Why The Mediterranean Diet Is 'It'

(CBS)  A traditional Mediterranean diet is part of the culture in countries such as Italy, Spain and Greece. It is high in fruits, vegetables and legumes such as beans, peas, nuts, unrefined whole grain foods and olive oil.

It includes a moderate amount of fish, a low to moderate amount of dairy products such as cheese or yogurt, and a moderate intake of wine, usually with meals. It contains low amounts of meat, poultry and saturated fats.

The Early Show medical correspondent Dr. Emily Senay reports that the research has shown the diet improves heart health by reducing risk factors for heart disease such as obesity, fat buildup in the arteries, high blood pressure and inflammation.

Olive oil contains healthy unsaturated fat, and ingredients known as phenolic compounds that are thought to have antioxidant properties that protect the body's cells against damage, as well as anti-inflammatory and clot-reducing effects. A new study from Spain in the Journal of the American College Of Cardiology provides more evidence that these compounds are an important part of olive oil's benefits.

Study Results

Researchers fed breakfasts with olive oil — either high or low in phenolic compounds — to people with high cholesterol and found that blood vessels appeared healthier after people consumed olive oil high in the compounds.

Previous research has demonstrated that a diet high in bad saturated fat is bad for blood vessels and circulation. The researchers say these new results suggest the beneficial effect of the Mediterranean diet on heart disease and hardening of the arteries is most likely a result of the combined effects of the different nutrients contained in the food, rather than any one factor. Olive oil is an example of a dietary component with extra healthy ingredients in addition to unsaturated fat.

Different olive oils contain different levels of phenolic compounds depending on how they are processed. Generally speaking, "extra virgin" olive oil that is naturally produced preserves the natural ingredients of the olive and contains higher levels of phenolic compounds.

Standards on olive oil production vary around the world but "extra virgin" oils, with a sharper taste, undergo less processing. More study is needed to confirm the benefits.

The Mediterranean diet does allow dairy fat and alcohol in moderation. Monthly servings of meat and weekly meals of poultry, eggs and sweets are also allowed. But healthier items such as vegetables, fruits, nuts, legumes, unrefined cereals, olive oil and fish are eaten most often.