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'Good' and 'bad' cholesterol levels healthy for the brain

Category: General Wellness

Managing cholesterol levels can be a balancing act for some individuals as they work to prevent the risks associated with hypertension and cardiovascular disease. However, a new study published in JAMA Neurology detailed the link of cholesterol levels with amyloid plaque buildup that can cause Alzheimer's disease.

Led by Bruce Reed, Ph.D., the lab tests were carried out at the University of California-Davis Alzheimer's Disease Center in Sacramento. The 74 participants in the study were 70 years of age or older and were recruited from support groups, senior facilities and stroke clinics around California. Of the participants, 38 had mild cognitive impairment, 33 had no impairment and three had mild dementia. In order to measure their amyloid levels, the researchers used a tracer that bonded to the plaques and were imaged by PET scans.

Their cholesterol tests showed that high levels of LDL (bad) and low levels of HDL (good) were associated with a bigger buildup of amyloid plaques in the brain. This marked the first time that cholesterol levels have been correlated to the buildup of amyloid.

"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," explained Reed, associate director at the Alzheimer's Disease Center.

Although increased cholesterol has been tied with Alzheimer's disease before, the team's study specifically connected unhealthy patterns of cholesterol to deposits of amyloid in living human participants. The link similarly mirrors the relationship that irregular hypertension numbers has with the development of heart disease.

Not adhering to new guidelines
Following the recent update to cholesterol guidelines provided by a collaborative study involving the American College of Cardiology, the National Heart, Lung and Blood Institute and the American Heart Association, the experts suggested LDL levels should be altered. However, Reed's study strays away from this report with its results.

"This study provides a reason to certainly continue cholesterol treatment in people who are developing memory loss regardless of concerns regarding their cardiovascular health," Reed concluded.

Their findings may suggest that older patients can modify their cholesterol in order to decrease amyloid buildup in the brain. Doing this early enough can reduce the risk of developing Alzheimer's disease later in life, which has been the focus of years of scientific and drug research.

Knowing 'good' from 'bad'
Cholesterol levels might be one of the most complex medical topics in the field. Too much "good" cholesterol or not enough "bad" could put an individual at higher risk of developing heart disease or experiencing a stroke. It's important to understand the differences between them and how cholesterol interacts with the body.

There are two sources of cholesterol: food and the body. Roughly 75 percent of blood cholesterol is produced by the liver and other cells. The rest comes from food, which is only found in products from animals.

"Good" cholesterol is HDL and "bad" cholesterol is LDL, both of which can be determined by cholesterol testing. HDL helps prevent heart attacks and stroke by keeping LDL from clogging arteries. Many people inherit genetic cholesterol problems from their parents, causing their bodies to produce too much LDL.

According to the American Heart Association, an HDL level of 60 milligrams per decilitre (mg/dL) of blood is ideal in protecting against the risk of heart disease. If a person's HDL drops below 40 mg/dL, the risks of health problems increase. The optimal level for LDL cholesterol is less than 100 mg/dL. Once LDL levels approach 160 to 180 mg/dL, the possible risks begin to rise.