High cholesterol does not cause stroke

[ShottleBop 545]

And from Dr. Briffa's blog for March 3:

High cholesterol does not cause stroke (but carbohydrate might)

 

Posted on 3 March 2011

 

We’ll probably all be familiar with the idea that raised cholesterol levels cause heart disease. The idea here is that high levels of cholesterol cause fatty deposits on the inside of the arteries around the heart. If one or more of vessels should block off completely, the heart muscle is starved of blood and, if this persists, the part of the heart supplied after the point of blockage will die. This is what a heart attack is, and the technical term for it is a ‘myocardial infarction’.

 

Narrowing of arteries doesn’t just occur around the heart. It can happen in other vessels too including those that supply blood to the brain. Blocking off of these vessels here can cause what is known as a stroke. However, a minority of strokes are caused not by blockage of vessels, but by bleeding from them. These two types of stroke are called ‘ischaemic stroke’ and ‘haemorrhagic stroke’ respectively.

 

In a way, we can think of ischaemic strokes as a ‘heart attack of the brain’. So, we might expect there to be about as strong a relationship between cholesterol levels and risk of stroke as there is said to be between cholesterol levels and risk of heart attack. Actually, previous research has found very weak or non-existent relationships between cholesterol levels and stroke [1,2]. The suggestion here, therefore, is that cholesterol does not cause strokes. In which case, it’s unlikely to cause heart attacks either.

 

Some researchers have suggested that the lack of a relationship between cholesterol levels and strokes is because studies have included haemorrhagic strokes as well as ischaemic strokes in their analyses. The idea here is that cholesterol does cause ischaemic stroke, but the effect is masked by including haemorrhagic strokes that are unlikely to have anything to do with cholesterol.

 

Well, now a study has been published which casts considerable doubt on this theory. It also asks serious questions about the conventional advice that our diet should be low in fat and high in carbohydrate.

 

The study in question was published earlier this month in the journal Annals of Neurology [3]. In this study, about 14,000 men and women were followed for more than 30 years. The relationship between cholesterol levels and risk of stroke was analysed. The analysis was confined to ischaemic stroke only (so no chance of haemorrhagic strokes diluting the results here).

 

The results showed:

 

no relationship at all in women

no increased risk of stroke in men unless cholesterol levels were extremely raised (9.0 mmol/l or more – equivalent to 348 mg/dl or more)

In other words, overall, there was little or no relationship between cholesterol levels and risk of ischaemic stroke. These findings suggest that cholesterol has little or no causative role to play in the development of ischaemic stroke.

 

This study also analysed the relationship between levels of blood fats known as triglycerides and stroke risk. The result? The higher the triglyceride levels, the higher the risk of stroke. In other words, risk of stroke was much more closely linked with triglycerides levels than cholesterol levels.

 

From a so-called ‘epidemiological’ study of this nature we cannot know if triglycerides cause ischaemic stroke, or are merely associated with an increase risk of this condition. However, it is worth bearing in mind that previous evidence has linked triglycerides with enhanced risk of heart disease and stroke [4].

 

So, what are triglycerides and where do they come from? Triglyceride is a form of fat used to transport fats around the bloodstream. Triglycerides are also the form of fat used to store fat in our fat tissue as well as elsewhere. Triglycerides in the bloodstream are made in the liver. The major stimulus for their manufacturing the liver is not fat, but carbohydrate (sugar and starch).

 

It’s well known that if individuals adjust their diet to contain less fat and more carbohydrate (as they’re often encouraged to do), triglyceride levels go up. In short, it seems conventional nutritional advice induces changes in the blood stream associated with enhanced risk of stroke.

 

The idea that we should be taking out saturated fat from our diets and replacing it with carbohydrate is based on the belief that saturated fat is bad for the heart and circulation and carbohydrate is better. I wouldn’t be too sure about that.

 

References:

 

1. Cholesterol, diastolic blood pressure, and stroke: 13,000 strokes in 450,000 people in 45 prospective cohorts. Prospective studies collaboration. Lancet 1995;346(8991-8992):1647-53.

 

2. Imamura T, et al. LDL cholesterol and the development of stroke subtypes and coronary heart disease in a general Japanese population: the Hisayama study. Stroke 2009;40(2):382-8

 

3. Varbo A, et al. Nonfasting triglycerides, cholesterol, and ischemic stroke in the general population. Annals of Neurology. Article first published online: 18 FEB 2011

 

4. Kannel WB, et al. Triglycerides as vascular risk factors: new epidemiologic insights. Curr Opin Cardiol. 2009 Jul;24(4):345-50.

[NickP 32]

The question was LDL ,and there is significant correlation between LDL and cardiac disease

 

You can find one study here Optimal low-density lipoprotein is 50 to 70 mg/dl: Lower is better and physiologically normal -- O'Keefe et al. 43 (11): 2142 -- Journal of the American College of Cardiology

 

 

The mechanism of coronary artery disease begins with LDL and is described here http://www.medscape.com/viewarticle/545401_2 It's not your TG, it's not your HDL,. it's your LDL that injures your arteries. The TG and HDL and LDL oxidation are important only in so far as they affect the LDL injury to the coronary arteries

 

So there you have it, epidemiological evidence and mechanistic description. O'keefe's article are probably as close as you can get as to why the OP's Doc wants LDL levels below 77

 

That said , statins probably have other benefits than simple lowering of LDL.

