As we get older, the brain changes physically. It begins to shrink in size after the age of 40 and especially after the age of 70. The prefrontal cortex – associated with cognitive function – is particularly susceptible to shrinkage. The volume of both white and gray matter is reduced in elderly individuals. With increasing age, there are reductions in the levels of the neurotransmitters acetylcholine, dopamine, and serotonin [Mantle 2021].
Ageing Brain More Vulnerable to Oxidative Stress
Moreover, increasing age is associated with mitochondrial dysfunction in the brain tissue cells. The mitochondrial dysfunction is characterized by 1) reduced ATP energy production and 2) increased generation of harmful free radicals. The resulting oxidative stress has been associated with normal ageing processes and with the development of neurodegenerative diseases [Mantle 2021].