A Story with Bearing: Cholesterol

By Michael Pickering

Years ago our friend Peggy told us that her doctor had prescribed a diet devoid in cholesterol, as her blood test indicated worrisome numbers.  The doctor recommended that all of the usual suspects be excluded from her diet, such as egg yolks and butter, but it was all to no avail.  Regardless of how long she maintained the exclusive diet, her blood numbers did not budge.  So, she decided to experiment with her own dietary exclusions.  One of her first experiments was targeted at a food everyone who knows Peggy is well aware that she is addicted to – milk chocolate.  It was only then that her blood cholesterol numbers improved.

While it is true that one’s diet is an important factor in the level of cholesterol in one’s blood, the amount of cholesterol in one’s diet is not germane.  Unlike the essential amino acids and minerals which must be harvested from the diet, the cholesterol in our blood is synthesized inside our bodies from smaller synthons (many acetates, a popular biosynthetic mode, see flavonoids).

So the issue isn’t whether cholesterol is in one’s diet, but rather how cholesterol is behaving in one’s blood.

The key link between the importance of diet and the behavior of cholesterol in one’s blood is the amount and type of fat you ingest.  Highly saturated fats have the most negative impact on the solubility of cholesterol in the blood.

Blood chemistry is necessarily dominated by water soluble processes.  Magnesium, sodium, citrate, and all manner of water soluble nutrients must course around freely.  However, cholesterol is not water soluble, even though it must move as freely through our veins.  The body’s solution is to cloak the cholesterol with a hydrophobic interior (cozy coat) with a hydrophilic exterior (sort of like a 1960’s Bill Blass coat with the mink on the inside and the satin on the outside).

These water taxis are called LDL and HDL: low density lipoproteins and high density lipoproteins.  Our body considers the HDL to be better than the LDL because, among other things, it’s easier to void.   Tom Scheve’s description of the reason for this in his article for Discovery Health, entitled “What’s the difference between LDL and HDL Cholesterol” eloquently expresses my own musings:

When the lipoprotein has more protein than cholesterol [HDL], it resembles a Ferrari, gunning through your body without stopping until the cholesterol arrives at your liver, where it’s converted into bile acids.  […]  When the lipoprotein has more cholesterol than protein [LDL], however, this makes for a rickety    ride, and that jalopy doesn’t get too far.  Cells have special receptors that bind tightly to these lipoproteins as they pass.  This LDL sputters down the road, careening off the arteries, running into things and leaving bits all over the place.  While the HDL Ferrari sees a pileup and nimbly speeds around it, the LDL jalopy crashes right into it, adding to the jumble of tangled fenders and tailpipes (or platelets and plaque).

The overall solubility of cholesterol in the blood is governed by a ternary phase diagram. Maintaining these three components in the proper ratio crates a zone of solubility in the triangle.  If the diet (the source of phospholipids and fats) biases the ratio out of the soluble zone, the cholesterol precipitates with the fenders and tailpipes.  And like all solids in a moving fluid, they deposit in the zones of slowest flow.  In a vascular system the slowest flow is in the arteries.

The lipids (fats) in our diet can be broadly sorted into two categories: 1) naturally occurring, and 2) man-made.  Obviously the naturally occurring fats and oils are derived from plants and animals.  The man-made fats are partially hydrogenated vegetable oils.  The saturation level determines the melting point and viscosity regardless of the source.  So highly unsaturated lipids like sesame oil have a low melting point and viscosity and so are inappropriate for frying, whereas poly-saturated lard and butter have a high melting point and viscosity, and are well suited for frying.  Similarly, an award-winning pie crust can be made with lard or butter, but not with unsaturated oil.  Partial hydrogenation thus controls the melting point of the fat and establishes its suitability for any particular application.

However, a side reaction also occurs during the hydrogenation: isomerization.  Natural unsaturation tends to be cis-configuration but hydrogenation isomerizes the bonds to trans-configuration.

While the hydrogenation controls the melting point precisely (which is essential for processed foods), the resulting fat is not recognized by the body as food.

Our wild type diet is clearly designed around whole grains as the staple, a source uniquely rich in unsaturated (cis-) fats, phospholipids, and protein.  The goal is to manage the trace chemistry in our blood, the hydrophobic components.  So the lesson is: eat as little saturated (mostly animal) fat as you can tolerate, eat whole grains and exclude all partially hydrogenated vegetable oil.  Read the label!

