Functional and Structural Benefits Induced by Omega-3 Polyunsaturated Fatty Acids During Aging

Abstract

BackgroundOmega-3 polyunsaturated fatty acids (n-3 PUFA) are structural components of the brain and are indispensable for neuronal membrane synthesis. Along with decline in cognition, decreased synaptic density and neuronal loss, normal aging is accompanied by a reduction in n-3 PUFA concentration in the brain in both humans and rodents. Recently, many clinical and experimental studies have demonstrated the importance of n-3 PUFA in counteracting neurodegeneration and age-related dysfunctions.MethodsMethods: This review will focus on the neuroprotective effects of n-3 PUFA on cognitive impairment, neuroinflammation and neurodegeneration during normal aging. Multiple pathways of n-3 PUFA preventive action will be examined.ResultsNamely, n-3 PUFA have been shown to increase the levels of several signaling factors involved in synaptic plasticity, thus leading to the increase of dendritic spines and synapses as well as the enhancement of hippocampal neurogenesis even at old age. In elderly subjects n-3 PUFA exert anti-inflammatory effects associated with improved cognitive functions. Interestingly, growing evidence highlights n-3 PUFA efficacy in preventing the loss of both gray and white matter volume and integrity.ConclusionThis review shows that n-3 PUFA are essential for a successful aging and appear as ideal cognitive enhancers to be implemented in nutritional interventions for the promotion of healthy aging.

Neuroprotective Role of Dietary Supplementation with Omega-3 Fatty Acids in the Presence of Basal Forebrain Cholinergic Neurons Degeneration in Aged Mice

“…This neuroprotective effect was observed in the presence of global hippocampal atrophy and lack of volumetric modifications in the DG. Specific volumetric preservation of Ammon's Horn in n-3 PUFA lesioned mice may be related to the already demonstrated n-3 PUFA neuroprotective properties, such as the reduction in apoptosis, neuronal density loss and glial degeneration in aged mice [23,39]. Moreover, although neurogenic proliferation is a prerogative of DG, newborn neurons may migrate into CA1 and CA3 regions of the hippocampus, where they integrate into existing circuitry and contribute to repair [114].…”

“…Beneficial effects of n-3 PUFA treatment on behavioral performance, especially on memory functions, during aging have been demonstrated in many experimental models of pathological and non-pathological aging [2,3,23,[38][39][40], but this is the first study investigating the behavioral effects of pre-lesional treatment with n-3 PUFA in aged mice and also the first one evaluating astrogliosis, neurogenesis, and volume modifications in the hippocampus.…”

“…Longer-chain n-3 fatty acids (EPA and DHA) are synthetized by shorter-chain n-3 fatty acids (ALA) [19,20]. However, biological conversion is inefficient, especially during aging [19,[21][22][23][24]. In addition, shorter-chain fatty acids cannot be synthesized by humans [21,25].…”

“…Notably, n-3 PUFA are reported to exert beneficial and neuroprotective effects on the aging brain [23], when deterioration in neuronal function and decline in cognitive performance, mainly those hippocampal-dependent, have been consistently reported. These age-related impairments are reflective of synaptic loss, decreased neurogenesis, synaptic plasticity, neuronal density, and gray matter volume, particularly in the hippocampal circuits [28][29][30][31][32][33].…”

Low-ω3 Fatty Acid and Soy Protein Attenuate Alcohol-Induced Fatty Liver and Injury by Regulating the Opposing Lipid Oxidation and Lipogenic Signaling Pathways

“…Soy proteins (SP) are found in soybean legume containing all 8 essential amino acids and very low saturated fat [20]. In recent times, both omega-3 PUFA and SP have received increased attention due to their beneficial effects against cardiovascular disease, obesity, type 2 diabetes, and certain cancers, among others [19, 21, 22]. Low omega 3 fatty acids (low- ω 3FA) are known to have lipid lowering effects in humans [23] while SP lowers plasma and liver cholesterol and triglycerides in both animals and humans [24].…”