Natural Health Products in the Prevention and Management of Alzheimer’s Disease: A Systematic Review of Randomized Clinical Trials

Supplementation with natural compounds, referred to as Natural Health Products (NHPs), is emerging as an applicable strategy in all phases of Alzheimer’s disease (AD) management, alongside pharmacological therapy. Several studies have investigated the potential of NHPs to modulate neurochemical and inflammatory processes associated with clinical decline; however, the results remain inconclusive. To evaluate the influence of NHPs on the clinical outcomes of AD patients, a systematic review was performed by searching the PubMed, Scopus, Cochrane, and Clinical Trials.gov databases for randomized clinical trials (RCTs) exploring the effects associated with NHP supplementation for the treatment of AD. Out of the 34 RCTs analyzed, 50% reported improvements in cognitive function and reductions in neuroinflammatory markers following NHP supplementation, suggesting a potential but inconsistent therapeutic effect. The strongest evidence of benefit in AD patients was found with the use of vitamin D, selenium, and probiotics. A certain incidence of depressive disorders and delirium highlights the necessity to better evaluate the safety and tolerability of B vitamin supplements. Overall, this systematic review found mixed results regarding the use of NHPs in the management of AD. Further evidence is needed to support their use in clinical practice.