Final answer:
Cognitive impairment, including conditions like Alzheimer's disease, is a potential effect of aging on the brain, with lifestyle factors playing a role in the onset and progression of cognitive decline.
Step-by-step explanation:
Cognitive impairment is indeed a potential effect of the normal aging process on the brain. As individuals enter old age, they may experience a decline in brain cell numbers and a less efficient immune system, leading to an increased risk of illnesses such as cancer and pneumonia. Nearly half of individuals over age 85 show signs of at least mild cognitive impairment (MCI), which is a condition that stands between normal aging and dementia and can manifest in decreased cognitive functions that are not typical for the person's age.
Conditions like Alzheimer's disease are more prevalent among the elderly and can cause significant and irreversible cognitive decline. This condition is characterized by plaques in the brain resulting from cell death, leading to severe forgetfulness and the loss of critical daily functions. However, lifestyle factors like engagement in mentally and physically stimulating activities have been shown to reduce the incidence of mild cognitive impairment and dementia, potentially delaying the onset of cognitive decline.