Research has shown that the traditional Mediterranean diet reduces the risk of heart disease. In fact, a recent analysis of more than 1.5 million healthy adults demonstrated that following a Mediterranean diet was associated with a reduced risk of overall and cardiovascular mortality, a reduced incidence of cancer and cancer mortality, and a reduced incidence of Parkinson’s and Alzheimer’s diseases.
For this reason, most if not all major scientific organizations encourage healthy adults to adapt a style of eating that resembles the Mediterranean diet for prevention of major chronic diseases.
Many of the benefits of any healthy diet are sometimes attributed to weight loss. But now there is further evidence that a Mediterranean-style diet achieved heart healthy benefits even without weight loss.
Three different types of “balanced” diets were given to 164 non-diabetic people with slightly elevated blood pressure. The three different diets were consumed for six consecutive weeks, with two to four weeks off in between each diet. Insulin and blood glucose were measured by blood tests. Insulin regulates blood glucose levels and reduced insulin action can lead to diabetes and thus a higher risk for heart disease.
The three diets were rich in either refined carbohydrates as pasta and white bread, protein, or unsaturated fats, provided by olive oil, nuts, and avocados. The results showed that the diet rich in unsaturated fats improved insulin use significantly more than the high carbohydrate diet.
Unsaturated fats have less hydrogen than saturated fats. They tend to be liquid at room temperature and are mostly found in plant foods. Unsaturated fats are classified by their degree of saturation. If only one carbon-carbon bond in the fatty acid is unsaturated, the fat is called “monounsaturated”. If two or more carbon-carbon bonds are unsaturated with hydrogen, the fat is called “polyunsaturated”.
The Mediterranean Diet emphasizes olive oil, whole grain breads and cereals, nuts, dried beans, vegetables and fruits – all excellent sources of unsaturated fats. Wine is consumed in moderation; red meat is limited to a monthly intake; sweets, eggs, poultry, and fish weekly.
“A lot of studies have looked at how the body becomes better at using insulin when you lose weight”, Dr. Meghana Gadvil, a postdoctoral fellow in the division of general internal medicine at the John Hopkins University School of Medicine. “We kept the weight stable so we could isolate the effects of the macronutrients. What we found is that you can begin to see a beneficial impact on heart health even before weight loss”.
This study was presented at a recent meeting of the American Heart Association and ideally should be viewed as preliminary until it is published in a peer-reviewed medical or nutrition journal.