Dr. Nadir Ali | Is LDL Cholesterol Bad, Why LDL Goes Up on a Low Carb Diet, & Risks of StatinsFeb 11, 2021
Dr. Nadir Ali is a leading low-carb interventional cardiologist. In this episode, we talk about whether LDL cholesterol is “bad” and why LDL cholesterol goes up on a low carb lifestyle. Dr. Ali explains the risks of statins, and why if all other numbers are going in the right direction, we need not be fearful of elevated LDL. He also provides alternative methods for determining cardiovascular risk.
Is LDL Cholesterol Bad? Native Vs Oxidized LDL Cholesterol
If you want to take a deeper dive into this topic, read the article by Anthony Culpo called LDL Cholesterol: “Bad” Cholesterol or Bad Science? or a more scientific approach to the topic in the article: Effects of Native and Modified Low-Density Lipoproteins on Monocyte Recruitment in Atherosclerosis.
To call LDL “bad” cholesterol is oversimplified. There are major differences in the atherogenic properties of "standard" LDL cholesterol and "modified" LDL cholesterol, discussed later in this article.
Cholesterol plays several crucial roles in the body. Cholesterol is needed for the synthesis of bile acids, which are essential for the absorption of fats, and of many hormones such as testosterone, estrogen, dehydroepiandrosterone (DHEA), progesterone, and cortisol. Cholesterol, together with sun exposure, is required to produce vitamin D. Cholesterol is an essential element of every cell membrane in our body, where it provides structural support and may even serve as a protective antioxidant. It also helps conduct nerve impulses.
Why LDL Goes Up on a Low Carb Diet
LDL cholesterol goes up on a low-carb diet simply because a low-carb diet typically includes more animal products with saturated fat. In essence, LDL goes up because you are eating more cholesterol. As Dr. Ali discussed in this interview, if you eat a vegan or vegetarian diet low in fat, your liver will produce all the cholesterol you need, which requires more effort than if you simply eat cholesterol.
However, it is important to note the difference in “standard” LDL and “modified” LDL. Standard LDL is the type that your body makes for critical functions stated above like building hormones. Modified LDL has undergone a damaging alteration, the most widely studied modified LDL is “oxidized” LDL.
Oxidized LDL appears to increase when our diet is lacking antioxidants and omega-3 fatty acids, and is increased by a diet high in processed omega-6 fatty acids such as vegetable oils or foods fried in them. A well-structured low-carb diet that includes anti-inflammatory foods may increase standard LDL and reduce oxidized LDL, thus proving to be protective against heart disease and mortality.
One place in medicine where I think we recognize elevated LDL alone is not a health risk factor is in the diagnostic criteria for metabolic syndrome. Metabolic syndrome is a cluster of risk factors for cardiovascular disease. Various medical entities have slightly differing diagnostic criteria, the five most common being:
- Abdominal Obesity
- >102 cm (>40 in) for men
- >88 cm (>35 in) for women
- Elevated Triglycerides
- ≥150 mg/dL
- Low HDL Cholesterol
- <40 mg/dL for men
- <50 mg/dL for women
- High Fasting Glucose
- ≥100 mg/dL
- High Blood Pressure
- ≥130/≥85 mm Hg
Notice LDL is not on this list. Nor is it on the extended list of other risk factors for metabolic syndrome. The primary purpose of clinically diagnosed metabolic syndrome is to determine if someone has an increased risk of heart disease. With the American Association of Clinical Endocrinologists (AACE), the World Health Organization (WHO), and the National Cholesterol Education Program’s Adult Treatment Panel III (ATP III), all leaving off elevated LDL from this list, I believe major parties are beginning to recognize that perhaps we’ve oversimplified LDL, and focusing on other risk factors is more beneficial to determine cardiovascular health.
Oxidized LDL is a better predictor of atherosclerosis and cardiovascular disease than standard LDL cholesterol. The stronger association between oxidized LDL and cardiovascular disease suggests that a person’s antioxidant status is a far more important determinant than standard LDL levels for the risk of developing atherosclerotic plaques, and the rupturing of those plaques leading to strokes or heart attacks.
However, there was no association between oxidized LDL and total LDL concentrations. In other words, you can have high LDL and high oxidized LDL with an increased risk of heart disease, or you can have high LDL and low oxidized LDL with a reduced risk of heart disease. They are independent variables.
Atherosclerotic Plaques: Not Just Fat & Cholesterol
While we tend to think of plaques in our blood vessels as a glob of fat, in reality they are very complex and have numerous substances in them including smooth muscle cells (the type of muscle that makes up your arterial walls), calcium, connective tissue, white blood cells (trying to fight inflammation), cholesterol, and fatty acids.
