Research from a Missouri University shows too much “good cholesterol” may not be so good.

Dr Ziyad Al-Aly - Photo courtesy of Washington University School of Medicine

Dr Ziyad Al-Aly – Photo courtesy of Washington University School of Medicine

It’s commonly known bad cholesterol, or “LDL”, can build up and block heart vessels, causing cardiovascular disease and stroke.  For years, good cholesterol, or “HDL’, has been credited with helping to remove bad cholesterol from arteries.

But according Dr. Ziyad Al-Aly, who authored the study at the Washington University School of Medicine in St. Louis, a massive study just released raises some red flags about good cholesterol.  “If you have too low of the HDL level, it’s actually bad for the health which increases the risk of death” said Al-Aly.  “What we were finding in this study is that, also, too high of a level, or too high HDL cholesterol, is also a bad thing.  So too much of a good thing, so to speak, is actually bad.”

The research shows high levels of good cholesterol may increase the risk of premature death.

Al-Aly says the study is much more in-depth than previous examinations, encompassing 1.7 million veterans for over nine years – 2001-to-2013 “The reason we’re seeing this now, and why it was largely obscured before is that they were looking at small sample sizes.  They were looking at only a few thousand people and trying to study the relationship between HDL cholesterol and the risk of death” said Al-Aly.  “Now we’re looking at it with a magnifying glass, so to speak, of big data…It enables you to see the relationship between HDL and the risk of death in a much more nuanced and much more sophisticated way.”

Al-Aly says he and his colleagues were surprised by the results of the study.  “We were skeptical that we seeing actually a true thing.  But the data is the data. This is, again, 1.7 million people were followed for 9.1 years, almost a decade of life.”

The association between high levels of good cholesterol and death is still unclear.  Al-Aly says more research is needed.  It’s also unknown whether or not intermediate levels help lengthen life spans.  Al-Aly says more research is needed to provide more clarity of the effects of HDL.



Missourinet