A major benefit of the Mediterranean diet is its emphasis on whole, unprocessed foods like fruits, vegetables, legumes, and fish. This is a much healthier diet than a typically American diet full of fast food and other artery-cloggers like cheese, butter, red meat, processed meats, refined flour, sugar, and salt.
A major disadvantage of the Mediterranean diet is that it is too rich in oil. In very small amounts, as we recommended at the Pritikin Longevity Center (no more than 2 teaspoons daily), oils are relatively harmless.
But if Americans start using more, they may never shed excess weight, as was the case with the individuals in the newly published Mediterranean diet study. For five years they followed the Mediterranean diet, and for five years their weight remained the same.
It’s really no surprise. Oil is the most calorie-dense food on earth. Ounce for ounce, oil has even more calories than butter or bacon. By the pound, butter and bacon each tally up 3,200 calories. Olive oil and all other oils pack in more than 4,000 calories per pound.
Too much oil and other refined fats will likely add, not subtract, to our already plump waistlines, heightening the risk of all sorts of devastating diseases, including this country’s #1 killer: heart disease.
The Mediterranean diet, rich in oil and nuts (another calorie-dense food), is best suited for very active people who are close to their ideal weight. (How many Americans are very active and close to their ideal weight?)
There is also considerable science to suggest that the much-promoted message that “olive oil is heart healthy” is questionable at best.
Several studies have poked holes in olive oil’s heart–health claims. For example, when researchers from the University of Crete compared residents of Crete who had heart disease with residents free of the disease, they found that the residents with heart disease ate a diet with “significantly higher daily intakes” of monounsaturated fats (principally from olive oil) as well as higher fat intake overall.*
Another study investigated how well people’s arteries could dilate (expand) to accommodate increased blood flow after they had eaten several different meals. Each meal emphasized a different component of the Mediterranean diet. After the meal rich in olive oil, the ability of people’s arteries to dilate was significantly impaired.**
This supposedly “good” olive oil–rich meal, in effect, elevated blood fats and crippled the workings of the endothelium (the inside skin of the arteries), which put the squeeze on blood flow and reduced the arteries’ ability to deliver more blood to tissues. Research has shown that things that impair endothelial function in the short term usually contribute to clogged arteries in the long run.
No problems with impaired endothelial function occurred with meals enriched in other parts of the Mediterranean diet, including vegetables, fruits, fish, and legumes (beans).
“The beneficial components of the Mediterranean diet,” concluded the study’s lead author Robert Vogel, MD, and colleagues at the University of Maryland School of Medicine, “appear to be antioxidant–rich foods, including vegetables, fruits, and their derivatives such as vinegar, and omega–3–rich fish…”
These foods “appear to provide some protection against the direct impairment in endothelial function produced by high–fat foods, including olive oil.”
So if you’re not eating fruits and veggies, you’re not getting protection from olive oil’s damaging effects. If you’re pouring olive oil on an already bad diet – one devoid of protectors and full of destroyers like cheeseburgers – you’ve only made that diet worse.
A study published in the Journal of the American College of Cardiology also found that “dilation was worse” after 24 people, 12 healthy and 12 with high cholesterol levels, consumed olive oil.***
Written by Gayl Canfield, PhD, RD, Director of Nutrition at the Pritikin Longevity Center in Miami, Florida
* British J of Nutr, 2004; 91 (6); 1013.
** J Am Coll Card, 2000; 36: 1455
*** J Am Coll Card, 2006; 48: 1666
What is your opinion about the benefits of the Mediterranean Diet? Is this a diet or should be a lifestyle? Share your opinion in the comments section please.