A reduction in behavioural pattern separation is attenuated by dietary supplementation with a magnesium-rich marine mineral blend in middle-aged rats

EK Crowley, S Grabrucker, CM Long-Smith, A Stack, DM O’Gorman & Y Nolan

Published: Journal of Medicinal Foods (2021) 1-6 

Background: Middle-age is a critical period where cognitive decline can be targeted with lifestyle interventions such as diet and exercise. Research shows that dietary factors play a crucial role in brain health and cognitive function and may help protect against cognitive impairment. A reduction in pattern separation ability is frequently observed in healthy older individuals, where similar but not identical experiences are distinguished from one another. This is a feature of age-associated, mild-cognitive impairment and often presents during middle-age. In the absence of effective treatments, novel dietary approaches to lessen age-related cognitive impairment are essential. 

 Aim: Magnesium has been shown to enhance learning and memory, and reverse cognitive impairment. Magnesium deficiency is associated with impaired memory formation. This study was designed to evaluate if supplementation with a magnesium-rich marine mineral blend (MMB, a 50:50 mix of Aquamin F: Aquamin Mg) could influence age-related cognitive impairment in middle-aged rats. 

 Study Details: Young (12 week) and middle-aged (16-month) rats were maintained for 4 weeks on either a control diet or MMB supplementation before undergoing a series of behavioural assessments. 

 Results: 

·         MMB supplementation had no overall effects on body weight, food intake or general locomotor activity. The figure on the bottom left shows how much less middle-aged animals move as compared to younger animals. This figure also indicates how movement in the arenas was measured. 

·         Supplementation did not affect performance in behavioural tasks that assessed working memory and recognition memory such as the Y-maze, and open field experiments. 

·         Pattern separation is a key component of episodic memory e.g. parking your car in a shopping centre car park. A similar but not the same spot each time. 

·         In this study, middle-aged animals demonstrated a significant impairment in pattern separation, compared to young animals. This impairment was reversed with 4 weeks of MMB supplementation.

Conclusions: Supplementation with MMB significantly reduced the age-associated deterioration in pattern separation task by middle-aged animals. This is of interest as an improvement in this type of cognition requires a unique brain plasticity or flexibility and neurogenesis (the new growth of neurons).