2.1. Study Design and Participants
WAHA
The WAHA study was a 2-year parallel group, observer-blinded randomized controlled trial (RCT) examining the effect of the usual diet supplemented with walnuts at 15% (30–60 g/d) of energy compared to a walnut free habitual diet on the aging outcomes in elderly participants [Detailed information about the WAHA study has been published elsewhere [