Tuesday, August 14, 2012

Egg yolk consumption almost as bad as smoking when it comes to atherosclerosis

Egg yolk consumption almost as bad as smoking when it comes to atherosclerosis

Thanks to Mark for alerting me to this press release.  Excerpts: 

"Surveying more than 1200 patients, Dr. Spence found regular consumption of egg yolks is about two-thirds as bad as smoking when it comes to increased build-up of carotid plaque, a risk factor for stroke and heart attack. The research is published online in the journal Atherosclerosis."

"The study also found those eating three or more yolks a week had significantly more plaque area than those who ate two or fewer yolks per week. "

"The mantra 'eggs can be part of a healthy diet for healthy people' has confused the issue. It has been known for a long time that a high cholesterol intake increases the risk of cardiovascular events, and egg yolks have a very high cholesterol content. In diabetics, an egg a day increases coronary risk by two to five-fold," says Dr. Spence, a Professor of Neurology at Western's Schulich School of Medicine & Dentistry and the Director of its Stroke Prevention and Atherosclerosis Research Centre (SPARC) at the Robarts Research Institute. "What we have shown is that with aging, plaque builds up gradually in the arteries of Canadians, and egg yolks make it build up faster - about two-thirds as much as smoking. In the long haul, egg yolks are not okay for most Canadians."
 Spence and co-author Jenkins had already previously published "Dietary cholesterol and egg yolks: Not for patients at risk of vascular disease"  in the Canadian Journal of Cardiology. 

Tuesday, August 7, 2012

My August 2012 Lipid Profile

contains this graph:

Which shows that human foragers, wild primates, and wild mammals all have mean total cholesterol levels less than 150 mg/dL.  Unfortunately, for some reason the authors of this paper failed to include easily available data collected on cholesterol levels among people from traditional plant-based, primarily grain-based agricultures.  Other populations with high immunity to cardiovascular diseases also have average serum cholesterols below 150 mg/dl, including rural Chinese (127 mg/dl, 6), Tarahumaras (125 mg/dl, 7), and Caucasian men eating macrobiotic diets (147 mg/dl, 8).

All of this data indicates that the physiologically natural level of serum cholesterol among mammals (including humans) lies below 150 mg/dL, and thus that levels above this constitute an excess of cholesterol in the blood.  Populations exhibiting these low levels of total cholesterol also have low levels of LDL.

The O’Keefe et al article presents the evidence obtained from lipid-lowering trials which indicates that “the LDL level at which the cardiovascular event rate is predicted to approach 0 is 57 mg/dL for primary prevention and 30 mg/dL for secondary prevention.  These data implicate LDL as a requisite catalyst in the atherosclerosis process whereby extremely low LDL may prevent CHD events regardless of other risk factors.” [Emphasis added]

O’Keefe et al also note that two recent studies found that reduction of LDL to physiologically natural levels (i.e. less than 70 mg/dL) halted atherosclerosis, whereas moderate lowering allowed continued progression.  Caldwell Esselstyn likewise proved that a plant-based diet that produces an LDL of less than 70 mg/dL will reverse coronary artery disease without the use of statin drugs (here).

In other words, if you get your LDL down to about 60 mg/dL (a level found in healthy wild animals and neonates) you can prevent and reverse atherosclerosis.  Since atherosclerosis occurs throughout the body, impairing oxygen and nutrient delivery to and waste removal from all tissues and organs, cardiovascular disease promotes disease of all tissues and organs, and reversal of cardiovascular disease helps to restore health to all tissues and organs. 

In fact, all of the following diseases can be outcomes of  atherosclerosis impairing blood flow to the specific tissues:

  • Macular degeneration (retina)
  • Degenerative disk disease (spinal disks)
  • Impotence (genitals)
  • Hearing loss and tinnitus (ears)
  • Strokes (brain)
  • Aneurysm (aorta)
  • Kidney failure (kidneys)
  • Intermittent claudication (legs)

Similar to this, traditional Chinese medical theory maintains that the heart rules all other organs and all disease includes impaired flow of qi and blood, and thus that effective therapy must always involve improving heart and spirit function and qi and blood circulation.

