What are LDL and HDL?
In order for cholesterol (and other fats, fat soluble vitamins and antioxidants) to be transported around the body in the blood, it has to be carried by special proteins called lipoproteins that are soluble in water. These lipoproteins are classified according to their density; two of the most important in cardiovascular disease are low-density lipoprotein (LDL) and high-density lipoprotein (HDL).
Why do LDLs often get the name “Bad Cholesterol”?
Science used to tell us that the amount of cholesterol being carried around the bloodstream was an important measure for heart disease risk. When you get your LDL level tested it is measuring the amount of cholesterol in the particles.
Now we know that it’s actually the number of LDL particles that tells us more. The more particles there are in the blood, the more likely they are to crash into the lining of the artery and penetrate the artery wall. This would be where the damage starts to happen. This is not something your doctor typically measures but more LDL particles doesn’t necessarily mean more cholesterol in the LDLs and vice versa.
Get in touch for a more in depth Lipoprotein panel so you can see what your risk is. Also know that risk factors are just that, risk factors. A high number of LDL particles does not mean that you have heart disease!
What is the most common cause of high LDL particle number?
You’re probably sure the answer to this one is eating animal foods containing saturated fat. But no, that’s not the case!! Recent cholesterol feeding studies show that dietary cholesterol has very little impact on blood cholesterol levels in about 75% of us. This is because the body controls production levels of cholesterol tightly; when dietary cholesterol goes up, production in the liver goes down. The remaining 25% of the population show modest increases in both LDL and HDL, but it does not affect the ratio of LDL to HDL or increase the risk of heart disease. In other words, eating cholesterol isn’t going to give you a heart attack.
So, back to the most common cause…
The typical pattern for high LDL particle number is metabolic syndrome. The more factors for metabolic syndrome that you have, the more likelihood there is that your LDL particle number is elevated. These include insulin resistance, leptin resistance, obesity (especially abdominal obesity), high blood pressure and high triglycerides. Since triglycerides, along with cholesterol, are also carried in the blood by LDLs, when there are more triglycerides there need to be more LDL particles to transport them around even though the cholesterol in the particles may not be high.
If this is you, then eating a low carbohydrate diet is going to be a helpful track to follow to reduce your LDLs. Improving your body’s ability to handle the glucose-insulin interaction by making sure you have the right levels of the micronutrients involved is also key. Let us know if you’d like help navigating this with dietary changes and micronutrient testing.
Other causes to consider or rule out
- Poor thyroid function can impact LDL levels in a number of ways, impacting production, absorption and metabolism. This can be the case even in subclinical hypothyroidism, where T3 and T4 are normal but TSH is elevated. Make sure you get these tested if you are concerned or have symptoms of poor thyroid function.
- Infections like H Pylori (symptoms include burping, bloating, abdominal pain or burning and nausea) and others can also be responsible for a high cholesterol profile, including high LDLs. The exact mechanism for this is not yet well understood. It is possible that the infections alter lipid metabolism in the infected cells. Alternatively it may be that LDLs have protective antimicrobial qualities.
- A leaky gut can be a cause. When your intestinal barrier is not strong it can leak toxins produced by gut bacteria into the bloodstream and cause an immune response. That immune response involves particles that are carried through the bloodstream by LDLs and so can increase LDL particle number. Let us know if you’d like to check on your intestinal permeability and get help healing a leaky gut.
- Genetics can play a role. Those with Familial Hypercholesterolemia have genetic mutations that impact the ability of LDLs to deliver nutrients to the cell so that they cannot be removed from the blood. Cholesterol levels can be anywhere from 350 to 1000 mg/DL for these individuals.
Check out my blog next time for my list of heart-healthy nutrition and lifestyle choices. In the meantime, let me know if you have questions or comments. I’d love to hear from you.