"What Does a Low White Blood Cell Count Mean?"
If you took a drop of blood and smeared it between two pieces of glass
and looked at it under a microscope,
it might look something like this:
a whole bunch of little round red blood cells
and then this big white blood cell.
Red blood cells carry oxygen,
and white blood cells are our immune system foot soldiers.
We may churn out 50 billion new ones a day.
In response to inflammation or infection,
that number could shoot up to a 100 billion or more.
In fact, that’s what pus is largely composed of:
millions and millions of white blood cells.
Testing how many white blood cells we have at any given time,
our white blood cell count is one of the most common
laboratory tests doctors order.
We order it hundreds of millions of times a year.
So, for example, if you end up in the emergency room with abdominal pain,
having a white blood cell count above about 10 billion per quart of blood
may be a sign you may have appendicitis.
Most Americans fall between 4.5 and 10,
but most Americans are unhealthy.
Just because 4.5 to 10 is normal, doesn’t mean it’s ideal.
It’s like having a normal cholesterol level in a society
where it’s normal to die of heart disease– the #1 killer.
The average American is overweight; so, if your weight is “normal,”
that’s actually a bad thing.
In fact, having excess fat itself causes inflammation within the body.
So, no surprise those who are obese walk around
with 2 billion more white cells per quart in their blood.
So, maybe obese individuals should have their own normal values?
Someone with a 47-inch waist walking into an emergency room
with a white count of 12, 13, 14 may not have appendicitis or an infection—
that may just be their baseline, normal level,
given all the inflammation they have
in their body from the excess fat.
So, normal levels are not necessarily healthy levels.
It’s like smoking.
If you take identical twins and one smokes and the other doesn’t,
the smoker is going to end up with a
significantly higher white cell count.
In Japan, for example, as smoking rates have steadily dropped,
so has the normal white count range,
such that about 8% of never smoking men would now be flagged
as having abnormally low white counts if you used a cut-off like 4.
But, that’s because most people were smoking before,
when they set that cut-off.
So, maybe 3 would be a better lower limit.
The inflammation caused by smoking may actually be one of the reasons
cigarettes increase the risk of heart attacks, strokes,
and other inflammatory diseases.
So, do people who have lower white counts have less
heart disease, cancer, and overall mortality?
Yes, yes, and yes.
People with lower white blood cell counts live longer.
Even within the normal range, every one point drop
may be associated with a 20% drop in the risk of premature death.
This is a log scale; so, there’s like an exponential increase
in risk as white count goes up,
even within the so-called normal range.
This is for men; the same is found for women.
The white blood cell count is a “widely available
and inexpensive measure of systemic inflammation.”
At around age 85 in this study, half of women who started out
with white counts under 5.6 were still alive,
whereas 80% of those that started out over 7 were dead.
And, 7, 8, 9, or 10 would be considered normal.
Being at the high normal range may place one at 3 times the risk
of dying from heart disease compared to being at the lower end.
Same link found for African- American men and women.
Same in middle age.
Same at age 75.
Same at age 85.
Same even in our 20s and 30s:
a 17% increase in coronary artery disease incidence
for every single point higher.
The higher your white count, the worse your arterial function
and the stiffer your arteries.
So, no wonder white blood cell count (WBC count) is a useful
predictor of artery disease in your heart, brain,
legs, and neck, and high blood pressure.
Even diabetes?
Even diabetes, according to a compilation of 20 different studies.
Everything from fatty liver disease to having an enlarged prostate.
And, having a higher white blood cell count is associated
with an increased risk of dying from cancer as well.
And, these are all within the normal range.
So, what would the ideal range be?
I’ll cover that, next.