EBSCOhost - printed on 2/13/2023 11:18 AM via . All use subject to https://www.ebsco.com/terms-of-use

EBSCOhost - printed on 2/13/2023 11:18 AM via . All use subject to https://www.ebsco.com/terms-of-use

EBSCOhost - printed on 2/13/2023 11:18 AM via . All use subject to https://www.ebsco.com/terms-of-use

EBSCOhost - printed on 2/13/2023 11:18 AM via . All use subject to https://www.ebsco.com/terms-of-use

EBSCOhost - printed on 2/13/2023 11:18 AM via . All use subject to https://www.ebsco.com/terms-of-use

Neurodegenerative diseases are identified by the progressive loss of selectively sensitive neuron popula­tions resulting from metabolic or toxic disorders. Especially with aging, the development of neurodegen­erative disorders accelerates. Up to date, more than 600 nervous system disorders that affect the normal function of the brain, spine, or the nerves have been described. The structures, electrophysiological and neurochemical properties of the brain, spinal cord and nerves can be affected. Any condition that leads to neurodegeneration may result in a disorder that affects cognitive and motor functions. Neurodegenerative diseases can have a number of clinical manifestations which are largely dependent on the pathological

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mechanisms occurring in various parts of the brain. Chronic degeneration of the brain may develop due to changes at molecular and cellular level. However, these mechanisms have not been fully elucidated. Among these mechanisms, the most well-known are; neuroinflammation, protein aggregation due to failure of protein degradation pathways including the ubiquitin-proteasome system, chronic oxidative stress, mitochondrial dysfunction, impaired axonal transport, changes in RNA metabolism, and failure in triggering of apoptosis (Friese et al., 2014; Goodfellow et al., 2020).

2020). Realizing the positive effects of bioactive components on health has spawned new therapeutic approaches that play an important role in reducing neurodegeneration. Studies have shown that using supplements that contain polyphenolic compounds found in fruits and vegetables provides beneficial effects such as preventing and reversing the harmful effects of aging on neuronal function and behavior. This protection is likely due to the antioxidant and anti-inflammatory properties of fruits and vegetables (Rice-Evans & Miller, 1996).

This chapter aims to present a comprehensive review of the potential benefits of dietary bioactive compounds to reduce the incidence of neurodegenerative diseases.

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very different mechanisms. Pathomechanism of neurodegeneration seems to be affected by more than one factor as toxic reactions such as glutamatergic neurotoxicity, inflammation, depletion of endogenous antioxidants, increases in nitric oxide and iron levels, and reduced activity of ubiquitin-proteasome pathway cause neuronal cell death. In addition to all these disrupted mechanisms, the rapidly increasing lifespan of humans also increase neurodegeneration. As we know, aging is a major risk factor for many diseases characterized by apoptosis, cell cycle, cell senescence, and changes in expression of mitochon­drial genes. Other causes include gender, low education level, endocrine disorders, smoking, exposure to chemical substances, stroke, diabetes, vitamin deficiencies, depression, hypertension, head trauma, infection, tumors, immune and metabolic conditions (Ulatowski & Manor, 2015; Zhang & Butterfield, 2017; Di Meo et al., 2019). Among all these complex mechanisms, neuroinflammation, oxidative stress and excess accumulation of proteins are common pathological features of neurodegenerative diseases (Uddin et al., 2020).

Chronic neuroinflammation and oxidative stress are two key pathological factors enmeshed in neu­rodegenerative diseases and aging of the brain, and one can be the consequence of the other. The never­ending cycle between oxidative stress, neuroinflammation and neurodegeneration can initiate chronic and progressive neurodegeneration. Reactive oxygen species (ROS) act as physiological signaling molecules and have significant roles in many biological processes such as post-translational processing of pro­teins, cell growth, synthesis of molecules, immune response, and metabolic processes. However, if the levels of ROS increase more than required, they can oxidize nucleic acids, lipids and proteins, thereby contributing to aging and the development of various diseases, including cancer, diabetes, obesity, ath­erosclerosis, cardiovascular and neurodegenerative diseases (Angelova & Abramov, 2018). The major factors contributing to the formation of oxidative stress are endoplasmic reticulum (ER) stress and Ca

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Inflammation is a cellular and immune response to an attack aimed at restoring normal tissue struc­ture and function. When the metabolism is unable to prevent the damage caused by ROS at the desired level, oxidative damage occurs. Astrocytes and microglia are major cells that take part in the fight against inflammation in the brain. They are in charge of producing inflammatory and immune reaction associated molecules While reactive astrocyte products generally have a tendency to protect the neurons, inflammatory cytokines and other microglia-derived factors cause neurotoxicity (Sharman et al., 2019). Since the neurodegenerative mechanisms and the integration of these mechanisms with each other are not fully clarified, living conditions and dietary habits become more important. Studies have linked diet to the risk of developing neurodegenerative diseases. It has been shown that having an unhealthy diet (such as a diet high in calories or saturated fat) increases oxidative stress and inflammation (Erro et al., 2018; Ramirez-Salazar et al., 2021). Research has shown that in diabetes mellitus, a metabolic disease that is closely related to nutrition, brain aging may be related to abnormal insulin levels and may affect cognitive abilities. Studies have shown that hyperinsulinemia may affect the pathophysiol­ogy of AD and exacerbate clinical symptoms and, is responsible for a decrease in memory performance (Bourdel-Marchasson et al., 2010; Cholerton et al., 2011; Sanz et al., 2012). Since this relationship is also related to the cerebrovascular system, vascular dementia may occur (Strachan et al., 2011). Despite being under the effect of genetic factors, insulin resistance largely develops as a result of lifestyle. It seems that cognitive and physical brain damage are inevitable due to neuronal degeneration that will occur after increased resistance to insulin. One can suggest that dietary modifications are one of the most important factors that need to be regulated in order to prevent the emergence of such disorders. Understanding such relationships not only contributes to understand the mechanisms, but also helps explore new therapeutic approaches.

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neurodegeneration, it can inhibit the ROS activity that causes oxidative stress by increasing the activity of endogenous antioxidants. Oxidative stress can directly initiate neuronal cell death. Excitotoxicity,

Traditional foods naturally contain bioactive components with health benefits and are whole, unmodi­fied foods such as fruits and vegetables, fish, dairy products and cereals (Chauhan et al., 2013). Modified foods are normal foods enriched with functional food compounds such as plant extracts (Lafarga et al.,

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