So while the amount of cholesterol present in a milk chocolate bar (24 g) is comparable to that of a tablespoon of butter (30 g), the two had very different effects on Peggy’s blood work.  Cocoa fat is among the most saturated of the vegetable oils.  The melting point is so high that the bars are wax-like at room temperature.  The chocolate was in effect creating an excess of LDL jalopy wreckage in Peggy’s blood stream, by causing the LDL and HDL levels to get out of whack.

The cholesterol had no bearing.

Editor’s Note: Always consult a physician first. The views presented herein are strictly editorial in nature.

-By Michael Pickering

One tour of Denali National Park is a bus ride on a dirt and stone road.  The buses are old but so well designed that they are easy to maintain in good working order and well suited to the motorway.  The motorway is in itself a thing of beauty and wonder.  A notch on the flank of a mountain that persists, with some hand maintenance, intact in spite of the onslaught of enormous amounts of erosive rain, snow, and wind.  It is a day replete with photo opportunities, epic vistas, glaciers disguised as mountains, wildlife and flowers, and the lore of Alaska.

Denali

Alaska State Flower – the Forget Me Not

When anyone on the bus sees a critter they yell out and the tour guide/bus driver stops and adjusts the position so that all who want a photo can get a good shot.  The grizzlies are much smaller than the famous Kodiaks, as they eat little meat.  They are also blonde, not dark brown, so they are easy to spot at a distance.

Grizzly Crossing

Grizzly Bear and her cubs

Denali is the indigenes’ name for Mount McKinley.  It was and is formed by a rising granite pluton that is still growing.  His wife, Mount Foraker, was similarly formed.  All the posters of Mt. McKinley on display had the named taped over and the handwritten DENALI in its place.

Denali National Park and Preserve

Denali

When the old world migrants traveled across the land bridge to Alaska, they encountered two main tribes and their languages.  The descendants of these peoples in the lower 48 states are Apaches and Navahos, as evidenced by custom and vocabulary.  Native Alaskans call themselves “sourdoughs,” although all those that I met did not know the origin of the term.  Being a Californian, I of course informed them.  Non-natives can achieve “sourdoughness” by staying for three to four years.  It is sort of a tenure track.  To a person, they are Alaskan.  We, the other 49, are America.  The sourdoughs like to tease Texans (who doesn’t?) by telling them that if Alaska was cut in half, Texas would be the third largest state.  They are also welcoming and generous.  One sensed my interest in plants and spontaneously gave me a recipe for a hypoallergenic flower infusion called “homesteaders honey.”  Of course I will.  

The grandeur of Alaska is enough to draw worldwide tourism, as the languages spoken on our train ride and bus tour can attest.  For us, however, it was our first opportunity to visit our daughter, son-in-law, and grandchildren, who had moved to Anchorage a year earlier.  The train ride across the state and bus tour in the park were our mutual amusement. 

Me (left) and the family

Mt. Eielson

The title of this column is “Random Tangents.”  It was assigned to me by the editor, Wendy.  The “T” part I get; I regularly spout them during discussions.  To me, the “T’s” are perfectly germane.  The “R’s” are different though.  The “R” part I suspect is a kindness.  I think it’s the editor cutting me some slack.  So it isn’t a job, like a 500 word essay an assigned topic; an opportunity to be creative and/or amusing.

RANDOM: The eight hour train ride from Anchorage to Fairbanks is lined with antique telephone poles.  Most of the glass insulators, predominantly blue, are still in place.  For that matter, so is much of the wiring. 

TANGENT: It intercepted me ¾ of the way into the bus tour.  The topic was about the cyclic relationship between the snowshoe hares and the bobcats.  They are locked in an approximately seven year cycle of too many and too few.  Those studying the relationship are looking for a correlation factor.  One theory is that it is related to sunshine.  Sun spot/flare activity has a seven year cycle.  I suspect something more prosaic.  The hares preferred food is Willow outer bark.  Willow is the most common bush in the lowlands.  The decline in the hare population is caused by an increasing amount of salicylic acid ingestion.  It weakens the hare, causing attrition and sickens the bobcats alike.

Since the salicylic acid is synthesized only in the inner bark, the Cambrian layer, perhaps the hares engineer their own decline.  After denuding the environment of outer bark, only inner bark is available for forage.  Maybe, exposed to the sun, the Cambrian produces excessive salicylic acid, accelerating the die-off.