Dietary Components Consisting of Bioactive Molecules in the Prevention of Neurodegenerative Diseases

Introduction

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 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).

Cognitive dysfunctions, motor disabilities and progressive synaptic loss are common in many neurodegenerative diseases, causing ravaging changes for patients. Recent studies have shown that having atherosclerosis, hypertension, obesity and type 2 diabetes are among the most common risk factors for Parkinson's disease (PD), Alzheimer's Disease (AD) and Hungtinton's disease (HD)-related dementia (Farooqui, 2018). Since we do not know the pathogenesis of most of these diseases, environmental factors become even more important. Regulating some environmental conditions may help prevent or delay neurodegeneration. Neurodegeneration can be directly affected by our lifestyle. We can assume that one of the most important changes is the regulation of eating habits. Memory loss and other cognitive problems have been associated with reduced intake of certain dietary nutrients, particularly in older individuals. Even though aging is a natural process and is influenced by a number of variables such as stress and lifestyle, environment and genetics, the process of aging can be controlled by diet. By maintaining neuron health, a quality life and a healthy mind and body can be achieved. Understanding the mechanisms of risk factors causing neurodegeneration has led to development of new therapeutic strategies. Recent data have demonstrated the significance of natural food-based approaches in disease management. In modern era, researchers have published more publications focusing on benefits of health-related products and how food products can boost and sustain a healthier life.

Bioactive compounds which are abundantly found in nature are mainly the secondary metabolites found in plants and in addition to their nutritional value, they have other functions such as stimulation of growth for their metabolism and protection against biotic and abiotic stress (Nogueira et al., 2020). Since bioactive components have many biological functions, including but not limited to their anticoagulant, antihypertensive, antiproliferative, antioxidative, antithrombotic, antidiabetic, anti-inflammatory and cardioprotective effects, they can also play important roles in the prevention of many diseases such as cancer, neurodegeneration and cardiovascular diseases (Acevedo-Fani et al., 2020; Stacchiotti & Corsetti, 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.