By now virtually everyone has heard of the benefits of the Mediterranean diet, even more so now that bold new research, called the PREDIMED study and just published in the New England Journal of Medicine, has shown that such a diet can reduce the risk of heart attacks, strokes and heart-related deaths by about 30 percent. When compared to a standard low-fat diet, the results were so staggeringly positive that the researchers stopped the study early, after only five years, because they considered it unethical to deprive the low-fat group of the better diet.
What Defines the “Med Diet”?
Ask this question and you’ll get more answers than there are Mediterraneans. Most people think it’s all about pouring olive oil over everything and eating a lot of fish. Well, yes and no. The PREDIMED participants were divided into two groups. One was asked to eat at least a quarter of a cup of olive oil daily, the other to have two tablespoons of olive oil plus an ounce of nuts. No total calorie restriction was advised, nor was physical activity promoted. The rest of the Med diet was the same for both groups:
- Three servings of fruit and two servings of vegetables;
- Beans and fatty fish at least three times a week each;
- If you drink wine, then seven or more glasses a week, but only with meals;
- A few times a week or less: red meat, soda, “spread fats” (e.g., butter and margarine).
There are a few other inclusions, but you get the idea. (Click here to see a detailed food list and the quantities recommended to the study participants.) The other group studied was given instructions for a “low-fat” diet. Results seemed to be the same for either form of the Med diet.
The people following the Med diet fared much better than those who followed the low-fat diet, making the low-fat diet look not so healthy—but the key word here is “followed.” The Med diet subjects were tested for certain compounds in the blood and urine that are present when people eat olive oil and nuts, to ensure that they were complying with the diet. No such compliance was verified for the low-fat diet group, and it was not easy to get the latter group to follow the diet. If compliance was poor—and it probably was—then the researchers weren’t really studying the effects of a low-fat diet. They were testing the effects of a typical bad diet—the kind that put the participants at risk in the first place.
Where’s the Beef?
Beef can fit on the Med diet, but not much of it; that’s a problem for many Americans, and with some reason. But there are some 19 cuts of beef with about the same amount of fat, ounce for ounce, as chicken or turkey. So what’s significant may be a matter not of whether you choose beef or fish, but of how much and which cuts of beef you eat. The problem is, no one has studied such specifics.
Where the Med Diet Stumbles
The PREDIMED study focused on heart health only. That’s fine, because heart disease is our number one killer. But there’s more to being healthy than just having a healthy heart. The PREDIMED study diet didn’t address low-fat or fat-free dairy foods much, and gave participants little guidance either way about dairy products, other than saying they could be included.
This is my problem with the Mediterranean diet in general. It’s terrific, but it could use a good infusion of low-fat and fat-free dairy foods. A healthy heart shouldn’t have to pump blood through a hip replacement, and there’s a mountain of research showing that a good intake of calcium-rich foods produces bones that are stronger. And low-fat dairy foods have been shown to be important for reducing blood pressure—a risk factor for heart disease. The landmark DASH (Dietary Approaches to Stop Hypertension) diet proved how the combination of dairy and produce could lower blood pressure. DASH has even been endorsed by the U.S. Department of Agriculture.
Salt Wars
Speaking of blood pressure—and I hope Mayor Bloomberg is reading this—there was no mention at all in the PREDIMED study of sodium intake on either the Med diet or the low-fat diet. This is interesting, because the majority of people get more sodium than most government health departments recommend. Unless people are really motivated to cut their sodium, they probably won’t. Some of the participants (an equal number in each group) were on diuretics or other medications to reduce blood pressure, so they may have been trying to limit their sodium intake, but we don’t know for sure. Either way, better results prevailed for the people on the Med diet, so maybe sodium is less of an issue for heart health than we thought.
Heavy Stuff—or at Least Not Light
No group—Med diet or not—in the PREDIMED study lost weight. This is important. Even a heart-healthy Med diet won’t be enough to slim you down. Olive oil may be good for your heart, but it has as many calories as any other fat, and that doesn’t help your waistline. If you’re happier with your diet, though, you may be satisfied with a realistic amount of food and less tempted to overdo it.
The REAL Mediterranean Diet
One side note that I feel compelled to point out: the Med diet in this study isn’t the original Mediterranean diet.
On this issue, I have some street cred. I’m Greek on my mother’s side, and the original Mediterranean diet existed long before researchers began studying it. I can tell you that it looked nothing like the Med diet of today. It was heavily tied to religion and included a lot of “fasting days” on which one category or another of foods was avoided. You would be giving up meat, bread, cheese or even fish and olive oil at various times during the year. There were about 150 days a year when at least some type of food was being avoided! The reasons for this are debated, but it may have been a way to make food stretch when it was scarce. People follow religious rules more carefully than they follow “suggestions.”
At any rate, what we think of as a “traditional Mediterranean diet” is probably an adaptation of the original one. I’m not advocating for all that sacrifice, mind you, just saying that the real traditional Mediterranean diet is a bit different than the one we see today.
The Best Part of the PREDIMED Study
We need to deal with chocolate. It was not known to the Greeks before modern times, but I have to think that if they’d known about it, they would have valued it as much as the rest of us do. In the PREDIMED study, there was no particular limit on it, only the rule that it be at least 50 percent dark chocolate, as least according to an article in the New York Times. The New England Journal of Medicine study did not discuss this specifically, but the authors may have elaborated to the Times reporter, and it’s good news for chocoholics. Most chocolate research says that the benefits from chocolate come when it’s at least 70 percent cocoa solids. Real chocolate connoisseurs will have no trouble with that. Being one myself, I’m in—at least until the next landmark study emerges.
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Interesting article and some valid points but one I do have to question is the reference to ‘low fat dairy or fat free dairy’ as being a way to reduce blood pressure and heart disease. As far as I’m aware there hasn’t been one conclusive study done on heart disease being caused by fat laden dairy products. I feel inclined to agree with two time nobel prize winner, Linus Pauling’s findings that the real cause is the lack of vitamin C which leads to arterial damage and then athlerosclerosis. This is merely looking at the symptoms rather than the cause.
A growing number of respected doctors, including Dean Ornish, Caldwell Esselstyn, and Joel Fuhrman among others are strongly opposed to the use of olive oil; especially for those facing heart problems. Former U.S. President Bill Clinton has personally eliminated oils as well as animal products from his diet in attempt to recover from heart disease. As you correctly mentioned the traditional Mediterranean diet and lifestyle differed dramatically from today’s. We must not forget that earlier generations living in Greece were also more physically active, a significant factor in contributing towards better health.
Dr. Ayoob, this is an excellent breakdown of another diet that on the whole seems to be well-suited for the healthy lifestyle. But as you point out, always proceed with caution and moderation. I especially appreciated the point that this isn’t to be viewed as a weight loss regimen. So true and so valuable to remind those that may start if for the wrong reasons. Thank you doc!