European scientists found that following the Mediterranean diet (MedDiet) has a dose-dependent protective effect against atherosclerotic plaque. This means that the more closely people adhere to the eating plan, the less their arteries will be clogged, a benefit that lowers their risk of heart attack and stroke.
Of all the diets that we've studied, everybody comes back and says the Mediterranean diet is the one we should follow.
Lead author Rocio Mateo-Gallego, of the Hospital Universitario Miguel Servet in Zaragoza, Spain, presented the study’s results recently at the European Atherosclerosis Society 2017 Annual Congress. She said the MedDiet was associated with reduced presence, thickness and number of atherosclerotic plaques, adding that the link was strongest in the artery in the thigh, called the femoral artery. The benefit was particularly robust among smokers.
Mateo-Gallego explained that studies on atherosclerosis mainly involve the artery in the neck, termed the carotid artery. In an earlier randomized controlled clinical trial evaluating the effects of the MedDiet, researchers found it was associated with the regression of carotid plaque over several years.
However, recent research suggests plaques in the femoral artery are better predictors of the risk of cardiovascular disease. The presence of plaque in this blood vessel is also highly correlated with calcium in the arteries of the heart. Therefore, Mateo-Gallego sought to investigate the effect of the MedDiet on the femoral artery, as well as the aorta and the carotid artery.
Tomography was used to determine the extent of atherosclerotic plaque in 2,523 middle-aged auto workers who didn’t have a history of cardiovascular disease. Plaque was present in 1,983 of the participants.
A 134-food item questionnaire was employed to assess the degree of adherence to the MedDiet. This eating plan consists of fruits, vegetables, whole grains, nuts, legumes and fish. The main source of fat in the diet is olive oil, but it also includes moderate amounts of saturated fat and dairy products.
Scores denoting adherence to the MedDiet can range from 0 to 9, with higher scores indicating food choices that more closely resemble the plan. The average overall score was 4.19, which suggested moderate adherence.
When participants in the highest quartile of 6 to 9 were compared to those in the lowest quartile of 0 to 2, a significant reduction was seen in plaque in the femoral arteries. Although less plaque was also noted in the aortas of those in the highest quartile, it wasn’t statistically significant after adjustments were made for other factors. No differences were seen in the carotid arteries between participants in the two quartiles.
A big advantage was found for smokers, as the presence of plaque in the femoral artery was decreased 61 percent among those in the highest quartile. Mateo-Gallego said adherence to the MedDiet was inversely associated with the number of plaques in all blood vessels tested with the exception of the carotid artery.
While the MedDiet is linked to a reduced likelihood of cardiovascular disease, the mechanisms of action that underlie this benefit aren’t known. The new findings reveal that part of the advantage stems from the fact that it may prevent the formation of plaque that lines the inner walls of arteries.
As research progresses, more of the reasons that underlie the MedDiet’s positive effects will become understood. However, integrative physician Michael Wald, director of longevity services at Integrated Nutrition in Mount Kisco, New York, shared with Olive Oil Times what has already been discovered on the subject.
“The high content of omega-3 fatty acids from fish, oleic oil from olive oil and monounsaturated fats from avocados give the MedDiet its protective effects for all manner of inflammatory diseases, including, but not limited to, heart and blood vessel disease. Omega-3 fatty acids reduce the formation of prostaglandins-1 and 2, substances that promote heart and vessel disease; while they increase the formation of prostaglandin-3, an anti-inflammatory compound,” Wald said.
“The omega-9 fatty acids in olive oil further reduce inflammation and decrease the thickness or viscosity of blood, which helps offset blood clots, hardening of arteries and even hypertension. Avocados are high in the monounsaturated fats believed to improve the flexibility of arteries, thus helping maintain circulation and overall cardiovascular health,” he said.