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4:52
Transcript
0:06
Water is virtually everywhere,
0:08
from soil moisture and ice caps,
0:11
to the cells inside our own bodies.
0:14
Depending on factors like location,
0:16
fat index,
0:17
age,
0:18
and sex,
0:19
the average human is between 55-60% water.
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0:23
At birth, human babies are even wetter.
0:27
Being 75% water,
they are swimmingly similar to fish.
0:32
But their water composition drops to 65%
by their first birthday.
0:37
So what role does water
play in our bodies,
0:40
and how much do we actually need to drink
to stay healthy?
0:44
The H20 in our bodies works to cushion
and lubricate joints,
0:48
regulate temperature,
0:49
and to nourish the brain and spinal cord.
0:53
Water isn't only in our blood.
0:56
An adult's brain and heart are almost
three quarters water.
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1:00
That's roughly equivalent to the amount
of moisture in a banana.
1:04
Lungs are more similar to an apple at 83%.
1:08
And even seemingly dry human bones
are 31% water.
1:14
If we are essentially made of water,
1:16
and surrounded by water,
1:17
why do we still need to drink so much?
1:20
Well, each day we lose two to three liters
through our sweat,
1:24
urine,
1:25
and bowel movements,
1:26
and even just from breathing.
1:28
While these functions
are essential to our survival,
1:30
we need to compensate for the fluid loss.
1:33
Maintaining a balanced water level
is essential to avoid dehydration
1:37
or over-hydration,
1:39
both of which can have devastating
effects on overall health.
1:43
At first detection of low water levels,
1:45
sensory receptors
in the brain's hypothalamus
1:48
signal the release
of antidiuretic hormone.
1:51
When it reached the kidneys,
it creates aquaporins,
1:54
special channels that enable blood
to absorb and retain more water,
2:00
leading to concentrated, dark urine.
2:03
Increased dehydration can cause
notable drops in energy,
2:06
mood,
2:07
skin moisture,
2:08
and blood pressure,
2:10
as well as signs of cognitive impairment.
2:13
A dehydrated brain works harder
to accomplish the same amount
2:17
as a normal brain,
2:18
and it even temporarily shrinks
because of its lack of water.
2:22
Over-hydration, or hyponatremia,
2:25
is usually caused by overconsumption
of water in a short amount of time.
2:30
Athletes are often the victims
of over-hydration
2:33
because of complications
in regulating water levels
2:36
in extreme physical conditions.
2:39
Whereas the dehydrated brain amps
up the production of antidiuretic hormone,
2:43
the over-hydrated brain slows,
or even stops, releasing it into the blood.
2:49
Sodium electrolytes in the body
become diluted,
2:51
causing cells to swell.
2:54
In severe cases,
2:55
the kidneys can't keep up with
the resulting volumes of dilute urine.
2:59
Water intoxication then occurs,
3:01
possibly causing headache,
3:03
vomiting,
3:04
and, in rare instances, seizures
or death.
3:08
But that's a pretty extreme situation.
3:10
On a normal, day-to-day basis,
3:12
maintaining a well-hydrated system
is easy to manage
3:15
for those of us fortunate enough
to have access to clean drinking water.
3:19
For a long time, conventional wisdom said
that we should drink eight glasses a day.
3:23
That estimate has since been fine-tuned.
3:26
Now, the consensus is that the amount
of water we need to imbibe
3:30
depends largely on our weight
and environment.
3:33
The recommended daily intake varies from
between 2.5-3.7 liters of water for men,
3:39
and about 2-2.7 liters for women,
3:42
a range that is pushed up
or down if we are healthy,
3:46
active,
3:46
old,
3:47
or overheating.
3:49
While water is the healthiest hydrator,
3:51
other beverages,
3:52
even those with caffeine
like coffee or tea,
3:55
replenish fluids as well.
3:57
And water within food makes up
about a fifth of our daily H20 intake.
4:02
Fruits and vegetables like strawberries,
4:04
cucumbers,
4:05
and even broccoli are over 90% water,
4:08
and can supplement liquid intake while
providing valuable nutrients and fiber.
4:14
Drinking well might also have various
long-term benefits.
4:17
Studies have shown that optimal hydration
can lower the chance of stroke,
4:21
help manage diabetes,
4:23
and potentially reduce the risk
of certain types of cancer.
4:27
No matter what, getting the right amount
of liquid makes a world of difference
4:32
in how you'll feel,
4:33
think,
4:34
and function day to day.
— end of transcript —
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