There are several patterns of eating and the Mediterranean diet is celebrated for its health benefits. It is one of the diets that following and adhering to for long term is easy and sustainable.

The Mediterranean diet is commonly associated with improved heart health. Heart disease is a common health problem and claims many lives more than any disease in the world. Lower incidences and prevalence of this disease in countries around the Mediterranean like Italy and Greece, are linked to following this type of diet. This type of eating is based on plant foods such as fruits, legumes, vegetables, whole grains, nuts, seeds, bread, and potatoes. Numerous randomized controlled studies have looked at the potential benefits of this diet. This article reviews some of the controlled studies on the Mediterranean diet.

The Studies

The studies discussed in this article involved participants who had health problems such as diabetes, heart disease, and metabolic syndrome. Researchers dwelt on common markers of health such as risk factors of heart disease, diabetes, and weight. Some even looked at the prevalence of heart attack and death.


This is a large study that used 7,447 participants who were highly predisposed to heart disease. It was carried out for 5 years, a period during which participants were put on either of the following diets:

  • the Mediterranean diet plus extra virgin olive oil.
  • the Mediterranean diet plus nuts.
  • a low-fat diet for the control group.

During the whole study period, no participant was allowed to reduce calories or increase physical performance. The data collected during PREDIMED study have been investigated to determine the effects of the diet on various risk factors. Below are journals based on the PREDIMED study.

Estruch R, et al. Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra Virgin Olive Oil or Nuts. The New England Journal of Medicine, 2018.

This study was conducted for 4 years 8 months and involved 7,447 participants. They followed a Mediterranean diet plus olive oil, Mediterranean diet plus nuts, or a low-fat diet for control group. The specific objectives of this study focused on the effects of this diet on heart attack, stroke, and death. At the end of the study, those on the Mediterraneandiet plus olive oil had reduced risk of heart attack, stroke, and death by 31 percent while those on the Mediterranean diet plus nuts reduced the risk by 28 percent. Additionally, those on the control group had a higher drop out rate by up to 11.3 percent. It was concluded that a combination of the Mediterranean diet with nuts or olive oil can significantly lower the risk of heart attack, stroke, and death from cardiovascular diseases.

Salas-Salvado J, et al. Effect of a Mediterranean Diet Supplemented With Nuts on Metabolic Syndrome Status. JAMA Internal Medicine, 2008. Details.

This study analyzed data collected from the PREDIMED study on 1,224 participants after following the diet for 12 months. The main focus of the study was on the effects of the diet on treating or reversing metabolic syndrome. The study results indicated that those on the Mediterranean diet plus olive oil had reduced prevalence of metabolic syndrome by 6.7 percent while those on this diet with added nuts had 13.7 percent. It thus concluded that supplementing the Mediterranean diet with nuts may significantly reverse metabolic syndrome.

Montserrat F, et al. Effect of a Traditional Mediterranean Diet on Lipoprotein Oxidation. JAMA Internal Medicine, 2007.

This study included 372 participants with increased risk of heart disease after following either of the diets in the PREDIMED study for 90 days. It emphasized on markers of oxidative stress, oxidized low-density lipoprotein (LDL) “bad” cholesterol in particular. The results showed that the levels of oxidized LDL (bad) cholesterol were reduced in both groups of the Mediterranean diet, and little to no significance on the low fat control group. In conclusion, the researchers said that the Mediterranean diet may help reduce oxidized LDL (bad) cholesterol.

Salas-Salvado J, et al. Reduction in the Incidence of Type 2 Diabetes With the Mediterranean Diet: Results of the PREDIMED-Reus nutrition intervention randomized trial. Diabetes Care, 2011.

Scientists analyzed data from 418 participants who were non-diabetic on the PREDIMED study for four years. The study emphasized on the likelihood of developing type 2 diabetes. The results showed that those on the Mediterranean diet plus olive oil and nuts groups had reduced risk of developing diabetes with only 10 percent and 11 percent respectively developing the disease. 17.9 percent of people on the control group developed the disease. In addition, the diet was found to be effective at reducing type 2 diabetes by up to 52 percent. The researchers then concluded that following the Mediterranean diet without restricting calories can reduce the likelihood of developing type 2 diabetes.

Estruch R, et al. Effects of a Mediterranean-Style Diet on Cardiovascular Risk Factors. Annals of Internal medicine, 2006.

Researchers looked at data collected from 772 individuals on the PREDIMED study after following the diet for 3 months. The study looked at the effects of the diet on cardiovascular risk factors. The results indicated that those on the Mediterranean diet groups experienced marked improvements on the certain cardiovascular risk factors. Specifically, they saw improvements in blood sugar levels, ratio of total to high-density lipoprotein (HDL) “good” cholesterol, and levels of C-reactive protein, which is a common marker of inflammation. In addition, blood sugar for those on the Mediterranean groups fell by 0.30 and 0.39 mmol/L, systolic blood pressure dropped by 5.9 and 7.1 mmHg, total to HDL cholesterol ratio fell by 0.38 and 0.26, and marker of inflammation C-reactive protein dropped by 0.54. The researchers thus concluded that the Mediterranean diet could help improve risk factors of heart disease.


The Mediterranean diet is an effective diet that can help improve heart health. It involves eating plant-based foods such as whole grains and vegetables. When supplemented with olive oil or nuts, this diet can significantly lower the risk of heart disease and type 2 diabetes. It is even better than a low-fat diet.

Julia Davis

Mental health expert MS, University of Latvia I am deeply convinced that each patient needs a unique, individual approach. Therefore, I use different psychotherapy methods in my work. During my studies, I discovered an in-depth interest in people as a whole and the belief in the inseparability of mind and body, and the importance of emotional health in physical health. In my spare time, I enjoy reading (a big fan of thrillers) and going on hikes.