Let Dr. Friedewald rest in peace

In the 1960s, doctors struggled with the concept of cholesterol and its relationship to heart disease. It was becoming clear that higher levels of cholesterol were predictive of heart disease. It was also becoming clear that the low-density fraction of cholesterol, or LDL, was somewhat better than total cholesterol in predicting heart attack.

Cholesterol was easily measurable in the 1960s. LDL was not. So, Dr. Friedewald, a noted lipid researcher at the National Institutes of Health, proposed an easy method to calculate LDL cholesterol from total choleseterol, HDL, and triglycerides:

LDL cholesterol = Total cholesterol – HDL cholesterol – triglycerides/5

This simple manipulation would put LDL cholesterols into the hands of the practicing physician and the American public. Dr. Friedewald recognized that this calculation only represented an approximation of LDL cholesterol and that it was thrown off, sometimes substantially, by any abnormal rise in triglycerides or reduction in HDL. But it served its purpose at an age when most doctors hadn’t even heard of cholesterol and the public was still sold on whole milk and “farm-fresh” butter, and Chesterfields were the cigarette choice of most doctors.



The world has since changed. Most doctors have heard about cholesterol and, along with the public, have been drowned in drug company marketing for cholesterol-reducing drugs. Most people with some level of common sense and health awareness no longer use butter or whole milk, and no longer believe that the brand of cigarette you choose can be healthy. But we’re still using Dr. Friedewald’s original calculation for LDL cholesterol. When you get an LDL cholesterol from your clinic, doctor, or hospital, >99% of the time it is obtained using Dr. Friedewald’s calculation.

Is it because there’s nothing better available? No, it’s not. There’s two reasons why your neighborhood primary care physician or cardiologist is still using this dinosaur of testing called LDL:

1) The lag in science to practice is 20 years. Accept that most primary care doctors are 20 years behind the times on many issues, LDL cholesterol included.

2) Insurance companies vigorously discourage testing beyond conventional lipids. The array of objections we get from insurance companies is mind-boggling. It would be funny if human life and finances weren’t at stake. These “new” tests are “experimental”, “unproven”, not endorsed by standard guidelines, not approved by some internal committee, or simply “We don’t know what this test is” ?we’ve heard them all.

What are the tests that are superior to Dr. Friendewald’s calculated LDL? There are several, listed here in order of best to worst:

1) LDL particle number--the value generated by NMR lipoprotein testing. This is the gold standard, most reliable test available, and the one I recommend.

2) Apoprotein B--More widely available even from conventional laboratories in hospitals. Not as accurate as NMR LDL particle number, but a pretty good choice. Apo B is the principal protein in LDL, VLDL, and IDL particles, and so it’s a better reflector of risk from all of these lipoprotein fractions, not just LDL.

3) “Direct” LDL--This is LDL that is actually measured. Unfortunately, it ignores the issues of LDL size and has some other pitfalls, but it’s still better than calculated LDL

4) Non-HDL cholesterol--So-called because it incorporates all undesirable cholesterol-containing lipids except good HDL, thus “non-HDL”. This is another calculation, though better than LDL (because it sums up the risk from other apoprotein B-containing lipoproteins). Non-HDL is calculated from Total cholesterol – HDL. It’s therefore available from any standard lipid panel. It’s little used in everyday practice, however, because most people and their physicians find it confusing.

5) Friedewald calculated LDL--You can see that calculated LDL is last on a list of choices. Yet this is the measure that doctors use day in, day out. It’s the measure that drug companies base billions of dollars of revenue and profits on.

It’s an everyday occurrence in my office that calculated LDL is 89 mg/dl, but the real value is somewhere between 160 and 200 mg/dl. That’s a big difference. Imagine your realtor tells you your house’s estimated value is $200,000 and that’s what you sell it for to an eager buyer. After closing, you find out your house was really worth $300,000. You’d be upset. But that’s what you’re often getting with LDL cholesterol?a bum deal.

It’s part of the reason people will say, “My doctor said my cholesterol was fine and that no cause for my heart disease can be found. He said it was genetic.” In reality, they could have sky-high LDL cholesterol revealed by LDL particle number or apoprotein B.

