Although we generally consider high-density lipoprotein beneficial when it comes to heart health, questions about why people with high levels of HDL (good cholesterol) still get heart attacks have troubled researchers for years.
Now, after nearly a decade of research involving the DNA structure of cholesterol, Annabelle Rodriguez, an endocrinologist at the University of Connecticut Health Center for Vascular Biology, has discovered evidence that mutations in SCARB1 genes (key components in the body’s ability to metabolize cholesterol) may actually sabotage the protein’s ability to sufficiently clear the waxy substance from blood vessels so it can be processed by the liver and then eliminated through the intestines in bile.
As a result, Rodriguez told Discovery Magazine “more cholesterol circulates in the bloodstream increasing the buildup of plaque, leading to arterial disease.” In fact, data collected from 6,000 patients participating in a 2015 Multi-Ethnic Atherosclerosis (MESA) Study found that those possessing the SCARBI variant actually had a 50% hike in cardiovascular disease.
This has led other researchers, including Sekar Kathiresan, director of preventative cardiology at Massachusetts General Hospital to provide more evidence that the amount of HDL cholesterol in one’s body may actually be “secondary to its importance than its functionality.”
Meanwhile, it should be noted that the above mutation is only one of 46 known variants of the SCARB1 gene. Each of these effect the body in unique ways, ranging from interfering with another gene called lymphocyte activation gene III’s ability to produce a protein known as LAG3. :LAG3 is linked to the immune system and has the ability to shut off the body’s response to inflammation.
It was also found that carriers of this variant, known as rs10846744, had “5-times lower levels of RNA” “in their cells. Rodriguez and her colleagues are currently working to develop better diagnostic tools to detect LAG3 deficiency and create new drugs to treat it.
HDL and infertility
Most people know that we need cholesterol to make vitamin D, and substances that help us digest our food, Yet, many readers may be surprised to learn that HDL not only transports cholesterol to the liver, it also carries it to the adrenal glands and ovaries, where it plays an important part in creating hormones such as progesterone (vital to early embryo development). However a defect in SCARB1 can cause some women to produce lower levels of progesterone than women without the mutation, leaving them infertile.
Finding a cure
While Rodriguez, Kathiresan and other experts are hard at work trying to develop diagnostic tools to better identify LAG3 protein deficiencies, as well as medications to combat its affects, many cardiologists still feel that it is important for them to concentrate treating elevated LDL (low-density lipoprotein) cholesterol, which can build up within the walls of your blood vessels and narrow the passageways eventually leading to the possibility of stroke or heart attack with the use of statins. The most common of these include Lipitor (atorvastatin) and Zocor (simvastatin).
Note: While there is growing evidence that HDL cholesterol may not be as “good” as once believed, most cardiologists still maintain that reducing ‘bad’ LDL (low density lipoproteins obtained by eating food animal products such as meat, dairy, and eggs, etc), should remain their top priority in preventing heart attacks and strokes.
In addition to diet and exercise, the most common treatment is prescribing statins, such Zocor (simvastatin) and Lipitor (atorvastin). Statins, however, can have serious side effects including increased risk of diabetes, muscle pain (and in rare cases muscle pain and damage as well as liver problems.