January 27/Huddersfield Daily Examiner -- Eating poor food can put you in a low mood, new research suggests.

Scientists have found a link between consuming harmful trans fats and an increased risk of depression; however, olive oil and healthier polyunsaturated fats appear to have the opposite effect, helping to keep people cheerful.

The research may provide a clue to why southern Europeans tend to be less depressed than northerners, say the researchers.

Mediterranean diets are rich in healthy ingredients such as fish, fresh fruits and vegetables, as well as olive oil. People in the U.K. and other northern European countries, on the other hand, are more likely to consume foods laden with saturated and trans fats.

"Eating a heart-healthy diet with olive oil can lower the risk of depression," says researcher Almudena Sanchez-Villegas, PhD, associate professor of preventive medicine at the University of Las Palmas de Gran Canaria in Las Palmas, Spain. The study included more than 12,000 people.

"The participants with an olive oil consumption higher than 20g a day (about 0.7 ounces) had a 30% lower risk of depression than those without consumption or with a very low consumption of olive oil," Sanchez-Villegas.

From the February 7, 2011, Prepared Foods E-dition