Brain Senescence and Neuroprotective Dietary Components

Senescence is an ageing process characterized by progressive and irreversible dysfunction of various physiological systems. Physiological senescence with advancing age is not a disease, but it affects the life-span and life-quality of elderly people. Brain functions such as cognition and motor skills, as with other organ systems, are impaired in almost all elderly people. Neuroprotective dietary components can play a key role in ensuring healthy ageing of the brain. Although the causative mechanisms of senescence are complex and not yet fully elucidated, enhanced oxidative stress is thought to be an important contributor. Dietary antioxidants from fruits and vegetables have preventative effects on oxidative stress. Catechin, a polyphenol found in green tea, has a potent antioxidative effect. Recently, catechin has been reported to protect against reduced ageing-related cognitive functions such as those associated with learning and memory, and ischemic brain damage. Catechin may act as a neuroprotective agent in progressive neurodegenerative disorders such as Parkinson's and Alzheimer's diseases. The neuroprotective effects and putative mechanisms of action of catechin and other antioxidants are examined and discussed in this review.