This study investigated whether the Mediterranean diet can reduce blood pressure, blood sugar and cholesterol levels in patients at high risk of having a cardiovascular event (such as a heart attack) and with high blood pressure.

High blood pressure (hypertension) occurs when pressure inside blood vessels is too high.  High blood pressure causes the heart to have to work harder in order to pump blood against the extra pressure.

Over time, the heart becomes stiff and loses its ability to pump blood efficiently and can result in blood clots forming. Uncontrolled hypertension increases the risk of cardiovascular events, such as a heart attack, stroke and heart failure.

Diet, in particular the Mediterranean diet (MedDiet), seems to play an important role in controlling blood pressure. The MedDiet is primarily plant-based diet, where every meal is based around fruit and vegetables, grains, olive oil, beans, nuts, and seeds which are high in monounsaturated fatty acids. 

This study investigated whether a MedDiet reduces blood pressure, blood sugar and blood cholesterol in elderly patients at high risk of having a cardiovasacular event.  A total of 235 individuals were included in the study, 85% of whom had high blood pressure. The average age was 67 years old.

Participants were either assigned the MedDiet with olive oil, MedDiet with nuts, or a non-MedDiet (control) for 1 year. The effect these diets had on blood pressure was determined by measuring 24 hour “ambulatory” blood pressure (where units of blood pressure is mmHg). This involves measuring an individual’s blood pressure for 24 hours at regular intervals.

Average systolic blood pressure, which is the pressure in arteries when the heart is beating or contracting, was reduced by 2.3 mmHg in the MedDiet with olive oil, 2.6 mmHg in the MedDiet wth nuts, and increased by 1.7 mmHg in the non-MedDiet. Average diastolic blood pressure, which is the arterial blood pressure when the heart is relaxed reduced by 1.2 mmHg in both the MedDiets and increased by 0.7 mmHg in the non-MedDiet. 

Blood sugar was reduced by 6.1 mg/dL in the MedDiet with olive oil, 4.6 mg/dL in the MedDiet with nuts, and increased by 3.5 mg/dL in the non-MedDiet. Blood cholesterol was reduced by 11.3 mg/dL in the MedDiet with olive oil, 13.6 mg/dL in the MedDiet with nuts, and 4.4 mg/dL in the non-MedDiet. 

The study concluded that the MedDiet supplemented with extravirgin olive oil or nuts reduced 24-hour ambulatory blood pressure, and blood cholesterol and sugar  in individuals at high cardiovascular risk and/or high blood pressure.

The study was based on a relatively small group of participants. 

If you or someone you know have high blood pressure or are at high risk of having a cardiovascular event, talk to a doctor or dietician about introducing the Mediterranean diet into your lifestyle and the benefits it can have on your health.