The New World of HDL Cholesterol

Byron's Comments:

This information on HDL will change the nature and meaning of cardiovascular health.

Study Title:

HDL: bridging past and present with a look at the future.

Study Abstract:

Clinical and epidemiological studies have shown that HDLs, a class of plasma lipoproteins, heterogeneous in size and density, have an atheroprotective role attributed, for years, to their capacity to promote the efflux of cholesterol from activated cholesterol-loaded arterial macrophages. Recent studies, however, have recognized that the physical heterogeneity of HDLs is associated with multiple functions that involve both the protein and the lipid components of these particles. ApoA-I, quantitatively the major protein constituent, has an amphipathic structure suited for transport of lipids. It readily interacts with the ATP-binding cassette transporter ABCA1, the SR-B1 scavenger receptor; activates the enzyme lecithin-cholesterol acyl transferase (LCAT), which is critical for HDL maturation. It also has antioxidant and antiinflammatory properties, along with the HDL-associated enzymes paraoxonase, platelet activating factor acetylhydrolase (PAF), and glutathione peroxidase. Regarding the lipid moiety, an atheroprotective role has been recognized for lysosphingolipids, particularly sphingosine-1-phosphate (S1P). All of these atheroprotective functions are lost in the post-translational dependent dysfunctional plasma HDLs of subjects with systemic inflammation, coronary heart disease, diabetes, and chronic renal disease. The emerging notion that particle quality has more predictive power than quantity has stimulated further exploration of the HDL proteome, already revealing unsuspected pro- or antiatherogenic proteins/peptides associated with HDL.

For a number of years, HDL has been identified as serving an atheroprotective role by promoting reverse cholesterol transport, a process facilitating the efflux of cholesterol from cholesterol-loaded macrophages in the artery wall. This notion has been in keeping with the information derived from epidemiological studies indicating an inverse relationship between low plasma HDL cholesterol levels and coronary disease. Subsequent structural-functional studies have drawn attention to the critical role played by the unique helical make up of the two constitutive protein components of HDL, ApoA-I and ApoA-II. In particular, ApoA-I has been the most abundant and most extensively studied of the two, having besides its ready tendency to undergo delipidation/relipidation both in vitro and in vivo, the ability to interact with the ATP-binding cassette transporter ABC1 and the SR-B1 hepatic receptor as well as activate LCAT. Besides these lipid-related functions, apoA-I has gained increasing recognition for its antioxidant and antiinflammatory properties and even as a modulator of innate immunity. With the introduction of advanced MS techniques, quantitatively 100 “minor” proteins, some related and some unrelated to lipoprotein metabolism, have been identified in addition to special HDL associated lysosphingolipids with an atheroprotective role. We have now come to view the various subclasses of HDL as “dynamic platforms” harboring at their surface, proteins/peptides, mobilized from tissues likely via the ubiquitous ATP-binding cassette transporters Fig. 5 . We have also come to recognize that in the presence of systemic inflammatory settings, apolipoproteins and lipids may lose their atheroprotective role so that, for instance, high plasma levels of HDL rather than protective may be proatherogenic. Conversely, low plasma levels such as in familial hypoalphalipoproteinemia, the loss of protectiveness will result in a proatherogenic profile. From the therapeutic viewpoint, we have seen the promising entry into the clinical arena of ApoA-I mimetic peptides properly designed to favor the redistribution of HDL into atheroprotective prebeta migrating species. Clearly, the HDL field is ripe for systems biology studies in which interdisciplinary approaches lead to a clarification of the many unknowns that still surround this complex lipoprotein class.

From press release:

If you think your levels of “good cholesterol” are good enough, a new study published in the December 2008 issue of The FASEB Journal suggests that you may want to think again. In the report, researchers from the University of Chicago challenge the conventional wisdom that simply having high levels of good cholesterol (HDL) and low levels of bad cholesterol (LDL) is necessary for good heath.

Instead, they show that the good cholesterol has varying degrees of quality and that poor quality HDL is actually bad for you.

“For many years, HDL has been viewed as good cholesterol and has generated a false perception that the more HDL in the blood, the better,” said Angelo Scanu, M.D., a pioneer in blood lipid chemistry from University of Chicago and first author of the study. “It is now apparent that subjects with high HDL are not necessarily protected from heart problems and should ask their doctor to find out whether their HDL is good or bad.”

The researchers came to this conclusion after reviewing published research on this subject. In their review, they found that the HDL from people with chronic diseases such as rheumatoid arthritis, kidney disease, and diabetes is different from the HDL in healthy individuals, even when blood levels of HDL are comparable. They observed that normal, “good,” HDL reduces inflammation, while the dysfunctional, “bad,” HDL does not.

“This is yet one more line of research that explains why some people can have perfect cholesterol levels, but still develop cardiovascular disease,” said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. “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.”

High Cholesterol

According to the U.S. Centers for Disease Control and Prevention, approximately 17 percent of all American adults have high total cholesterol, putting them at risk for heart disease. Cholesterol is a waxy, fat-like substance used by the body to maintain the proper function of cell membranes and is encapsulated within two types of proteins as it travels in the body—low density lipoproteins (LDL) and high density lipoproteins (HDL). High levels of LDL or total cholesterol are an indicator of increased risk for heart disease. High blood cholesterol elicits no physical symptoms, making medical screenings necessary for detection.

Study Information:

Angelo M. Scanu and Celina Edelstein. HDL: bridging past and present with a look at the future. The FASEB Journal.  2008 December 
University of Chicago.

