By James Limbach
ConsumerAffairs.com
August 5, 2009
Elevated cholesterol levels in midlife -- even levels considered only borderline elevated -- significantly increase the risk of Alzheimer's disease and vascular dementia later in life, according to a new study by researchers at Kaiser Permanente's Division of Research and the University of Kuopio in Finland.
The four-decade study, appearing in the journal Dementia & Geriatric Cognitive Disorders, found that having high cholesterol in midlife (240 or higher milligrams per deciliter of blood) increases, by 66 percent, the risk for Alzheimer's disease later in life.
Even borderline cholesterol levels (200-239 mg/dL) in midlife raised risk for late-life vascular dementia by nearly the same amount: 52 percent. Vascular dementia, the second most common form of dementia after Alzheimer's disease, is a group of dementia syndromes caused by conditions affecting the blood supply to the brain. Scientists are still trying to pinpoint the genetic factors and lifestyle causes for Alzheimer's disease.
"Our study shows that even moderately high cholesterol levels in your 40s puts people at greater risk for Alzheimer's disease and vascular dementia decades later," said Rachel Whitmer, Ph.D., a research scientist and epidemiologist at the Kaiser Permanente Division of Research in Oakland, Calif. "Considering that nearly 100 million Americans have either high or borderline cholesterol levels, this is a disturbing finding. The good news here is that what is good for the heart is also good for the mind, and this is an early risk factor for dementia that can be modified and managed by lowering cholesterol through healthy lifestyle changes."
This study, funded by the National Institutes of Health, adds to other research emphasizing the importance of addressing dementia risk factors in midlife, before an underlying disease or symptoms appear, the researchers said.
"Our findings add to the existing body of evidence on a degree of overlap between two dementia types in terms of risk factors, symptoms and neuropathology," said the study's lead author, Alina Solomon, MD, a researcher with the Department of Neurology at the University of Kuopio, Finland. "Dementia and cardiovascular disease are common major health problems, share several risk factors and often occur simultaneously, interacting with one another. A holistic approach that addresses multiple major health problems simultaneously is needed to effectively manage these disorders."
The study tracked members of Kaiser Permanente's Northern California Medical Group from 1967 to 2007 by using the multiphasic testing records pioneered by Kaiser Permanente founding physician Morris Collen, MD, who is widely regarded worldwide as a health care informatics pioneer. Of the original 9,844 participants, 598 were diagnosed with Alzheimer's disease or vascular dementia between 1994 and 2007, when they were between 61 and 88 years old.
The study did not examine the mechanism of the link between cholesterol levels and dementia.
