Dietary prevention of visual function and cognitive decline by omega-3 polyunsaturated fatty acids in senescence accelerated mouse P8 (SAM P8)

Purpose Cerebral and retinal neurons contain high amounts of omega-3 polyunsaturated fatty acids and especially docosahexaenoic acid (DHA). DHA levels decrease in the aging brain together with the cognitive performances. We evaluated the effects of a dietary supplementation with DHA on mood, cognition and visual functionality in a mouse model for aging, the SAM P8. Methods SAM P8 and control animals were fed from weaning until 12 months of age with a standard diet or a diet supplemented with DHA (6%). After 5 and 12 months of diet, we evaluated the scotopic ERG, the working memory and the despair behaviour. The fatty acid content of the retina and the brain were determined by gas chromatography. Results DHA supplementation led to its significant incorporation in the retina and the brain. An age-related loss of the ERG b-wave amplitude was observed from 5 to 12 months of age in control SAM P8 whereas this visual impairment was prevented by DHA supplementation. Dietary DHA supplementation reduced the despair behaviour of control mice but not that of SAM P8. Conclusion Dietary supplementation of DHA increased its retinal and cerebral incorporation. DHA successfully prevented the age-related loss of visual function in SAM P8 but did not improve the depression-like symptoms.