[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:07.15,0:00:10.84,Default,,0000,0000,0000,,Steroids: they’re infamous \Nfor their use in sports.
Dialogue: 0,0:00:10.84,0:00:15.75,Default,,0000,0000,0000,,But they’re also found in inhalers, \Ncreams to treat poison ivy and eczema,
Dialogue: 0,0:00:15.75,0:00:18.34,Default,,0000,0000,0000,,and shots to ease inflammation.
Dialogue: 0,0:00:18.34,0:00:23.40,Default,,0000,0000,0000,,The steroids in these medicines aren’t \Nthe same as the ones used to build muscle.
Dialogue: 0,0:00:23.40,0:00:27.19,Default,,0000,0000,0000,,In fact, they’re all based on \Nyet another steroid—
Dialogue: 0,0:00:27.19,0:00:31.64,Default,,0000,0000,0000,,one our body produces naturally, \Nand we can’t live without.
Dialogue: 0,0:00:31.64,0:00:35.34,Default,,0000,0000,0000,,Taking a step back, the reason \Nthere are so many different steroids
Dialogue: 0,0:00:35.34,0:00:39.94,Default,,0000,0000,0000,,is because the term refers to substances \Nwith a shared molecular structure,
Dialogue: 0,0:00:39.94,0:00:42.88,Default,,0000,0000,0000,,rather than shared effects on the body.
Dialogue: 0,0:00:42.88,0:00:45.75,Default,,0000,0000,0000,,Steroids can be naturally occurring \Nor synthetic,
Dialogue: 0,0:00:45.75,0:00:49.90,Default,,0000,0000,0000,,but what all steroids have in common \Nis a molecular structure
Dialogue: 0,0:00:49.90,0:00:54.97,Default,,0000,0000,0000,,that consists of a base of four rings \Nmade of 17 carbon atoms
Dialogue: 0,0:00:54.97,0:00:59.05,Default,,0000,0000,0000,,arranged in three hexagons \Nand one pentagon.
Dialogue: 0,0:00:59.05,0:01:03.68,Default,,0000,0000,0000,,A molecule must contain \Nthis exact arrangement to be a steroid,
Dialogue: 0,0:01:03.68,0:01:06.75,Default,,0000,0000,0000,,though most also have side chains—
Dialogue: 0,0:01:06.75,0:01:12.08,Default,,0000,0000,0000,,additional atoms that can dramatically \Nimpact the molecule’s function.
Dialogue: 0,0:01:12.08,0:01:16.04,Default,,0000,0000,0000,,Steroids get their name \Nfrom the fatty molecule cholesterol.
Dialogue: 0,0:01:16.04,0:01:20.03,Default,,0000,0000,0000,,In fact, our bodies make steroids \Nout of cholesterol.
Dialogue: 0,0:01:20.03,0:01:23.24,Default,,0000,0000,0000,,That fatty cholesterol base \Nmeans that steroids
Dialogue: 0,0:01:23.24,0:01:27.60,Default,,0000,0000,0000,,are able to cross fatty cell membranes \Nand enter cells.
Dialogue: 0,0:01:27.60,0:01:31.42,Default,,0000,0000,0000,,Within the cell, they can directly \Ninfluence gene expression
Dialogue: 0,0:01:31.42,0:01:33.79,Default,,0000,0000,0000,,and protein synthesis.
Dialogue: 0,0:01:33.79,0:01:37.40,Default,,0000,0000,0000,,This is different from many other types \Nof signaling molecules,
Dialogue: 0,0:01:37.40,0:01:39.47,Default,,0000,0000,0000,,which can’t cross the cell membrane
Dialogue: 0,0:01:39.47,0:01:42.86,Default,,0000,0000,0000,,and have to create their effects \Nfrom outside the cell,
Dialogue: 0,0:01:42.86,0:01:45.63,Default,,0000,0000,0000,,through more complicated pathways.
Dialogue: 0,0:01:45.63,0:01:51.18,Default,,0000,0000,0000,,So steroids can create their effects \Nfaster than those other molecules.
