limit fat to 20-35% of calories.)
But the research just keeps pouring out—the Mediterranean diet reduces your risk of heart disease, cancer, diabetes, and Alzheimer’s. It slows aging, boosts weight loss, protects memory, and even enhances academic performance in kids. (See below for a few of the most recent papers.)
Yet, in the best-selling book, The Big Fat Surprise, journalist Nina Teicholz argues that the Mediterranean diet is overrated and based on shabby science. Is our current infatuation with olive oil and red wine based on a hoax? Are all the studies bogus?
Teicholz and her publishers went out of their way to position The Big Fat Surprise as a hugely controversial book, one that would stand the conventional dietary wisdom on its head. But her central argument—that dietary fats (and saturated fat, in particular) are not the enemies they were once made out to be—is just not that controversial. The book is exhaustively researched and impressively well-documented, but I’m afraid that by the time it was published, no one really needed convincing anymore. Most of the nutrition world had already come to the same conclusion.
See also: Is the Link Between Cholesterol and Heart Disease Bogus?
But this ancillary attack on the Mediterranean diet did take me by surprise. Could we have made the same mistake with the Mediterranean diet as we did with low-fat diets, basing them on faulty premises and then unwittingly designing biased studies that would confirm our convictions?
The Mediterranean diet pattern is big on whole grains, legumes, fruits, vegetables, olive oil, nuts, and red wine, with smaller amounts of fish, eggs, chicken, and whole fat dairy, and very little red meat. In other words, it’s a plant-based (but not strictly vegetarian), whole-food diet.
Now, I have to admit: I do have a dog in this fight. Although I firmly believe that there are many ways to build a healthy diet and that no one solution is right for everyone, the Mediterranean Diet is my personal preference. I like the cuisine, it’s a good fit with my lifestyle and the way I like to cook, and I find it satisfying and sustainable.
So, it was not without trepidation that I decided to look into these charges further. Would my favorite way to eat healthy turn out to be not so healthy after all?
This whole story started when some nutritional epidemiologists observed that the inhabitants of the island of Crete were unusually long-lived and healthy and decided to see what they were doing right.
At the center of Teicholz’s complaint is that the diet that was documented in the Greek Islands during the 1950s didn’t reflect the usual diet of the inhabitants. “They were surveyed shortly after WWII, when their economy was in ruins,” Teicholz told Dr. Frank Lipman in an interview. “Also, their diet was sampled during Lent, when animal foods were severely restricted. The data was therefore not any good and never grew any better.”
It may be true that the dietary pattern that became known as the Mediterranean Diet was an aberration. I don’t know what Cretans typically ate before the war or when it wasn’t Lent. It doesn’t really matter. Because this dietary pattern has now been extensively researched in populations around the world and has been found to be far more healthful than the standard Western modern diet.
Why has the Mediterranean diet been studied so much? The answer is partly because it’s become an increasingly good bet. Researchers like to find stuff that works and the Mediterranean diet has established a pretty good track record for generating positive outcomes. Teicholz, on the other hand, argues that the real reason so many researchers have cottoned to the diet is that the Mediterranean is a nice place to visit.
“There's no question that the reason everybody got interested in that diet was partly the allure of the Mediterranean junket,” Teicholz told Medscape. “There are long-lived people in the Siberian Steppe, but nobody wants to go to food conferences in Siberia.”
OK, but does that disprove the research's validity? Of course not. And Teicholz admits that the Mediterranean diet has performed extremely well in clinical trials—but she asserts that any diet similarly high in fat would perform well when compared to a low-fat diet. “A higher-fat German diet or a higher-fat Chilean diet or a higher-fat Finnish diet would probably also look better than the low-fat diet,” she told Medscape.
Having lived several years in Germany, I have my doubts about whether a high-fat German diet would beat the Mediterranean diet on any measure of health. But that’s a testable claim. By all means, let’s stop pitting the Mediterranean diet against low-fat diets (which no one really endorses anymore) and start comparing it to other diets with similar fat composition and see what we can learn.
Other dietary patterns may be under-researched, but the enthusiasm surrounding the Mediterranean diet has a lot of good data to back it up. Of course, the closer you adhere to the pattern, the better your results are likely to be. Want to find out how your diet compares with the Mediterranean diet? You can calculate your Mediterranean diet score here.
References
Esteban-Cornejo I, Izquierdo-Gomez R, et al. Adherence to the Mediterranean diet and academic performance in youth: the UP&DOWN study. Eur J Nutr. 2015 May 15. Morris MC, Tangney CC, et al. MIND diet associated with reduced incidence of Alzheimer's disease. Alzheimers Dement. 2015 Feb 11.
Sleiman D, Al-Badri MR, Azar ST. Effect of mediterranean diet in diabetes control and cardiovascular risk modification: a systematic review. Front Public Health. 2015 Apr 28;3:69.
Trichopoulou A, Lagiou P, et al. Cancer and Mediterranean dietary traditions. Cancer Epidemiol Biomarkers Prev. 2000 Sep;9(9):869-73.
Valls-Pedret C, Sala-Vila A, et al. Mediterranean Diet and Age-Related Cognitive Decline: A Randomized Clinical Trial. JAMA Intern Med. 2015 May 11.