A Boy Ate Only Potato Chips & French Fries for 10 Years.
This Is What Happened To His Eyes.
DA is a 17 year old boy, presenting to the emergency room with a progressive deterioration
in hearing, sight, and vitality.
He tells the admitting nurse that his field of vision had been slowly going dark over
the last several months and a ringing in his ears had been washing out his hearing for
some time.
You see, DA was an average teenager.
He didn’t take any medicines or have any past history of disease.
At his age, he didn’t have any records of recurring behavior.
A few years earlier, a 14 year old DA came in for his regular checkup.
He reported good health, but some chronic tiredness and told the doctor that he preferred
eating only french fries, potato chips, and white bread because he enjoyed their texture.
A blood test at this visit noted that DA had macrocytic anemia.
An meaning without and emia meaning presence of blood.
His blood cells were larger than normal, and, he didn’t have a lot of them floating around
in his body.
Less blood cells means less oxygen getting to the brain, which could explain his chronic
tiredness.
This was accompanied by a marked vitamin B12 deficiency, unifying all his problems.
Low vitamin b12 causes anemia.
Potato chips, French fries, and white bread are completely devoid of vitamin b12.
The body doesn’t make b12 on it’s own, but that’s ok because basic foods like eggs,
beef, yogurt, and fortified cereals have it, so it’s almost impossible to miss.
But his levels are low, so DA was given vitamin injections to boost his levels.
The doctor gave him dietary advice to add more variety in his foods, and 14 year old
DA was sent home with no problems.
Several months after that first visit, DA was examined by a different doctor.
He complained that there were spots hanging out in front of his eyes.
An MRI of his brain found no abnormalities and a slit lamp exam returned normal.
Nothing seemed to be the problem, and there were no signs of immediate life threatening
injury, so come back if you have more problems, they told him.
Over the next several months, DA noticed something wrong when his field of vision started going
dark.
Maybe looking at screens for too long, he thought.
One day, he turned his headphones to the maximum volume and could barely hear anything.
Probably watched too many of those loud meme videos, he thought.
Skin-deep, DA appeared to be healthy.
But, a neuro-ophthalmology examination finds bilateral central visual field defects, confirming
blind spots in his field of view.
Nerve fiber loss was detected in both eyes.
But his motor and cognitive functions were normal.
All of this pointing to some potential neurodegeneration localized to his optic nerves.
There was definitely something happening to him.
As the days go by, DA is acutely aware of the deteriorating sight in both his eyes.
Normal vision is typically 20/20, meaning that you can see something that’s 20 feet
away.
But DA’s vision is 20/200, meaning for an object that’s 200 feet away, he needs to
be 20 feet from it to see it.
That is the E on the chart, and by definition, 20/200 is legally blind in the United States.
A repeat slit lamp examination finds no abnormalities in optic nerve appearance.
No visible damage can be seen.
Typically, an injury to the brain may cause visual field defects, but a second MRI confirmed
no lesions present.
These need to be ruled out immediately because they could signal an immediate life threatening
emergency.
A test was administered for Leber hereditary optic neuropathy.
Neuro referring to the nerves.
opathy- meaning a disorder and optic referring to the eye.
A disorder of the nerves of the eyes.
This genetic disease is characterized by painless, vision loss in both eyes, that disproportionately
affects young males.
It’s not common.
It’s almost a perfect fit.
But the test returned negative.
Analysis of DA’s blood reveals the same macrocytic anemia found at his original checkup
from 3 years ago, but this time, something’s wrong.
Malnutrition is well documented to cause optic neuropathy, but subsequent testing of his
liver, thyroid, and vitamin b12 levels return normal.
DA’s history of B12 injections from 3 years ago had lapsed meaning he hadn’t received
them for quite some time now.
If it’s possible that a lack of this vitamin could be causing DA’s vision loss, but his
b12 levels are normal, and he still has that anemia from his initial visit, then what could
be going on?
Well, there’s some biochemistry to be known here.
Vitamin B12 is a coenzyme, meaning it’s a chemical needed by an enzyme to function.
An enzyme, is a protein that makes a chemical reaction happen.
If there’s a problem with an enzyme in the body, no chemicals, or maybe the wrong chemicals
are made in the cells, which would cause disease.
In humans, vitamin B12 coenzymes for 2 specific enzymes.
In the mitochondria, powerhouse of the cell, B12 works on Methylmalonyl Coenzyme A mutase
to feed into the cycle that produces ATP, which is what the cell uses for energy.
—
In the cell nucleus, Vitamin B12 works on the enzyme methionine synthase, which drives
the process of synthesizing DNA, allowing cells to generate the necessary genetic material
to function.
—
Both these processes either generate or consume a unique chemical.
If normally, homocysteine is consumed in the nucleus to help make DNA, then high levels
of it would mean it’s not being consumed by the process involving vitamin B12, meaning
B12 is likely absent.
If methylmalonic acid is produced in high amounts instead of the correct chemical to
produce energy for the cell, then it means vitamin B12 is absent.
—
As the medical team orders homocysteine and serum methylmalonic acid levels in DA, the
results come in at 3 times higher then the upper limit of normal for both, meaning even
if DA’s B12 levels in blood are “normal,” he is functionally deficient.
But, how?
In America, Europe, and Australia, a common cause of B12 deficiency is malabsorption.
Mal meaning bad and absorption denoting the process whereby one mass is incorporated into
another, meaning that it’s not that people aren’t consuming it, but that their body
doesn’t allow them to have it.
B12 is almost everywhere and clinical starvation is not usual in the overwhelming majority
of people in these countries.
