Animal studies have shown that deficiency of the omega-3 fatty acid, docosahexaenoic acid (DHA), is associated with memory loss and diminished cognitive function. SAMP8 mice have earlier manifestations of aging such as learning disability and loss of memory than normal mice. The impact of omega-3 fatty acids from dietary fish oil on brain DHA status, learning and memory ability in aged SAMP8 mice were investigated.

Methods – Ten months old SAMP8 mice were either fed the Breeder Chow (low-DHA) or Fish oil Chow (high-DHA) diet for eight weeks. The T-maze foot shock avoidance was tested, and the proportions of DHA were determined in membrane lipids of hippocampus (n = 8-10) and amygdala (n = 8-10) from the 12-month-old mice.

Results – The 12-month-old mice fed high-DHA diet contained higher proportions of DHA in membrane lipids of hippocampus and amygdala than the mice fed low-DHA diet. The mice fed high-DHA diet had improved (P < 0.01) acquisition and retention of T-maze foot shock avoidance compared with the mice fed low-DHA diet.

Conclusion – The study demonstrates that regular consumption of dietary omega-3 fatty acids of marine origin might prevent the decline in learning ability and memory loss during aging.