-
Water is virtually eveywhere,
-
from soil moisture and ice caps,
-
to the cells inside our own bodies.
-
Depending on factors like location,
-
fat index,
-
age,
-
and sex,
-
the average human is between 55-60% water.
-
At birth, human babies are even wetter.
-
Being 75% water,
they are swimmingly similar to fish.
-
But their water composition drops to 65%
by their first birthday.
-
So what role does water
play in our bodies,
-
and how much do we actually need to drink
to stay healthy?
-
The H20 in our bodies works to cushion
and lubricate joints,
-
regulate temperature,
-
and to nourish the brain and spinal cord.
-
Water isn't only in our blood.
-
An adult's brain and heart are almost
three quarters water.
-
That's roughly equivalent to the amount
of moisture in a banana.
-
Lungs are more similar to an apple at 83%.
-
And even seemingly dry human bones
are 31% water.
-
If we are essentially made of water,
-
and surrounded by water,
-
why do we still need to drink so much?
-
Well, each day we lose two to three liters
through our sweat,
-
urine,
-
and bowel movements,
-
and even just from breathing.
-
While these functions
are essential to our survival,
-
we need to compensate for the fluid loss.
-
Maintaining a balance water level
is essential to avoid dehydration
-
or over-hydration,
-
both of which can have devastating
effects on overall health.
-
At first detection of low water levels,
-
sensory receptors
in the brain's hypothalamus
-
signal the release
of antidiuretic hormone.
-
When it reached the kidneys,
it creates aquaporins,
-
special channels that enable blood
to absorb and retain more water,
-
leading concentrated, dark urine.
-
Increased dehydration can cause
notable drops in energy,
-
mood,
-
skin moisture,
-
and blood pressure,
-
as well as signs of cognative impairement.
-
A dehydrated brain works harder
to accomplish the same amount
-
as a normal brain,
-
and it even temporarily shrinks
because of its lack of water.
-
Over-hydration, or hyponatremia,
-
is usually caused by overconsumption
of water in a short amount of time.
-
Athletes are often the victims
of over-hydration
-
because of complications
in regulating water levels
-
in extreme physical conditions.
-
Whereas the dehydrated brain amps
up the production of antidiuretic hormone,
-
the over-hydrated brain slows,
or even stops releasing it into the blood.
-
Sodium electrolytes in the body
become diluted,
-
causing cells to swell.
-
In severe cases,
-
the kidneys can't keep up with
the resulting volumes of dilute urine.
-
Water intoxication then occurs,
-
possibly causing headache,
-
vomitting,
-
and in a rare instances, seizures
or death.
-
But that's a pretty extreme situation.
-
On a normal, day-to-day basis,
-
maintaining a well-hydrated system
is easy to manage
-
for those of us fortunate enough
to have access to clean drinking water.
-
For a long time, conventional wisdom said
that we should drink eight glasses a day.
-
That estimate has since been fine-tuned.
-
Now, the consensus is that the amount
of water we need to imbibe
-
depends largely on our weight
and environment.
-
The recommended daily intake varies from
between 2.5-3.7 liters of water for men,
-
and about 2-2.7 liters for women,
-
a range that is pushed up
or down if we are healthy,
-
active,
-
old,
-
or overheating.
-
While water is the healthiest hydrator,
-
other beverages,
-
even those with caffeine
like coffee or tea,
-
replenish fluids as well.
-
And water within food makes up
about a fifth of our daily H20 intake.
-
Fruits and vegetables like strawberries,
-
cucumbers,
-
and even broccoli are over 90% water,
-
and can supplement liquid intake while
providing valuable nutrients and fiber.
-
Drinking well might also have various
long-term benefits.
-
Studies have shown that optimal hydration
can lower the chance of stroke,
-
help manage diabetes,
-
and potentially reduce the risk
of certain types of cancer.
-
No matter what, getting the right amount
of liquid makes a world of difference
-
in how you'll feel,
-
think,
-
and function day to day.