Cholesterol: What is it?
Cholesterol is a waxy, fat-like substance that’s made primarily in the liver and found in all cells of the body. Your body uses cholesterol for many crucial functions:
- Hormone production – cholesterol is the backbone of sex hormones (estrogen, testosterone, progesterone) and corticosteroids (cortisol)
- Vitamin D production – cholesterol is required to synthesize vitamin D from sunlight
- Digestion – bile salts, which are necessary for the breakdown of carbohydrates, protein and fats, are created by cholesterol
- Nervous system – cholesterol makes up cell membranes and the myelin sheath that surrounds nerve cells; it is also important for healthy synapses, which are the junctions between cells where cellular communication takes place
- Intestinal wall – cholesterol helps maintain the intestinal wall, helping to reduce inflammation and improve the immune system
- Immune system – when damage and inflammation occur in blood vessels, cholesterol acts like an antioxidant and rushes in to make repairs
Cholesterol does not dissolve in water. For it to travel through the blood to other parts of the body, it does so in little packages, called lipoproteins, in which water-soluble proteins surround the fat and cholesterol.
Lipoproteins – Does size matter?
Lipoproteins come in a variety of sizes, and this is where things start getting interesting. Low-density lipoproteins, or LDL, are often referred to as “bad” cholesterol, because these lipoproteins have been thought to bring cholesterol to artery walls where they cause a build-up of plaque, leading to atherosclerosis, or hardening of the arteries. However, we now know that the plaque has very little cholesterol in it. When the lining of a blood vessel is damaged, the immune system kicks into gear to repair it. This is in the form of inflammation. Many researchers believe that the presence of LDL cholesterol at the site of blood vessel damage is because it is trying to repair the injured blood vessel.
Studies have shown that the total LDL cholesterol is not as important as particle number and particle size. Some LDL particles have a lot of cholesterol, while others have very little. In addition, LDL can be divided in size: large, fluffy particles and small, dense, sticky particles. Everyone has a combination of these LDLs, with one type being more dominant than the other.
Pattern A refers to having a greater proportion of large, fluffy LDLs and is linked to better cardiovascular health. Pattern B refers to having a greater proportion of small, dense, sticky LDLs that are more prone to oxidation, which causes atherosclerosis and increased risk of a cardiovascular event.
This oxidation is the real problem as it causes inflammation, which is the true root cause of cardiovascular disease. A recent study published in the New England Journal of Medicine showed that lowering inflammation independent of cholesterol reduces cardiovascular risk. In this study of more than 10,000 individuals, reducing IL-1, an inflammatory cytokine, reduces the risk of another cardiovascular event in people who have already had a heart attack.
If LDLs are the “bad” guys, then high-density lipoproteins, or HDLs, are considered the “good” guys. HDLs have been thought to transport cholesterol away from arteries and back to the liver for recycling. Similar to more recent findings on LDLs, the size of the HDLs matters. Smaller HDL particles may be better at transporting cholesterol from the lining of blood vessels elsewhere, reducing inflammation, preventing clotting and better handling oxidized free radicals.
Know Your Numbers
If all this information is making your head spin, you’re not alone. However, we have come a long way in the past 30 years when it comes to the importance of knowing your numbers and how they translate into cardiovascular disease risk. A simple blood panel that measures total cholesterol, LDL, HDL and TG (triglycerides) does not provide enough information. Getting a more specialized test to know your particle sizes is key, especially if you have a family history of heart disease or you have multiple risk factors for heart disease, which include increased waist circumference (>35 inches in women and >40 inches in men), high blood pressure, and pre-diabetes or diabetes. These tests include the NMR LipoProfile test (LabCorp), VAP Test (VAP Diagnostics), LipoProtein Particle Test (Spectracell), and Cardio IQ Test (Quest Diagnostics). A cardiologist or functional medicine practitioner are best suited for interpreting the results of these tests and explaining your risk of cardiovascular disease.
In addition to knowing your particle sizes, you also want to know your triglyceride to HDL ratio. A study published in the journal Circulation found that people with the highest TG:HDL ratio were 16 times more likely to develop heart disease than those with the lowest ratios. Ideally, your TG:HDL ratio should be no more than 2:1, so if your TGs are 100 mg/dL, then your HDL should be at least 50 mg/dL.
Diet's Impact on Cholesterol
Thirty years ago, we were told to limit cholesterol intake to no more than 300 mg per day and to eat a low-fat, high-carbohydrate diet to reduce blood cholesterol. Unfortunately, that dietary advice was wrong and only served to increase rates of heart disease.
Fact: Dietary cholesterol does not raise blood cholesterol.
The 2015-2020 Dietary Guidelines for Americans advice regarding cholesterol now reflects this and says, “Cholesterol is not considered a nutrient of concern for overconsumption.” So, foods high in cholesterol such as eggs, shrimp and lobster are no longer considered off-limits. This information needs to be better disseminated because we still have people believing this incorrect dietary advice.
What we do know is that sugar, refined carbohydrates, trans fats, most vegetable oils and oxidized fats increase inflammation and small, dense LDLs, and decrease HDL and large LDLs. Some additional dietary influence that we now know includes:
- Clean saturated fats increase large, fluffy LDLs.
- Reducing carbohydrate intake may decrease small, dense LDLs.
- Weight loss improves LDL patterns in overweight men.
- A high-carb, low-fat diet may shift you from a Pattern A to Pattern B LDL profile.
The commonly held advice to lower cholesterol levels includes a low-fat diet and use of statin drugs. We now know that this advice is incomplete and short-sighted. Studies have shown that up to 75% of people hospitalized for heart attacks have normal to optimal LDL cholesterol levels and that looking solely at total cholesterol is an outdated marker.
First, let’s look at dietary advice that we know helps promote a better overall lipid profile, especially that which will impact the size of the LDL particles. The Mediterranean diet is highly regarding for it’s ability to reduce one’s risk for heart disease. Ironically, this diet is rather high in fat (including lots of saturated fat), but the fats are typically farm-fresh and not refined, hydrogenated or oxidized. This diet is also high in plants—fruits, vegetables, whole grains, legumes, nuts and seeds—which means plenty of fiber and antioxidants.
As for using statins to treat elevated cholesterol, we encourage you to understand that these drugs have many adverse side effects, including:
- Extreme muscle pain (also known as rhabdomyolysis)
- Nerve damage
- Congestive heart failure
- Memory problems
- Increased rate of suicide
There are natural supplements that can be used as an alternative to statin medications and without the side effects. A registered dietitian nutritionist or functional medicine practitioner can best guide you to the correct supplements that can be used in place of statin medications.
Can your cholesterol be too low?
For decades, it was thought that the lower your cholesterol numbers were, the lower your risk of heart disease. Unfortunately, there is a danger to having levels of total and LDL cholesterol that are too low. Low cholesterol numbers decrease the function of serotonin receptors in your brain, which affects brain function (dementia and Alzheimer’s) and mood, resulting in higher levels of anxiety and depression. In addition, aggressive and antisocial personalities are associated with low cholesterol numbers. Lastly, women with low cholesterol numbers are more likely to give birth to preterm and low birth-weight babies.
We believe that diet and lifestyle changes are always the first line of treatment because we know that they will be effective. Find a registered dietitian nutritionist who specializes in heart health or functional medicine to get personalized dietary advice to help you correct any abnormalities in your lipid profile or to further reduce your risk of heart disease even if your numbers look good.