More good cholesterol in the body associated with less chance of Alzheimer's
Higher levels of good, HDL cholesterol levels in the body may mean a lower risk of developing Alzheimer's disease, suggest researchers at Columbia University's Taub Institute, New York.
The scientists conducted an analysis of blood lipid profiles among 1,130 older adults, seeking those whose HDL cholesterol levels were 55 milligrams per deciliter or more to find whether Alzheimer's disease and cholesterol are connected.
The authors write, "Dyslipidemia [high total cholesterol and triglycerides] and late-onset Alzheimer's disease are highly frequent in western societies. More than 50 percent of the U.S. adult population has high cholesterol. About 1 percent of people age 65 to 69 years develop Alzheimer's disease, and the prevalence increases to more than 60 percent for people older than 95 years."
The study included Medicare recipients in Northern Manhattan, age 65 and older, chosen randomly. None of the subjects had memory deficits or Alzheimer's disease.
The authors used information from neurological and neuropsychological evaluations, assigning a diagnosis of "possible" Alzheimer's disease when other brain and nervous system disorders were present, including Parkinson's disease and stroke.
"In this study, higher levels of HDL cholesterol were associated with a decreased risk of both probable and possible Alzheimer's disease," the authors concluded. During the follow-up period, there were 89 possible new cases of Alzheimer's disease and 12 probable cases.
The study authors note, "An important consideration in the interpretation of the results is that it was conducted in an urban multiethnic elderly community with a high prevalence of risk factors for mortality and dementia." Subjects who did develop dementia were primarily Hispanic and more had diabetes at the start of the study.
Because the average age was 83, and there were a high number of diabetics in the study, the authors said, ..."our results may not be generalizeable to cohorts with younger individuals or to cohorts with participants with a lower morbidity [disease] burden."
In the study, higher levels of HDL cholesterol was associated with a decreased risk of both probable and possible Alzheimer's disease, even after adjustments were made for vascular risk factors and lipid lowering therapies. The researchers failed to find the same reduced risk of Alzheimer's disease in relation to non-HDL and LDL cholesterol levels, following the adjustments.
Arch Neurol. 2010;67(12):1491-1497. doi:10.1001/archneurol.2010.297