Is Lowering LDL Cholesterol by Diet Helpful?

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Is lowering LDL Cholesterol by diet helpful?

A recent google search provided me with the following top results:

  • 11 Foods that Lower Cholesterol – Harvard Health Publishing…
  • How to Lower Cholesterol with Diet: MedlinePlus
  • Top 5 lifestyle changes to improve your cholesterol – Mayo Clinic
  • Cholesterol: Top foods to improve your numbers – Mayo Clinic
  • 10 Tips to Lower Cholesterol With Your Diet – Healthline
  • 13 Cholesterol-Lowering Foods to Add to Your Diet Today
  • …. and the list is much longer

Clearly, none of these articles was able to answer my question.

Is Lowering LDL-Cholesterol by Diet Helpful?

However, there is no doubt that we can lower LDL cholesterol by changing our diet. The most effective way to do so is probably by reducing the intake of saturated fats.

Indeed, this is the reason why reducing the amount of saturated fat in our diet has been a central theme of public health recommendations since the late 1970s (1).

But, lowering a number is one thing. The big question is whether lowering LDL cholesterol by diet improves health and reduces the risk of heart disease.

LDL Cholesterol and Heart Disease

Scientific evidence certainly shows a positive association between serum cholesterol and the risk of dying from cardiovascular disease (2,3,4).

It is also evident that LDL particles play a causal role in developing of atherosclerotic cardiovascular disease (ASCVD) (5).

Furthermore, a consensus panel of respected scientists recently concluded that any mechanism of lowering plasma LDL particle concentration should reduce the risk of ASCVD events proportional to the absolute reduction in LDL cholesterol (6).

But the same panel also concluded that this is true “provided that the achieved reduction in LDL cholesterol is concordant with the reduction in LDL particle number and that there are no competing deleterious off-target effects.”

I want to emphasize these two key issues:

  • provided that the achieved reduction in LDL cholesterol is concordant with the reduction in LDL particle number
  • and that there are no competing deleterious off-target effects

Saturated Fats, LDL Particle Size and Number

Low-density lipoprotein occurs as large buoyant LDL particles, and as small dense LDL particles (7).

Large LDL particles are more cholesterol-enriched, whereas small dense LDLs carry less cholesterol per particle.

Large LDL particles have a much weaker association with ASCVD than do smaller LDL particles (8,9).

Lowering LDL cholesterol by reducing the intake of saturated fats primarily reflects reduced levels of large LDL particles, whereas, in most individuals, the number of small LDL-particles is not reduced by reducing saturated fats (10).

Many recent studies have concluded that the number of LDL-particle present is a strong predictor of cardiovascular risk.

It is possible indeed, that the association between the number of small LDLs and heart disease reflects an increased number of LDL particles in patients with predominantly small particles. Therefore, the number of LDL particles could be more significant in terms of risk than the particle size itself (11).

Lowering LDL cholesterol by reducing the intake of saturated fats primarily reflects reduced levels of large LDL particles, whereas, in most individuals, the number of small LDL-particles is not reduced by reducing saturated fats

Moreover, decreasing saturated fat intake also lowers the levels of high-density lipoprotein (HDL) cholesterol which may have a negative impact on the risk of ASCVD (12).

Also, as recently pointed out in a blog article here, a low-fat, high-carbohydrate diet may increase lipoprotein (a) levels compared to a high-fat, low-carbohydrate diet(13). Lipoprotein(a) is strongly associated with the risk of ASCVD.

The PURE study reported that the association between saturated fat and ASCVD events does not fit a relation with plasma LDL cholesterol but is related to the ratio of apolipoprotein B (apo B) to apo A1(14).

Interestingly, ApoB correlates with LDL particle number (15).

In fact, several randomized trials have shown that changes in LDL cholesterol achieved by modulating the intake of saturated fat do not correlate with the risk of ASCVD (16,17,18)

This is brilliantly discussed by Arne Astrup and colleagues in a state-of-the-art-review published last year in the Journal of the American College of Cardiology (10).

As the review article points out, “the potential benefit of dietary restriction of saturated fat could be substantially overestimated by reliance on the change in LDL cholesterol levels alone.”