Dialogue: 0,0:01:51.18,0:01:55.06,Default,,0000,0000,0000,,Back to the steroids \Nin anti-inflammatory medications:
Dialogue: 0,0:01:55.06,0:02:00.02,Default,,0000,0000,0000,,all of these are based on a naturally \Noccurring steroid called cortisol.
Dialogue: 0,0:02:00.02,0:02:03.26,Default,,0000,0000,0000,,Cortisol is the body’s \Nprimary stress signal,
Dialogue: 0,0:02:03.26,0:02:05.81,Default,,0000,0000,0000,,and it has a huge range of functions.
Dialogue: 0,0:02:05.81,0:02:07.96,Default,,0000,0000,0000,,When we experience a stressor—
Dialogue: 0,0:02:07.96,0:02:11.21,Default,,0000,0000,0000,,anything from a fight with a friend, \Nto spotting a bear,
Dialogue: 0,0:02:11.21,0:02:13.94,Default,,0000,0000,0000,,to an infection or low blood sugar—
Dialogue: 0,0:02:13.94,0:02:19.94,Default,,0000,0000,0000,,the brain reacts by sending a signal from \Nthe hypothalamus to the pituitary gland.
Dialogue: 0,0:02:19.94,0:02:24.48,Default,,0000,0000,0000,,The pituitary gland then sends a signal \Nto the adrenal glands.
Dialogue: 0,0:02:24.48,0:02:28.95,Default,,0000,0000,0000,,The adrenal glands produce cortisol, \Nand release some constantly.
Dialogue: 0,0:02:28.95,0:02:32.52,Default,,0000,0000,0000,,But when they receive the signal \Nfrom the pituitary gland,
Dialogue: 0,0:02:32.52,0:02:34.84,Default,,0000,0000,0000,,they release a burst of cortisol,
Dialogue: 0,0:02:34.84,0:02:38.46,Default,,0000,0000,0000,,which spurs the body to generate \Nmore glucose for energy,
Dialogue: 0,0:02:38.46,0:02:42.88,Default,,0000,0000,0000,,decrease functions not immediately \Nrelated to survival, like digestion,
Dialogue: 0,0:02:42.88,0:02:46.76,Default,,0000,0000,0000,,and can activate \Na fight-flight-or-freeze response.
Dialogue: 0,0:02:46.76,0:02:51.03,Default,,0000,0000,0000,,This is helpful in the short term, \Nbut can cause undesirable side effects
Dialogue: 0,0:02:51.03,0:02:55.30,Default,,0000,0000,0000,,like insomnia and lowered mood \Nif they last too long.
Dialogue: 0,0:02:55.30,0:02:59.68,Default,,0000,0000,0000,,Cortisol also interacts \Nwith the immune system in complex ways—
Dialogue: 0,0:02:59.68,0:03:01.01,Default,,0000,0000,0000,,depending on the situation,
Dialogue: 0,0:03:01.01,0:03:04.78,Default,,0000,0000,0000,,it can increase or decrease \Ncertain immune functions.
Dialogue: 0,0:03:04.78,0:03:06.77,Default,,0000,0000,0000,,In the process of fighting infection,
Dialogue: 0,0:03:06.77,0:03:09.93,Default,,0000,0000,0000,,the immune system \Noften creates inflammation.
Dialogue: 0,0:03:09.93,0:03:14.18,Default,,0000,0000,0000,,Cortisol suppresses the immune system’s \Nability to produce inflammation,
Dialogue: 0,0:03:14.18,0:03:17.34,Default,,0000,0000,0000,,which, again, \Ncan be useful in the short term.
Dialogue: 0,0:03:17.34,0:03:20.35,Default,,0000,0000,0000,,But too much cortisol \Ncan have negative impacts,
Dialogue: 0,0:03:20.35,0:03:25.99,Default,,0000,0000,0000,,like reducing the immune system’s ability \Nto regenerate bone marrow and lymph nodes.
