What do I mean by “misunderstood?” Look no further than the common misnomer of “good” or “bad” cholesterol.

Good and Bad Cholesterol

While it may be true that High-Density Lipoprotein (HDL) has potentially beneficial functions (reverse cholesterol transport), we have to remember there is no such thing as good and bad cholesterol. The cholesterol carried by HDL is the same as that carried by LDL. The only thing that makes it good or bad is if it ends up synthesizing our hormones or bile acids (good), or if it ends up in our vessel walls (bad).

If it’s true there is no such thing as good and bad cholesterol, why do we care about our HDL levels?

First, let’s start with the basics.

HDL is the smallest and most densely packed lipoprotein and has one or more ApoA protein on its surface. HDL can help lipids move around in circulation by accepting triglycerides or cholesterol from other particles, thus helping a VLDL turn into an LDL, or helping an LDL contain less cholesterol (turning a small dense LDL into a less densely packed LDL).

Like LDL, HDL transports cholesterol to the liver for recycling or excretion, or to the hormone producing cells like in the adrenals. Unlike LDL, HDL does not have the potential to get retained in the vascular wall and does not, therefore, contribute to plaque formation. In fact, functioning HDL can remove cholesterol from the vessel wall, thus putting it back into circulation and possibly removing it from the body.

Back to the question at hand.

Why should we care about HDL levels?

Early epidemiological trials showed that lower HDL levels were associated with a higher risk of cardiovascular disease and even death.  With such a strong association, the medical profession promoted elevated HDL levels as protective and low levels as something we need to avoid.

Since these were observational epidemiological studies, they do not prove that the low HDL caused the problems, only that HDL was associated with it. For instance, HDL is also known to be low in diabetes, metabolic syndrome and insulin resistance. It may, therefore, simply be a marker of underlying metabolic dysfunction that contributes to increased risk.  Yet, HDL’s function in reverse cholesterol transport, and its ability to remove cholesterol from vessel walls suggests a more direct impact on cardiovascular health.

It is also important to note that the Framingham data suggested that increased cardiovascular risk with elevated total cholesterol and LDL-C was lost in the presence of high HDL. In fact, very low levels of LDL combined with very low HDL levels had a much higher risk than markedly elevated LDL levels when combined with elevated HDL.

Thus, HDL proves to be a useful marker to help predict cardiovascular risk. For instance, one large meta-analysis showed that total cholesterol/HDL ratio was a much stronger predictor of cardiac mortality than total cholesterol alone.

In addition, the PURE study, an observational trial in over 135,000 subjects, showed that when considering lipid changes brought about by nutritional changes, ApoB/ApoA1 (essentially LDL-P/HDL-P ratio) is the best predictor of clinical outcomes.

Thus, HDL level is important in assessing cardiovascular risk.

Drugs Muddy the Picture

While HDL may be a good predictor of risk, raising it with drugs does not seem to confer added benefit.

For instance, cholesterol ester transferase protein inhibitors (CETP inhibitors) significantly reduced LDL by 20-30% and increased HDL 100-fold, yet showed either no clinical benefit or even worse, an increased risk of death.

This was a shock to many in the lipid world as the notion of “good” and “bad” cholesterol would clearly predict lowering LDL and raising HDL would confer dramatic health benefits. So much so, that multiple pharmaceutical companies invested hundreds of millions of dollars developing these drugs only to abandon them when the trials showed no benefit.

Part of the issue is that not all HDL lipoproteins function the same. There are subsets of people with genetically determined markedly elevated HDL levels who have an increased risk of CVD. They may have plenty of cholesterol circulating in HDL particles, but the HDL particles are dysfunctional and therefore  do not effectively remove cholesterol from vessel walls or LDL and do not effectively transport it to the liver. Conversely, there are those with a specific genetic mutation called ApoA1 Milano who have very low HDL-C and lower cardiovascular risk.

Simply measuring the HDL cholesterol content, therefore, may not accurately reflect its function. While we do not have easily available tests to measure HDL function, we can potentially use HDL particle assessment as well as the company it keeps (i.e. low triglycerides, larger less dense LDL particles) to better assess the potential benefits of HDL. Thus, if there is any concern about potentially dysfunctional HDL, I usually recommend advanced lipid testing to see the specific subtypes of HDL.

What can we conclude from all the HDL confusion?

Raising HDL with drugs does not reduce cardiovascular events, yet having a naturally low HDL is associated with increased risk.

