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 Wednesday in the journal, Neurology . Advertisement 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