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 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, rather than shared effects on the body. 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, though most also have side chains— 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 and protein synthesis. This is different from many other types

of signaling molecules, which can’t cross the cell membrane and have to create their effects

from outside the cell, through more complicated pathways. 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, and it has a huge range of functions. When we experience a stressor— anything from a fight with a friend,

to spotting a bear, to an infection or low blood sugar— 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, they release a burst of cortisol, 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— depending on the situation, it can increase or decrease

certain immune functions. In the process of fighting infection, 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 to release more cortisol. 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: they enhance the body’s cortisol supply, which in turn shuts down

the hyperactive immune responses that cause inflammation. 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— the skin, or the lungs. 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. A constant low dose of steroids can help keep this renegade

immune response under control— but because of the negative psychological

and physiological effects of longterm exposure, 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.