By Robert Preidt
"Our study has a strong public health message that modest changes in known cardiovascular disease risk factors, particularly those relating to inflammation, glucose metabolism and insulin resistance, contribute to the long-term benefit of a Mediterranean diet on cardiovascular disease risk," said study lead author Shafqat Ahmad. He is a research fellow at Brigham and Women's Hospital in Boston.
"This understanding may have important downstream consequences for the primary prevention of cardiovascular disease," Ahmad added in a hospital news release.
For the study, the researchers followed more than 25,000 U.S. women for up to 12 years. The women were grouped according to low, medium or high adherence to a Mediterranean diet. That's a style of eating that is high in plant-based foods and olive oil, and low in meats and sweets.
Compared to those with low adherence, the risk of heart disease was 23 percent lower among those with medium adherence and 28 percent lower among those with high adherence, or 25 percent lower when both groups were combined.
The risk reduction is similar to that provided by cholesterol-lowering statin drugs or other medications to prevent heart disease, according to the study authors.
Previous studies have also linked a Mediterranean diet to reductions in heart disease, but the reasons have been unclear, so the authors of this study took a closer look at that.
Ahmad's team found an association between a Mediterranean diet and reduced inflammation, accounting for 29 percent of heart disease risk reduction. Improvements in glucose metabolism and insulin resistance accounted for about 28 percent, and lower body mass index, about 27 percent, the findings showed.
The investigators also found connections between a Mediterranean diet and changes in blood pressure and cholesterol.
The findings were published online Dec. 7 in the journal JAMA Network Open.