A significant study, published on December 29, 2025, in *Neurology*, the medical journal of the American Academy of Neurology, reveals a compelling link between the body's internal clock, known as the circadian rhythm, and the risk of developing dementia in later life. Researchers observed that older adults exhibiting weaker, more fragmented, or irregular circadian rhythms faced a substantially higher likelihood of dementia. Specifically, participants with the weakest rhythms had nearly 2.5 times the risk of dementia compared to those with strong, well-aligned rhythms. The study, which involved monitoring the rest and activity patterns of over 2,000 older adults (average age 79) who were dementia-free at the outset, also found that the timing of peak daily activity played a crucial role. Individuals whose activity levels peaked later in the afternoon (2:15 p.m. or later) showed a 45% increased risk of dementia compared to those with earlier activity peaks (between 1:11 p.m. and 2:14 p.m.). Experts suggest that disruptions in circadian rhythms may impact brain health through various mechanisms, including altering inflammatory processes, interfering with sleep patterns, and potentially influencing the accumulation or clearance of amyloid plaques, which are associated with Alzheimer's disease. While the study establishes a strong association, it clarifies that it does not prove a direct causal relationship between irregular circadian rhythms and dementia. The findings, however, open new avenues for research into potential interventions, such as light therapy or lifestyle modifications, to strengthen circadian rhythms and potentially mitigate dementia risk. This global scientific discovery underscores the importance of maintaining a robust and consistent body clock for long-term cognitive well-being. The Press Trust of India, along with other credible news outlets, widely reported on these significant findings.