This problem of absorption, is important because the vitamin doesn’t just float around in
your body, it has to be carefully escorted in the GI tract.
You see, the stomach isn’t just a bag that holds chewed food.
It produces a protein known as intrinsic factor, which binds to B12 and this intrinsic factor-vitamin
b12 complex gets absorbed in the far end of the small intestines.
The problem is, the body can sometimes send the immune system to wrongly attack the stomach,
preventing intrinsic factor production, so that B12 never gets absorbed.
This autoimmune disease can become worse in a person and attack other parts of the body,
like the pancreas and cause type 1 diabetes.
But DA has no evidence of autoimmune disease, or genetic disease, or underlying brain injury,
meaning that the small detail of his diet actually consisting of only French fries,
and potato chips is the cause of this malnutrition.
This is not to say he was lying and wasn’t believable about his dietary intake, but without
writing down and recording meticulously everyday what you eat, it’s easy to miscalculate
details about one’s own food.
This concentrated lack of variety in his diet and absence of a vital nutrient, is the cause
of his problems, bringing us back to the idea of a coenzyme.
DA presented at age 14 with macrocytic anemia.
To be oversized, means something was wrong in the cellular DNA.
And DNA, is in the cell nucleus, where Vitamin B12 cofactors for the enzyme methionine synthase
to help drive the cycle to produce genetic material.
Without B12, those materials aren’t properly made.
This impairs the maturation of the nucleus, limiting the rate of DNA repair, and limiting
the blood cell’s ability to hold oxygen.
But the cell’s overall maturation isn’t impaired, and this dysynchrony means less
cells are created, and each one is larger than normal bringing us directly to the definition
macrocytic anemia.
Without a presence of blood, where each cell is larger.
But this isn’t the end of DA’s problems.
In the cellular mitochondria, absence of B12 prevents the production of ATP, which is energy.
But as the mitochondria tries to make more energy, it starts to use the wrong chemicals.
This might be ok in tissues that don’t really need constant fresh sources of energy.
The muscles can recycle some of the correct molecules and still function.
Other parts of the body that don’t move don’t need so much mechanical energy, so
they can do for some time without it too.
But how about the nerves?
The nerves are covered in a fatty myelin sheath to help conduct signals.
Fat is energy dense.
It absolutely needs the right molecules to be properly formed.
If the wrong chemicals are being used, because the right chemicals just aren’t present,
then the myelin sheath doesn’t develop properly.
Small vacuoles begin to creep their way in forming gaps.
Over time, swelling and separation of the sheaths develop into lesions that begin to
scatter.
The myelin becomes spongy and no longer the formed sheath it should be, coalescing into
a combined degeneration, impairing nerve conduction.
If the nerves can’t properly conduct a signal, minimal communication happens.
Without a signal, the brain can’t interpret sensory information.
And if parts of his optic nerve become damaged because vitamin b12 wasn’t present for methylmalonyl-CoA
mutase to convert propionyl CoA to succinyl CoA so that the Krebs cycle in the cell can
properly produce the ATP and fatty acids needed for synthesis of its myelin sheath, then this
could explain why DA has become legally blind from his strict diet of French fries, and
potato chips, because these are foods that are devoid of vitamin b12.
This didn’t have to happen.
Optic neuropathy has a long list of causes.
Nutrition is not typically the first thing anyone medically trained in America, Europe,
and Australia think of because, malnutrition especially in the context of Vitamin B12 is
simply not common.
DA’s bodyweight was well within average for his height.
He didn’t look malnourished from the outside.
If doctors just thought of nutritional optic neuropathy right from the start, and just
simply stopped and didn’t look into the other causes of his blindness, in this case,
they would have been correct.
But what if it wasn’t nutritional in origin?
What if they missed a more common and life threatening cause of his blindness and let
that disease progress?
You can’t just stop at a nutritional cause in this case without ruling out the possible
etiolgies.
There’s a lot of CYA in medicine, this is a very clear example of it.
Do you remember the name of the stomach protein intrinsic factor?
Well, humans didn’t know what was the extrinsic factor that binds to it to alleviate the pernicious
anemia that these patients were getting.
In the late 1800s, humans starting feed patients with this deficiency raw animal liver, with
some success.
This was the dietary extrinsic factor at play as liver has a lot of B12.
A Nobel Prize was won in 1934 for those experiments.
Decades later, humans used X-ray crystallography to see what extrinsic factor or what we know
as vitamin b12 is today, looks like.
And Professor Dorothy Hodgkin was the winner of the Nobel Prize, for doing exactly that,
paving the way for it to be synthesized in the lab.
To be added to foods.
To make supplements out of it and injection formulations of it if their stomach won’t
allow them to absorb it.
To have it so most people can’t miss it, because we know without it, the deficiency
will cause anemia and neurodegeneration ranging from mood impairment to blindness and dementia.
. But some will always slip through the cracks.
The people most susceptible to b12 deficiency today are those who follow an abnormally strict
vegetarian or vegan diet.
Who wrongly refuse supplementation.
Who don’t eat cereals, which in the US are almost all fortified with vitamin B12.
For DA, vitamin B12 injections were restarted.
He was counseled for his eating habits.
Problems coming from vitamin B12 deficiency can be reversible if caught early.
And while his rate of vision loss stabilized, DA’s optic neuropathy and associated hearing
loss was not reversed.
Thank you so much for watching.
Take care of yourself.
And make sure you get your vitamins, although, not 150 gummy vitamins for breakfast.
And Be Well.