These data show that in patients with mild Alzheimer's disease, who are not taking other medications, Souvenaid might improve some measures of memory. In people with higher (worse) cognitive function scores (ADAS-Cog), Souvenaid might also improve cognitive function.
Note that I use the word "might" improve memory and cognitive function. The reason is that these data are still considered preliminary. In the world of evidence-based medicine, this simply isn't very strong evidence because the studies are relative small and short-term.
Nonetheless, the findings are promising and the product appears to be well-tolerated and likely safe based on the ingredients it contains. For someone facing Alzheimer's, this is worth a discussion with their personal neurologist.