Traditional Mediterranean diets feature vegetables, legumes, fruits, grains, olive oil, fish, cheese, yogurt, wine with meals, and relatively little poultry or meat, note the researchers, who included Nikolaos Scarmeas, MD, of New York's Columbia University Medical Center.
Today, the researchers report that the Mediterranean diet may also have longevity benefits for Alzheimer's patients.
Data came from nearly 200 Alzheimer's patients in New York. The patients completed surveys about their dietary habits during the past year. They weren't asked to change their eating habits.
The patients were interviewed every 18 months. Those who most closely followed a Mediterranean diet lived the longest.
"Alzheimer's patients who adhered to the diet to a moderate degree lived an average 1.3 years longer than those people who least adhered to the diet. And those Alzheimer's patients who followed the diet very religiously lived an average of four years longer," says Scarmeas in a news release.
Alzheimer's disease affects memory. So the researchers tested the dietary survey on another group of people who didn't have dementia but later developed Alzheimer's disease. The link between the Mediterranean diet and lower death rates held.
The findings also held when Scarmeas and colleagues considered other factors, including age, ethnicity, level of education, BMI (body mass index), diabetes, heart disease, and genetic risk for Alzheimer's disease.
However, the researchers can't rule out other influences, so they call for other studies on the topic.
An editorial accompanies the study in today's edition of the journal Neurology.
Editorialist James Galvin, MD, MPH, of Washington University's medical school in St. Louis observes that physical exercise and mental stimulation may also benefit Alzheimer's patients -- and everyone else, too.
"It is interesting that considering all the medical and pharmaceutical advances made in the last century, perhaps the most important things we can still tell our patients, regardless of why they come to the office, is to stay mentally active and physically fit and to eat a healthy and balanced diet," writes Galvin.