The best answer, therefore, is to live a lifestyle that helps you have a “not low” HDL level. This means first and foremost avoiding the medical conditions associated with low HDL (i.e. insulin resistance, diabetes, and metabolic syndrome).

Textbooks predictably state the interventions to naturally raise HDL include exercise and moderate alcohol intake. Unfortunately, these have minimal effects. In fact, they pale in comparison to a low carb high fat lifestyle. In my 20+ years in the medical field, I have never seen an intervention as effective as LCHF in raising HDL, and the studies agree.

This brings us back to our question once again.

Why are HDL levels important?

HDL levels are important because it is a reflection of our underlying metabolic health and our lifestyle. A properly constructed LCHF lifestyle lowers triglycerides, raises HDL, and reduces the small dense LDL, among other benefits. Such a lifestyle likely reduces overall cardiovascular risk and will likely be shown to improve longevity and health span. While HDL may not be the main reason for this, we can’t ignore its role simply because it is more nuanced than “good” and “bad” cholesterol.

My advice, therefore, is to see the whole picture. Embrace the nuance. And make sure you get a thorough and proper evaluation of your cardiovascular risk.

If you are hungry for more, I created my Truth About Lipids program, a program focused on Cholesterol, to help break through the confusion and provide you with everything you need to thoroughly understand cholesterol and its impact on your health.

Learn more: Truth About Lipids Program

If you still have questions, you may want to consider a one-on-one health coaching consultation so you can get the individual attention you deserve  with a thorough assessment of your lifestyle and its impact on you as an individual.

Please comment below if you have any questions or comments that may help further the discussion.

Thanks for reading.

Bret Scher MD FACC

Can we be certain that elevated LDL (Low-density lipoprotein) particles have no meaning and can be completely ignored?

Certainly not.

Can we be certain that all LDL particles are deadly and need to be treated to microscopically low levels?

Certainly not.

So, what do we do?

I have seen countless second opinion consults and enrolled numerous clients in my Boundless Health Program who have this exact question.  What’s the deal with LDL? Do we worry or don’t we?

Life is much easier when it is black and white, good and bad. I, however, believe in looking for the nuance and trying to understand things a little deeper.

But first, let’s back up a little.

What is LDL and LDL-P?

Cholesterol can be a complex topic that we frequently oversimplify, which I am about to do. In brief, LDL is known as the “bad” cholesterol, the cholesterol that is found in plaque buildup in our hearts. But the truth is that LDL is not inherently bad. In fact, LDL has a purpose in our bodies as part of our immune response and as a fuel and vitamin delivery mechanism to name a few.  If vascular injury and inflammation are present, then modified LDL may invade vessel walls and participate in a cascade of events leading to plaque buildup and an eventual heart attack.

LDL-C is a measure of the total amount of cholesterol in our LDL lipoproteins. LDL-P is the total number of the LDL lipoproteins. Studies show that LDL-P is a much better marker for CVD risk than LDL-C. As an analogy, the number of cars on the road matter more than the number of people in the cars.

What are the risks of LDL-P?

On the one hand, trials in the general population show that elevated LDL-P is a risk factor for cardiovascular disease (CVD).  This includes a combination of observational trials, genetic mutation trials (mendelian randomization), and drug treatment trials.

All things being equal, based on these trials alone, we should want our LDL-P to be low.

But does LDL alone cause heart attacks and death? Or are there other factors involved?

Of course there are other factors involved in CVD. Vascular injury and inflammation being the two most prominent factors.

Can lowering our LDL-P have risks greater than the potential benefits for certain populations?

Absolutely.  Since primary prevention statin trials show we have to treat over 200 people for five years to prevent one heart attack with no difference in mortality, it seems reasonable that certain populations will experience more potential risk than reward.

The Low Carb High Fat Reality

How many LDL or statin trials have specifically looked at individuals on a healthy, real foods, LCHF diet?

None. Not a single one.

How many LDL or statin studies have looked specifically at red headed, left handed boys born the second week of March? 

None, at least to the best of my knowledge.

This seems glib but bear with me.

Is there any reason to think a red headed, left handed boy born the second week of March would behave any differently than everyone else in these LDL studies? Not really. Especially if they are eating a standard American diet or a low -fat diet as was almost exclusively studied in every cholesterol or statin trial.

Here’s the more important question. Is there reason to believe individuals on a healthy, real foods, LCHF diet would behave any differently than everyone else in the decades of lipid and statin studies?