"The heart is the sovereign of all organs and represents the consciousness of one's being. It is responsible for intelligence, wisdom, and spiritual transformation...decision-making is the king's job.  If the spirit is clear, all the functions of the other organs will be normal....If the spirit is disturbed and unclear, the other organs will not function properly.  This creates damage.  The pathways and roads along which the qi flows will become blocked and health will suffer.  The citizens of the kingdom will also suffer."  The Yellow Emperor's Classic of Medicine, Chapter 8

With all of this in mind, since re-adopting a plant-based diet about 8 months ago, I have aimed  for a total cholesterol of less than 150 mg/dL and an LDL of less than 70.  

I last had my lipids checked in July of 2007.  At that time I had  eating a grain-free, paleo-style diet as described in the “practically paleo” book I published with Rachel Albert in 2004.  That diet, consisting of meat, poultry, fish, eggs, vegetables, and fruits, supplied about 25% of energy as protein (mostly animal), 40-45% as fat, and 30-35% as carbohydrate. Here’s the part of that report containing the lipid profile:

As the report shows, I had a total “cholesterol” (actually, total lipoproteins) of 231, an LDL of 138, HDL of 85, VLDL of 8, and triglyceride of 47.  The cholesterol to HDL ratio was 2.7.  Thus, my total was about 100 points above that of wild mammals, and my LDL was twice the healthy level.
I suspect that between 2007 and 2011, I had further elevation of my total and LDL, but I didn’t confirm my suspicion with lab work.  My suspicion arises from the fact that by 2009 I was eating more total fat (about 50-60% of energy from fat) and less vegetable starch (particularly fewer sweet and white potatoes) than in 2007, and I had by 2011 developed some signs associated with and thought to be caused by elevated blood lipids, particularly xanthomas . 

So, during my later paleo daze my total cholesterol was at least 231 and my HDL was at least 138.  

I had my blood drawn on the first of August, 2012, and received this report about 36 hours later:

This shows that my total cholesterol has dropped at least 50 points, and my total LDL has dropped at least 32 points since ditching my paleo daze and re-adopting a whole foods plant-based diet.  My fasting triglycerides and VLDL remain in the normal range, although higher than in 2007.    I have been eating quite a bit of fresh fruit this summer, and this may be the reason my triglycerides are higher than at the last test, although still in the healthy range.

Due largely to the substantial (at least 22%) drop in total cholesterol, my HDL level declined (by 38%) but is still well (36%) above the desired 39 mg/dL.

As noted above, in 2007 my total cholesterol to HDL ratio was 2.7, and in this latest test it was 3.4, still well below the supposedly desired 3.5.  However, recent research has shown that people who have genetic variation giving them naturally higher HDL levels do not enjoy a lower incidence of cardiovascular disease, casting very serious doubt on the hope that a high HDL level or low cholesterol to HDL level protects against cardiovascular disease. Further, we also have evidence that some fractions of HDL are harmful.  These data indicate that a high HDL does not protect against the ill effects of high total and LDL levels, so I am not concerned by the decline in my HDL level; it is still high and complements the substantial reduction in my total and LDL levels.

Finally, to reiterate, as noted by O’Keefe et al and demonstrated by Esselstyn, if you lower total cholesterol and LDL sufficiently (to less than 150 and 70 mg/dL, respectively) you will halt or reverse atherosclerosis regardless of your levels for HDL or triglycerides.

The data from wild species provides good evidence that a total blood cholesterol (lipoprotein) level above 150 mg/dL constitutes a condition of excess.  People have found many ways to rationalize this (HDL levels, LDL particle size, HDL ratio, etc), but I don't believe that these incantations will make the vascular and hemodynamic effects of excess serum LDL disappear. Simply put, mammalian cardiovascular biology is adapted to total cholesterol levels under 150 and LDL levels under 70.  Levels above these signify metabolic disorder as surely as chronically elevated fasting blood sugar.

Although my numbers have substantially moved in the right direction, they still fall short of my goals of having LDL less than 70 mg/dL and total lipoproteins less than 150 mg/dL.   To me this illustrates that it can take some time to establish a natural lipid profile after spending some years on a high cholesterol, high fat, high animal protein diet, and tells me that I can expect improvements in health as I reach physiological levels of blood lipids.  Although the National Heart, Lung, and Blood Institute recommends that adults have their blood lipids tested once every five years, I may decide to do it more frequently to monitor the effects of my whole foods plant based diet.