High blood pressure, also known as hypertension, is a major contributor to the risk for multiple cardiovascular diseases (CVD) and overall heart health. “In 2003, the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure estimated that hypertension affects approximately 1 billion people worldwide” (1). Treatments used for lowering blood pressure are anti-hypertensive medications and also adhering to healthy lifestyle changes such as diet. The PREDIMED trial (randomized controlled trial) studied the effects of the Mediterranean diet (MD) on blood pressure. Overall, the study concluded that adherence to either the traditional MD or a low-fat diet illustrated positive results for decreasing and controlling blood pressure.
The PREDIMED trial had 7,158 individuals participate in their study (men ages: 55-80, women ages: 60-80), for which the average age was 67 years old. The participants were required to be at risk for CVD, but could not actually have CVD. Three different interventions were created for the participants, which were: a controlled diet (low-fat diet), a MD with extra virgin olive oil, and a MD with mixed nuts (walnuts, almonds, and hazelnuts) (1). Each individual participant was randomly selected for the intervention that he/she would adhere to. Along with a description and counseling for each diet, both MD’s were given the additives (extra virgin olive oil and the mixed nuts) to their diet for free. This long-term trial followed the participants over 4 years, and a blood pressure reading was recorded before the interventions began and annually after the interventions were in progress. All three interventions showed a decrease in overall blood pressure (both systolic and diastolic) during the follow up period of the trial (P-value for within-group changes: P<0.001) (1).
Similar to all other studies, there are both strengths and limitations exhibited in this trial. Limitations for this trial include: differences in blood pressure is a secondary end-point not a primary end-point, many participants (from all three interventions) were already adhering to a diet similar to the MD prior to the study, some of the data during the follow up was not available for some of the participants in the control diet, and all of the participants had similar factors such as risk for CVD so it may have ruined the ability to generalize to a broadened population (1). The strengths associated with this study were: it was randomized, there was strong adherence to the interventions, there was a lengthy follow up in comparison to past studies, and it contained a large sample size (1).
Not only does eating a MD help with hypertension, but it also can contribute to other factors such as weight. “The Mediterranean diet (which is rich in fruits and vegetables, cereals, legumes, fish and olive oil), was inversely related to obesity” (2). Being overweight or obese is strongly correlated with other risk factors including hypertension and CVD (2). Another study shares, “Those that consume more unhyrdogenated polyunsatured and monounsatured fats such as olive oil have lower rates of heart disease” (3). Olive oil is an essential part of the MD, and it is positively associated with having decreased risks of heart disease. Fish is another nutrient source consumed by those following the MD diet. Omega-3 and Omega-6 fatty acids found in fish oil have been found to protect against heart disease and lower blood pressure (in certain cases, dependent upon original blood pressure readings, etc.) (4).
Overall, hypertension will cause risk for CVD so any effort to adhere to a healthier lifestyle is in the right direction. Adherence can be difficult when trying to change a lifestyle or habit, but it is worth it for the health benefits. Specifically looking at the research, the MD has been shown to reduce hypertension and other risks for CVD including obesity. In being at risk for CVD I would definitely try the MD to hopefully get rid of the risk factors and in turn get rid of the potential for CVD.
1. Toledo E, Hu F, Martinez-Gonzalez M, et al. Effect of the Mediterranean diet on blood pressure in the PREDIMED trial: results from a randomized controlled trial. BMC Medicine. October 2013; 11(1):1-9. Available from: http://web.a.ebscohost.com.dist.lib.usu.edu/ehost/pdfviewer/pdfviewer?sid=f6bcf9d4-98de-4d78-b061-8b465bacef12%40sessionmgr4003&vid=5&hid=4212. Accessed February 18, 2014.
2. Tyrovolas S, Bountziouka V, Panagiotakos D, et al. Adherence to the Mediterranean diet is associated with lower prevalence of obesity among elderly people living in Mediterranean islands: the MEDIS study. International Journal of Food Sciences & Nutrition. November 4, 2009; 60:137-150. Available from: http://web.b.ebscohost.com.dist.lib.usu.edu/ehost/pdfviewer/pdfviewer?sid=a057cb16-828f-4778-b85b-0ad70cbff881%40sessionmgr115&vid=8&hid=127. Accessed February 18, 2014.
3. Adams S, Standridge J. What Should We Eat? Evidence from Observational Studies. Southern Medical Journal. July 2006; 99(7):744-748. Available from: http://web.b.ebscohost.com.dist.lib.usu.edu/ehost/pdfviewer/pdfviewer?sid=a057cb16-828f-4778-b85b-0ad70cbff881%40sessionmgr115&vid=8&hid=127. Accessed February 18, 2014.
4. Beilin L, Burke V, Cox K, Hodgson J, Mori T, Puddey I. Non Pharmacologic Therapy and Lifestyle Factors in Hypertension. Blood Pressure. October 2001; 10(5/6):352-365. Available from: http://web.b.ebscohost.com.dist.lib.usu.edu/ehost/pdfviewer/pdfviewer?sid=a057cb16-828f-4778-b85b-0ad70cbff881%40sessionmgr115&vid=8&hid=127. Accessed February 18, 2014.
5. Colliver V. February 26, 2013. Primary Prevention of Cardiovascular Disease with a Mediterranean Diet with Walnuts. [Photograph]. Available from: http://www.sfgate.com/health/article/Mediterranean-diet-s-benefits-confirmed-4308008.php#photo-4251849 (image web address).
Reviewed by Viktoriya Wolff