Dialogue: 0,0:03:25.99,0:03:29.14,Default,,0000,0000,0000,,To prevent levels \Nfrom staying high for too long,
Dialogue: 0,0:03:29.14,0:03:32.94,Default,,0000,0000,0000,,cortisol suppresses the signal \Nthat causes the adrenal glands
Dialogue: 0,0:03:32.94,0:03:35.14,Default,,0000,0000,0000,,to release more cortisol.
Dialogue: 0,0:03:35.14,0:03:39.83,Default,,0000,0000,0000,,Medicinal corticosteroids channel \Ncortisol’s effects on the immune system
Dialogue: 0,0:03:39.83,0:03:44.01,Default,,0000,0000,0000,,to fight allergic reactions, \Nrashes, and asthma.
Dialogue: 0,0:03:44.01,0:03:46.84,Default,,0000,0000,0000,,All these things are forms \Nof inflammation.
Dialogue: 0,0:03:46.84,0:03:50.92,Default,,0000,0000,0000,,There are many synthetic steroids \Nthat share the same basic mechanism:
Dialogue: 0,0:03:50.92,0:03:53.40,Default,,0000,0000,0000,,they enhance the body’s cortisol supply,
Dialogue: 0,0:03:53.40,0:03:56.91,Default,,0000,0000,0000,,which in turn shuts down \Nthe hyperactive immune responses
Dialogue: 0,0:03:56.91,0:03:59.10,Default,,0000,0000,0000,,that cause inflammation.
Dialogue: 0,0:03:59.10,0:04:04.04,Default,,0000,0000,0000,,These corticosteroids sneak into cells \Nand can turn off the “fire alarm”
Dialogue: 0,0:04:04.04,0:04:08.89,Default,,0000,0000,0000,,by suppressing gene expression \Nof inflammatory signals.
Dialogue: 0,0:04:08.89,0:04:13.91,Default,,0000,0000,0000,,The steroids in inhalers and creams impact\Nonly the affected organ—
Dialogue: 0,0:04:13.91,0:04:16.12,Default,,0000,0000,0000,,the skin, or the lungs.
Dialogue: 0,0:04:16.12,0:04:20.88,Default,,0000,0000,0000,,Intravenous or oral versions, used \Nto treat chronic autoimmune conditions
Dialogue: 0,0:04:20.88,0:04:26.32,Default,,0000,0000,0000,,like lupus or inflammatory bowel disease, \Nimpact the whole body.
Dialogue: 0,0:04:26.32,0:04:30.74,Default,,0000,0000,0000,,With these conditions, the body’s \Nimmune system attacks its own cells,
Dialogue: 0,0:04:30.74,0:04:35.42,Default,,0000,0000,0000,,a process analogous to a constant \Nasthma attack or rash.
Dialogue: 0,0:04:35.42,0:04:37.77,Default,,0000,0000,0000,,A constant low dose of steroids
Dialogue: 0,0:04:37.77,0:04:41.65,Default,,0000,0000,0000,,can help keep this renegade\Nimmune response under control—
Dialogue: 0,0:04:41.65,0:04:45.26,Default,,0000,0000,0000,,but because of the negative psychological \Nand physiological effects
Dialogue: 0,0:04:45.26,0:04:46.70,Default,,0000,0000,0000,,of longterm exposure,
Dialogue: 0,0:04:46.70,0:04:51.49,Default,,0000,0000,0000,,higher doses are reserved \Nfor emergencies and flare-ups.
Dialogue: 0,0:04:51.49,0:04:55.50,Default,,0000,0000,0000,,While an asthma attack, poison ivy welts, \Nand irritable bowel syndrome
Dialogue: 0,0:04:55.50,0:04:59.58,Default,,0000,0000,0000,,might seem totally unrelated, \Nthey all have something in common:
Dialogue: 0,0:04:59.58,0:05:03.79,Default,,0000,0000,0000,,an immune response \Nthat’s doing more harm than good.
Dialogue: 0,0:05:03.79,0:05:07.09,Default,,0000,0000,0000,,And while corticosteroids \Nwon’t give you giant muscles,
Dialogue: 0,0:05:07.09,0:05:10.62,Default,,0000,0000,0000,,they can be the body’s best defense \Nagainst itself.