A study presented at the American Heart Association's Scientific Sessions 2024 reveals that unexplained fluctuations in cholesterol levels may help identify older adults at risk for dementia. The research, conducted on nearly 10,000 adults in their 70s over a six-year period, found that those with stable cholesterol levels had a significantly lower risk of developing dementia or showing cognitive decline compared to those with fluctuating levels.
Lead author Zhen Zhou, Ph.D., a postdoctoral research fellow at Monash University in Melbourne, Australia, emphasized the importance of monitoring older individuals with fluctuating cholesterol levels, particularly those experiencing significant year-to-year variations. The study utilized data from the ASPirin in Reducing Events in the Elderly (ASPREE) clinical trial, which included participants from Australia and the United States.
The research findings indicate that high fluctuations in total cholesterol were associated with a 60% increase in dementia risk and a 23% increase in cognitive decline. Additionally, variations in low-density lipoprotein (LDL) cholesterol, often referred to as 'bad' cholesterol, were linked to faster declines in overall cognitive health, memory, and reaction speed.
While the exact relationship between cholesterol variability and dementia risk requires further investigation, Zhou suggested that significant fluctuations in total and LDL cholesterol levels may destabilize atherosclerotic plaques, potentially impacting brain function. However, the study has limitations, including the predominantly white participant pool and the observational nature of the research, which cannot establish a cause-and-effect relationship.
Fernando D. Testai M.D., Ph.D., FAHA, a professor of neurology and rehabilitation at the University of Illinois Chicago and American Heart Association volunteer expert, noted that this study adds an important piece to the puzzle of preserving brain health. He emphasized that the results cannot be explained by the effect of statins, as the study excluded people who started or stopped taking lipid-lowering medications during the study period.
The implications of this research are significant, given the projected increase in dementia cases among older adults. According to the U.S. Centers for Disease Control and Prevention, the number of adults aged 65 and older with dementia is expected to nearly double from 7 million in 2014 to 14 million by 2060.
This study underscores the importance of maintaining stable cholesterol levels through consistent healthy lifestyle practices, such as following a balanced diet and regular exercise. It also highlights the potential for using cholesterol variability as a biomarker for dementia risk, which could lead to earlier interventions and improved prevention strategies.
As research in this area continues, healthcare providers may need to pay closer attention to cholesterol fluctuations in older patients, even when absolute levels remain within normal ranges. This approach could contribute to more comprehensive risk assessments and personalized prevention strategies for dementia and cognitive decline.
The findings from this study open new avenues for research into the complex relationship between vascular health and cognitive function. Future studies may focus on understanding the mechanisms behind cholesterol variability and its impact on brain health, potentially leading to novel therapeutic targets for dementia prevention and treatment.
