Neuroprotective Potential of Nutraceuticals in Cognitive Impairment: A Narrative Review

Cognitive decline comprises a range from subjective memory complaints (SMC) to mild cognitive impairment (MCI) and major neurocognitive disorders such as Alzheimer’s disease (AD). Early identification and intervention are essential, yet many individuals with initial symptoms neither seek medical advice nor implement preventive lifestyle changes. Nutraceuticals have gained increasing attention as complementary strategies in the early phases of cognitive decline due to their potential neuroprotective effects, favourable safety profile, and accessibility. This narrative review summarizes current evidence on six nutraceutical compounds: docosahexaenoic acid (DHA), folic acid, selenium, vitamin D, lutein and zeaxanthin, and choline, in the context of cognitive impairment. These compounds, especially in adequate and studied doses, have been proposed to influence cognitive function through antioxidant, anti-inflammatory or methylation-related mechanisms, and in some cases by supporting neurogenesis or synaptic plasticity. Clinical studies suggest potential benefits in specific cognitive domains, particularly memory, attention, and executive function, especially among individuals with SMC or MCI. The review also highlights the high prevalence of suboptimal intake of neuroprotective nutrients among older adults and the rationale for nutritional intervention in early stages of decline. Notably, nutrient combinations appear to yield greater benefits than single-nutrient approaches, reflecting the multifactorial nature of cognitive deterioration. Although emerging evidence is promising, further well-designed studies are needed to confirm efficacy, determine optimal formulations, and define which populations may benefit most. In any case, nutraceuticals may represent a valuable, low-risk option to support cognitive health and delay progression across the cognitive impairment spectrum.