Recent research underscores the critical role of selenium in maintaining brain health during aging, particularly through its influence on neural progenitor cell viability, redox balance, neuroinflammation regulation, synaptic plasticity, and protection against ferroptosis.

Selenium's neuroprotective effects are primarily mediated by selenoproteins, which help reduce oxidative stress and support neural plasticity, especially in the hippocampus, a region vital for memory and spatial orientation.

The review highlights selenium's potential to mitigate age-related cognitive decline and neurodegenerative diseases such as Alzheimer's and Parkinson's by promoting hippocampal neurogenesis.

Animal studies reveal that selenium deficiency can impair hippocampal structure and function, leading to deficits in spatial memory and cognition, emphasizing the importance of adequate selenium levels.

As people age, a decline in adult hippocampal neurogenesis is linked to memory issues and increased risk of neurodegenerative diseases, making the stimulation of neurogenesis a promising intervention.

Monitoring selenium status through biomarkers like serum selenium and selenoproteins could be crucial in clinical settings to assess and manage cognitive health risks in aging populations.

Despite promising mechanistic insights, human studies on selenium's neuroprotective effects remain limited and often inconsistent, highlighting the need for more rigorous, long-term, multi-omics research.

Selenium intake varies globally based on soil content and diet, with recommended daily allowances set at 55 micrograms by WHO, but both deficiency and excess pose health risks.

Translating selenium's neuroprotective potential into clinical practice faces challenges, including determining optimal dosing and accounting for differences in selenium metabolism across species.

Animal models suggest that selenium supplementation can enhance hippocampal neurogenesis by activating pathways like PI3K-Akt-GSK3β-Wnt, thereby improving cognition in aged or diseased subjects.