Use LDL cholesterol in a pinch when you’ve got nothing else. It’s also helpful to gauge any treatment effect of diet, functional foods, drugs, etc. But it is a seriously flawed tool to diagnose your initial level of risk.

Comments (1) -

  • buy jeans

    11/3/2010 9:04:52 PM |

    It’s part of the reason people will say, “My doctor said my cholesterol was fine and that no cause for my heart disease can be found. He said it was genetic.” In reality, they could have sky-high LDL cholesterol revealed by LDL particle number or apoprotein B.

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Even mummies do it

Even mummies do it


Lady Rai, nursemaid to Queen Nefertari of Egypt, died in 1530 BC, somewhere between the age of 30 and 40 years. Her mummy is preserved in the Egyptian National museum of Antiquities in Cairo.

A CT scan of her thoracic aorta revealed calcium, representing aortic atherosclerosis, reported by Allam et al (including my friend from The Wisconsin Heart Hospital, Dr. Sam Wann, who provided me a blow-by-blow tale of this really fascinating project). Ladi Rai and 14 other Egyptian mummies were found to have vascular calcification of a total of 22 mummies scanned. (The hearts of the mummies were too degenerated to make out any coronary calcium.)

But why would people of that age have developed atherosclerosis?

The authors of the study comment that "Our findings that atherosclerosis was not infrequent among middle-aged and older ancient Egyptians of high social status challenges the view that it is a disease of modern humans. . . Although ancient Egyptians did not smoke tobacco or eat processed food or presumably lead sedentary lives, they were not hunter-gatherers. [Emphasis mine.] Agriculture was well established in ancient Egypt and meat consumption appers to have been common among those of high social status."

Fascinating. But I don't think that I'd blame meat consumption. Egyptians were also known to have cultivated grains, including wheat, and frequently consumed such sweet delicacies as dates and figs. Egyptians were also apparently beer drinkers. Unfortunately, no beer steins were seen in any of the scans.

Comments (16) -

  • Jim Purdy

    11/20/2009 8:52:23 AM |

    "hunger-gatherers"?

    The original article said hunter-gatherers.

    However, I like hunger-gatherers better.

    Hunger is certainly quite a motivator to go seek food.

  • Peter

    11/20/2009 11:05:33 AM |

    As a person who can't figure it out, the mummy scans are interesting.

    It's not clear to me if saturated fat or grains and sugar are largely to blame for heart disease, or something else.

    It made an impression on me that Jimmy Moore (low carb blogger who eats mostly meat) and Dean Ornish (who eats mostly grains and vegetables) both scored zero on their heartscans.  They both avoid flour and sugar, that might be a point of agreement and a possible explanation.  I wish I was privy to the nutritional studies that come out a hundred years from now: long-term studies of different diets.

  • bronkupper

    11/20/2009 11:45:39 AM |

    On what ground are they basing their assumption that meat is the culprit?

    It is just blatant and annoying!

  • billye

    11/20/2009 12:18:34 PM |

    Dr. Davis, I love the way your mind works.  Which only proves once again, that the advent of agriculture produced diseases of the metabolic syndrome, even in ancient Egypt.  Wheat, Beer, and date consumption indeed.  If the ancient Egyptians avoided all starch, grains, legumes, and sweet fruit in excess, particularly high fructose types, it is quite apparent that they would have been healthier and lived longer, even in those ancient times.  We should all take heed, and throw out the so called and wrong "healthy diet", the diet that advcates eating low fat and high carbohydrates. This is the dogma that for the last 60 years pervades all medical decisions.  For the sake of our good health we must,MUST all switch to the very healthy low carbohydrate and high saturated fat diet that our ancient genes crave.  If this is not true, how did we all get here?

  • renegadediabetic

    11/20/2009 1:55:47 PM |

    Yep, the always ASSUME it's the meat or fat.  It just couldn't be all those "healthy whole grains."  Smile

    It seems to me that the Egyptian diet was a nutritionist's dream.

