Good Cholesterol May Reduce Alzheimer’s Risk

Dyslipidemia, where total cholesterol and triglycerides are elevated, often correlates to late-onset Alzheimer's Disease.  Christiane Reitz, from Columbia University (New York, USA), and colleagues studied 1,130 older adults to examine the association of blood lipid (fat) levels with Alzheimer's disease. The study included a random sampling of Medicare recipients 65 or older residing in northern Manhattan, with no history of dementia or cognitive impairment. The researchers defined higher levels of HDL cholesterol as 55 milligrams per deciliter or more. The team collected data from medical, neurological and neuropsychological evaluations, and assigned a diagnosis of "probable" Alzheimer's Disease when onset of dementia could not be explained by any other disorder or a diagnosis of "possible" Alzheimer's Disease was made when the most likely cause of dementia was Alzheimer's disease but there were other disorders that could contribute to the dementia, such as stroke or Parkinson disease.  During the course of follow-up, there were 101 new cases of Alzheimer's Disease, of which 89 were probable and 12 were possible. The mean (average) age of individuals at the onset of probable and possible Alzheimer's Disease was 83 years, and compared with people who were not diagnosed with incident Alzheimer's Disease, those who did develop dementia had a higher prevalence of diabetes at the start of the study.  Reporting that higher plasma levels of HDL cholesterol were associated with a decreased risk of both probable and possible Alzheimer's Disease, even after adjusting for vascular risk factors and lipid-lowering treatments, the researchers conclude that: “High HDL-C levels in elderly individuals may be associated with a decreased risk of [Alzheimer's Disease].”