My father was a science teacher and despite the fact that I make my living with words, I have a secret fascination for science. I just love watching as researchers continue to peel back the layers of the mystery that is our health and make new discoveries that just may result in a healthier future for all of us. Research regarding cholesterol, specifically high-density lipoprotein (HDL) or “good” cholesterol, is one of the areas where science has recently made some interesting discoveries.
Because it’s long been believed that HDL cholesterol provided protective benefits to the heart, research has been more focused on understanding and reducing levels of the “bad” or low-density lipoprotein (LDL) cholesterol levels than understanding HDL cholesterol. This trend has been changing and HDL cholesterol has recently been the focus of some interesting studies. One of the more interesting discoveries is that not all good cholesterol is created equal. New research indicates that some HDL cholesterol is, well, of better quality than other HDL cholesterol.
In findings published in the December, 2008, edition of the Federation of American Societies for Experimental Biology (FASEB), University of Chicago researchers revealed that some people did not enjoy protective benefits from HDL cholesterol, even when their HDL levels were normal or high. Basically, the view has been that as long as HDL levels were normal, you were in good shape in terms of developing heart disease or suffering a cardiovascular event (heart attack, angina, etc.). The University of Chicago findings challenge the traditional view that high levels of HDL cholesterol automatically provides protective benefits for the heart.
Researchers discovered that not only does HDL cholesterol fail to provide protective heart health benefits to some people, but that HDL cholesterol also comes in various levels of quality. The study found that the HDL cholesterol was not the same in healthy persons when compared to those who suffered from chronic illnesses such as diabetes or rheumatoid arthritis. The quality of HDL cholesterol in persons with chronic diseases was very poor in comparison to their healthy counterparts. Not surprisingly, poor quality HDL cholesterol is not a good thing for your heart health. In fact, poor quality HDL, even if the HDL levels are normal, can be very bad for you. Even when HDL levels were the same, persons with good quality HDL enjoyed reduced inflammation (greater protection for the heart) while those with bad quality HDL showed no reduction in inflammation and less protective benefit for the heart.
According to Angelo Scanu, M.D. (first study author), it’s no longer enough to simply know your overall HDL cholesterol level. Dr. Scanu recommends that everyone should “…ask their doctor to find out whether their HDL is good or bad.” These findings related to good and bad quality of HDL certainly shed light on why some people with normal HDL levels may still develop heart disease. I think that Dr. Gerald Weissmann (editor of FASEB) summed it up best - “Just as the discovery of good and bad cholesterol rewrote the book on cholesterol management, the realization that some of the 'good cholesterol' is actually bad will do the same."
Sources:
HDL cholesterol: How to boost your 'good' cholesterol, The Mayo Clinic, 24 Jul 2008, http://www.mayoclinic.com/health/hdl-cholesterol/CL00030
Federation of American Societies for Experimental Biology (2008, December 3). Some 'Good Cholesterol' Is Actually Bad, Study Shows. ScienceDaily. Retrieved May 31, 2010, from http://www.sciencedaily.com¬ /releases/2008/12/081201081713.htm
HDL Not Always the Good Cholesterol We Think Says University of Chicago Study, Senior Journal, 01 Dec 2008, http://seniorjournal.com/NEWS/Health/2008/20081201-HDLNotAlwaysTheGood.htm