Name: Can steroids save your life? - Anees Bahji
Uploaded: 2020-06-21T15:32:03.000Z
Duration: 5 min 32 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Steroids: they're infamous  for their use in sports.

But they're also found in inhalers,  creams to treat poison ivy and eczema,

The steroids in these medicines aren't  the same as the ones used to build muscle.

In fact, they're all based on  yet another steroid—

one our body produces naturally,  and we can't live without.

Taking a step back, the reason  there are so many different steroids

is because the term refers to substances  with a shared molecular structure,

Steroids can be naturally occurring  or synthetic,

but what all steroids have in common  is a molecular structure

that consists of a base of four rings  made of 17 carbon atoms

arranged in three hexagons  and one pentagon.

A molecule must contain  this exact arrangement to be a steroid,

additional atoms that can dramatically  impact the molecule's function.

Steroids get their name  from the fatty molecule cholesterol.

In fact, our bodies make steroids  out of cholesterol.

That fatty cholesterol base  means that steroids

are able to cross fatty cell membranes  and enter cells.

Within the cell, they can directly  influence gene expression

This is different from many other types  of signaling molecules,

and have to create their effects  from outside the cell,

So steroids can create their effects  faster than those other molecules.

Back to the steroids  in anti-inflammatory medications:

all of these are based on a naturally  occurring steroid called cortisol.

Cortisol is the body's  primary stress signal,

anything from a fight with a friend,  to spotting a bear,

the brain reacts by sending a signal from  the hypothalamus to the pituitary gland.

The pituitary gland then sends a signal  to the adrenal glands.

The adrenal glands produce cortisol,  and release some constantly.

But when they receive the signal  from the pituitary gland,

which spurs the body to generate  more glucose for energy,

decrease functions not immediately  related to survival, like digestion,

and can activate  a fight-flight-or-freeze response.

This is helpful in the short term,  but can cause undesirable side effects

like insomnia and lowered mood  if they last too long.

Cortisol also interacts  with the immune system in complex ways—

it can increase or decrease  certain immune functions.

the immune system  often creates inflammation.

Cortisol suppresses the immune system's  ability to produce inflammation,

which, again,  can be useful in the short term.

But too much cortisol  can have negative impacts,

like reducing the immune system's ability  to regenerate bone marrow and lymph nodes.

To prevent levels  from staying high for too long,

cortisol suppresses the signal  that causes the adrenal glands

Medicinal corticosteroids channel  cortisol's effects on the immune system

to fight allergic reactions,  rashes, and asthma.

All these things are forms  of inflammation.

There are many synthetic steroids  that share the same basic mechanism:

which in turn shuts down  the hyperactive immune responses

These corticosteroids sneak into cells  and can turn off the “fire alarm”

by suppressing gene expression  of inflammatory signals.

The steroids in inhalers and creams impact only the affected organ—

Intravenous or oral versions, used  to treat chronic autoimmune conditions

like lupus or inflammatory bowel disease,  impact the whole body.

With these conditions, the body's  immune system attacks its own cells,

a process analogous to a constant  asthma attack or rash.

can help keep this renegade immune response under control—

but because of the negative psychological  and physiological effects

higher doses are reserved  for emergencies and flare-ups.

While an asthma attack, poison ivy welts,  and irritable bowel syndrome

might seem totally unrelated,  they all have something in common:

an immune response  that's doing more harm than good.

And while corticosteroids  won't give you giant muscles,

they can be the body's best defense  against itself.