Related Entries: Master Enzyme Switch Deactivated In Chronic Fatigue Syndrome and Fibromyalgia
Cinnamon Provides Impressive Benefits for Blood Sugar, Heart Health, Inflammation and More
Gastric Bypass Nutritional Consequences
Toxic Mineral Linked with Bowel Inflammation, Mitochondrial Damage, and Alzheimer’s
Magnesium and Vitamin B1 - Team Players Needed for Brain, Muscles, Metabolism, and More
Vitamin B1 / Thiamin - Are you getting enough?
H. Pylori and Autoimmune Link
Common Medications That Rob the Body of Nutrients
The Many Faces of Gluten Intolerance
Supplement Quality - Are You Getting What’s On the Label?
Statin Drugs Cause Atherosclerosis and Heart Failure
Heart Disease and Depression: A Two Way Street
Broken Heart Syndrome
Ten Things that Interfere with Thyroid Function
Vaccine Injury with Chronic Fatigue Syndrome and Fibromyalgia
Bone Loss Caused by Thyroid Meds and Other Drugs
Five Key Tips for a Healthy 2015
Top Health Stories of 2014
Combat the Winter Blues
Carnosine – Amazing Benefits for Athletes, Heart, Brain, Eyes, and Diabetes
ADT Prostate Cancer Therapy Does More Harm Than Good
Musicians: A Note on Taking Care of the Body
Infections Linked to Autoimmune Thyroid Problems
Noni: Tropical Super Fruit – Powerful Support for the Immune System, Brain, Bones, and more
Enlarged Adenoids Linked with Food Allergies
Combat Ear Infections and Congestion Naturally
Glaucoma: Protecting Against a Silent, Devastating Disorder
Protect and Energize Your Immune System
GMOs, Roundup, and Sunscreen Linked with Diminished Brain Resiliency
Signs of Concussions and Mild Traumatic Brain Injury
Sleep – Molecular Clean Up Time for the Brain
Artificial Sweeteners Provoke High Risk for Diabetes
Hypothyroidism, Brain Stress, and Season Changes
Alcohol, Adolescents, and Young Adults – A Neurological Disaster Waiting to Happen
GABA: Managing Brain Stimulation, Anxiety, and Other Consequences
Brain Fatigue: Fundamental Solutions
Brain Fatigue 101
Astonishing Benefits of Cranberries
Summer Heat Stress – More Than Just Dehydration
Chronic Active Epstein Barr Virus: Additional Tools for the Battle
Pine Nut Oil Reduces Inflammation, Clotting Risk, and Fatty Liver Congestion
New Findings with Epstein Barr Virus: The Sleeping Giant
Type 1 Diabetes: Risk Factor Alert
Disrupted Gut Clocks Linked with IBS, GERD, Obesity, and Other GI Concerns
Body Clocks and Weight Management – It’s All About Timing
Saturated Fat Myth – Debunked Again
Powerful Nutrition for Common Chemical Exposures
Endocrine Disruptor Compounds and Natural Solutions
Endocrine Disruptor Compounds and Your Hormones
Low Blood Pressure Linked with Brain Atrophy
Vitamin K, Leptin, AGEs, and Arthritis
Advanced Solutions for Osteoarthritis
Osteoarthritis: Good Oils versus Bad Oils and Inflammation
High Levels of Omega 6 Fatty Acids Found in Bones of Osteoarthritis Patients Worsens Joint Breakdown
Lipoic Acid Protects the Heart and Immune System from Acute Emotional Stress
Whiplash, Thyroid, and Adrenals
Brain Inflammation Now Documented in Chronic Fatigue Syndrome
Brain Protective Effects of Proathocyanidins
Nutrient Highlight: Discover the Best Form of Folate
Lutein and Zeaxanthin Offset Gene Weaknesses that Cause Macular Degeneration
Lycopene Builds Its Anti-Prostate Cancer Case
Carotenes Improve the Quality of Semen
Vitamin B12 as Methylcobalamin Repairs Nerves & Lowers Pain
Folic Acid Activates Neural Stem Cells for Brain Rejuvenation
Chromium Improves Insulin Function & Reduces Binge Eating
How Fiber and Niacin Protect Against Colon Inflammation and Cancer
Berries Have Anti-Aging Impact on Immune System
Strawberries Reduce Cardiovascular Risk
Friendly Flora Improves Fatty Liver Disease
Flavonoid Intake Improves Cardio Health in At-Risk Men
Polyphenols and Essential Fatty Acids Reduce Cardio Risk in Overweight People
Vitamin C Reduces the Risk for Hemorrhagic Stroke
Testosterone Therapy Increases Heart Attack Risk
Magnesium Intake Linked to Lower Cardiovascular Inflammation
Q10 Boosts Energy, Nerves, Muscles & Metabolism
Coenzyme Q10 Remarkably Improves Circulation
Tyrosine Helps Maintain Mental Ability Under Stress
Green Tea Extract Lowers Blood Pressure, Cholesterol, Blood Sugar & Inflammation
Poor Flexibility is a Sign of Stiff Arteries
A Sluggish Lymph System Causes Snoring & Sleep Apnea
DHA is Vital to Cardiovascular Wellness
Magnesium Supplements Lower Blood Pressure, Prevent Calcification
Magnesium for the Prevention of Heart Disease
Pomegranate Protects HDL Cholesterol from Damage
Pomegranate Blocks Flu Replication
Tocotrienols:  Twenty Years of Dazzling Cardiovascular and Cancer Research
Is Resveratrol the Fountain of Youth?
Grape Seed Extract Lowers Blood Pressure
Scientists Tout Resveratrol as a Primary Nutrient for Cardio Health

Most Popular News:

Connect with Wellness Resources:

Connect on Facebook Follow us on Twitter Wellness Resources on Pinterest Wellness Resources YouTube Channel Get RSS News Feeds
Thyroid and Metabolism