Is There A Downside of Diets that Lower LDL Cholesterol?

Dietary guidelines usually recommend replacing saturated fatty acids with cis-unsaturated fatty acids.

The recently published guidelines for Americans 2020-2025 discuss the importance of limiting intakes of saturated fat to support healthy dietary patterns (19).

The major purpose of these measures appears to be to lower blood cholesterol and reduce the risk of cardiovascular disease.

Among other things the guidelines suggest using lean meats and low-fat cheese or substituting beans in place of meats as the protein source.”

It is also pointed out that “saturated fat can also be reduced by substituting certain ingredients with sources of unsaturated fat (e.g., using avocado, nuts, or seeds in a dish instead of cheese). Cooking with oils higher in polyunsaturated and monounsaturated fat (e.g., canola, corn, olive, peanut, safflower, soybean, and sunflower) instead of butter also can reduce intakes of saturated fat.”

However, it is often forgotten that saturated fats are a heterogenous group of fatty acids that differ on the basis of their carbon chain length.

Furthermore, saturated fats are obtained from foods that have other ingredients that may modify their health effects.

In my opinion, judging the health effects of foods based on their amount of saturated fat is unwise and may promote bad food choices.

Also, remember that a Mediterranean-style diet appears to reduce the risk of ASCVD without reducing LDL cholesterol (20).

So, if we are to recommend food choices that lower LDL cholesterol, we have to be sure that the same recommendations do not include any competing deleterious off-target effects.

Is Lowering LDL Cholesterol Helpful?

So, let’s go back to the initial question.

Is Lowering LDL Cholesterol by Diet Helpful?

As my google search showed, there are tons of articles explaining how we can lower our cholesterol by changing our diet.

But, is it helpful?

Does it lower our risk of developing heart disease?

Frankly, I’m far from convinced. And, due to the fact that I have been studying the scientific data for more than thirty years, I believe I’m entitled an opinion.

I think that LDL cholesterol is a lousy surrogate marker and I fear that letting it control our dietary choices may lead to more harm than good.

And, yes. I know I am a cardiologist.




8 thoughts on “Is Lowering LDL Cholesterol by Diet Helpful?”

  1. Doesn’t lowering Cholesterol over the age of 65 increase All-Cause-Mortslity?

    Also, I don’t see any RCT’s on the association between Statins & Alzheimers, but there appears to be one in that Alzheimers has increased dramatically since the introduction of statins. Coincidence?

    I’m 66 and my total cholesterol is 200 and my LDL-C is 120 with HDL around 45. I have some plaque in my arteries and my calcium score is 400+.

    I recently had a PET scan and my doc says that my blood flow is that of a 24 yr old athlete & he is amazed. I should add that I exercise a lot and that I don’t eat crap I eat little sugar & carbs & no fried foods whatsoever.

    So, I don’t take a statin like my doc wants me to, but he says my heart should still take me to 100.

    Reply
  2. Hi John, do you have any research/links supporting the “association between statins and Alzheimer”…most of what I’ve seen seems to indicate otherwise:

    https://www.alzheimers.org.uk/about-dementia/risk-factors-and-prevention/cholesterol-and-dementia (“A meta-analysis looking at observational studies investigating statins and the risk of dementia looked at data from 11 studies, involving over 23,000 participants, who had been taking statins for between 3 and nearly 25 years on average. When all of the data was analysed together, the researchers found that those people taking statins had a 29 per cent reduced risk of developing dementia.”)

    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5830056 (“Statins have been linked with reduced risk of all-cause dementia and even Alzheimer’s disease as well. It is possible that statins are affecting Alzheimer’s pathology directly”).

    I’ve had mixed feelings about statins myself, however decided to start taking them after the calcium score/test indicated I do have artherosclerosis (score was 100 or so) and my oldest brother had a quadruple bypass. I don’t have any other risk factors, my HDL has always been high, no high blood pressure, diabetes, etc…so, not exactly thrilled about having to take Crestor for the rest of my life :).

