A new study suggests that older adults whose cholesterol levels change significantly over time may have a higher risk of developing dementia compared to those whose cholesterol remains stable. The findings, published in Neurology on January 29, 2025, highlight cholesterol variability as a potential new biomarker for identifying people at risk of cognitive decline.
Cholesterol Changes vs. Dementia Risk
The study, led by Dr. Zhen Zhou from Monash University in Melbourne, Australia, does not prove that changing cholesterol directly causes dementia. However, it establishes a strong association between cholesterol fluctuations and an increased risk of cognitive impairment.
“These results suggest that fluctuating cholesterol, measured annually, may be a new biomarker for identifying people at risk of dementia, providing more information than cholesterol levels taken at a single point in time,” said Dr. Zhou.
How the Study Was Conducted
The study followed 9,846 adults with an average age of 74 who had no memory problems or signs of dementia at the start. Researchers measured cholesterol levels at the beginning and at three additional annual visits, then tracked participants’ cognitive health for an average of 5.5 years. Participants were tested on memory skills each year.
People who started or stopped taking cholesterol-lowering drugs (statins) during the measurement period were excluded to ensure that medication-related fluctuations did not affect the results. However, participants who had been consistently using statins before the study were included.
Key Findings
The participants were divided into four groups based on how much their cholesterol levels fluctuated over the four-year period. Those with the largest swings in cholesterol levels showed an average yearly change of 91 mg/dL, while those with the most stable levels had an average change of 22 mg/dL.
Over the course of the study, 509 participants developed dementia. Among those with the highest cholesterol fluctuations, 147 out of 2,408 developed dementia, a rate of 11.3 cases per 1,000 person-years. In contrast, among those with the most stable cholesterol levels, only 98 out of 2,437 developed dementia, with a lower rate of 7.1 cases per 1,000 person-years.
After adjusting for other dementia risk factors such as age, smoking status, and high blood pressure, researchers found that those with the largest cholesterol changes were 60% more likely to develop dementia than those with stable cholesterol.
LDL Cholesterol and Cognitive Impairment
Further analysis revealed that fluctuations in LDL cholesterol—often referred to as “bad” cholesterol—were linked to both dementia and milder cognitive impairment that did not meet the criteria for dementia. However, no such connection was found for HDL (“good”) cholesterol or triglycerides.
What This Means for Older Adults
These findings suggest that monitoring cholesterol changes over time could be just as important as measuring overall cholesterol levels. Dr. Zhou emphasized the importance of regular cholesterol checks:
“Older people’s cholesterol should be monitored for changes over time to help identify those who may be at risk of cognitive impairment or dementia. Interventions could include lifestyle changes or ensuring that patients take their statins consistently to prevent fluctuations and potentially reduce dementia risk.”
Study Limitations and Future Research
One limitation of the study is that while researchers excluded participants who started or stopped statin use, they did not have information on dosage adjustments or missed medications, which could have influenced cholesterol variability.
Future research should explore whether stabilizing cholesterol levels through medication or lifestyle changes can lower dementia risk.
For now, this study reinforces the importance of regular cholesterol monitoring, not just for heart health but also for maintaining brain function in older age.
If you care about dementia, please read studies that eating apples and tea could keep dementia at bay, and Olive oil: a daily dose for better brain health.
For more health information, please see recent studies what you eat together may affect your dementia risk, and time-restricted eating: a simple way to fight aging and cancer.
The research findings can be found in Neurology.
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