Comprehending the complexities of brain ageing and dementia has long been a top priority in the field of neuroscience. Global ageing populations are contributing to an increase in the prevalence of dementia and cognitive decline, which presents serious problems for public health systems and society at large. But new studies have illuminated the main variables linked to dementia risk and brain ageing, providing hope for possible interventions and therapies. In this article, we examine the critical components that shape cognitive health in later life by delving into the ground-breaking discoveries of experts in this subject.