How Exactly Does Smoking Kill?

Hey guys Julia here for DNews In 1964, a landmark report U.S. Surgeon General
Luther Terry made the case for the link between smoking and cancer and heart disease. In the
years since, there the evidence pile against smoking has only gotten larger. There’s
a more than a few ways smoking harms the body, but let’s just focus on a few certain compounds. Smoking is lethal in a few ways. In those
early studies I mentioned, researchers found that cigarette smoke causes ciliostasis. Which
is when those little hairs lining your airways die. Without those hairs, your body has a
hard time filtering out bad things, like cigarette smoke. Smoke isn’t just one thing, it’s a
combination of particles that result when you burn cigarettes. As the more you smoke,
the more smoke gets in your lungs and the more likely tumors will form due to the damaging
particles. As you know, tobacco smoke has lot of carcinogens.
According to a study published in the journal Molecular Cancer Research there’s over 60
compounds known to cause cancer. Compounds like polycyclic aromatic hydrocarbons
(PAH). Which are formed when things like oil, gas, and yup, tobacco are burned. They can
even form if you char things like steak. And once those compounds get past the dead cilia,
they find their way to vulnerable parts of your lungs. Some of these PAHs lead to chronic inflammation
of the lung, a condition which raises the risk of cancer[1]. Some of these chemicals
trigger mutations when they bind to the DNA. The compounds get stuck, forming what’s
called an adduct that makes it really hard for the DNA to replicate, which can potentially
lead to mutations. When this does happen, one of the most significant
mutations occurs in a protein called p53[2]. The protein handles a lot of cell regulation,
and its function depends on a variety of factors, but often it’s a tumor suppressor. When
this protein experiences a mutation, that function gets switched off, allowing tumors
in the lungs to grow and spread. One study published in the journal Clinical Cancer Research
found that a mutation in p53 was a maker of poor cancer prognosis. And polycyclic aromatic hydrocarbons aren’t
linked with just cancer, but research published in the journal The FASEB Journal, found that
these compounds can trigger heart disease too[3]. Basically these compounds cause an
overproduction of certain fatty acids in endothelial cells, the cells that line your blood vessels,
which causes them to die. So yeah, smoking literally kills your blood vessels. Smoking
also increases the risk of heart disease by narrowing the blood vessels and increasing
the formation of clotting plaque, which can lead to deadly heart attacks. In fact it counts
for 33% of all heart disease related deaths in the US. Still don’t believe smoking hurts? Well
it can literally turn your lungs black. two recent studies confirm that yup. Smoking is
deadly. The smoking gun? Carbon nanoparticles. Similar to black lung syndrome, when coal
miners inhaled coal dust, these particles from cigarettes get stuck in the lung and
wreak havoc. In smokers the particles can build up and lead to severe emphysema. A nasty
and potentially fatal condition that makes it harder to breathe. The particles come from material that hasn’t
burned up all the way, which in this case is the tobacco itself. They’re small, around
30 and 40 nanometers in size; about half the width of a human hair. But over time these
nanoparticles build up and can do some serious damage. The first study published in the journal
eLife, found that they are so small that once they get into the dendritic cells they can
break apart DNA. So yeah, there’s lots of ways cigarette
smoke causes cellular damage through variety of molecular mechanisms. With all this scientific
evidence against it, I’m baffled why so many people still smoke. But hey it’s a
comforting habit for some, and as we’ve discussed before, an addicting one too. Thanks nicotine.
But there’s some good news. Studies show that some of the effects might be reversible…
except those particles. You’re stuck with those. So the evidence is overwhelming. You
should probably quit smoking now. Plus it’s just gross.