• Posted January 30, 2025

Cholesterol Changes in Seniors Linked to Brain Health

Seniors whose cholesterol levels spike and plummet year-to-year could be at increased risk of dementia and failing brain health, a new study suggests.

Those whose cholesterol fluctuated the most had a 60% increased risk of dementia, researchers report in findings published Jan. 29 in the journal Neurology.

They also had a 23% increased risk of mild cognitive impairment, an early stage of brain aging that can lead to dementia, researchers found.

“These results suggest that fluctuating cholesterol, measured annually, may be a new biomarker for identifying people at risk of dementia, providing more information than the actual cholesterol levels measured at a single time point,” lead investigator Zhen Zhou, a research fellow at Monash University in Melbourne, Australia, said in a news release.

High cholesterol levels in middle age have been identified as a risk factor of cognitive decline and dementia later in life, researchers mentioned in background notes.

However, research into the impact of cholesterol on brain health in seniors has yielded mixed results. 

Some studies have said cholesterol has no impact on the brain in old age, while others have found that low cholesterol might actually increase dementia risk.

For this study, researchers tracked the brain health of more than 9,800 people 65 and older who started off with no dementia or other memory problems.

The participants’ cholesterol levels were measured at the beginning of the study, and at three annual visits afterward. They also took memory skills tests every year.

After their third visit, participants were followed for an average of more than five years. During the study, 509 people developed dementia.

Among the people with the largest amount of cholesterol change during the four years, 147 out of 2,408 developed dementia -- a rate of 11.3 per 1,000 person-years, results show.

But among those with the least cholesterol change, 98 out of 2,437 developed dementia, or 7.1 per 1,000 person-years. Person-years reflect the number of people in a study and the amount of time each spends in the study.

The risk of dementia and mild cognitive impairment was specifically linked to fluctuations in total cholesterol levels and levels of “bad” LDL cholesterol, researchers said.

They didn’t find any link between brain health and fluctuations in “good” HDL cholesterol or triglycerides.

Researchers also noted that the study could not prove a direct cause-and-effect between changing cholesterol and dementia. It only shows an association between the two.

“Older people’s cholesterol should be monitored for changes over time to help identify people who may be at risk of cognitive impairment or dementia and could benefit from interventions, which could include lifestyle changes or making sure they start or keep taking statins to prevent fluctuations in their cholesterol and potentially reduce the risk of dementia,” Zhou said.

Changing cholesterol levels might damage the brain by altering the composition of fatty plaques on the walls of arteries, increasing the risk of either clogging blood flow to brain cells or sparking a full-fledged stroke, researchers speculated.

These cholesterol fluctuations also might be a side effect of other chronic diseases that are the real reason behind a person’s cognitive decline, the team concluded.

More information

Harvard Medical School has more on lowering cholesterol to protect the heart and brain.

SOURCE: American Academy of Neurology, news release, Jan. 29, 2025