There are some very interesting questions coming out regarding the benefits of HDL cholesterol.
High HDL cholesterol has always been encouraged because people with higher HDL cholesterol levels have a reduced risk for heart disease. If you have low HDL cholesterol levels it’s likely that your doctor recommended you to boost levels through diet and exercise or by taking niacin supplements. This is due to the long held belief that HDL cholesterol reduces heart disease risk by “picking up” artery clogging cholesterol from circulation.
A new study utilizing modern genetic testing is challenging this theory, finding that there may not be a direct cause-and-effect relationship between reduced heart disease risk and high HDL cholesterol levels. Study findings indicate the high HDL levels themselves may not be protective on their own. These high HDL levels may be an indicator of something else reducing heart disease risk.
This study was published in the Lancet back in August 2012. Researchers wanted to study the effects of LDL cholesterol versus HDL cholesterol individually. Participants with genetic variations predisposing them to higher or lower HDL and LDL cholesterol were studied. For LDL cholesterol, those with naturally high levels were more likely to have heart disease. Those genetically predisposed to low LDL cholesterol levels had a reduced risk of heart disease as expected.
When looking at HDL cholesterol, researchers began by studying 116,000 individuals looking for a specific genetic variant for raising HDL. This variant is seen in about 2.6% of the population. Researchers did not find an association between this HDL-raising variant and heart disease risk.
Researchers then began to study data on 53,000 individuals looking into an additional 14 genetic variants that also impact HDL levels. Once again they were surprised to find no association between genetically high HDL levels and reduced heart disease.
This leads researchers to speculate that it isn’t the HDL cholesterol resulting in reduced heart disease risk, but something else the HDL is associated with that does affect risk. This “something else” is unknown at this time.
Interestingly enough, this speculation can be backed by the results of clinical trials on four drugs to increase HDL cholesterol. The four drugs raised HDL levels, but were not successful at lowering heart disease risk.
Now, much more research is needed to determine whether the long held beliefs on the role of HDL cholesterol no longer hold true or not. Continue to work with your doctor to treat your cholesterol as appropriate for your situation.
Be sure to sign up for the free ecourse “How to Lower Cholesterol in 8 Simple Steps” at http://lowercholesterolwithlisa.com.
All the best,
Lisa Nelson RD