According to a recent study, older adults who experience fluctuating cholesterol levels over time may be more susceptible to dementia. The researchers propose that annual cholesterol monitoring might help evaluate older people’s risk of dementia and cognitive impairment.
The liver produces cholesterol, a waxy, fat-like substance necessary for the synthesis of cell membranes, some hormones, and bile salts for fat digestion. However, high cholesterol levels can lead to a variety of health issues, including heart disease.
Besides high cholesterol, fluctuating cholesterol levels may also impact health, according to recent research.
A new study has discovered that in older persons, annual variations in cholesterol levels may raise the risk of dementia and cognitive loss.
First presented at the Scientific Sessions 2024 of the American Heart Association, the work was eventually published online in January 2025 in the American Academy of Neurology’s official magazine, Neurology [1].
Types of Cholesterol: Is All Cholesterol Harmful?
Numerous foods, such as meat, seafood, poultry, eggs, and dairy products, contain cholesterol. However, the Centers for Disease Control and Prevention (CDC) recommends that people avoid eating too many cholesterol-rich meals because it may result in health issues such as heart attacks and strokes [2].
In addition to food and lifestyle factors, genetics, certain medical disorders, and certain drugs can all contribute to high cholesterol. According to the CDC, approximately 25 million persons in the United States have high cholesterol (240 mg/dL or more) [3].
There are two types of cholesterol, and they have different health effects [4]:
- High-density lipoprotein cholesterol (HDL-C) is also known as “good” cholesterol since it absorbs cholesterol in the blood and sends it back to the liver to eliminate it from the body.
- Low-density lipoprotein (LDL-C), also known as “bad” cholesterol, accounts for most cholesterol in the body, and high levels cause it to build up in the arteries, leading to heart disease and stroke.
Could annual cholesterol evaluations assist with dementia diagnosis?
The present study’s participants were all involved in the ASPirin in Reducing Events in the Elderly (ASPREE project), a significant study conducted in the US and Australia to investigate the relationship between older individuals’ health and low-dose aspirin.
All 9,846 participants were in their 70s, with 87% residing in Australia and the remaining in the United States. At the beginning of the study, none of them had dementia, and 32% were taking cholesterol-lowering drugs, which they continued to use.
During three years of the study, participants underwent annual testing of their total cholesterol, LDL-C, HDL-C, and triglycerides – another fatty material present in the blood and derived from diet.
Based on the degree of fluctuation in their cholesterol levels, the researchers divided individuals into four groups, ranging from the highest to the lowest.
They then followed the patients for six years to see if they developed dementia or had cognitive deterioration. A team of experts examined cognitive test results, self-reported cognitive issues, and medical reports of dementia diagnosis or medication prescription.
Next, the research team compared the numbers to dementia and cognitive impairment in the highest and lowest changing cholesterol groups.
Fluctuating cholesterol levels linked to dementia
During the 6-year follow-up, about 509 participants got dementia, while 1,760 experienced cognitive impairment without dementia.
The researchers discovered that while there were no correlations between dementia and fluctuating HDL-C or triglycerides, there were between dementia and fluctuating levels of total cholesterol and LDL-C.
Compared to those with the most stable cholesterol levels, those with the highest variations in total cholesterol levels were 23% more likely to experience cognitive decline and 60% more likely to develop dementia.
The risk of dementia was 48% higher, and the risk of cognitive impairment was 27% higher for those with the highest variations in LDL-C.
Additionally, they exhibited more rapid declines in memory, reaction time, and general cognitive functioning.
The next step: can cholesterol be a dementia biomarker?
In a press release, lead author Zhen Zhou, PhD, a postdoctoral research fellow at Monash University’s School of Public Health and Preventive Medicine in Melbourne, Australia, stated that older adults with fluctuating cholesterol levels that are not related to whether they were taking lipid-lowering drugs, especially those who have significant year-to-year variations, may benefit from closer monitoring and proactive preventive measures [4].
According to Zhou, this topic requires more research. In the press release, she said further research is needed to understand the connection between dementia risk and cholesterol variability. She also questioned if cholesterol variability levels are a real risk factor, a precursor, or a biomarker of dementia risk.
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References
- Zhou, Z., Moran, C., Murray, A.M., Zoungas, S., Magnussen, C., Chong, T.T.J., Shah, R.C., Sheets, K.M., Nelson, M., Zhu, C. and Tonkin, A.M., 2025. Association of year-to-year lipid variability with risk of cognitive decline and dementia in community-dwelling older adults. Neurology, 104(4), p.e210247.
- Preventing High Cholesterol. CDC, https://www.cdc.gov/cholesterol/prevention/index.html. Published Online: 15th May, 2024. Accessed: 12th February, 2025.
- High Cholesterol Facts. CDC. https://www.cdc.gov/cholesterol/data-research/facts-stats/?CDC_AAref_Val=https://www.cdc.gov/cholesterol/facts.htm. Published Online: 24th October, 2024. Accessed: 12th February, 2025.
- Unexplained changes in cholesterol may help identify older adults at risk for dementia. American Heart Association – Newsroom. Press Release. https://newsroom.heart.org/news/unexplained-changes-in-cholesterol-may-help-identify-older-adults-at-risk-for-dementia. Published Online: 11th November, 2024. Accessed: 12th February, 2025.
- Lang, K. Cholesterol fluctuations may be a tell-tale sign of dementia. Medical News Today. https://www.medicalnewstoday.com/articles/cholesterol-fluctuations-may-be-a-tell-tale-sign-of-dementia. Published Online: 30th January, 2025. Accessed: 12th February, 2025.
- Fluctuating cholesterol linked to higher risk of dementia in older adults. News Medical. https://www.news-medical.net/news/20250129/Fluctuating-cholesterol-linked-to-higher-risk-of-dementia-in-older-adults.aspx. Published Online: 29th January, 2025. Accessed: 12th February, 2025.
