Experts theorize that diet may play a role in the development of Alzheimer's disease but epidemiological data on diet and Alzheimer's is conflicting and general dietary patterns have not been previously studied. To address this paucity of data, researchers led by Nikolaos Scarmeas of Columbia University Medical Center, designed a prospective community-based study of 2,258 non-demented people in New York City.
For each subject, the researchers gathered medical and neurological history, did a standardized physical and neurological exam, and conducted an in-person interview to assess health and neuropsychological function. This information was used to diagnose a presence or absence of dementia. Subjects were reassessed approximately every 18 months for an average of 4 years.
The researchers also obtained dietary data from each subject using a semi-quantitative food frequency questionnaire. They determined a Mediterranean Diet score (0-9) based on a previously described method. During the course of the study, 262 members of the study population were diagnosed with Alzheimer's disease.
"Higher adherence to the Mediterranean diet was associated with significantly lower risk of developing Alzheimer's disease," the authors report. For each additional point to Mediterranean diet scores, Alzheimer's risk dropped by 9 to 10 percent. Compared with the subjects in the least adherent group that adhered to a Mediterranean diet the least, subjects in the middle tertile had 15 to 21 percent lower risk of developing Alzheimer's disease, and those in the highest tertile had a 39 to 40 percent lower risk, suggesting a significant dose response effect. The association remained significant even after adjusting for potential confounders such as age, gender, ethnicity, education, caloric intake, BMI, smoking and comorbid conditions.
MEDICA.de; Source: John Wiley & Sons, Inc.