  • caphuff

    11/20/2009 3:11:22 PM |

    Thanks for blogging on this fascinating topic, doc.

    Unfortunately, the media reports seem to emphasize meat consumption as if that was the conclusion of the researchers.

    I'm betting they don't actually go that far in the JAMA article.

  • Dr. William Davis

    11/20/2009 3:50:34 PM |

    Ooops!

    Yes, hunter-gatherers, not hunger-gatherers.

  • LPaForLife

    11/20/2009 4:55:44 PM |

    I have been reading about the wealthy ancient Egyptian diet. It is interesting that they used many types of vegetable oils. Many were high in omega 6. They often fried foods. The rich ate meat, bread and some dairy products. They used Honey(fructose) as a sweetner. So I ask the qestion. Was their diet much different than the modern diet?

  • Anonymous

    11/20/2009 7:49:57 PM |

    I understand the McTut burger, although quite unhealthy, was all the rage.
    This could explain it.

  • Dan

    11/20/2009 10:15:46 PM |

    I love how the LA Times summed things up in their article about this study.

    "Both groups, however, share some risk factors. The high-status Egyptians ate a diet high in meat from cattle, ducks and geese, all fatty.

    And because mechanical refrigeration was not available, salt -- another contributing factor in heart disease -- was widely used for food preservation."

    Sigh...

  • Helen

    11/21/2009 5:01:13 PM |

    It occurs to me that the atherosclerosis could have been at least partially due to a vitamin D deficiency resulting from eating grain, which depletes the body of vitamin D.  

    Dr. Davis, are you familiar with the theory that Europeans lost their skin pigment in part as an adaptation to eating grain?

    If this was the dawn of grain-eating, it could also have been the dawn of selecting for lighter (not to say white, necessarily) skin pigments in grain-eating peoples.  (I think the same vitamin D depletion may hold true for eating dairy, so if they ate this, too, even more so.)  

    I wonder if this was also the dawn of largely indoor living for some members of the population - like the wealthy and their servants - and if this could have contributed to a vitamin D deficiency.

  • Anonymous

    11/21/2009 5:22:27 PM |

    but here we are again; Peter points out that there was no difference in calcium score between the veggie and meat diets, yet those of the paleo-diet religion will summarily dismiss this and continue to believe a meat diet is the healthy true diet for humans.  What was the life expectancy of Paleolithic man.... under 20 years maybe?  It wasn't until the diversification of diet that life span increased.... but maybe that is irrelevant if your point is to justify one's own choices

  • Dr. William Davis

    11/22/2009 2:46:42 AM |

    Hi, Helen--

    No, I wasn't aware of that particular theory. I am aware of the notion that northern Europeans lost dark pigmentation as they settled in sun-poor regions. I was not aware that grain had added to it.

  • Allen

    11/23/2009 7:22:15 PM |

    @Anonymous who claims that food diversity was the chief cause of the increase in life expectancy. First, ancient hunter-gatherers had a life expectancy of around 35 years. This dropped to under 20 years AFTER the advent of agriculture. Ask ANY anthropologist who can tell at a glance whether the bones they've found are pre or post agriculture (pre are strong, straight and healthy with no dental decay. Post are small, brittle, and diseased with plenty of dental decay.)

    As to food diversity. It is estimated that hunter-gatherers had hundreds of different food choices ranging from animals great to small, insects, and hundreds of indigenous plants/nuts/seeds/fruits. Early agriculturists primarily ate the grains that could be cultivated locally, and their food choices dropped perilously.

    As for mummies, only Egyptian royalty were mummified and ancient Egyptian royalty were known for their high-carb food depravity, where meals included plenty of honey, grains, starches, and beer. The feasts were frequent and included ritual bulimia so that the eating could continue indefinitely. That these people had heart disease should be no surprise to anyone.

    As a final note, life expectancy is much less about living long, and more about infant mortality. Infant mortality did not go down significantly until the advent of modern medicine and birthing techniques in the 19th and 20th centuries (at least for western societies.)