There absolutely is reason to believe they may behave differently. There is not clear proof, but there is plenty of reason to suspect it.

Think about the benefits of a LCHF lifestyle.

• Lowers inflammation
• Reverses insulin resistance
• Naturally raises HDL and lowers TG
• Converts majority of LDL particles to larger, more buoyant particles
• Lowers blood pressure
• Reduces visceral adiposity

Could these create an environment where an elevated LDL is less of a concern?

It sure could.

To be clear, I openly acknowledge that we do not have definitive proof that we should have no concern with LDL in this situation. In my opinion, this is a specific scenario that the existing trials simply do not address one way or the other.

So, it seems we have two choices.

1. Since we don’t have any proof we can ignore LDL in this setting, we plug the numbers into the 10-year ASCVD calculator and start a statin if the risk is above 7.5%, or we ask the individual to change their lifestyle in hopes the LDL will come down.
2. If the individual is enjoying multiple health benefits from their lifestyle, and they are rightly concerned about the potential risks of statin therapy, then we can follow them for any sign of vascular injury or plaque formation, or any worsening of their inflammatory markers or insulin sensitivity. In the absence of any potentially deleterious changes, we can reason that the risk is low, and the benefits of living the healthy lifestyle may outweigh the risks.

The “problem” is that the second option requires a detailed discussion of the risks and benefits. It requires close monitoring and follow up. It requires us to think outside general guidelines and consider everyone as an individual with their own unique circumstance. These are qualities that our current healthcare system sorely lacks.  Yet that is the exact care that each individual deserves.

What do we do in the meantime?

I hope someday soon we will have definitive long-term evidence that a high number of large buoyant LDL particles along with elevated HDL, low TG and low inflammatory markers is perfectly safe.

Until that day, we will have to continue to talk to our patients. To see them as individuals. To weigh the lifestyle benefits with the possible risks. That includes seeing the risks in real numbers- not quoting a 30% benefit with statin therapy. Instead, having a real discussion that statins may reduce your risk a heart attack by 0.6% with an increased risk of muscle aches, an increased risk of diabetes, and a potential increased risk for cognitive and neurological dysfunction.

And we will have to understand that the answer won’t be the same for each person. And we can be OK with that.

So, do you have to worry about your LDL? I don’t know. But I welcome the opportunity to explore the question and reach the best answer for you.

Do you have questions about what your lipids may mean for you? What they mean when taken in the context of your lifestyle and overall health picture? If so, you may want to learn more about my Health Coaching Consult.

Thanks for reading,

Bret Scher, MD FACC

In the fall of 2018, I was diagnosed with Type 2 Diabetes. I was educated enough to know that there was something I could do about it and set out to change the path I was on by adopting a low carbohydrate/Ketogenic Diet to control my blood sugars. Fortunately, it worked right away- but soon after I discovered that I had some red flags on my cholesterol test results. There is a history of Cardiovascular disease in my family and I was disappointed that I might have to yet again make diet changes but was willing to do what was best for my whole health. After an appointment with a local Cardiologist, I felt somewhat confused about how to move forward. I wanted more information and not just a prescription.

I contacted Dr. Scher for a consult because I wanted to confer with someone who not only understood my condition but who could also give me the latest and soundest advice on how I might treat it and move forward in the best way for me as an individual- not as a statistic. I needed someone who came from a low carb perspective as well as a medical background. My interaction with him was positive, informative and went a long way to making me feel like I could make informed choices without the black and white thinking of well-meaning physicians. He sees the WHOLE person and not just one aspect of their health. Wellness is a journey- and having Dr. Scher along the way is a great way to make the trip!

Lisa K.

Don’t look now, but the updated clinical practice cholesterol guidelines from the American College of Cardiology, the American Heart Association and others are getting personal. Although the guidelines still contain their familiar approach — that I consider too aggressive with drug therapy — the latest 2018 version of the guidelines now includes an impressive update to emphasize lifestyle intervention, plus a more individualized approach for risk assessment.

MedPage Today: AHA: Revised Lipid Guide Boosts PCSK9s, Coronary Calcium Scans

Could this be the start of a progressive trend away from shotgun statin prescriptions? I sure hope so.

Prior guidelines emphasized the 10-year ASCVD risk calculator as the main determining factor for statin therapy. In the 2018 update, the guidelines acknowledge that the calculator frequently overestimates the risk in those individuals who are more involved with prevention and screening. (In other words, those patients more interested in and proactive about their health; I find many in the low-carb world fall into this category.)

