Nutritional Factors Affecting Adult Neurogenesis and Cognitive Function

Abstract

Adult neurogenesis, a complex process by which stem cells in the hippocampal brain region differentiate and proliferate into new neurons and other resident brain cells, is known to be affected by many intrinsic and extrinsic factors, including diet. Neurogenesis plays a critical role in neural plasticity, brain homeostasis, and maintenance in the central nervous system and is a crucial factor in preserving the cognitive function and repair of damaged brain cells affected by aging and brain disorders. Intrinsic factors such as aging, neuroinflammation, oxidative stress, and brain injury, as well as lifestyle factors such as high-fat and high-sugar diets and alcohol and opioid addiction, negatively affect adult neurogenesis. Conversely, many dietary components such as curcumin, resveratrol, blueberry polyphenols, sulforaphane, salvionic acid, polyunsaturated fatty acids (PUFAs), and diets enriched with polyphenols and PUFAs, as well as caloric restriction, physical exercise, and learning, have been shown to induce neurogenesis in adult brains. Although many of the underlying mechanisms by which nutrients and dietary factors affect adult neurogenesis have yet to be determined, nutritional approaches provide promising prospects to stimulate adult neurogenesis and combat neurodegenerative diseases and cognitive decline. In this review, we summarize the evidence supporting the role of nutritional factors in modifying adult neurogenesis and their potential to preserve cognitive function during aging.

Adult neurogenesis in the mammalian dentate gyrus

“…Such focus could lead to discoveries that will improve health. The prospect of improved and continuous proliferation and generation of new neurons that improves the plasticity of adult mammalian brains could provide substantial therapeutic potential to treat neurodegenerative diseases and other disorders of the central nervous system (Poulouse, Miller, Scott, & Shukitt‐Hale, ).…”

Current understandings of the trajectory and emerging correlates of cognitive impairment in bipolar disorder: An overview of evidence

“…Growing preclinical and clinical evidence has shown that diet and physical activity are key to maintaining brain health and cognitive function, especially during ageing . Nutritional factors in particular, may stimulate adult neurogenesis and help to protect cognitive function in the elderly, as well as those with brain disorders . However, the evidence for the link between cognition and diet/nutrition in BD is scarce, although findings from a recent 6‐week randomized trial did indicate that an adjunctive nutraceutical, creatine monohydrate, was associated with improved verbal fluency in depressed BD patients …”

“…140 Nutritional factors in particular, may stimulate adult neurogenesis and help to protect cognitive function in the elderly, as well as those with brain disorders. 141 However, the evidence for the link between cognition and diet/nutrition in BD is scarce, although findings from a recent 6-week randomized trial did indicate that an adjunctive nutraceutical, creatine monohydrate, was associated with improved verbal fluency in depressed BD patients. 142 Finally, BD is associated with substantial rates of alcohol/substance misuse, which in turn may further worsen patients´ cognitive function, especially in the executive and verbal memory domains.…”

Role of phytochemicals as nutraceuticals for cognitive functions affected in ageing

“…Its antioxidant mechanisms explain its ability to improve memory in many of these studies, including via reduced oxidative damage through enhancing glutathione (GSH) and decreasing lipid peroxide levels in brain tissue (Perry & Howes, ; Sarker & Franks, ; Williams et al, ). Animal studies also show curcumin improves memory tasks and it can reverse stress‐induced reductions in neurogenesis, associated with brain‐derived neurotrophic factor (BDNF; Poulose, Miller, Scott, & Shukitt‐Hale, ). In the well‐established scopolamine model to assess memory retrieval in vivo , curcumin (50 or 100 mg·kg −1 orally for 10 days) restored the induced memory deficits in mice and prevented the scopolamine‐induced changes in Akt/glycogen synthase kinase‐3β, which is significant as the latter has been implicated in neurodegeneration and impaired cholinergic function (SoukhakLari, Moezi, Pirsalami, Ashjazadeh, & Moosavi, ).…”

“…As the ageing process and neurodegenerative diseases have been characterised as pro-inflammatory states (Nelson & Tabet, 2015;Poulose et al, 2017), anti-inflammatory mechanisms of curcumin may also underpin its relevance to ameliorate cognitive decline (Table 1).…”