No doubt about that. In fact, it's an absolutely essential component in the animal cell membrane.
At a high level, a few of the essential things it does in the body...
Membrane Structure and Function
http://www.cytochemistry.net/cell-biology/membrane_intro.htm
Closer look at cell membrane shows cholesterol 'keeping order'
http://www.physorg.com/news/2011-03-closer-cell-membrane-cholesterol.html
Plasma membrane cholesterol controls the cytotoxicity of Alzheimer’s disease
http://www.fasebj.org/content/16/12/1526.full.pdf
CHOLESTEROL AND CHOLESTEROL ESTERS
STRUCTURE, OCCURRENCE, BIOCHEMISTRY AND ANALYSIS
Cholesterol has vital structural roles in membranes and in lipid metabolism in general. It is a biosynthetic precursor of bile acids, vitamin D and steroid hormones (glucocorticoids, oestrogens, progesterones, androgens and aldosterone). In addition, it contributes to the development and working of the central nervous system, and it has major functions in signal transduction and sperm development. It is found in covalent linkage to specific membrane proteins or proteolipids ('hedgehog' proteins), which have vital functions in embryonic development. However, because plasma cholesterol levels can be a major contributory factor to atherogenesis, media coverage has created what has been termed a ‘cholesterophobia’ in the population at large.
Of course, don't go eating an unhealthy diet...just realize that the human body absolutely must have cholesterol to function normally. It's an essential lipid in animal cells.
On a side, but related note, this makes for interesting reading:
High cholesterol or low vitamin D?
Published March 22, 2011 | By Dr. Craig Keebler
"One area receiving little attention is the role of vitamin D in the development of atherosclerosis, stroke, and heart attack.Isn’t cholesterol the cause of “hardening of the arteries” and the related problems of stroke and heart attacks?
Yes, it’s one cause. But the story goes much deeper. How does that cholesterol in the blood get stuck inside artery walls? First, the artery wall has to get inflamed. Just like a cut in your skin can get red, swollen, and inflamed from an infection, artery walls can experience the same process. When that happens, white blood cells get drawn into the artery wall. From there, they reach out and gobble up cholesterol from the bloodstream, bringing it into the artery wall. Thus, the process begins.
It turns out that vitamin D is a potent inhibitor of this type of inflammation in artery walls. Vitamin D activates dozens of different genes that keep inflammation under control and prevent this process from getting started in the first place. People with bad atherosclerosis have extremely low levels of vitamin D – a fraction of the levels that are needed for maintaining good health.
High cholesterol affects about 37% of Americans. Low vitamin D levels affect a surprising 77% of us. Among African-Americans and others with darker skin, low levels are found in over 90%. Both high cholesterol and low vitamin D predispose to stroke, heart attacks, and atherosclerosis.
So when someone has a stroke at 41, I wonder what the vitamin D level is.
Do you know what yours is?
You should. Chances are it’s low.
How low?
Only a blood test can tell you. Testing your vitamin D also helps prevent overdose when you are using vitamin D supplements.
What’s a healthy level of vitamin D?
Researchers say between 32 and 90 ng/mL However, many experts believe truly healthy levels are more like 40 to 80.
How can I get my levels in that range?
Years ago, when most of us worked outdoors or got around on foot, we got most of our vitamin D from sunlight – at least in spring and summer months. Nowadays, most people prefer air-conditioned comfort on hot sunny days, prefer driving to get places, and use vitamin D blocking sunscreens when outdoors for any length of time. Those are some of the reasons why our levels of vitamin D have dropped in half over the past few decades.
With today’s indoor lifestyles and our concerns about skin cancer, the logical way to get enough vitamin D today is through inexpensive supplements. As I said in last week’s post, correcting low vitamin D is both easy and cheap.
A few pennies a day can purchase the vitamin D drops or pills to provide the 2,000 to 4,000 units a day that will get most Americans to healthy levels over several months.
Reaping long-term health benefits, however, requires maintaining those good levels indefinitely, which means taking the right amount of vitamin D forever.
Don’t forget about cholesterol though. If you want to lower your risk of stroke or heart attack, have your vitamin D level checked along with your cholesterol level. Get both of them into healthy ranges. It could save your life."
On a personal note, about 1.5 years ago, my Dr. started including Vitamin D test's during blood work for Cholesterol levels in his patients.
Mine was found to be pretty low, so he advised me to include a 2,000 IU Vitamin D with my daily Vit/Min (& Krill Oil, CoQ10). About 6 months later, I was right in the middle of the healthy range.
It appears that the benefits of testing for, and controlling Vitamin D levels is gaining popularity amongst the medical community.
A few additional resources that back up the role of inflamation in this process:
New Culprit in Atherosclerosis
http://www.sciencedaily.com/releases/2012/01/120109102922.htm (A Macrophage is a type of white blood cell, as mentioned above)
Heart-Disease Sleuths Identify Prime Suspect: Inflammation of Artery.
http://drkaslow.com/html/arterial_inflammation.html
Inflammation, aspirin, and the risk of cardiovascular disease in apparently healthy men.
http://www.ncbi.nlm.nih.gov/pubmed/9077376.1
Inflammation, atherosclerosis, and coronary artery disease.
http://www.coryi.org/cardiology/Hansson.pdf(From the New England Journal of Medicine)
Atherosclerosis: Basic Mechanisms
Oxidation, Inflammation, and Genetics
http://circ.ahajournals.org/content/91/9/2488(From the Journal Circulation)
Thanks for the links. Will take some time to review. Thanks again.