There is much less on diet and progression of AD than on diet and the onset of AD. However, here are a couple of recent articles that you may find interesting Article The Ketogenic Diet as a Potential Treatment and Prevention S...
and
Article Diet and biomarkers of Alzheimer’s disease: a systematic rev...
Nutritional interventions and cognitive-related outcomes in patients with late-life cognitive disorders: A systematic review.
Solfrizzi V, Agosti P, Lozupone M, Custodero C, Schilardi A, Valiani V, Santamato A, Sardone R, Dibello V, Di Lena L, Stallone R, Ranieri M, Bellomo A, Greco A, Daniele A, Seripa D, Sabbà C, Logroscino G, Panza F.