The ensuing discussion with a healthcare provider should then focus on:

[T]he burden and severity of CVD risk factors, control of those other risk factors, the presence of risk-enhancing conditions, adherence to healthy lifestyle recommendations, the potential for ASCVD risk-reduction benefits from statins and antihypertensive drug therapy, and the potential for adverse effects and drug–drug interactions, as well as patient preferences regarding the use of medications for primary prevention… and the countervailing issues of the desire to avoid “medicalization” of preventable conditions and the burden or disutility of taking daily (or more frequent) medications.

I appreciate the attention the new guidelines bring to the depth of the discussion that should ensue between doctor and patient. Considering the treatment burden is equally as important as the burden of disease, and possibly even more important in patients who have not been diagnosed with heart disease, these individualized discussions about trade-offs are critical to personalized care.

Also worthy of mention is the increased use of coronary artery calcium scores (CAC) to help individualize risk stratification. The updated guidelines specify CAC may be useful for those age 40-75 with an intermediate 10-year calculated risk of 7.5%-20%, who after discussion with their physician are unsure about statin therapy. They specify that a CAC of zero would suggest a much lower risk than that calculated by the ASCVD risk formula, and thus take statins off the table as a beneficial treatment option.

This is huge. I cheered when I read this! I have been critical of prior guidelines that focused on ways to find more people to place on statins. The mention of finding individuals unlikely to benefit from statins is a giant step in the right direction.

The guidelines go even further: they mention that a CAC either over 100 or greater than the 75th percentile for age increases the CVD risk and the likely benefit of a statin. A CAC between 1-99 and less than the 75th percentile does not affect the risk calculation much and it may be worth following the CAC in five years in the absence of drug therapy. I would still argue that a CAC >100 does not automatically equal a statin prescription and we need to interpret it in context, but I greatly appreciate this attempt at a more personalized approach.

The guidelines also go beyond the limited risk factors included in the ASCVD calculator by introducing “risk modifying factors” such as:

• Premature family history of CVD
• Metabolic syndrome
• Chronic kidney disease
• Chronic inflammatory conditions such as rheumatoid arthritis and psoriasis
• Elevated CRP > 2.0 mg/L
• Elevated Lp(a) > 50 mg/dL or 125 nmol/L
• Elevated triglycerides > 175 mg/dL

Although they use these criteria to define an increased risk, the opposite would likely hold true. An absence of those criteria could define a lower risk situation.

Some changes deserve mention from a controversy standpoint as well. For instance, the new guidelines recommend checking lipid levels as early as two years old in some circumstances. Two!

They also recommend statin therapy for just about everyone with diabetes with no mention of attempting to reverse diabetes before starting a statin, a drug that has been shown to worsen diabetes and insulin resistance. In addition, the new guidelines do not mention the likely discordance between LDL-C and LDL-P in those with diabetes.

Last, the new guidelines define an LDL-C > 190 mg/dL as an absolute indication for statin therapy with a treatment goal of 190 mg/dL is in familial hypercholesterolemia populations (and even then has heterogenous outcomes). There is a clear lack of data supporting that same recommendation for metabolically healthy individuals with no other cardiac risk factors and no other characteristics of familial hypercholesterolemia. This is a clear example of when a guideline turns from “evidence based” to “opinion based.”

In summary, the guideline committee deserves recognition for its emphasis on an individualized care approach, its use of CAC, and its broader description of discussing potential drawbacks of drug treatment. It still combines opinion with evidence and believes all elevated LDL is concerning, but I for one hope it will continue its progression away from generalizations and someday soon see that individual risk variations exist, even at elevated LDL-C levels.

Thanks for reading,
Bret Scher MD FACC

Originally Posted on the Diet Doctor Blog 

Dr. Scher’s six-month program has been helping me make progress on my health journey. I started the program five months ago after I decided to get more serious about my health and reduce my coronary heart disease (CHD) risk by making healthy diet and lifestyle changes.

The program is not only providing me with excellent video and written content that helps me progressively realize my health goals with effective plans of action, but also individualized attention via email and with monthly video calls with Dr. Scher. I’m grateful for this individualized attention and for Dr. Scher’s insights and suggestions. His advice has honored my preference to continue following a low-carbohydrate lifestyle and has helped me select appropriate macronutrient targets such as daily intake of carbohydrates and protein based on my goals and his review of my medical history and lab test results.

Ken Carrillo
Chemical Engineer