Q: I’m trying to convince my father (age 68) to adopt a healthier diet. If he hears it will help protect his brain, I might be able to get him to stick with it. Suggestions please.

— Gregory T., Baltimore

Dr. Mike Roizen is the founder of www.longevityplaybook.com, and Dr. Mehmet Oz is global advisor to www.iHerb.com, the world’s leading online health store. Roizen and Oz are chief wellness officer emeritus at Cleveland Clinic and professor emeritus at Columbia University, respectively. Together they have written 11 New York Times bestsellers (four No. 1’s).