"High Blood Pressure May Be a Choice"
For the first 90% of our evolution, we ate diets containing
less than a quarter teaspoon of salt a day,
because for the first 90% of our evolution
we ate mostly plants.
We went millions of years without salt shakers,
and so our bodies evolved into salt conserving machines,
which served us well until we discovered salt
could be used to preserve foods.
Without refrigeration, this was a big boon
to human civilization.
Of course this may have led to a general rise in blood pressure,
but who cares if the alternative is starving to death
since all your food rotted away.
But where does that leave us now,
when we no longer have to live off of pickles and jerky?
We are genetically programmed to eat
ten times less salt than we do now.
Even many low salt diets can be considered high salt diets.
That’s why it’s critical to understand what
the concept of “normal” is when it comes to salt.
Having a “normal” salt intake can lead to a “normal” blood pressure,
which can help us to die from all the “normal” causes,
like heart attacks and strokes.
Doctors used to be taught that a “normal” systolic blood pressure
is approximately 100 plus age.
“Systolic” blood pressure means the top number,
and indeed that’s about what we’re born with.
Babies start out with a blood pressure around like 95 over 60,
but then as we age that 95 can go to 120 by our 20’s
then 140 in our 40’s (the official cut-off for high blood pressure),
and keep climbing as we age.
That was considered normal, since everyone’s blood pressure
creeps up as we get older.
And if that’s normal then heart attacks and strokes are normal too
since risk starts rising
once we start getting above the 100 we had as a baby.
But if blood pressures over a 100 are associated with disease,
maybe they should be considered abnormal,
perhaps caused by our abnormally high salt intake—
ten times more than what our bodies were designed to handle.
Maybe if we just ate a natural amount of salt,
our blood pressures naturally would not go up with age,
and we’d be protected.
Of course to test that theory you’d have to find a population
in modern times that doesn’t use salt
or eat processed food or go out to eat.
For that you’d have to go deep into the Amazon rainforest.
Meet the Yanomamo people, a no-salt culture.
Lowest salt intake ever reported,
which is to say normal-for- our-species salt intake.
And so what happens to their blood pressure?
They start out with a blood pressure of about 100 over 60
and end up with a blood pressure of about 100 over 60.
Though theirs is described as a salt deficient diet,
that’s like saying they have a diet deficient in Twinkies.
They’re the ones, it seems, eating normal salt intakes
apparently leading to truly normal blood pressures.
Those in their 50’s have the blood pressure of a 20 year old.
The percentage of the population tested
that had high blood pressure?
Zero.
Whereas elsewhere in Brazil,
up to 38% of the population may be affected.
The Yanomamos probably represent the ultimate human example
of the importance of salt on blood pressure.
But look it could have been other factors:
they didn’t drink alcohol, ate a high-fiber,
plant-based diet, lots of exercise,
no obesity.
There’s a number of plant-based populations eating little salt
that experience no rise in blood pressure as they age,
so how do we know what exactly is to blame?
Ideally we’d do an interventional trial.
Imagine, if you took people literally dying from
out of control high blood pressure,
so called malignant hypertension
where you go blind from bleeding into your eyes,
your kidneys shut down, your heart fails,
and then you withhold from those people blood pressure medications
so their fate is certain death,
and THEN you put them on a Yanomamo level of salt intake,
a normal-for-the-human- species salt intake,
and if instead of dying, they walked away
cured of their hypertension,
that would pretty much seal the deal.
Enter, Dr. Walter Kempner and his rice and fruit diet.
Patients came in with blood pressures
of 210 over 140 dropping down to 80 over 60.
Now, the reason he could ethically withhold
all modern blood pressure medications and treat with diet alone?
The drugs hadn’t been invented yet—
this was back in the 1940’s.
Now, the diet wasn’t just extremely low salt,
but strictly plant-based, extremely low fat, protein, and calories.
But there is no doubt that Kempner’s rice diet achieved remarkable results
and Kempner is now remembered as the person
who demonstrated beyond any shadow of a doubt
that high blood pressure can often be lowered
by a low enough salt diet.
Forty years ago it was acknowledged
that the evidence is very good if not conclusive
that a low enough reduction of salt in the diet would
result in the prevention of essential hypertension—
that rising of blood pressure as we age—
and its disappearance as a major public health problem.
It looks like we knew how to stop this four decades ago.
In that time, how many people have died?
Today, high blood pressure may wipe out
400,000 Americans every year.
1,000 unnecessary deaths every day.