The Multicultural Healthy Diet (MHD) is a pilot randomized controlled clinical trial designed to test the effects of an 18 month intervention on cognitive function among 326 middle-aged individuals (40-65 yr) who have suboptimal diets. MHD is an anti-inflammatory diet tailored to a multicultural population. The emphasis of the intervention is on plant-based foods and limited animal and high saturated fat foods with focus on anti-inflammatory foods/food components specific to the cultural context of the participants. The trial will employ a parallel group design comparing the effects of the dietary intervention (MHD) on cognitive status to those of the control diet or usual diet plus modules on self-care matters such as dealing with aches and pains of aging, obtaining a health care proxy ,etc. To show that MHD can be adapted to this population serum biomarkers indicative of the MHD diet pattern such as fatty acid profile as well as other key nutrition biomarkers will be evaluated. Other aims include testing whether the MHD intervention can benefit cognitive function using real-time ambulatory assessments. The investigators will also assess plasma markers of oxidative stress and inflammation. Components of the MHD diet that are associated with stable or improved measures of cognition will also be evaluated. The clinical site for the proposed study is at the Albert Einstein College of Medicine; the ambulatory cognitive assessment reading center is at Pennsylvania State University, State College; the statistical core is at the University of Pennsylvania and the laboratory for biospecimen analysis is at the University of Minnesota.