Mediterranean Diet Benefits Cardiovascular Profile of At-Risk Adults

The Mediterranean diet (often designated the MedDiet) is one of the healthiest diets that one can consume. Indeed, the consumption of a Mediterranean diet is statistically associated with a reduced risk for the future development of insulin resistance and type 2 diabetes, the metabolic syndrome, hypertension, cardiovascular disease (CVD), as well as numerous cancers and some neurodegenerative diseases. Epidemiological studies have demonstrated that a Mediterranean-style diet is associated with antiatherogenic effects. Atherogenesis refers to the processes in the development of atherosclerosis, the formation of fatty streaks in the vessels and the precursor pathology to CVD. The antiatherogenic effects of the Mediterranean diet include reduction in blood pressure, improvements in blood lipid profiles (cholesterol and triglycerides), reductions in vascular endothelial cell dysfunction (endothelial cells line the blood vessels), reduction in oxidative stress, and reductions intravascular inflammation. Increased inflammation within the blood vessels is a primary activator of the pathology of CVD.

The Mediterranean diet is typically defined as a diet that focuses eating plant-based foods, such as fruits and vegetables, whole grains, legumes and nuts. Although not exclusively a vegetarian diet, the meats in the Mediterranean diet are primarily fish and poultry. Animal fats are reduced in the Mediterranean diet with, for example, butter being replaced with healthy fats such as olive oil and canola oil. For an review of healthy fats, and their primary sources, for your diet read my previous post covering this topic:

BENEFICIAL DIETARY OILS: FATS ARE NOT ALWAYS BAD FOR YOU

A recent report in the Journal of Nutrition adds to the clinical data showing that there is a definitive long-term cardiovascular benefit with the consumption of a Mediterranean-style diet. Specifically this new study demonstrates that the Mediterranean diet can significantly reduce intravascular inflammation in adults at high risk of CVD:

Long-Term Immunomodulatory Effects of a Mediterranean Diet in Adults at High Risk of Cardiovascular Disease in the PREvencion con DIeta MEDiterranea (PREDIMED)


In this randomized controlled study 165 adult males, who were at high risk for cardiovascular disease (CVD), were assigned to one of three different diets and. One diet consisted of a typical Mediterranean diet supplemented with extra-virgin olive oil, the second diet was a Mediterranean diet supplemented with nuts, and the third diet was a low fat diet (LFD) where total energy intake from fats was less than 15%. Each study participant was followed for 5 years. Clinical data relative to cardiovascular health was collected at the outset of the study and at 3 years and 5 years. Some of the parameters examined were high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), tumor necrosis factor alpha (TNFa), and monocyte chemattractant protein 1 (MCP1). All of these proteins are diagnostic for the level of intravascular inflammation.

The results from this 5 year study were striking indeed. All of the parameters associated with an increased risk for development of CVD declined in the two groups of volunteers who consumed the Mediterranean diets, whereas, the group eating the low fat diet did not see positive changes. Both systolic (the first and higher of the two blood pressure values) and diastolic (the second and lower) blood pressure values significantly decreased in both Mediterranean diet groups. Reductions in serum triglyceride, total cholesterol, and LDL cholesterol were observed in both Mediterranean diet groups along with an increase in HDL cholesterol. Compared to the Mediterranean diet groups, which saw decreases in serum glucose levels, the low fat diet group had increased serum glucose and this correlated to increased glycosylated hemoglobin (designated A1c). The low fat diet participants also saw their rate of development of type 2  along with their BMI, whereas both of these parameters declined in the Mediterranean diet participants.

The most significant clinical findings in this new study were with respect to blood markers of intravascular inflammation. Both Mediterranean diet groups saw significant reductions in serum hs-CRP, IL-6, TNFa, and MCP1. In comparison, there were no significant changes in these inflammation markers in the low fat diet group. Reducing inflammation in the blood vessels is a sure fire way to extent the health, and thus life, of ones vessels, in particular the large vessels of the heart. 

The TAKE HOME from this impressive 5 year randomized controlled study is that there is clear clinical justification for changing the composition of ones diet and that significant health improvements can be made from a Mediterranean diet EVEN in already at risk populations. The beauty of the Mediterranean diet is that it is not that difficult a diet to adhere to nor is it a significant expense compared to a more dangerous typical Western style diet.  

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