The growth and rupture of these plaques occurs for various reasons as well including nutrient deficiencies, poor glycemic control, smoking, homocysteine, stress, nitric oxide depletion, high iron levels, microbial infection, dietary trans fatty acids, excessive refined carbohydrate intake, and excessive omega-6 fatty acid intake and/or deficient omega-3 fat intake. Click here to learn more about the differences in dietary fat including which ones are healthy, neutral, and unhealthy for your heart.
As Dr. Nadir Ali commented in this interview, the hypothesis that LDL cholesterol is involved in triggering or aggravating the inflammatory state that can lead to a heart attack or stroke is not well supported by research. In fact, cholesterol, like white blood cells found present in the plaques, may be there as part of the repair mechanism working to reduce inflammation.
This hypothesis is furthered by research that has found lowering standard LDL does not cause changes in calcified plaque progression in coronary vessels. The coronary heart scan is a test recommended and used by Dr. Nadir Ali to better estimate a person’s risk of heart disease than serum LDL cholesterol levels.
Health Benefits and Risks of Statins
While statins are a widely prescribed medication, their efficacy in reducing overall mortality is poor for most of the population. Statin drugs have only been shown to have a consistent (slight) mortality-lowering benefit in middle-aged men with existing heart disease, and in diabetic patients.
In those trials showing decreased mortality with statins, the reduction in death rates are no greater than, and often inferior to, that seen with other interventions, such as omega-3 fatty acid supplementation, fruit-and-vegetable-rich diets, and exercise.
In women of any age, statins have not been shown to exert any reduction in cardiovascular, or all-cause mortality when used for primary prevention. In other words, when someone has elevated LDL but no cardiovascular disease. Statins also have no reduction in all-cause mortality in women when used for secondary prevention. Stated differently, if a woman already has cardiovascular disease and starts a statin, she is not at a reduced risk of dying, no matter the cause.
In research, statins have shown some positive qualities independent of LDL status including slowing or reversal of plaque formation, improvements in arterial function and blood flow, anti-clotting effects, anti-inflammatory effects, antioxidant effects, prevention of plaque rupture, prevention of heart enlargement, and inhibition of smooth muscle cells from entering vascular plaques.
So while research is showing some benefits of statins, for most people they do not reduce mortality, and they are not better than lifestyle changes such as exercise, eating more antioxidant rich fruits and vegetables, eating more omega-3 fatty acids, and eating less processed omega-6 fatty acids and refined carbohydrates.
In fact, taking a statin for the sole purpose of reducing standard LDL poses the potential for several common side effects of statins including but not limited to: muscle pain, liver damage, increased blood sugar and risk for weight gain and type 2 diabetes, fatigue, and cognitive/memory problems. Women are at an increased risk from suffering these side effects.
Better Indicators of Heart Disease Risk: Coronary Calcium Scan, Oxidized LDL, & LDL Size
If your primary care provider has prescribed a statin based solely on elevated LDL levels, please refer them to this article and interview. I encourage you to become your own best health advocate.
Dr. Nadir Ali suggested getting a coronary calcium score as a much better indicator of your heart health. From my independent research, it also appears that getting your oxidized LDL checked is more beneficial information than just LDL cholesterol alone, as oxidized LDL is a better predictor of atherosclerosis and cardiovascular disease.
The Book "Why We Get Sick" by Dr. Benjamin Bickman is a must-read if you're interested in learning more about the link between insulin resistance and many chronic disease. In it, Dr. Bickman describes that there are two LDL patterns, named pattern A and pattern B.
Pattern A refers to an LDL molecule that is larger and less dense, and B refers to the LDL being smaller and denser. People with LDL pattern B are more likely to experience cardiovascular complications than people with pattern A.
While there are blood tests to determine the size of your LDL, Dr. Bickman share's a "poor man's" method. "By dividing the level of triglycerides (in mg/dL) by HDL (in mg/dL; TG/HDL), we get a ratio that is surprisingly accurate in predicting LDL size. The lower the ratio (e.g., ~<2.0), the more prevalent the larger, buoyant LDL particles; that is to say, LDL A predominates. But as the ratio climbs (~>2.0), the small, dense LDL B particles are more common." Why We Get Sick, page 18, Kindle Edition.
It is important to consider other risk factors described above for metabolic syndrome including elevated blood pressure, triglycerides, insulin, and blood sugar, abdominal obesity, and reduced HDL cholesterol. If you'd like a second opinion about if you should be taking a statin or not, Dr. Ali does provide virtual consultations.
Contact Dr. Nadir Ali
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