Whole-diet approach, Mediterranean diet, and Alzheimer disease.

Very recently, Scarmeas and colleagues reported the results of a community-based study involving 2258 nondemented individuals in New York in which adherence to a traditional Mediterranean diet (MeDi) was associated with significant reduction in risk for incident Alzheimer disease. Scarmeas and colleagues used in this report a scale indicating the degree of adherence to the traditional MeDi: a value of 0 or 1 was assigned to each of 9 indicated components with the use of the sex-specific median as the cut-off.However, in the study of Scarmeas and colleagues, the ratio of the median daily intake of monounsaturated fatty acids to saturated fatty acids (one of the hallmarks of the MeDi) for individual food categories by MeDi score tertiles was <1 and overall about times lower than the same value calculated from other studies on MeDi.In the last years, the study approach was to associate single micronutrients or macronutrients to age-related cognitive decline, mild cognitive impairment, Alzheimer disease, or vascular dementia. Findings from the Italian Longitudinal Study on Aging demonstrated that in a 8.5-year follow-up, high monounsaturated fatty acid, polyunsaturated fatty acid, and total energy intake was significantly associated with a better cognitive performance in time.5 Furthermore, in the same sample, high intake of polyunsaturated fatty acids appeared to have a borderline nonsignificant trend for a protective effect against the development of mild cognitive impairment.