Benfotiamine is a synthetic derivative of thiamine (Vitamin B1) with higher bioavailability. Its use in Alzheimer's Disease (AD) is primarily supported by preclinical and limited clinical evidence, rather than tradition. Laboratory studies have shown that thiamine-dependent processes are impaired in Alzheimer's patients, with reduced thiamine levels observed in the brains and blood of AD patients. Benfotiamine, by raising thiamine levels more effectively than standard thiamine supplements, has been hypothesized to support neuronal metabolism and reduce pathological features of AD such as amyloid deposition and tau phosphorylation.

In animal models, benfotiamine has demonstrated neuroprotective effects, including decreased amyloid plaque formation and improved cognitive performance. Early-phase clinical trials are limited but suggest possible cognitive benefits. Notably, a 2020 randomized, placebo-controlled pilot study (Pan et al., J Alzheimers Dis. 2020) found that benfotiamine supplementation over 12 months was associated with slower cognitive decline compared to placebo in patients with mild to moderate AD, though the sample size was small and further research is necessary.

In summary, there is scientific rationale and low-to-moderate preliminary evidence for benfotiamine's use in Alzheimer's Disease, but robust, large-scale clinical trials are needed before it can be considered a standard or well-validated therapy.