Mediterranean-style diet is back in the news with Harvard University researchers saying that the diet can help young workers reduce heart disease risk.

According to the American Heart Association, over half of fat calories in a Mediterranean diet come from monounsaturated fats (from olive oil), which makes it healthier than the American diet. Recently, there have been a number of studies showing that a diet high in fruits and vegetables is good for the heart and that it protects against obesity and diabetes.

"Our study adds more evidence showing the health benefits of a Mediterranean diet, even after adjusting for exercise and body weight," said Stefanos Kales, associate professor in the Department of Environmental Health at HSPH, according to a news release.

The latest Harvard study was based on data from 780 male firefighters in the Midwest. Researchers looked at the participants' dietary habits and medical records to see how closely the firefighters followed a healthy diet and how the diet affected their heart, weight and overall health.

Data analysis showed that firefighters with greatest adherence to a Mediterranean-style diet had a 35 percent lower risk in developing metabolic syndrome.

Metabolic syndrome means that the person has a higher risk of developing chronic conditions like cardiovascular disease, diabetes type-2 or stroke.

Participants following Mediterranean diet also had a 43 percent lower risk of weight gain and high levels of good HDL cholesterol compared with other people in the study, researchers found. Obese or overweight participants were more likely to have unhealthy eating habits.

"The logical next steps from our investigation are studies using the workplace to specifically promote Mediterranean dietary habits among firefighters and other U.S. workers," said Justin Yang, lead author of the study and a post-doctoral fellow at HSPH. Researchers at Cambridge Health Alliance also worked on the study.

The study, "Modified Mediterranean diet score and cardiovascular risk in a North American working population," is published in the journal PLOS One.

Recently, the Mediterranean diet claimed third spot in the third Best Diets Overall category in a survey by U.S. News. The diet is  moderately expensive and requires time to prepare, which makes it rather difficult to follow.