  • Yelena

    11/24/2009 10:35:56 PM |

    @Allen - There's no evidence that ancient Egyptian royalty engaged in ritual vomiting during feasts. Perhaps it may have happened right at the end of the last dynasties when Rome's influence was strong, as purging during a Roman feast was not uncommon. BTW, feasting Romans would just vomit right at the table and a slave would clean it up. A vomitorium is not for vomiting, it's a kind of passageway.

    Talking about an 'Ancient Egyptian diet' is a little silly anyway. Which kingdom/era? We're talking over thousands of years here with influences from many cultures and changing weather and environmental conditions. Modern analysis of residue in beer jars over various times shows that the ancient Egyptian beer was actually almost opaque and had a relatively high protein content, interestingly.

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Heart scan tomfoolery 2

Heart scan tomfoolery 2

In the last Heart Scan Blog post, I discussed the significance of the apparent discrepancy between Steve's heart scan score and volume score. This post addresses his second question, also a FAQ about heart scan scores.

Steve noted that his second scan compared to his first showed:

- Left Main volume went up from 22.4 to 35.6
- LAD went down from 95.2 to 91.3
- LCX volume went down from 23.2 to 0
- RCA volume went up from 0 to 9.3

So there are apparent divergences in behavior in the left main that increased and both LAD (left anterior descending) and LCX (left circumflex) that decreased.

The explanation is simple: When heart scans are "scored," they are viewed in horizontal "slices." When the heart is viewed as horizontal slices, the LAD and LCX originate from the common left main stem. In other words, it's like a tree with the left mainsteam representing the trunk, the LAD and LCX representing two main branches.

Plaque can form, obviously, in all three arteries, but it can do so by starting in the left main, for instance, and extending into either the LAD or LCX, or both. The left main plaque can therefore bridge any 2 or all 3 arteries.

When the plaque is "scored" by taking the computer mouse and circling the calcified plaque in question (to allow the computer program to generate the calcium score and volume score of that particular plaque), the plaque that may extend from left main into the LAD and/or LCX might be labeled "left main," or it might be labeled "LAD" or "LCX." There is no reliable way to "dissect" apart the plaque into the three arteries, since the plaque is coalescent and continuous. So the scoring technologist or physician simply arbitrarily declares the artery "LAD," for instance.

The problem comes when two different interpretation methods are used: Perhaps it's a new technologist or physician, or there was no attention paid to how the previous scan was read. One reader calls it "left main" and the next calls it "LCX."

So the apparent discrepancy has to do with flaws in the methods of segregating plaque location, as well as inattention to scoring techniques. The total score, however, remains unaffected.

Nonetheless, Steve has enjoyed a modest reduction in the score of the left main/LAD/LCX from his original 140.8 down to a second left main/LAD/LCX score of 126.9.

The right coronary artery (RCA), however, is not subject to this difficulty and Steve score shows a modest increase in score. (Why the divergent behavior between left main/LAD/LCX and RCA? There is no clear explanation for this, unfortunately.)

All in all, the news for Steve is good: He achieved these results on his own using nutritional techniques. Because he, in all practicality, stopped the progression of his heart scan score and avoided the "natural" rate of increase of 30% per year, all he needs to do is "tweak" his program a bit to achieve reversal, i.e., reduction of score.


Here's an image from another previous Heart Scan Blog post (about the relationship of osteoporosis and coronary disease) that shows such a plaque that starts in the left mainstem yet extends into both the LAD and LCX:

Comments (2) -

  • Leigh

    11/9/2010 8:14:33 PM |

    I am concerned about the amount of radiation in one heart scan, not to mention having one done every year or even five years. When I called my hospital and inquired about the amount of heart scan radiation, I was told it was equivalent to about 30 chest x-rays.

    If I gain knowledge of my heart's condition, but end up with cancer, what have I accomplished?

  • Dr. William Davis

    11/10/2010 12:39:42 AM |

    Hi, Leigh--

    Your hospital told you wrong.

    A 64-slice MDCT device exposes you to around 8 chest x-rays equivalent of radiation. Not great, but not bad.

    Too bad there's no alternative.

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