    Thanks,
    Daniel

    Reply
  3. It is recommended that saturated fatty acids be swapped for linoleic acid. Many have followed that advice. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6213099/
    Problem is, high linoleic acid can cause varicose veins. http://www.actabp.pl/pdf/1_2011/89.pdf
    Note that varicose veins are associated with reduced risk for death from heart attack.
    https://pubmed.ncbi.nlm.nih.gov/15156364/
    Note also that varicose veins are associated with increased risk for congestive heart failure. https://pubmed.ncbi.nlm.nih.gov/20087281/
    Congestive heart failure is on the rise. https://www.heart.org/en/news/2018/05/01/heart-failure-projected-to-increase-dramatically-according-to-new-statistics
    In my view, to avoid both heart attack and congestive failure, the best thing to do is reduce both linoleic acid and arachidonic acid intake to pre-industrial levels. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5093368/
    Of course, the edible oils industry and the American Heart Association are against lowering linoleic acid intake. https://thesoynutritioninstitute.com/linoleic-acid-not-to-blame-for-the-obesity-epidemic/

    Reply
  4. Hello Daniel,

    In answer to your question about a source, first of all, I’m not a doctor so I’m not giving medical advice, just my opinion. As an engineer I know how to read and interpret data though.

    Take a look at the following:
    https://pubmed.ncbi.nlm.nih.gov/18757771/

    As far as studies go, I found a good book that gives insight into how poor scientific studies can mislead us: https://www.amazon.com/Rigor-Mortis-Richard-Harris-audiobook/dp/B074WGYMP8/ref=mp_s_a_1_3?dchild=1&keywords=rigor+mortis+book&qid=1625034970&sprefix=rigor+mortis&sr=8-3

    Pay close attention to the explained difference between “absolute risk” and “relative risk.” We are bombarded with “relative risk” numbers and that may not be the best way to look at how beneficial drugs are.

    Also, since 50% of the people that present with heart attacks at the ER have perfectly normal cholesterol levels, I started researching all I could about heart disease.

    I found this book to be very informative: https://www.amazon.com/Beat-Heart-Attack-Gene-Revolutionary/dp/1681620227/ref=mp_s_a_1_3?dchild=1&keywords=beat+the+heart+attack+gene&qid=1625034653&sprefix=beat+the+heart&sr=8-3

    I agree that “inflammation” is the issue.

    John

    Reply
  5. Hi, confused… diet lowered my Total Cholesterol from 300 to 240. At 67, with high HDL, low triglycerides and extremely high LP(a), should I be taking statins?

    Reply
    • Hi Edith,

      Again, I’m not a doc so I don’t give medical advice.

      My wife id 65 and her Total C is 220, her LDL-C is around 130, her trigs ate low, I can’t remember her number, AND her HDL is in the 70’s.

      She had a Calcium Scan of her heart last year and her score was 0., indicating that she has no plaque whatsoever in her arteries.
      Her doc doesn’t want her on a statin with no plaque & high HDL.

      As far as I can tell, inflammation is the root cause of heart disease. I have my HsCRP, my homocysteine and my fibrinogen, all inflammatory markers, checked with my annual bloodwork and they are now down in the dirt.

      For many years I ate the SAD (standard American diet) and I was a sugar fanatic. I now avoid sugar, eat low carb and avoid fried foods completely because the vegetable oil restraints deep fry in isn’t good for us.

      John

      Reply
    • Hi Edith,

      I forgot to mention that Lp(a) is very difficult to lower. I believe that it is inherited. I’m fortunate that mine measures at 6, yet I still have some plaque in my arteries.

      I believe that my CAD is due to an absolutely horrible high sugar/carb diet until the age of 60, low inherited HDL and severe obstructive sleep apnea (OSA) that was undiagnosed until three years ago. I use a CPAP every night and now sleep like a baby.

      Also, i’d talk to your doctor about getting a “calcium scan“ of your heart. It’s not covered by insurance and only runs around $100. It can give you peace of mind. If your score is above zero, at least you have a baseline to start from.

      Talk to your doctor about getting one, but some doctors have never heard of the test.

      Again, not giving medical advice. Please work with your doctor.

      John

      Reply

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