 

If you want a technical review of the opposite point of view ( that LDL is not the problem) you can read one here Is atherosclerosis caused by high cholesterol?

 

Sorry georgepds....I strongly disagree.

 

All LDL is not created equal. First, LDL is calculated at a simple lipids blood test. You must request a VAP to get a detailed breakdown of your LDL (to see if you have predominantly Type A or Type . Today, the Type "A" LDL (large, fluffy particles) is not considered "bad" for your CV health.

 

Second, medical research is still arguing about which lipid is the best at estimating your risk of CVD (note - this article is 6 years newer than yours....It comes from JAMA, which is a highly respected (and in my opinion "biased") publication.

 

College of American Pathologists - Cholesterol

 

The JAMA report, says Dr. Tracy, notes that the risk of coronary artery disease is lowest when HDL cholesterol is above 70 mg/dL—and highest when it’s below 34. And the risk is “graded all the way” between those two points, he notes. “The highest adjusted risk for non-HDL is around 2.2, and the highest adjusted hazard ratio for very low HDL is around 1.5.”

 

Everyone...I apologize if I am passionate about this issue, but we are being fed a load of BS from the Pharm Industry who is in the business of making big money. Check out this website...it is from the author of "29 Billion Reasons to lie about Cholesterol"

 

29 Billion Reasons to lie about Cholesterol - Blog

 

 

Even the mainstream media is finally starting to wake up! Check out this recent newscast:

 

 

Channel 4 News

 

 

I agree that for some people, statins can have some benefits. However, for some people, statins have horrible side effects and impacts. I really don't think the risks and unknowns from statins outweight the 1% of the population that would see a benefit.

 

Just IMHO....again YMMV!

[georgepds 296]

I have seen this posted in the cholesterol results by several low carb "friends" - it is not that unusual for a strict low carber to have elevated LDL results.

.....

 

FWIIW

 

Here is a list of people with high LDL on paleo and/or low carb diets

Perfect Health Diet » Low Carb Paleo, and LDL is Soaring

 

The site starts with a discussion of a low carber whose LDL goes through the roof (from 103 to 295 mg/dl after 7 months on a lo carb diet)

 

and who tops the list? Jimmy more. lo-carb afficianado

LipoScience’s NMR LipoProfile Test: A Revolutionary, More Accurate Lipid Profile Particle Size Screening « Jimmy Moore's Livin' La Vida Low Carb Blog and he is not the highest, one guy posts an LDL of 487

 

Granted, this is not a peer reviewed publication, but it does go to the association of low carb diets and high LDL.

 

IF your LDL ever gets in that range, I'd think long and hard about the traditional lower your LDL for heart health approach of the AHA

[NickP 32]

FWIIW

 

and who tops the list? Jimmy more. lo-carb afficianado

LipoScience’s NMR LipoProfile Test: A Revolutionary, More Accurate Lipid Profile Particle Size Screening « Jimmy Moore's Livin' La Vida Low Carb Blog and he is not the highest, one guy posts an LDL of 487

 

IF your LDL ever gets in that range, I'd think long and hard about the traditional lower your LDL for heart health approach of the AHA

 

Again, georgepds, I respectfully disagree.

 

If you take a chance to read Jimmy Moore's Book "21 Life Lessons from Livin La Vida Low Carb," you would have read an entire chapter that Jimmy dedicates to his LDL, and all the testing that he undergone that demonstrates that he has a healthy heart and CV System. It is really an interesting read.

 

Again, not all LDL is created equal, so an evelated LDL number by itself means nothing. Only after your LDL has been analyzed can you better determine your risk. Plus, there is still is a lot of conversation going on about what is important in trying determine heart health and risk.

 

BTW....I listed to Jimmy Moore's podcasts all the time. He does a great bi-weekly podcast with some of the best names in the low carb world. Everyone should give him a listen....it's some great free education!

[samorgan 10]

After much reading on the subject, I think the only "LDL Goal" we need is for it to be "Pattern A" (large, fluffy and harmless particles). For that you need to request a VAP test. My "overall" numbers have always been "borderline" and then became "high" over the years (without changing) when they moved the border.

 

At diagnosis, my total was 226 pretty much where it's been for over 20 years. Unfortunately, I dont know the breakdown from prior years. At diagnosis, it was:

 

Total: 226

LDL: 158

Triglycerides: 158

HDL: 36

A1C: 10.7

 

All bad!

 

After 16 months of diet-only control, my lipids were:

 

A1C: 5.1

Total: 232 (+6)

LDL: 157 (-1)

Triglycerides: 57 (-101)

HDL: 59 (+23)

CRP: 0.9 (no previous but excellent: lowest risk category)

 

Clearly, the truly important numbers have improved dramatically. Am I concerned about LDL staying the same at 157? When it tests all Pattern A? Absolutely not. So, IMO, the best goals are:

 

- HDL as high as possible (>60 best)

- Triglyceride as low as possible (<60 best)

- VAP result: Pattern A (not Pattern B or "Mixed")

- CRP: at or below 1.0 (excellent)

- LDL: given all of the above, I couldn't care less about this number!

 

All of the above is what happens with great consistency on a LC/HF diet and is the best way to minimize cardiac risk.