One diet craze that's actually stood up to scientific scrutiny is the Mediterranean diet. Some of the benefits claimed for the Mediterranean diet include lower rates of heart disease, type 2 diabetes and certain types of cancer, as well as longer lifespan and better quality of life.

The Mediterranean diet is not really a diet like the low-carb or South Beach diets. The name refers to a style of eating and cooking that is common to places like Spain, Italy, Greece, and other countries bordering the Mediterranean Sea.

The Mediterranean diet is not new, but it is in the news again. Until now, many of the diet's health claims were based on observational studies with only limited support from experimental work, such as randomized clinical trials. Now a recent review of 35 studies has concluded that this type of diet is the real thing when it comes to reversing some of our most common health conditions.

The Mediterranean diet showed favorable effects on lipoprotein levels (HDL and LDL cholesterol), insulin resistance, metabolic syndrome, antioxidant capacity, and widening of arteries.  Changes in these health-related factors are the kinds of results that can be obtained from clinical trials. These findings would predict, but not prove, a reduced likelihood of diabetes and cardiovascular disease.

While people following a Mediterranean diet in the studies reviewed showed greater improvements in risk factors for coronary disease and type 2 diabetes, much longer and larger trials are needed to determine for sure whether a Mediterranean diet lessens the risk of developing these disorders or cancer.

Nonetheless, the review did conclude that the Mediterranean diet was associated with a decreased incidence of cancer and lower risk of death from cardiovascular disease.  

What is the Mediterranean diet? There is no single Mediterranean diet - at least 16 countries have coastlines on the Mediterranean Sea. Although the diets are not the same in countries like Greece, Morocco, southern Italy, France, and Spain, their diets have certain common features:

• Olive oil is a large source of mono-unsaturated fat.
• Large amounts of fruits, vegetables, bread and other cereals, beans, nuts, seeds, and potatoes are consumed.
• Little red meat is consumed.
• Dairy products, fish, poultry, and red wine are eaten in low to moderate amounts.
• Eggs are eaten zero to four times a week.
• Limited consumption of trans fat-containing processed foods. 

The Mediterranean diet does contain more total fat than recommended by the American Heart Association (AHA) and American Diabetes Association (ADA). But the Mediterranean diet contains far less saturated fat; more than half of the fat in the diet comes from mono-unsaturated fats which tend to lower harmful LDL cholesterol and raise helpful HDL cholesterol levels. Most of the other components of the Mediterranean diet are consistent with those recommended by the AMA and ADA.

How might the Mediterranean diet reduce cancer risk?  Population studies have shown that environmental factors, including diet, play a major role in the development of cancers. Most of these studies indicate that a high intake of vegetables and fruits protect against cancer.

Why am I writing about this old news? Well, even though the news about the health benefits of the Mediterranean diet have been out for years, Americans still don't come close to eating the amount of vegetables and fruits recommended by the U.S. Department of Agriculture in its revised Food Guide Pyramid, which is less than half the amount that people in some Mediterranean countries eat.  

I'm not an advocate of fad diets, most of which don't work anyway. But in this case I believe there is now ample evidence that many features of the Mediterranean diet can prevent heart disease. Am I convinced that the diet will reduce the likelihood of developing diabetes or cancer or prolong my life and yours? Not really, but it's possible the diet might help in these ways as well, and there seems little or no downside to trying the diet.