Can steroids save your life? - Anees Bahji
-
0:07 - 0:11Steroids: they’re infamous
for their use in sports. -
0:11 - 0:16But they’re also found in inhalers,
creams to treat poison ivy and eczema, -
0:16 - 0:18and shots to ease inflammation.
-
0:18 - 0:23The steroids in these medicines aren’t
the same as the ones used to build muscle. -
0:23 - 0:27In fact, they’re all based on
yet another steroid— -
0:27 - 0:32one our body produces naturally,
and we can’t live without. -
0:32 - 0:35Taking a step back, the reason
there are so many different steroids -
0:35 - 0:40is because the term refers to substances
with a shared molecular structure, -
0:40 - 0:43rather than shared effects on the body.
-
0:43 - 0:46Steroids can be naturally occurring
or synthetic, -
0:46 - 0:50but what all steroids have in common
is a molecular structure -
0:50 - 0:55that consists of a base of four rings
made of 17 carbon atoms -
0:55 - 0:59arranged in three hexagons
and one pentagon. -
0:59 - 1:04A molecule must contain
this exact arrangement to be a steroid, -
1:04 - 1:07though most also have side chains—
-
1:07 - 1:12additional atoms that can dramatically
impact the molecule’s function. -
1:12 - 1:16Steroids get their name
from the fatty molecule cholesterol. -
1:16 - 1:20In fact, our bodies make steroids
out of cholesterol. -
1:20 - 1:23That fatty cholesterol base
means that steroids -
1:23 - 1:28are able to cross fatty cell membranes
and enter cells. -
1:28 - 1:31Within the cell, they can directly
influence gene expression -
1:31 - 1:34and protein synthesis.
-
1:34 - 1:37This is different from many other types
of signaling molecules, -
1:37 - 1:39which can’t cross the cell membrane
-
1:39 - 1:43and have to create their effects
from outside the cell, -
1:43 - 1:46through more complicated pathways.
-
1:46 - 1:51So steroids can create their effects
faster than those other molecules. -
1:51 - 1:55Back to the steroids
in anti-inflammatory medications: -
1:55 - 2:00all of these are based on a naturally
occurring steroid called cortisol. -
2:00 - 2:03Cortisol is the body’s
primary stress signal, -
2:03 - 2:06and it has a huge range of functions.
-
2:06 - 2:08When we experience a stressor—
-
2:08 - 2:11anything from a fight with a friend,
to spotting a bear, -
2:11 - 2:14to an infection or low blood sugar—
-
2:14 - 2:20the brain reacts by sending a signal from
the hypothalamus to the pituitary gland. -
2:20 - 2:24The pituitary gland then sends a signal
to the adrenal glands. -
2:24 - 2:29The adrenal glands produce cortisol,
and release some constantly. -
2:29 - 2:33But when they receive the signal
from the pituitary gland, -
2:33 - 2:35they release a burst of cortisol,
-
2:35 - 2:38which spurs the body to generate
more glucose for energy, -
2:38 - 2:43decrease functions not immediately
related to survival, like digestion, -
2:43 - 2:47and can activate
a fight-flight-or-freeze response. -
2:47 - 2:51This is helpful in the short term,
but can cause undesirable side effects -
2:51 - 2:55like insomnia and lowered mood
if they last too long. -
2:55 - 3:00Cortisol also interacts
with the immune system in complex ways— -
3:00 - 3:01depending on the situation,
-
3:01 - 3:05it can increase or decrease
certain immune functions. -
3:05 - 3:07In the process of fighting infection,
-
3:07 - 3:10the immune system
often creates inflammation. -
3:10 - 3:14Cortisol suppresses the immune system’s
ability to produce inflammation, -
3:14 - 3:17which, again,
can be useful in the short term. -
3:17 - 3:20But too much cortisol
can have negative impacts, -
3:20 - 3:26like reducing the immune system’s ability
to regenerate bone marrow and lymph nodes. -
3:26 - 3:29To prevent levels
from staying high for too long, -
3:29 - 3:33cortisol suppresses the signal
that causes the adrenal glands -
3:33 - 3:35to release more cortisol.
-
3:35 - 3:40Medicinal corticosteroids channel
cortisol’s effects on the immune system -
3:40 - 3:44to fight allergic reactions,
rashes, and asthma. -
3:44 - 3:47All these things are forms
of inflammation. -
3:47 - 3:51There are many synthetic steroids
that share the same basic mechanism: -
3:51 - 3:53they enhance the body’s cortisol supply,
-
3:53 - 3:57which in turn shuts down
the hyperactive immune responses -
3:57 - 3:59that cause inflammation.
-
3:59 - 4:04These corticosteroids sneak into cells
and can turn off the “fire alarm” -
4:04 - 4:09by suppressing gene expression
of inflammatory signals. -
4:09 - 4:14The steroids in inhalers and creams impact
only the affected organ— -
4:14 - 4:16the skin, or the lungs.
-
4:16 - 4:21Intravenous or oral versions, used
to treat chronic autoimmune conditions -
4:21 - 4:26like lupus or inflammatory bowel disease,
impact the whole body. -
4:26 - 4:31With these conditions, the body’s
immune system attacks its own cells, -
4:31 - 4:35a process analogous to a constant
asthma attack or rash. -
4:35 - 4:38A constant low dose of steroids
-
4:38 - 4:42can help keep this renegade
immune response under control— -
4:42 - 4:45but because of the negative psychological
and physiological effects -
4:45 - 4:47of longterm exposure,
-
4:47 - 4:51higher doses are reserved
for emergencies and flare-ups. -
4:51 - 4:55While an asthma attack, poison ivy welts,
and irritable bowel syndrome -
4:55 - 5:00might seem totally unrelated,
they all have something in common: -
5:00 - 5:04an immune response
that’s doing more harm than good. -
5:04 - 5:07And while corticosteroids
won’t give you giant muscles, -
5:07 - 5:11they can be the body’s best defense
against itself.
- Title:
- Can steroids save your life? - Anees Bahji
- Speaker:
- Anees Bahji
- Description:
-
View full lesson: https://ed.ted.com/lessons/can-steroids-save-your-life-anees-bahji
Steroids: they’re infamous for their use in sports. But they’re also found in inhalers, creams to treat poison ivy and eczema, and shots to ease inflammation. The steroids in these medicines aren’t the same as those 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. Anees Bahji explores the science of corticosteroids.
Lesson by Anees Bahji, directed by Nick Hilditch.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 05:11
lauren mcalpine edited English subtitles for Can steroids save your life? | ||
Elise Haadsma approved English subtitles for Can steroids save your life? | ||
Elise Haadsma accepted English subtitles for Can steroids save your life? | ||
lauren mcalpine edited English subtitles for Can steroids save your life? |