A recent study at the University of California, Davis found a distinct correlation between the development of amyloid plaque deposits associated with Alzheimer’s disease and serum cholesterol levels.
According to Bruce Reed, lead study author and associate director of the UC Davis Alzheimer's Disease Center, “The relationship between elevated cholesterol and increased risk of Alzheimer's disease has been known for some time, but the current study is the first to specifically link cholesterol to amyloid deposits in living human study participants. Our study shows that both higher levels of HDL - good - and lower levels of LDL - bad - cholesterol in the bloodstream are associated with lower levels of amyloid plaque deposits in the brain,” Reed said.
Charles DeCarli, director of the Alzheimer's Disease Center and an author of the study said that the result of this study is a wake-up call.
“Just as people can influence their late-life brain health by limiting vascular brain injury through controlling their blood pressure, the same is true of getting a handle on their serum cholesterol levels. If you have an LDL above 100 or an HDL that is less than 40…you want to make sure that you are getting those numbers into alignment," DeCarli said.
For HDL cholesterol, a level of 60 mg/dl or higher is considered best for heart health. For LDL cholesterol, a level of 70 mg/dL or lower is recommended for people at very high risk of heart disease. In the U.S., cholesterol levels are measured in milligrams (mg) of cholesterol per deciliter (dL) of blood.
According to the UC Davis newsletter, the study was conducted with 74 male and female participants 70 years and older who were recruited from California stroke clinics, support groups, senior facilities and the Alzheimer’s Disease Center. The volunteers included three individuals with mild dementia, 33 who were cognitively normal and 38 who had been diagnosed with mild cognitive impairment (MCI).
Reed feels that this study provides a reason to continue cholesterol treatment in people who are developing memory loss “regardless of concerns over vascular health.”
He also feels that people should work to lower cholesterol levels in middle age before the brain plaques begin to build up. "If modifying cholesterol levels in the brain early in life turns out to reduce amyloid deposits late in life, we could potentially make a significant difference in reducing the prevalence of Alzheimer's, a goal of an enormous amount of research and drug development effort."
The study, titled "Associations Between Serum Cholesterol Levels and Cerebral Amyloidosis," is published online in JAMA Neurology.
New cholesterol treatment guidelines could lead to higher dose statin use
Last November, new guidelines for doctors who treat cholesterol problems were issued by the American Heart Association and American College of Cardiology. These guidelines are still controversial because they rely on a new assessment tool to determine a patient’s risk of having a heart attack or stroke that has not been tested in studies. The guidelines encourage doctors to prescribe more potent, higher-dose statins when statins are needed.
Time will tell whether these guidelines are a step forward or not. In the end, the medical community still considers high levels of LDL “bad” and high levels of HDL “good.” Although the actual target numbers for the cholesterol measurements regarding heart health may differ from the target numbers that are recommended for brain health, the philosophy remains the same.
To maintain optimum health, we should keep LDL low by consuming a healthy, balanced diet low in saturated fats and sugar while increasing HDL by consuming oily fish and often fish oil supplements. Exercise has been shown to contribute to healthy cholesterol readings, as well.
Most doctors would rather see their patients keep cholesterol levels in balance through diet and exercise than through the use of drugs. Therefore, while the UC Davis study about Alzheimer’s and cholesterol and the new hearth health guidelines make news and add to the overall body of medical knowledge, the old standbys of diet and exercise remain the safest way to keep both heart and brain healthy. Taking a pill may seem easier, but in the end, maintaining a healthy lifestyle will never be controversial.
Reed, B. et. al. (2013, December 30) High good and low bad cholesterol levels are healthy for the brain, too. UC Davis. Retrieved from http://www.ucdmc.ucdavis.edu/publish/news/newsroom/8555
Kotz, D. (2013, November 12) Cholesterol treatment guidelines could double number of Americans taking statins. Daily Dose. Retrieved from http://www.boston.com/lifestyle/health/blogs/daily-dose/2013/11/12/new-cholesterol-treatment-guidelines-could-double-number-americans-taking-statins/wd2PPKWS21BHyzrt1eLIKO/blog.html
Published On: February 12, 2014