Cholesterol Primer
Cholesterol is an organic molecule, lipid, or fatty acid that does not dissolve in water. Every one of your cells makes it. In fact, in your body, your liver, intestines, and brain make the most. It is essential for synthesizing Vitamin D. It also is essential for making all steroid hormones, including the sex hormones progesterone, estrogens, and testosterone. Gallstones are solid cholesterol!
Your cell walls are about 30% cholesterol, which keeps them flexible, stable, and durable. Cholesterol in the myelin sheath around some nerves serves as electrical insulation, helping make efficient cell signaling and nerve signal conduction.
Your body recycles it, and your liver excretes it into bile, a fluid that aids digestion. As a result, in your digestive tract, about 50% is reabsorbed by your body.
Eating cholesterol-rich foods modifies how much your body makes, and concentrations in the blood can increase. Seven to ten hours after eating it, though, cholesterol in food has little effect on its concentration in your bloodstream. Some people may have a genetic mutation that results in high cholesterol.
It’s not very soluble in water or blood
It dissolves in blood at very small concentrations and travels through blood via emulsification. LDL (i.e. Lower Density Lipids-transported-within-proteins) particles are the major blood cholesterol carriers. They are lipoproteins whose outward-facing surfaces are water-soluble and inward-facing surfaces are lipid-soluble.
A cell with plentiful cholesterol blocks its LDL receptor synthesis and prevents new LDL molecules from being taken up. Conversely, a cell deficient in cholesterol makes new LDL receptors.
When this LDL cholesterol receptor process gets unregulated
When the process breaks down, LDL molecules without receptors begin to appear in the blood. That LDL remains in the bloodstream longer than it should. There, LDL molecules oxidize and macrophage white blood cells engulf them. The macrophages swell with fluid and form foam cells that can get trapped in blood vessel walls and contribute to plaque formation. Plaque build-ups, or atherosclerosis, are made of cholesterol, fatty substances, cellular waste products, calcium, and fibrin (a clotting material in the blood). These plaques are the main causes of heart attacks, strokes, and other serious medical problems. As a result, we think of so-called LDL cholesterol as “bad” cholesterol that drives arterial disease.
What are HDL particles?
HDL (i.e. Higher Density Lipids-transported-within-proteins) particles take cholesterol back to your liver, either for excretion or for other tissues that make hormones. Large numbers of HDL particles mean better health outcomes, whereas low numbers may mean disease developing in your arteries. We think of HDL as “good” cholesterol that can regress arterial disease.
Food and cholesterol
All animal cells make it, and as a result, all animal-based foods contain it in varying amounts. Major dietary sources include red meat, egg yolks, and whole eggs, liver, kidney, giblets, fish oil, and butter.
Some plant foods, such as avocado, flax seeds, and peanuts, contain phytosterols, which compete with cholesterol for absorption in the intestines. Phytosterols reduce the absorption of both dietary and bile cholesterol, although a typical diet is not enough to have a significant impact on blocking absorption.
In 2016, the United States Department of Agriculture Dietary Guidelines Advisory Committee recommended that Americans eat as little dietary cholesterol as possible. Most foods that are rich in cholesterol are also high in saturated fat, and they may increase the risk of cardiovascular disease.
What are Triglycerides?
Triglycerides, fatty acids, are the most common type of fat in your body. They come from foods, especially butter, oils, and other fats you eat, and also come from extra calories. These are the calories your body does not need right away. Your body changes extra calories into triglycerides and stores them in fat cells. Your VLDL (Very Low-Density Lipoprotein) particles carry triglycerides to your tissues. When your body needs energy, it releases triglycerides.
Cholesterol testing
The American Heart Association recommends testing every 4–6 years for people aged 20 years or older. Patients taking statin medications should be tested 4–12 weeks after their first dose and then every 3–12 months thereafter.
The lab measures a lipid profile or estimate of a person’s lipoproteins from a blood sample after 12-hour fasting.
As a result, the lipid profile measures:
(a) total cholesterol
(b) cholesterol associated with HDL particles
(c) triglycerides
(d) (by a calculation and assumptions) cholesterol carried by LDL particles
Vedas is minutes from I-45 (Houston’s North Freeway) in The Woodlands. So easy to find, so easy to get to! Call 281-298-5476 to book your free consultation with Dr. Nangrani. Together, you will discuss testing and a treatment plan. We look forward to seeing you soon!
If you have atherosclerosis, it’s time to make a plan to slow its progress. Follow the link for tips on eating, exercise, and LDL-reducing statins.
Advanced Lipid Testing at Vedas
Primary source: Wikipedia
