Effective Nutraceuticals on Age-Associated Cognitive Decline: A Systematic Review

Abstract

Abstract Objectives The prevalence of neurodegenerative disorders such as dementia is positively correlated to aging. As there is insufficient evidence for the medicinal remedies of dementia, focusing on prevention strategies to use nutraceuticals could provide positive results. Therefore, this systematic review aimed to evaluate the effect of various nutraceuticals on age-associated cognitive decline. Methods Literature was searched using PubMed, EMBASE, Cochrane, and PsycINFO databases with the search terms being nutraceuticals in cognitive dysfunction. The literature was limited to human studies, randomized controlled trials, and a single material. Selection of literature, evaluation of the risk of bias, and assessment of the quality of evidence was conducted independently by two reviewers. Results We finally included 17 studies of literature after excluding the risk of bias ‘high.’ The evidence was rated ‘high’ quality for both omega-3 fatty acids and vitamin Bs. Other materials, including vitamins D & E, anserine/carnosine, and chromium were identified as ‘moderate’ quality. Omega-3 fatty acids (0.48–2.2 g of DHA and 203–720 mg of EPA) relieved cognitive decline and amyloid β related proteins in participants with mild cognitive impairment. However, the cognitive decline did not have an effect on dementia patients. Vitamin B (25–500 µg of B12 and 20 mg of B6) group exhibited decreased homocysteine levels, followed by enhanced cognitive function. However, vitamin D & E, anserine/carnosine, and chromium showed a shred of limited evidence owing to limited studies. Conclusions This study suggests that omega-3 fatty acids and vitamin B have protective effects against age-associated cognitive decline. Funding Sources This research was funded by Ottogi, grant number HY-201900000670003.