By: Eva von Schmilowski
The traditional food of Greece, Southern Italy and Spain is a great way to prevent heart disease and many associated chronic conditions.
The classic Mediterranean diet is known for an abundance of plant based foods - all sorts of fruits, vegetables, whole grain cereals, nuts and legumes; moderate in fish, poultry, eggs and red wine (with meals) and low in dairy products, red meat, processed meats, and sweets.
A number of studies and well designed long-term randomised controlled trials have been consistently showing that the Mediterranean diet backed up with extra virgin olive oil or nuts has a powerful positive impact on our overall health reducing the risk of major cardiovascular events, diabetes, obesity, metabolic syndrome and inflammation.
Mediterranean Diet and Cardiovascular Disease
One of the major and most influential trials is a Spanish PREDIMET study (1).
7447 randomly selected people at high cardiovascular risk, but without a diagnosed cardiovascular disease were enrolled to try one of three following diets:
Mediterranean diet supplemented with extra-virgin olive oil,
Mediterranean diet supplemented with mixed nuts,
Control diet (advice to reduce dietary fat).
The purpose of the study was to measure the link between a specific diet and the rate of major cardiovascular events such as heart attack, stroke, or death from cardiovascular causes.
Although the study had some limitations (differences in intensity of intervention or some losses in the follow-up group) the results were encouraging - a Mediterranean diet supplemented with extra-virgin olive oil or nuts significantly reduced the incidence of major cardiovascular events among high risk people.
In the same study researcher found out that during almost 5 year follow up, nut consumption was associated with a significantly reduced cardiovascular risk and cancer mortality. People eating nuts (more than 3 servings/week) had lower mortality risk than those who didn't add nuts to their diet (2).
Mediterranean Diet and Type 2 Diabetes
The PREDIMET-Reus study was another nutrition intervention designed to test the effect of two Mediterranean diet (either virgin olive oil or nuts) versus a low fat diet on type 2 diabetes. 418 non diabetic people entered the study for a period of 4 years.
The study has shown that the traditional Mediterranean diet enriched with virgin olive oil or mixed nuts decreases the incidence of type 2 diabetes by 51% in people at high cardiovascular risk after 4 years time, compared to a control diet. It is important to mention that the significant diabetes risk reduction occured despite the lack of significant changes in body weight or physical activity (3, 4, 5).
Mediterranean Diet and Metabolic Syndrome
A metabolic syndrome is a complex combination of various risk factors for cardiovascular disease such as abdominal obesity, dyslipidaemia (abnormal levels of blood cholesterol), high blood pressure, and hyperglycaemia (high blood sugar).
In this large multi-centre clinical trial 1224 people were recruited from the PREDIMED trial and randomised to assess the influence of the Mediterranean Diet on the primary prevention of cardiovascular disease. All participants were at high risk of developing cardiovascular disease. People were divided into 3 groups of diet (virgin olive oil or mixed nuts versus a low fat diet).
After 1 year of intervention, the prevalence of metabolic syndrome was reduced by 6.7%, in the Mediterranean diet with olive oil, by 13,7% in the Mediterranean diet with nuts and by 2% in the control group (6).
Mediterranean Diet and Weight Loss
In this 2-year dietary intervention study 322 moderately obese participants were randomly enrolled to a calorie restricted low fat diet, a calorie restricted Mediterranean diet, or an unrestricted low carb diet.
In result of the intervention, diabetic patients lost weight and had improved both blood glucose and insulin levels on the Mediterranean diet, compared to the low-fat diet. The low fat group lost 2.9 kg (6.4 lbs), the low carb group lost 4.7 kg (10.3 lbs) and the Mediterranean diet group lost 4.4 kg (9.7 lbs).
Researches concluded that the Mediterranean diet may be more effective for weight loss and improving symptoms of diabetes than the low fat diet (7).
Mediterranean Diet and Inflammation
Chronic inflammation plays an important role in both heart disease and many related chronic conditions. Various studies have proven that the formation, progression and rupture of atherosclerotic plaques in coronary arteries is a cause of a heart attack.
A C-reactive protein (CRP), is a marker in our blood reflecting our systemic inflammatory status. Very often high CRP is associated with an increased risk of coronary heart disease and type 2 diabetes.
Results from another controlled study on the Mediterranean diet suggest that
the traditional Mediterranean diet reduces systemic inflammation both in men and women (8).
Eva von Schmilowski is a Cardiologist and a Founder of the Silver-lined Heart www.thesilverlinedheart.org - a non-profit organisation helping people with heart disease and related chronic conditions develop healthy lifestyle habits.