The women in a 12-year study who adhered most closely to the diet had reduced heart disease risk similar to taking statins or other medications.

I know. We keep hearing (and hearing and hearing) about the miracles of the Mediterranean diet. The eating pattern made famous by the long-living people of the Mediterranean region is a plant-heavy diet that allows for healthy fats and a bit of wine, but limits red meat, sugar, and processed foods. Is it any wonder that it ranks amongst the healthiest diets in the world?

The mechanics behind the diet’s numerous health benefits have remained a bit of a mystery, but now a new study by researchers from Brigham and Women's Hospital, Harvard Medical School, and the Harvard T.H. Chan School of Public Health is shedding some light on the diet’s secrets.

The researchers followed more than 25,000 women in the United States who were part of the Women’s Health Study. At the beginning of the study, the women answered a comprehensive questionnaire asking about 131 different foods – they were then given scores between zero to nine based on how closely they followed the Mediterranean diet.

Of the 25 994 participants, 10,140 had a low score (less than 3), 9,416 had a middle score (4 to 5), and 6,438 had an upper score (6 to 9).

It’s those 6,438 that I want to talk about, because the results are significant.

When the researchers compared the data between the groups – calculated from the questionnaires, a panel of 40 biomarkers, and heart disease history – they found a 28 percent relative reduction of risk for cardiovascular disease in that upper group, a benefit that is similar in magnitude to statins or other preventive medications.

Think of that: By leaning towards a delicious diet of vegetables, fruits, nuts, whole grains, legumes, fish, healthy fats, and some wine, these women reduced their risk of cardiovascular disease by 28 percent.

The middle group saw good benefit too, with a 23 percent reduction in the risk of cardiovascular disease.

The researchers also learned a lot about how a Mediterranean diet might mitigate the risk of heart disease and stroke, by examining a panel of 40 biomarkers. They found that the way in which the Mediterranean diet fights inflammation to be the most significant factor. Glucose metabolism and insulin resistance, and body mass index were also significant, followed by blood pressure, traditional lipids and lipoprotein measures.

"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. This understanding may have important downstream consequences for the primary prevention of cardiovascular disease," said lead author Shafqat Ahmad, PhD, a research fellow at the Brigham and at the Harvard Chan School.

Given that heart disease is the leading cause of death for both men and women in the U.S., claiming more than 600,000 lives each year, this seems like a pretty simple way to help ease the burden on the health care system. Not to mention a great way to live longer! That eating less meat is also one of the best ways that individuals can help the environment, it seems like the only question remaining when considering a Mediterranean diet is ... "why not?"

To read the entire study – Assessment of Risk Factors and Biomarkers Associated With Risk of Cardiovascular Disease Among Women Consuming a Mediterranean Diet – at JAMA.