The Mediterranean diet is the (delicious) gift that keeps on giving: Not only do fish and olive oil — two of the diet’s staples — work to better slow diabetes than a low-fat diet, but olive oil and nuts cut risk for peripheral artery disease, as well as metabolic syndrome, according to a new study published in the Canadian Medical Association Journal.

Researchers cited that metabolic syndrome is a cluster of three or more cardio-metabolic risk factors (obesity and hypertension) that increase risk for diseases, such as type 2 diabetes and cardiovascular disease. Since no existing research has studied the long-term effects a Mediterranean diet has on incidence, even reversion of the syndrome, researchers analyzed data from the PREDIMED prevention trial: “a randomized, single-blinded, controlled trial conducted in Spanish primary healthcare centers.” The trial included 5,801 participants at high risk for heart disease, aged 55 to 80 years old.

Participants were assigned to either a control diet (low-fat) or one of two Mediterranean diets. The first Mediterranean diet was supplemented with extra virgin olive oil, while the other was supplemented with nuts. This just meant there was an increased amount of the respective foods. The control diet group was also educated on low-fat foods compared to the Mediterranean dieters who received nutritional education and actual free food. When researchers looked at the data collected nearly five years after the start of the study, the Mediterranean dieters had decreased their central obesity and blood sugar levels, and 958 participants no longer met the criteria of metabolic syndrome.

That’s pretty interesting considering almost 64 percent of the participants had metabolic syndrome going into the study. "We can speculate that a Mediterranean diet, particularly one supplemented with extra-virgin olive oil, which has anti-inflammatory properties, could exert positive effects on fat redistribution,” the researchers wrote.

However, researchers did not find supplementing a Mediterranean diet with olive oil and nuts reduces incidence of metabolic syndrome compared to a low-fat diet; it only significantly reversed the diagnosis. When you think about how healthy the major components of the Mediterranean diet are all on their own — ingredients in olive oil help lower blood pressure and monounsaturated fatty acids (the good-for-you fat) improve inflammation and insulin resistance — it makes sense this diet continues to be associated with optimal health.

That said, this kind of advice is not, ahem, one size fits all. Check with your doctor before adopting the Mediterranean diet in order to make sure it’s compatible with your individual patient history. Doing so without doc's approval could mean you miss out on vital nutrients.

Source: Babio N, Toleda E, Estruch R, Ros E, Martinez-Gonzalez M, Castaner O, et al. Mediterranean diets and metabolic syndrome status in the PREDIMED randomized trial. Canadian Medical Association Journal.. 2014.