A Mediterranean-style diet that appears to cut the risk of heart disease may also help prevent Alzheimer's disease, a new study suggests.

People who followed the diet were up to 40 percent less likely to develop Alzheimer's during the course of the research, American scientists reported.

Still, more research must be done before the diet can be recommended to ward off Alzheimer's, said Dr. Nikolaos Scarmeas of the Columbia University Medical Center in New York, lead author of the study. The work was recently published online by the Annals of Neurology.

The diet he tested includes lots of vegetables, legumes, fruits, cereals and fish, while limiting intake of meat and dairy products, drinking moderate amounts of alcohol and emphasizing monounsaturated fats, such as in olive oil, over saturated fats. Previous research has suggested that such an approach can reduce the risk of heart disease.

Prior research has also suggested that certain components of the Mediterranean diet can reduce the risk of developing Alzheimer's, Scarmeas said. But he said the previous work has tended to focus on individual nutrients like vitamin C or foods like fish. By studying a comprehensive diet, the new research could take possible interactions between specific foods and nutrients into account, he said.

The idea that a heart-healthy diet could also help fight Alzheimer's fits in with growing evidence that "the kinds of things we associate with being bad for our heart turn out to be bad for our brain," said Dr. Marilyn Albert, a Johns Hopkins neurology professor and spokeswoman for the Alzheimer's Association. The list includes high cholesterol, high blood pressure, obesity, smoking and uncontrolled diabetes, she said.

Editor: Donald