Similarly adjusted cognitive composites ( mean z scores with 95 % CIs ) for changes above baseline of the memory composite were 0.04 ( -0.09 to 0.18 ) for the Mediterranean diet plus olive oil , 0.09 ( -0.05 to 0.23 ; P = .04 vs controls ) for the Mediterranean diet plus nuts , and -0.17 ( -0.32 to -0.01 ) for the control diet .