FRIDAY, Sept. 12 (HealthDay News) -- People who eat a strict Mediterranean diet are at less risk of developing heart disease, cancer, Parkinson's and Alzheimer's disease, Italian researchers report.

A so-called Mediterranean diet is rich in olive oil, grains, fruits, nuts, vegetables and fish, and includes a moderate amount of red wine but is low in meat, dairy products and other alcohol.

"This study helps us to support all the recommendations and the nutritional guidelines on the benefit of Mediterranean diet on mortality from all the causes, as well as on the incidence of cardiovascular, neoplastic and degenerative diseases," said lead researcher Dr. Francesco Sofi, from the Department of Medical and Surgical Critical Area at the Thrombosis Centre at the University of Florence.

"By improving the food quality of the population, we would likely reduce the incidence of these diseases by nearly 10 percent," Sofi added.

The report was published in the Sept. 11 online edition of the British Medical Journal.

For the study, Sofi's team collected data on 1,574,299 people who participated in 12 international studies of dietary habits and health. People in these studies were followed from three to 18 years.

People who adhered strictly to a Mediterranean diet had significant improvements in health. These people saw an overall drop in mortality of 9 percent, a 9 percent drop in death from cardiovascular disease, and a 13 percent reduction in cases of Parkinson's and Alzheimer's disease, and a 6 percent drop in cancer.

These findings confirm the current guidelines and recommendations from all major scientific institutions that encourage a Mediterranean-like diet for the prevention of major chronic diseases, the researchers concluded.

"The Mediterranean diet has been reported to be associated with a favorable health outcome, with no differences among countries, gender and study quality," Sofi said. "By improving diet, we would reach a significant improvement of health quality and duration of life."

Dr. David L. Katz, director of the Prevention Research Center at Yale University School of Medicine, says that eating a healthy diet and being physically active is one of the most important keys to good health.

"It should come as no surprise that adhering to a healthful diet can reduce disease and death," Katz said. "Nor should it be too surprising that the Mediterranean diet qualifies as a very healthful way to eat."

Many studies have demonstrated that eating a diet rich in vegetables, fruits, whole grains, fish, nuts, seeds, olive oil and a moderate amount of red wine is good for health, Katz said.

"Virtually all studies of diet and health overlap in demonstrating the benefits of eating more plant foods, and more foods close to nature -- and less highly processed foods," Katz said. "The Mediterranean diet is one example of such a dietary pattern, but not the only one. We may learn as research continues which among several good dietary patterns the best is."

More information

For more on a healthful diet, visit the U.S. Department of Agriculture.