Maintaining stable cholesterol levels is crucial for heart health, but emerging research suggests it may also play a significant role in cognitive function. A recent study presented at the American Heart Association (AHA) 2024 Scientific Sessions indicates a link between fluctuating cholesterol levels and an increased risk of dementia and cognitive decline in older adults.
According to the AHA, high levels of low-density lipoprotein cholesterol (LDL-C), often referred to as “bad” cholesterol, are a significant health concern. In 2017-2020, 25.5% of US adults had high LDL-C levels (130 mg/dL or higher). Globally, excessive LDL-C contributed to 3.72 million deaths in 2021. Dementia is another growing health crisis, with an estimated 7 million US adults aged 65 and older affected in 2014, projected to nearly double by 2060.
Cholesterol buildup in artery. Image credit: © Rasi | stock.adobe.com
This new research highlights the importance of cholesterol stability, rather than just absolute levels, in brain health. “In the past, studies have focused on individual vascular risk factors and cognitive decline,” explains AHA volunteer expert Fernando D. Testai, MD, PhD, FAHA, a professor of neurology and rehabilitation at the University of Illinois Chicago. “However, increasing variability of bodily functions like blood pressure or blood sugar can be detrimental to both heart and brain health.”
Representation of cholesterol molecules.
Cholesterol Variability and Cognitive Decline: The ASPREE Study Findings
The study analyzed data from the ASPirin in Reducing Events in the Elderly (ASPREE) trial, which involved nearly 10,000 healthy older adults from Australia and the US. Participants underwent annual cholesterol monitoring, and the study specifically focused on those who did not alter their cholesterol medication during the follow-up period.
Researchers examined the first three cholesterol measurements to assess yearly fluctuations. Over nearly six years of follow-up, 509 participants developed dementia, and 1760 experienced cognitive decline without dementia. Individuals with the highest fluctuations in total cholesterol (top 25%) had a 60% greater risk of dementia and a 23% greater risk of cognitive decline compared to those with the most stable levels. Similar trends were observed for LDL-C fluctuations, with faster declines in overall cognitive test scores, memory, and reaction speed.
Implications for Dementia Prevention and Treatment
Interestingly, fluctuations in triglycerides or high-density lipoprotein cholesterol (HDL-C), known as “good” cholesterol, were not associated with cognitive decline. This underscores the specific role of LDL-C and total cholesterol variability in brain health.
“This study reinforces the importance of maintaining stable cholesterol levels for cognitive health,” states Dr. Testai. “Inconsistency in healthy lifestyle choices, such as diet and exercise, can exacerbate the negative impact of fluctuating cholesterol on the brain.”
Limitations and Future Research Directions
While the study provides valuable insights, it’s important to acknowledge its limitations. Cholesterol readings can vary due to numerous factors, and the observed association may be influenced by unanalyzed variables. Additionally, the predominantly white study population (96%) limits the generalizability of the findings. Further research is needed to explore these factors and confirm the causal relationship between cholesterol variability and dementia risk.
Conclusion: The Importance of Consistent Cholesterol Management
This study emphasizes the importance of consistent cholesterol management for overall health, including cognitive function. While medication can play a role, maintaining a healthy lifestyle with regular exercise and a balanced diet is crucial for stabilizing cholesterol levels and reducing the risk of dementia and cognitive decline. Consulting with a healthcare professional is essential for personalized treatment plans and guidance on maintaining healthy cholesterol levels.
