I agree. I'm not talking about a one-off study showing a minor improvement though (which would be likely to not replicate, etc.), I'm referring to a much stronger effect which in principle is addressing the origin of the disease.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6720297/ - a review of various studies, concludes that "Keto diet may modulate a broad array of metabolic and signaling changes underlying the pathophysiology of neurodegenerative disorders. Based on the limited animal studies and clinical trials, keto diet has beneficial effects for enhancing mitochondrial function and cellular metabolism. It is associated with improved cognitive performance in elderly adults with Alzheimer's disease. The improvement of the cognitive outcomes depends on the level and duration of ketosis."
https://alzres.biomedcentral.com/articles/10.1186/s13195-021... - study from video I linked above, concludes that "patients on the ketogenic diet improved in daily function and quality of life".
https://academic.oup.com/advances/article/11/6/1583/5864685?... - another review, concludes that "The results underline that, collectively, the efficacy of ketogenic therapy in MCI/AD appears promising, indicating that it is more than a symptomatic remedy (137). Nevertheless, research is still scattered and heterogeneous in terms of study design, intervention, participants, and outcomes of interest."
https://pubmed.ncbi.nlm.nih.gov/15123336/ - study on MCT oil which raises levels of ketones, abstract says "Higher ketone values were associated with greater improvement in paragraph recall with MCT treatment relative to placebo across all subjects (P=0.02). Additional research is warranted to determine the therapeutic benefits of MCTs for patients with AD and how APOE-4 status may mediate beta-OHB efficacy."
Additionally Alzheimer's is actually referred to by a large number of folks in the field as "type 3 diabetes" & as far as I understand there is a large amount of overlap between the two diseases; we have studies showing that diabetes can be nearly or totally cured by carbohydrate restriction:
https://pubmed.ncbi.nlm.nih.gov/29417495/ - of 349 participants, 94% were able to eliminate or reduce insulin therapy after 1 year (57% discontinued their prescriptions entirely).
The book "The Alzheimer's Antidote" by Amy Berger is a great resource if you are open minded enough to be willing to look at informational resources once step above scientific controlled studies (unfortunately many folks are not).